army aviation digest - feb 1973

8/12/2019 Army Aviation Digest - Feb 1973

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DIRECTOR OF ARMY AVIATION, ACSFORDEPARTMENT OF THE ARMYBG William J. Maddox Jr .

COMMANDANT, U. S. ARMY AVIATIONSCHOOLMG Allen M. Burdett Jr.

ASST COMDT, U. S. ARMY AVIATIONSCHOOLCOL Earl W. Fletcher

EDITOR, U. S. ARMY AVIATION DIGESTRichard K. Tierney

ABOUT THE COVERWhat path will the annual writtake? BG William J. Maddox Jr.,Director of Army Aviation, andLTC William H. Gardner discussthe matter in depth beginning onpage 2. Also, MAJ Paul G. Larishgives us a preview of the 1973annual writ beginning on page 24

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RMY

FEBRUARY 1973 VOLUME 19

Views From ReadersWhither The Writ, LTC William H. GardnerLet s Not Forget About VFR CW2 James T. MillerFuel Fallacies-Cobra Style, CPT Lawrence I. KarpmanToo Much Trust, CW2 Gerald E. RhoadsCharlie And Danny's Write-InWhat's Your IFRIQ? Charles A. Thomley, OACAeromedic, LTC Nicholas E. Barreca, M.D.The 1973 Annual Writ, MAJ Paul G. LarishNew Semitrailer Petroleum Testing Laboratory

Myron Wolfe, OACMaintenance MattersThe Cold FactsWrite To RightUnruly Weather SensePearl'sUSAASO Sez

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The mission of the U. S. ARMY AVIATION DIGEST Is to provide Information of antional or functional nature concerning safety and aircraft accident prevention, tramaintenance, operations, research and development, aviation medicine, and othlated data.The DIGEST s an official Department of the Army periodical published monthlythe supervision of the Commandant, U. S. Army Aviation School. Views expressedare not necessarily those of Department of the Army or the U. S. Army Aviation SPhotos are U. S. Army unless otherwise specifled. Material may be reprinted procredit is given to the DIGEST and to the author, unless otherwise indicated.Articles, photos, and Items of interest on Army aviation are invited. Direct commtion Is authorized to: Editor, U. S. Army Aviation Digest, Fort Rucker, AL 36360.This publication has been approved by Headquarters Department of the ArSeptember 1972.

Active Army units receive distribution under the pinpoint distribution system alined In AR 310-1. Complete DA Form 12-4 and send directly to CO, AG Publicationter, 2800 Eastern Boulevard, Baltimore, MD 21220. For any change in distribution rements, initiate a revised DA Form 12-4.National Guard and Army Reserve units under pinpoint distribution also shouldDA Form 12-4. Other National Guard units should submit requests through theiradjutants general.Those not eligible for official distribution or who desire personal copies of thecan order the magazine from the Superintendent of Documents, U. S. Government POffice, Washington, D. C. 20402. Annual subscription rates are 8.00 domestic andoverseas . Single copies are 7S cents each.


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J WSROME DERS

Sir:I don't agree with your answer toquestion 18 of the expanded instrumentcorner in the August 1972 edition.Paragraph 3-10g (1) specifically authorizes an Army aviator to ignore subse

quent ceiling and visibility reports oncea straight-in approach has been initiated. (Actually, changes in reportedceiling are somewhat academic in thiscase because visibility is all one needsto initiate a straight-in approach.) However, the same authorization to ignoresubsequent weather reports is not contained in paragraph 3-10g (2) for continuation of a circling approach.I was taught in the examiner coursethat this difference in specific authorization means an aviator cannot ignoresubsequent reports during a circling approach. Thanks.

MAJ Raymond E. EvansCommand and General Staff

CollegeRoom 31, Funston HallFort Leavenworth, KS 66027 All questions in the subject articlewere reviewed by the U. S. Army Aeronautical Services Office (USAASO). Thereason USAASO concurred with continuing the approach to the missed approach point (circling) is because theprotected airspace associated with themissed approach area begins only at themissed approach point (MAP). Reference AR 95-2, paragraph 3-10g 1) and(2) and TERPS, section 7.Sir:The School of Operational and Aerospace Medicine is interested in obtaining 100 reprints of the following articleswhich appeared in the u. S. ARMY AVIATION DIGEST, and would appreciate information as to availability and cost:a. Which Way Is Up?-Aeromedic,by Major Bennett G. Owens Jr., M.D. ,u. S. ARMY AVIATION DIGEST, April 1972,pp. 12-15 (Part 1).b. Vestibular Illusions and How toWhip Them-Aeromedic, by MajorFEBRUARY 1973

Bennett G. Owens Jr., M.D., u. s. ARMYAVIATION DIGEST, May 1972, pp . 12-15& p. 28 (Part 2) .c. Mention is made of a third article.We have misplaced one of the issues ofthis DIGEST, and it is possible the thirdpart may have been in that issue.

f reprints are not avai lable, we wouldask your permission to reproduce thesearticles for the School of Operationaland Aerospace Medicine. This wouldinclude a statement as to the originalsource of the article.Thank you.

Major J. SoutendamSchool of Operational andAerospace MedicineToronto M5N 2E4Ontar io, Canada

The DIGEST is unable to obtain thereprints you asked for. However, we arehappy to grant you the permission toreprint the articles yourself. The thirdarticle you mentioned is Visual Dlusions--Aeromedic which appeared inthe June 1972 issue. A copy of thisissue is on the way.Sir:

I read with interest the article in yourOctober issue written by LTC DonaldR. Hull , The Way of the Future: LowLevel.I am the Canadian Army Forces representative on the Joint , U . S. Army ,German Army and Canadian ForceEurope, Evaluation Group. We havespent the past 2 years conducting trialson helicopter operations in Europe. Theresults of the first two trials appear inthe following reports :USAREUR/7th Army Cavalry TroopEvaluati on (1970)

AH-l G (Cobra) Follow-On Evalua-tion (Joint) (1971)The third and final evaluation report,Joint Attack Helicopter InstrumentEvaluation (1972) should be put on distribution early in 1973. This trial utilized laser direct fire simulators toobtain real time kill assessment and em-

ployed OH-58As and AH-1Gs againstan aggressor force based on WarsawPact tactics and organizations. The objective of the evaluation was to obtainstatistics on the survivability of helicopters in the European environment.LTC Hull has correctly identified thethreat in Europe and the requirement to

fly at low level. Unfortunately his concept of low level and nap-of-the-earth(NOE) flying is not in keeping with theresults we obtained on the above threetrials. Flying at 50 feet as he advises inEurope, would not permit helicopters tosurvive against the tank machine gun(12 .7 mm) let alone the ZSU 23-4. Themajority of helicopter casualties thatoccurred on the Instrumented Evaluation were flying or hovering above thetrees. All three eva luations emphasizedthat helicopters must fly at an altitudeno greater than 10 feet. I prefer theterm contour flying, that is, taking advantage of the nap or contours, treesbuildings, hills, etc., to prevent line ofsight observation from the enemy orsuspected enemy. The only time a helicop ter hould fly above the trees is whentraver ing large forested areas.This type of flying, of course, placesthe pilot in the vicinity of wires, whichare numerous in Europe. This danger,however, has been overemphasizedthrough the years. The Canadian ArmedForces have been flying NO E, by mydefinition , on reconnaissance missionsin Europe since 1962. To my knowledgeonly two wire strikes have occurredsince that time. Both of them were attributed to pilot error because there wasno requirement for them to be NOE atthe time. They were both flying muchtoo fast under the conditions, returningfrom the exercise area. The Chief of theDefense Staff recently congratulated theunit in Europe for 3 th years of accident-free flying. An outstanding recordfor any unit , but especially for one thatsnends 90 nercent of their flving time atNOE . We flew over 1,200 hours on the

Continued on page 51


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-The following thought-provoking article,"Whither the Writ," should be of professionalinterest to all Army aviators, particularly sincemany of you have provided meaningful inputthrough surveys solicited by the author, LTCWilliam H Gardner.

As the "prime mover" in developing the 1969version of the annual writ, LTC Gardner iseminently qualified to assess the current annualwrit methodology. In so doing, he has identifiedmajor shortcomings that are worthy of consideration, some of which will soon be rectifiedwhen revisions of ARs 95-1 and 95-63 arecomplete.

As a preview of things to come, 1'm happy toreport that our aviation regulations are beingmodernized and streamlined to eliminate manyof the obsolescent and unnecessary regulatoryrequirements no longer serving a useful purpose.AR 95-1 will be a consolidation of ARs 95-1 and2 and provides for some of the concepts that thisarticle recommends. For example, all aviatorswill be required to take the annual writ, regardless of duty assignment, because we as Armyaviators have an obligation to remain as professionally qualified as possible. However, theexam will continue to be administered toward

the end of each fiscal year since this providesan excellent opportunity for the unit to conducta formal ground school and thus impart on anorganized basis the necessary instruction priorto administration of the writ. This basic reasonfor scheduling the writ in May and June still isvalid. Of course, instructor pilots still can provideappropriate instruction in conjunction with instrument card renewal and standardizationrides. AR 95-63 entitled "Army Aviation Standardization and Instrument Program" encompasses all aspects of VFR/IFR training and qualifications. It is envisioned that the new ARs 95-1and 63 will tie together our loose ends and enable Army aviation to maintain a posture thatis clearly "Above the Best "

While these new regulations might not makethe "best seller list, I encourage maximumreadership as it will impact across the full spectrum of aviation operations. Meanwhile, enjoyLTC Gardner's article as I have. Feedback of thisnature, originating from aviators in the field,provides the realistic, timely input so vital todecision making at the Department of the Army.

Brigadier General William J. Maddox Jr.Director of Army Aviation


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This article is a condensation of the author s treatise written in connection withthe communicative arts program at the 1971 ..1972 Command and General StaffCollege (CGSC . The treatise discusses the background of the annual writ (drawingon the author s experience as the author of the 1969 version); researches the aviation written examinations of the Army s sister services; and analyzes in depth asurvey regarding the future of the writ completed by 171 field grade aviators inattendance at CGSC as well as 50 senior warrant officers then enrolled in Aviation Warrant Officer Intermediate Course (AWOIC) 72 -1 at the U. S. ArmyAviation School, Ft. Rucker, AL. The article follows this same general format butcovers only the major recommendations and conclusions reached in the treatise

Lieutenant Colonel William H. GardnerI T IS ALMOST axiomatic thatwhen one changes an aspect ofa system radically, he should alsofully investigate the impact of thechange on other components of thesystem.

The Army aviation system recently has undergone significantchanges. Coincident with the drawdown in the Republic of Vietnam,the Army has shifted future emphasis almost entirely to rotarywing operations and to meet financial constraints flight excusal hasbeen implemented on a large scale.This leads to the question ofwhether or not another componentof the Army aviation system-theannual writ-should now also undergo some changes.

The 1973 writ will be the twentyfirst. It has grown from a singlebooklet with 100 questions in 1953to the current publication of four50-question examination versionsas well as a p r vi tor issue of astudy guide, reference data booklet(RDB), VFR map and IFR chart.This current format has remainedvirtually unchanged for the la t 10years. Its purpose ha al 0 remained unchanged, i.e., it is "aneducational tool designed to refreshArmy aviators on flight regulationsand procedures and to introducenew regulations and proceduresFEBRUARY 1973

that might not otherwise be familiar." The study guide is provided asboth a vehicle for updating aviatorson recent changes within Army aviation and as an assist to passing theexamination. The RDB containsextracts from the various flight information publication (FLIP) documents required and used by mostaviators for other than tacticalflights and serves as the basic reference for both the study guide andthe examination versions.Unless it is specifically waive redfor their current job or area of assignment, all Army aviators including appropriate Department of theArmy civilians (DACs) are required to take the annual writ ,either in April, Mayor June eachyear, or when returning to flyingfrom a waivered status. Army regulations require that an aviator musthave completed the current writprior to instrument renewal re

issue. Only failure to take the writwhen required, or failure to passone of its four versions , requiresfurther action under current regulations.The discussion of the other service must be prefaced by the factthat their aircraft , mis sions and rel-ative size differ significantly fromthe Army's and that their requirements are unique. Nevertheless ,

there is overlap particularly in thecommon goal of providing periodicwritten examinations for aviationpersonnel to update, refresh andevaluate individual and unit proficiency and training.The Air Force employs a 100-question open book, multiplechoice examination which is generally changed annually. It is administered in connection with instrument renewal (due the last dayof the aviator's birth month) and

follows a mandatory 2-day groundschool. This training consists of aminimum of 12 hours classroominstruction in regulations, weather,computer, flight instruments , navigational aids and spatial disorientation.The Air Force uses a comprehensive programed text, AF Pamphlet60-4, to supplement its groundschool. The document is publishedevery few years but can be readily

updated and corrected by publishing individual page changes. Thosefew Air Force aviators excusedfrom the ground school can use theprogramed text to prepare for theexamination. All training materialcommon for all Air Force pilots isprovided by the Instrument PilotInstructor School (lPIS) , 351 OthFlying Training Wing (ATe),Randolph AFB, TX , to each oper-


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ations section charged with the administration of the ground schooland exam. Each operations sectioncan and does embellish its groundschool sessions (usually heldmonthly or bimonthly) with thoseregulations and policies peculiar toits airfield or aircraft.The general thrust of the AirForce examination is the same sthe Army s in that roughly 60 percent of the questions cover variousAir Force manuals and the materialin Air Force Pamphlet 60-4 whilethe balance deals with appropriateFLIP documents. The questionspertain to both VFR and IFRprocedures.

The Air Force addresses its aircraft in a separate formal programt he annual proficiency writtenexamination-similar in makeup toa comprehensive dash 10 test. Thisprogram is conducted annually but6 months out of phase with instrument renewal. Minimum passingscore for the written examinationsis 85 percent corrected and critiqued to 100 percent.Major Air Force commandersmay waive classroom instructionrequirements or programed instruction under exceptional circumstances but the instrument writtenexamination is not waived.When an air crewmember fails awritten examination, he is alloweda maximum of 2 months after thedate of the first failure to completea successful reexamination. Everyreasonable effort is made to recertify the officer and commandingofficers determine the number ofreexaminations to be allowed basedon the individual s experience level,qualifications and number of hoursof training required and available.f a successful reexamination is notcompleted by the end of the 2-month period, the aviator will beplaced either in category A (non-

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Prior to an instrument requalificationcheck flight (right) the Army aviatormust first complete the annual writ

compliance because of circumstances beyond the control of theaviator-no further action is takenand , in effect, the requirement iswaived) or category B (continuedflying status to be determined by aflight evaluation board).

The major differences betweenthe Army and Air Force writtenexaminations are: The separate formal programsfor aircraft proficiency in the irForce. The Army does not have aformal Army-wide program in thisarea. One examination version inlieu of four. Administration at the time ofinstrument renewal. Mandatory ground school instruction prior to taking th e writtenexamination. A relatively permanent programed text instead of an annualstudy guide and reference databooklet.The Navy and the Marine Corpsprograms differ substantially fromthose of the Army and Air Force.Both the Navy and the MarineCorps use the Naval Air Trainingand Operating Procedures Stand

ardization NATOPS) program.The following paragraphs discussthe NATOPS program in detail.The NATOPS program is implemented through readiness squadrons located at various East CoastAIRLANT) and West CoastAIRPAC) Navy installations andby NATOPS officers found at station, squadron, wing ship, detachment or equivalent levels. There isa readiness squadron for each of

the basic Navy flight categories,e.g. , VP (patrol and land basedantisubmarine warfare aircraft);VA (attack aircraft); VF (fighteraircraft) ; VH (helicopters); and VS(carrier based antisubmarine warfare aircraft).Representatives of the two readiness squadrons for each categorymeet annually with representativesof all Navy and Marine elementswho fly the particular aircraft swell s the manufacturer. As a result maximum standardization isachieved in the NATOPS program.There are five particular aspectsof the NATOPS program which areconsidered pertinent to the annualwrit: Mandatory training upon ro-tation All naval aviators prior toreporting to a flying assignment,regardless of experience level , undergo refresher training at the appropriate readiness squadron. Thistraining , which may last up to 3months, includes standardization inthe aircraft in which he will be fly-ing and instrument rating renewal,even if it is not due. The instrumentcheckride is preceded by a NATOPS written examination. Qualification of unit N TOPSo i ers The readiness squadronsqualify selected naval aviators fromthe various squadrons/ installations/ units in the administration ofthe NATOPS program for theirorganization. This procedure issomewhat analagous to the Army sexaminer program except that thequalification is for both the aircraftand instrument flying and, unlessrecertified, valid for only 1 year.

th writ


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NATOPS teams flight check at leastone crew from each unit. Here a navalflight officer and an aviator climb intotheir F 4 Phantom, NAS, Oceana, VA

Additionally, serving as a NATOPSofficer is the aviator s primary duty. NATOPS flight manuals NA-TOPS manuals and flight manualsare prepared for specific aircraftand contain standard flight doctr ineand optimum operating proceduresfor the aircraft model concerned.Instrument flying procedures pertinent to that aircraft are includedbut general instrument flying considerations, i.e., pertinent Navyregulations, FLIP, etc. , are omitted.These manuals are used as the basisfor the development by each appropriate Navy echelon NATOPSofficer of a year long training program covering all aspects of flightin the particular aircraft. The manuals also serve as the basis , alongwith other references, e.g., FLIP,Navy regulations, etc., for the NATOPS written examination (prepared annually) and for locallyprepared instrument written examinations which must be approvedby AIRLANT or AIRPAC. TheNATOPS examinations normallyconsist of 200 or more questions ofmany types . . . fill-in , multiplechoice, etc. The NATOPS examcovers all aspects of flight in theparticular aircraft and is , in Armyterms, a combination of a thoroughdash 10 test and the annual writ.The locally produced instrumentexaminations are usually 100 questions. The NATOPS exam is bothopen and closed book, whereas thelocally produced instrument examsare generally open book. Annual evaluations The NATOPS program requires annualchecks of all Navy aviation units byNATOPS evaluation teams. This istheir principal duty and they travelfrom aviation unit to aviation unitthroughout the Navy where theirparticular aircraft is flown. As aFEBRUARY 1973

minimum the team will flight checkthe commanding officer, operationsofficer and local NATOPS officeras well as at least one crew. How-ever, all crew personnel are giventhe appropriate written examination based on the NATOPS manualfor the aircraft. This examination isadministered only by the team andnone of the examination material isdistributed to unit level. The NA-TOPS written exam normally takes2 days to administer. No groundschool is conducted by the NA-TOPS evaluation team per se andthe NATOPS exam, in addition totesting individual proficiency andknowledge, is also an excellent indicator of the effectiveness of thelocal training program.

Responsibilities of the unitNATOPS officer The NATOPSofficer at unit level is responsiblefor administering the remainingflight checks as required. However,though an instrument check is oftenincluded in the NATOPS flightcheck, most instrument renewals

U. S. Navy photo

are conducted by a local instrumentflight board of which the NATOPSofficer is normally a member. Theseboards conduct instrument evaluations of Navy and Marine Corpspilots to include aviators in nearbyunits where such facilities are notavailable. Renewal of instrumentratings in the Navy and MarineCorps) includes both a formal written examination and a flight check.Both must be accomplished in the60 days preceding an aviator sbirthday. Expiration of instrumentratings under NATOPS, as in theArmy, is the nearest birthday plus1 year.

Instrument renewal in the Navyand the Marine Corps requires attendance at a formal ground school,if one is available, and the satisfactory completion of the writtenexamination which must cover thefollowing areas: FAA regulations as they applyto flight under instrument conditions.Continued on page 9

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let s not forg t about:

Currently, emphasis is being placed on instrument flying, and as of 31 December 1972most Army aviators should have received a standard instrument qualification. It s always wise, however, to return to the basics we became so familiar with in initial entryflight training. That is the basics of visual flight rules, and interpreting the VFR chart

A LOT OF attention is paid toinstrument flight and emphasisis put on renewing instrument tickets. But what about a plain oleVFR cross-country? Is enough attention being paid to this?

From results of FAA AirmanWritten Examinations [one of theseis the comp (Military CompetenceExam test for rated aviators] thereis an indication that a knowledge ofVFR operation such as controlledairspace and the application ofpertinent Federal Aviation Regulations is a weak area in pilot education.Just as there are traffic laws andrestrictions regulating the operationof automobiles in certain areas orzones, there are regulations governing the operation of aircraft withindesignated airspace. These regulated areas are established only in

CW2 James T Miller

the interest of safety to apply theregulations pertinent to a particularairspace. A pilot must first be ableto determine whether he is withinthat airspace.Airspace is unlike streets andhighways where there are postedsigns or markers of some type; youdon t find street signs at 3,000 feet.Consequently, while operating incontrolled airspace the pilot mustbe able to properly interpret thesectional chart. Not everything isshown on sectional charts such asvertical limits and sometimes horizontallimits (for example, the limits of an airport traffic area .Also associated with controlledairspace are weather minimums forVFR operation in controlled anduncontrolled airspace. This information is not on the sectional chart

and is a bit of knowledge that everypilot must know.The following questions arebased on excerpts taken from theNew Orleans sectional showing theFt. Rucker, AL , local area but pertain to all areas. f you can answerthem with 100 percent accuracy,there is no need to read further; ifnot, read on for explanations.1 What are the limits of an airport traffic area?2. Which airports have trafficareas?3 How is an airport traffic areashown on the chart?4. Around Dothan airport there

is a broken line. What does thisrepresent?5. Around Great Northern airport there is an area that is coloredin magenta. What is this area andwhat are the limits of this area?U S ARMY AVIATION DIGEST


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6. What are the limits of the airspaces that are colored blue (greyin the figure) ?The answers to questions 1 and2 can be answered together with thedefinition of an airport traffic area.irport traffic area Unless otherwise specifically designated (FAR

Part 93) that airspace within ahorizontal radius of 5 statute milesfrom the geographical center of anyairport at which a control tower isoperating, extending from the surface up to but not including an altitude of 3,000 feet above the elevation of the airport. Reference:FLIP Planning, Section 1-12; FLIPPlanning, Section II (Arrival), paragraph IVE.

Question 3 might be a littletricky. An airport traffic area is notshown on a sectional chart. Theonly way to tell if a field has anairport traffic area is to look in theairport information on the sectional. f it says there is a controltower, then there is an airporttraffic area.

\

For example look at Dothan:

\ \ \

FSSDothan

\\ / /. /


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O YOU FALL into the cate-gory of AH-1G Cobra pilotswho are flying their snakesthrough the skies without fullyunderstanding the aircraft's fuelsystem. Now, no one is doubtingyour knowledge or proficiency. fyou are positive that you knowexactly what all of the cautionlights concerning the fuel systemmean, then now may be a goodtime for you to catch up on yourcrossword puzzles. But, if you'drather try your luck at the simplequiz below, go ahead; it may payoff some day, even though at themoment you feel knowing a threeletter word for an Aardvark's toesmay prove quite useful some day.1 Illumination of the worded segment ((FWD FUEL BOOST onthe AH-1G pilot's caution panelindicates:

a) Forward fuel boost pump isproducing 0 pressure.b) Forward fuel boost pump isinoperative, but fuel is still beingdrawn directly from the forwardfuel cell.

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c) Forward fuel boost pump isproducing less than 5 psi pressureand flight above 4,600 feet shouldbe avoided.d) Forward fuel boost pump isinoperative and all fuel in the forward cell is unusable.

2 With the ((AFT FUEL BOOSTcaution light illuminated, the pilotshould:a) Continue the flight, as thereare no restrictions.b) Descend below 4,600 feetpressure altitude.c) Land at the nearest available safe landing area.3. Illumination of the ((10%

FUEL caution light tells the pilotthat:a) A minimum of 20 minutesof usable fuel remains in all cases.b) 10 percent of total fuel capacity remains provided both fuelboost pumps are operational.c) Approximately 260 poundsof usable fuel remains, with eitherboost pump operational.4. The initial cause of the illumination of the ((FUEL FILTER caution light is:a) A totally clogged fuel filter.b) A partially clogged fuelfilter, which allows immediate bypass of the filter.c) A partially clogged filter.Answers to these questions arebelow

1 c) When boost pump pressure


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The Cobra pilot who fully understands theSkinny Huey fuel system will be in a better

position to make the best decision when oneof his caution panel segment lights illuminates

Captain Lawrence I. Karpmandrops below 5 psi, a pressure switchin the manifold senses this and illuminates the appropriate fuelboost pump caution light. Below4,600 feet pressure altitude the engine driven pump will siphon fromthe forward cell reg rdless of boostpump oper tion and will permituse of virtually all the fuel in theforward cell. Flight above 4,600feet should be avoided with eitherpump out since there is a very realchance of flame-out should theother one fail.2. (a) There are no restrictions toflight with an aft boost pump inoperative. However, it may be wiseas stated in 1 (c) above to descendbelow 4,600 feet with the aft boostpump out in the event the otherboost pump fails. The pump ofcourse should be repaired or replaced prior to the next flight.3. (b) The operation of the 10percent probes in each cell willcause, with both pumps operational, the first one being triggeredto be disregarded. Thus, when thesecond is triggered the light willilluminate and, if adjusted properly,160 pounds of fuel will be remaining. This makes b entirely correct.However, if one or both pumps areinoperable, then the first probe being triggered will cause the light toilluminate. This means that withone or either pump inoperable that20 percent of fuel is remaining.This would be 10 percent in thetank whose probe has been triggered plus 10 percent or more inthe untriggered tank. Since below4,600 feet virtually all fuel is usable, and since one should not beabove 4,600 feet with either or bothpumps inoperable, then at least 20percent of fuel will be remainingFEBRUARY 1973

even if both probes were triggeredsimultaneously. The idea of 20minutes of fuel remaining shouldbe used as a guide and only a guide,nothing more. Each aircraft willconsume fuel at different rates. Atthe start of each flight the air crewshould make a fuel consumptioncheck to determine the rate of consumption for that particular aircrafton that day. I'm sure that you havecome in contact with an AH 1 Gthat consumed about 600 poundsper hour. Well, at that rate our 10percent caution light would becomea 16 minute light instead of a 20minute light (600 pounds per hourequals 100 pounds per each 10minutes or 160 pounds equals 16minutes). So, if you fly 18 or 19minutes into your so-called 20minute light, you may find yourself surrounded by the sounds ofsilence and nothing to keep youcompany on the way down exceptthe low rpm warning audio echoingin your ears. Believe the 10 percentlight in all cases. And remember,normal policy requires landing assoon as it is practical once the 20minute light is illuminated, commensurate with tactical situationsand inflight conditions.4. (c) The FUEL FILTERcaution light indicates p rti l obstruction of the fuel filter. A pressure differential switch mounted inthe fuel line across the filter, sensesa difference in fuel pressure between the inlet and outlet of thefilter. When this pressure differential reaches about 0.85 to 0.87 psi ,the pressure switch will cause thecaution light to illuminate. Whenthis pressure differential builds to1.25 to 1.27 psi, the pressureswitch will cause the fuel to

bypass the fuel filter by closingthe filter bypass valve. A glance inthe dash 10 for the AH-IG (TM55-1520-221-10) will advise thepilot to land his aircraft within 30minutes. Again, we encounter aguideline. t is important for thepilot to understand exactly what istaking place. The figure 30 minutes is strictly a guide. It is basedupon the estimated maximum timethat the pressure differential between the inlet and outlet of thefilter will build from 0.85 to 0.87and 1.25 to 1.27. Once the bypassvalve in the filter opens, you aregoing to have contaminants flowdirectly to the fuel control. The pilot must keep in mind the fact thatit is the severity of the contamination that determines the length oftime between initial illumination ofthe fuel filter caution light and theactual bypassing of the fuel filter.f the aircraft was refueled in acombat environment at a hastily orpoorly constructed POL point andthe fuel filter caution light illuminates, it may be advisable to land(situation permitting) well beforethe 30 minute limitation.For those of you who successfully answered all of the short questions, we hope we have neverthelessprovided a brief refresher on someof the fuel system caution lights.

For those of you who may havemissed one or two, it may be timeto dust off the old operator's manual and refamiliarize yourself withthe Skinny Huey. Any way youlook at it, the pilot who fully understands what is taking place whenone of his caution panel segmentlights illuminates is in a far betterposition to make the best decisionthat the situation allows. . .


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Too uch TrustA more thorough briefing could have pre-vented the nearly disastrous chain of events

W WERE DEEPLY en-grossed in a pinochle gamein the alert room when the rattle ofthe field phone drew our attentionfrom the cards. t was a call fromthe operations clerk-a call settingthe mission machinery of Dustoffin motion. As I laid my cards downand started toward operations, therest of the crew departed for theUH-IH Huey to crank it and haveit ready to go when I arrived.Inside the operations office I began considering the pertinent factson the mission request sheet. ThreeKorean soldiers had received serious frag wounds on a mountain sidesoutheast of the An Khe pass in theRepublic of Vietnam. Landingwould e impossible because of theterrain, thus this would have to bea hoist mission. I instructed theradio operator to call gunships, aKorean interpreter and a flareshipbecause it was getting dark. Then Iheaded for the flight line.

The aircraft was prepared, startedand the crew ready to go. Themedic and crewchief had been incountry approximately 2 years andhad a great deal of experienceworking together as a Dustoff crew.They had numerous hoist missionsto their credit. The pilot had beenincountry 2 months and everybodywas satisfied with his performance.This, however, would be his firsthoist mission and I wasn t countingon him for too much assistance.Our Korean interpreter was a newman. He spoke excellent Koreanbut his command of the King sEnglish was less than iIppressive.

CW Gerald E RhoadsAs we broke ground I briefedthe crew on the number of patients,their location, and the type ofwounds, and began the seeminglyendless stream of radio calls to coordinate all the efforts involved.My radio call to the gunship wentunanswered. Since it was getting

dark fast and with the gunships apparently still on the ground, I gaveup hope of completing the hoistoperation within the remainingminutes of daylight. Performing themission in darkness would meanhovering over the treetops with thelanding and search lights o n a jobI didn t look forward to.The situation began to look alittle better when I turned the FMradio over to the Korean interpreterand he made contact with the menon the ground. A member of theirpatrol had triggered a mine andthree soldiers had sustained seriousfrag wounds. The remainder of thepatrol had already cut down severaltrees to provide a shaft into thejungle for our hoist cable. Enemytroops were known to be operatingin the area but no contact had beenestablished since the preceding day.

To my relief contact with thegunships was made as we arrived inthe vicinity of the pickup zonePZ) . The aircraft commanderCAe) of the lead gunship estimatedhis position at about 10 minutesfrom the PZ and the flareshi p wasclose behind.The area was dark enough at thistime to render smoke grenades useless, but we were able to identifythe location of the patients whenthey fired a distress flare. The 10

minutes passed quickly as the Korean interpreter relayed my instructions on the use of the jungle penetrator to the troops on the ground.After a briefing on the situationthe lead gunship decided on awagon wheel overhead and coordinated with the flareship. I began anapproach to the area with the gunships behind me as the first flareignited, lighted the area for a fewseconds and dropped out of sightbehind an adjacent mountain. Asecond flare appeared but sooncame to the same useless end as thefirst.I continued the approach and onshort final aimed the search light atthe PZ for a low recon. The flareship had adjusted his position and aflare ignited to reveal more detailsof the area. The patients were under 75-foot trees at the bottom of anarrow shaft in the higher treesaround the PZ. With the help of thecrew I hovered down into the opening until I could descend no further;then the medic began lowering thehoist cable.All was proceeding well as thejungle penetrator started down toward the Koreans. The crewchiefand medic kept a constant streamof position advice going and wewere able to remain centered overthe patients. Periodically a gunshipwould appear to the right front andthen disappear to the left front,circling overhead. The flareshipchased away the darkness with wellpositioned flares.Suddenly for no apparent reasonthe interpreter began shoutingsomething at the troops on the

1 U S ARMY AVIATION DIGEST


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ground. My earphones were filledwith his irritating chatter. Under-neath this noise I heard the medicannounce that we would be takingon weight in about 10 seconds.How many patients?" I shouted.Three, came the medic's weak

but audible reply.That's too many," I returned,not knowing whether or not I hadbeen heard. Don't pull them offthe ground ""What?" he shouted, but theKorean chatter covered his wordslike a shroud.Don't take on any weight " Ishouted. "Interpreter Tell thosepeople to get one of the men offthat hoist "

The Korean continued to talk,seemingly oblivious of anything Ihad said. t became obvious that hisconstant hollering had blockedcommunication between the medicand myself when I heard the medicshout, "Taking on weight ""No " was all I had time to say,but the hoist had already been ac-tivated. As the patients brokeground, their weight pulled the air-craft right and nose low. We hadgone beyond the center of gravity

limits.Put 'em down " I yelled as thecyclic hit the left aft stop.In a matter of a split second itwas too late to get the patients backon the ground safely. I pulled allthe pitch I dared and instructed thepilot to stand by on the cable cutter.His cyclic was equipped with ahoist control that would overridethe medic's controls, but it was al-ready too late to use it.The ship was nearly uncontrol-lable and drifting forward and tothe right toward the high trees. Itfinally began to climb but continuedto drift. I hit 50 pounds of torquein an attempt to clear the tall treesin front of us before the unbearableweight dragged us to certain dis-aster. We continued to climb, butat the same time we got closer andcloser to the trees.

FEBRUARY 1973

To cut the cable and release theweight would mean death to thethree men on the hoist. To continuedrifting could mean death to eightpeople. Should I risk the lives offive men to try to save three alreadyseriously wounded soldiers? Orshould I guarantee the safety of thefive by sacrificing the three? Thepossible consequences of eithercourse of action was not a pleasantthought.I made my decision and contin-ued to climb. The aircraft justbarely cleared the treetops, but 50feet below us three wounded menwere getting smacked and scratchedby the branches of a dense jungleas the cable freely swung to and fro.Finally the penetrator brokethrough the treetops and the dangerof entangling the cable was past.We were still drifting with onlymarginal control but at least werebeyond the reach of the deadly ob-stacles. Seconds later the patientswere aboard the aircraft and I hadit under control. I eased the cyclicforward picking up some air speedand we were on our way to thehospital.Hindsight reveals that poor crewcoordination had very nearly costthe lives of eight people. Severalvaluable lessons were learned-the

hard way.Partly because of the languagebarrier and time factor the Koreaninterpreter had not received ad-equate instruction in the use of thehoist. He did remember at the lastminute that quick, expeditiouswork was important to the successof a hoist mission. This was thereason for all the hollering on theradio. He had told the groundtroops to put all three patients onthe hoist together. Combine thiswith his deplorable radio pro-cedures and an already poor situa-tion got worse.The medic could not understandme because of the garbled chatterof the interpreter in his earphones.

He was forced to make a decisionthat normally would be made by anaircraft commander. He remem-bered correctly that the hoistcapacity is 600 pounds, that threeKorean soldiers would seldomweigh that much and that too muchtime at a high hover is dangerous.Putting these facts together he de-cided that bringing all three pa-tients up at once was a good ideain that it would reduce hover time.t is true that a hoist mounted on asolid platform should be able tolift 600 pounds, but it is poorjudgment to try lifting this muchweight from a Huey hovering 75feet in the air. This second aspecthad not been part of the medic's

education. Being more interestedin arteries than aircraft he had ac-cepted the 600 pounds limit at facevalue and never considered anyother factors.Mistakes were made by othersthat night but the ultimate re-sponsibility should be dumped intomy lap. Decision making and crewcoordination are an aircraft com-mander's reason for existing, andT failed on both accounts. Themission was successful by the graceof God and the guts of an H modelHuey-neither of which was ma-terially influenced by me. Based ontheir long experience incountryand length of time they had workedtogether, I assumed that the medicand crewchief were proficientenough to handle any situation. Bynot providing more detailed in-structions regarding the capacityof the jungle penetrator, I allowedthe ~ i t u t i o n to develop to a pointthat forced the medic and crew-chief to make a decision for whichthey were not prepared.

The most serious error, how-ever, was not providing the entirecrew with proper coordinating in-structions and guidance. morethorough briefing prior to theactual operation could have pre-vented the nearly disastrous chainof events from ever b e g i n n i n g ~


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15/52

What s Your

I FR IQCharles A. Thomley, D C

W H T DISTINGUISHES an instrument ratedaviator from a nonrated aviator? Is it just the10 additional hours of experience that one gets fromthe standard instrument program? Does an instrument rating make an IFR proficient aviator?Surely if one has an instrument rating on hiscertificate, he is entitled to the privileges that goalong with the rating. Does this necessarily mean'that he is qualified to use these privileges? Certainlyhe has fulfilled the requirements for obtaining therating and has completed the checkride to the satisfaction of the instructor pilot, and at the moment therating is issued he is at best a beginning instrumentrated aviator. He has met the minimum requirementsfor obt ining the instrument rating. Probably theaviator himself is the only person who knows hisproficiency.Let's look at a few questions which might serve asindicators in determining whether one has acquiredthe knowledge necessary for proficiency as an instrument rated aviator. Answer these questions and thendecide for yourself whether you are confident ofyourself with respect to IFR knowledge.

TRUE FALSE1. ( In order to legally carry a passenger you must have made at least five takeoffs andlandings to a full stop in an aircraft of the samecategory, class and type within the preceding 90 days.2. ) ( ) You may act as pilot in commandof an aircraft in IFR weather conditions without aninstrument rating provided you remain outside ofcontrolled airspace.FEBRUARY 1973

.3. ) ) Instrument flight rules do not ap-ply to IFR flight in uncontrolled airspace.4. ) ) You may operate legally underIFR in controlled airspace without an instrumentrating provided it can be accomplished in VFRweather conditions.5. ) ) IFR conditions always make itnecessary to fly the aircraft solely by reference toinstruments.6. ) ) t is solely the pilot's prerogativeto cancel his IFR flight plan.7. ) ) A pilot's retention of an IFRflight plan will afford him traffic pattern priority overVFR traffic.8. ) ) Except in the event of a two-wayradio communications failure, if a clearance beyondthe limit fix is not received before arrival over thefix the pilot is expected to hold at the fix.9. ) ) To authorize a pilot to execute hischoice of instrument approach the controller willsimply state that the flight is cleared for approach.10. ) ) Clearances authorizing instrumentapproaches are issued on the basis that if visual contact with the ground is made before the approach iscompleted the pilot will continue by using a contactapproach.11. ) ) Acceptance of a radar approachby a pilot waives the weather minimum requirements .12. ) ) Required airborne VOR equipment checks should be accomplished under VFR.13. ) ) DF approach procedures are notlanding procedures. They are emergency proceduresfor getting an aircraft below clouds and within visualcontact of the airport.

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14. ) ) An ARTCC clearance assures youof separation from VFR traffic.15. ) ) An ATC clearance must be obtained prior to operating an aircraft under IFR incontrolled airspace.16. ) ) The hands on the altimeter indicate in feet the difference between the actualatmospheric pressure being sensed and the pressureset in the Kollsman window.17. ) ) Increasing the altimeter settingresults in a decrease in indicated altitude.18. ( ) ( ) Operation on the emergency staticsource usually indicates a lower-than-actual altitude.19. ) ) An unattended VOR providesno air/ground communications service.20. ) ) The only positive method ofidentifying a VOR is by its coded or voice identification.21. ) ) Only L class VORs are used todescribe victor airways on the low altitude en routechart.22. ) ) When an IFR flight is controlledby radar, and the control of the flight is handed offfrom one controller to another, after the aviatormakes his initial contact on the frequency change thenew controller must state radar contact.23. ) ) The symbol found on approach charts applies to takeoff minima for militaryaviators.24. ) ) In planning for an IFR flight theestimated time enroute to destination is computedfrom takeoff to the final approach fix25. ) ) Under lost communication it isp.ermissible in some cases to descend and to climbwhile enroute.

nswers1 FALSE. An Army aviator who has completedqualification training in the particular type and modelaircraft and is currently proficient lAW AR 95-1,paragraphs 2-7a and b, is authorized to transportpassengers in Army aircraft lAW TC 1-34, sectionI, paragraph 4.2. FALSE. The pilot in command of an Army aircraft is prescribed in AR 95-2, paragraphs 2-la andb. Only Army aviators who hold a current instrumentqualiti cation may be cleared for flight under instrument conditions (AR 95-2, paragraph 3-7). AR 95-63, paragraphs 2-2a(l) ,b(1) and c(1) prescribeswhich Army aviators are authorized flight under instrument conditions.3. FALSE. FAR 91.119(a)(2)(i)&(ii) and FAR91.121 (b) give the IFR cruising altitude rules for usein uncontrolled airspace.4. FALSE. See AR references in answer 2, above.5. FALSE. The instrument aviator is off and on14

instruments many times during most instrumentflights, i.e., flight between layers, climbing/ descending through broken conditions, instrument approachesand takeoffs and many other flight/weather conditions too numerous to dwell upon. The definitionpertaining to IFR conditions concerning the Armyaviator is found in AR 95-2, paragraph 1-2q.6 TRUE. AR 95-2, paragraph 3-15, subparagraphc, states: An aviator operating with an IFR trafficclearance may cancel such clearance and proceedunder VFR conditions provided he is operating inVFR (visual flight condition) when such action istaken. The appropriate ATC agency will be advisedas soon as possible.7 FALSE. DOD FLIP Planning, section II, paragraph IV. F. I (Arriving) covers this information forArmy aviators.8 TRUE. DOD FLIP Planning, section II, paragraphs III. A. I., III.C. and IIL2.I.d. explain thisfor aviators.9. TRUE. DOD FLIP Planning, section II, paragraph IV.F. and TM 11-2557-29, paragraph 1020.10. FALSE. DOD FLIP Planning, section II, pilotprocedures IV, E.1, says: I f visual contact with theground is made before the approach is completed, thecomplete procedure will be followed unless the pilotreceives approval for a contact approach or cancelshis IFR flight plan.11. FALSE. Weather minimums for a radar approach are published in the IFR Supplement. Thoseare to be used.12. TRUE. VFR conditions must exist in order forthe aviator to reference some object to check theVOR equipment. The statement said irborne checks.13. TRUE. Reference is found in DOD FLIP IFRSupplement and TM 11-2557-29.14. FALSE. AIM, part I, under chapter titled ATCclearances/ separations, subparagraph adherence toclearances example 5 (2), says: Traffic clearanceswill only provide standard separation between IFRflights. During the time an IFR flight is operating inVFR conditions, it is the direct responsibility of thepilot to avoid other aircraft, since VFR flights maybe operating in the same area without the knowledgeof ATC.15. TRUE. Reference FAR 91.115.16. TRUE. TM 1-215, chapter 2-33, says that thepressure altimeter is essentially a pressure measuringdevice calibrated to correct atmospheric pressure toan altitude indication. The base for the altitude indication is the pressure that is set in the Kollsmanwindow.17 FALSE. The atmospheric pressure is alwaysgreater at ground level over a specific location than at

U. S ARMY AVIATION DIGEST


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altitudes above the location. Therefore, if you setin a higher pressure level, you have selected a loweraltitude for your altimeter to use as a reference. fyour position hasn't changed, then the altimeter willindicate a higher altitude.18. FALSE. The altimeter will lag but will indicatethe actual altitude with the same accuracy that itdid before the emergency static source became necessary.19. TRUE. AIM, part I, chapter 2 (navigationaids) under VOR, subparagraph 5, states: Ifno air/ground communications facility is associatedwith the ornnirange; 'airville unattended VOR'(VORTAC) will be heard. Those radio aids tonavigation not having air/ ground communicationservice are identified on DOD FLIP en route chartsby underlining of the frequency.20. TRUE. Reference TM 1-225, paragraph 10-5c.21. FALSE. Both Land H type VORs are used todepict or mark airways. The IFR Supplement liststhe class VOR under Radio Aids to Navigationfor each airfield and it also lists the class VOR foreach VOR listed in the supplement. For example,Montgomery VOR MGM on V-7 is an H VOR.22. FALSE. AIM, part T en route IFR, communications, paragraph 2g(3) flights in a radar environment,says: ATC will inform a pilot that he is in 'radarcontact' (a) when his aircraft is initially identified inthe ATC system; and (b) when radar identificationis reestablished This fact will not be repeated tothe pilot when handed off to another controller. . . .23. FALSE. a. The symbol W indicates that otherthan standard IFR takeoff minimums or departure

procedures apply for that aerodrome or civil usersb. AR 95-2 (paragraph 3-10.f) states takeoff minimafor Army aviators. However, when exercising thisauthority it is expected the pilot in command has considered all aspects stated in paragraph 3-9.b. ( 1) ,AR 95-2.c. Military aviators include all services. Unfortunately, each service has different IFR takeoff minimarules.24. FALSE. DOD FLIP, section II, under preflightprocedures in ETE section, we find for an TFR flightplan the ETE is the time from takeoff to the lastfix shown on route of flight section. Then in the samepreflight section of section II, under route of flightwe find the last fix entered (IFR) will be the initialapproach fix to the destination airfield. The questionis true when the FAF qualifies as an IAF (see NDBRwy 22, Campbell AAF, volume 6).25. TRUE. The IFR Supplement under emergencyprocedures, section I, procedures for two-way radiofailure IFR-VFR paragraph C (lFR) subparagraph(2) altitude, states for lost commo we should be atthe highest of the following altitudes or flight levelsfor the route segment being flown: the altitude orflight level assigned in the last ATC clearance received, the minimum en route altitude or the EFCaltitude. So if the last assigned altitude is 5,000 feetand the MEA for the next segment is 6,000 feet (andwith no EFC altitude), we would climb to 6,000 feet.Then if the next succeeding MEA is 3,000 feet thehigher of our two choices (5,000 feet and 3,000feet) would be lower than 6,000 feet, so he woulddescend to 5,000 feet.

JEWSODERS

ontinued from page 1latest evaluation with only one minorincident when an AH 1 G flew into wiresbut caused no damage to the aircraft.Therefore, the threat is not as seriousas it first appears. Pilots must be trainedto this environment and emphasis hasto be placed on a low air speed such as40 to 60 knots. t is impossible to doyour job at 100 knots anyway.I further disagree with LTC Hull inhis belief that there is a requirement forsophisticated new equipment in a helicopter, to aid the pilot in flying in this

environment. Scout helicopters or anantiarmor helicopter, have no requirement for electronic countermeasureequipment. That isn't their task. Thestate-of-the-art for radar scanning issuch that it could be utilized in helicopters without prejUdicing the weightlimitations. However, the main deficiency appears to be in a navigationalaid. This I do not believe is necessary.For one, the equipment does not workat NOE. Second, the equipment is seldom designed for the helicopter therefore is too costly in weight. Third . pilotsand observers can be trained to navigate NOE. We have trained personnelat different times for over 2 years forour trials. The Canadians have beendoing it for over 10 years successfully.Navigation in Europe is not difficult.There are many tricks-of-the-trade suchas all of the numerous towns and villages in West Germany have road signson all entrances to them. The roads,railroads, canals and rivers are numer-

ous and are excellent landmarks. But,once again, people have to be trainedproperly. In Canada we have an oldexpression in the Forces, Keep t Simple Stupid or KISS, which is exactlywhat is required of helicopters. Keep itsimple, inexpensive and designed for theprimary roles of reconnaissance and astank killers. That is the threat inEurope. Forget the HumRRO TechnicalReport 71-10. Train people in Europe ._where the real environment is.It is impossible to overemphasize therequirement to fly NOE especially inEurope. t is the key to survivaL notsophisticated equipment. Therefore,training should be initiated immediatelyif the helicopter units in Europe aregoing to be capable of fulfilling anyrole in USAREUR.

CPT B A. MuelanerHQ USAREURODCSOPSJoint Evaluation GroupAPO New York 09403

FEBRUARY 1973 15


18/52

I T IS BELIEVED that the firstreported incidence of bends oc

curred among U. S. Army aviatorsduring a series of flights being conducted to evaluate an electronicsystem. The unit conducting theevaluation consisted of seven Armyaviators who flew daily missions for2 days, then rested on the third.The aircraft flown was the U-21Ute an unpressurized , retractablegear, low winged monoplanepowered by twin turboprop engines. Each aircraft carried twopilots and an electronic payload.

The oxygen system aboard theaircraft consists of the MD-2oxygen regulator and the MS-22001 (A-13A) mask. This regulator is of the pressure demandtype that mixes ambient air withcylinder oxygen. As the flight altitude increases, the aneroid mechanism increases the oxygen COI).-tent of the gas delivered to themask. Above 32,000 feet 100percent oxygen is supplied automatically. The aircraft carries twobottles of high pressure gaseousoxygen which on normal settingwill last 8 hours for two pilots.

Two missions were flown eachday. Except for the ceiling theoperating procedure was indenticalin every flight. After takeoff thepilots climbed to the assigned altitude and at 10,000 feet utilizedthe normal oxygen setting on theregulator. The usual climb to altitude required 30 to 35 minutes.Once at altitude the planes orbitedfor 4 to 4 Ih hours and then landed.

During the first 3 weeks theflights were flown between 20,000and 24,000 feet without difficulty.During the next 10 flights the ceiling was raised to 26,000 feet. Fouraviators experienced joint pa in -each on two or more missions. Theother three did not. When thisproblem was brought to the flightsurgeon s attention all aviators weregrounded for 72 hours. No succeeding flights were permittedabove 24,000 feet. As an added16

lIer medicVERY OFTEN our misdirected efforts are so obviously costly to

man s vitality, operational performance and efficiency thatthey prompt immediate and obvious corrective action. However,there also are times when the subtle consequences of environmental stress devetop so insidiously-or marginally that theyescape attention or correction. Take for example the pain resulting from the bends as discussed in the following article.It has been said that igorance is bliss and that what you don tknow can t hurt you. While these may be comforting sentimentsin h l p ~ s s and futile moments, they are back turning and retrogressive in Army aviation. More intuitiv:ely translated, theymean: What you don t know, y u can t tell anyone about andthus you suffer or die with that lack of knowledge. In practicethe result is: What you don t know you overlook and frequentlysuffer with n ignorance.The U. S. Army Aviation School US AVNS) at Ft. Rucker, AL,has always guarded against these senti ents. A significant example is reflected in the steps taken by SAAVNS to emphasizethe Army air crewman s knowledge of his wn human capabilities and limitations. Since June 197 USAA NS has formaHyincorporated academic instruction in aeromedical subiects andphysiological training exercises into the maiority f its programsof instruction. The low pressure altitude chamber s one device

T o e n dOR

N o t T o e n dLieutenant Colonel William Caput, M. D.

precaution J00 percent oxygen wasselected from the ground up, allowing 45 minutes of denitrogenation.In the subsequent 6 weeks theseaviators did not experience anyproblems. The following case histories were recorded.Case No.1: Mr. S. is a warrantofficer who experienced symptoms

on three of his four flights to altitude. His first mission was completed without difficulty. On thesubsequent day, however, he noteda dull aching pain in his right kneeafter 30 minutes at 26,000 feet.He also noted a creeping itchysensation in the skin of his -armsand trunk. The intensity of the

U. S. ARMY AVIATION DIGEST


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Provided by the Society ofU. S. Army Flight Surgeons

acquired to mitigate the stresses discussed in the two previousAeromedic articles and exemplified in the adloining article.All Army air crewmen must be knowledgeable of environmental stresses and human physiological limitations even thoughthe frequency of encountering them may sma ll. The fact isthat most Army aircraft and missions are capable of introducingthese stresses. Whether it be due to individual or personnel motivation (Including daring), geographic I geophysical or geo

polhical constraints, air crewmen will eventual ly use their capabilities and those of the aircraft to complete the mission. For thisthey must be prepared. Unfortuna ely, the air crews discussed inthe following article did not have the benefit of USAAVNS latesteducational programs. It is co forting to know that future aircrewmen will be able to extend their mission performances andoperational efRciencies through an intimate knowledge of theirphysiological capabilities and limitations.

LTC NICHOLAS E. BARR,ECA M.D.Deputy DirectorOffice of Aeromedical Educationand TrainingU. S. Army Aviation SchoolFt. Rucker, Alabama

This is the last of three articleson evolved gas dysbarism. Inthis story are fow case r.e-ports of gas dysbarism experienced by U. S. Army aviators

Captain Tom Walker, M. D.

pain was at first minimal but progressed during the flight. He notedconsiderable relief upon descent to20,000 feet and complete disappearance of these symptoms beforetouchdown. This rapid resolutionof pain during descent was aninvariable pattern for all of theinvolved aviators.FEBRUARY 1973

Mr. S. also flew the afternoonflight of the second day. His painbegan almost simultaneously witharrival at altitude. The pain wasmore intense and soon spread toinvolve the right ankle and righthip. Despite his discomfort he wasable to complete the mission. Hewas again symptom-free at touch-

down except for a slight limp.After 48 hours rest Mr. S. flewhis final mission. The onset of painwas immediate and excruciating.His pain spread rapidly from theright knee to the right ankle andhip, and finally into the abdomen.

The itching sensation was againnoted, but was overshadowed bythe pain. Descent brought onlypartial relief and he was bent for24 hours with abdominal pains.Case No.2: Captain H. madethree flights on successive daysand developed symptoms duringeach flight. On the first day hispain was localized to the left kneeand was an annoyance only. On

the second flight the pain begansooner, spread to involve the lefthip and ankle, and was much moreintense. On the third flight his painwas severe. He stated he was ableto fly because at altitude the aircraft required no rudder control.He also noted a cold sweating sensation with the onset of pain. Painrelief was associated withreductionin altitude. Complete relief occurred by touchdown on everyflight except the last. Following thelast flight Captain H. was left witha limp that persisted several days.

Case No.3: Major S. experiencedsymptoms during both of his flightsto 26,000 feet. On the first flightthe onset of symptoms was delayedfor 3 hours. Major S. experienceda mild throbbing pain in the rightknee which he related to a draftblowing on his legs. The qualityof the pain was not altered bymovement of position. Descent afforded complete relief from pain,but he noted a lingering stiffness inthe right knee. After a 48-hour resthe flew his second mission. AfterI 1 2 hours his right knee began toache. Because of the intensity of thepain, Major S. considered aborting the mission but continued. Attouchdown he was pain free, butmarked stiffness was noted in theright knee for several days.

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aseNo 4: Captain F. was thefourth symptomatic aviator in thiscircumstance. His narrative wascompiled from flight records, medical records and interviews with hiscolleagues. He experienced pain onboth his flights to altitude. Duringthe initial flight he had moderatepain in the right knee. On the second flight the pain was much moresevere and involved the ankle andhip on that side. After the secondflight he was noted to limp forseveral days. Additional information such as other symptoms ofdysbarism, pain relief on descent,etc. , could not be gathered.Of seven aviators exposed at26 , feet, four developed symp

toms compatible with bends ontheir first or succeeding flight. Atleast two experienced symptomssuggestive of other forms of evolvedgas dysbarism. Each symptomaticaviator experienced symptomssooner and more intensely uponreexposure. Each reexposure produced a spread of symptoms to thelarger adjacent joints. Reductionof pain was proportioned to reduction of altitude and considerablerelief was obtained at 20,000 feet.These symptoms are very suggestive of evolved gas dysbarism;however, the incidence is considably higher than predicted fromavailable data. The problem to beaddressed then is one of diagnosis .Realistically, no firm diagnosis canbe proven in these cases. One can,however, evaluate special factorsthat may have produced an unusually high incidence of dysbarismand consider the logical alternativeto the diagnosis of bends.Physical exercise significantly increases the incidence of bends ataltitude. The only activity performed by the aviators was flyingthe aircraft. This duty was alternated on an hourly basis and in factdid not require use of the rudderpedals.Older aviators appear more susceptible to evolved gas dysbarism.

18

The range of ages for all pilots inthis series was from 24 to 34 years,with a mean of 2.1 years. The average age of symptomatic aviatorswas 27.6 years, while the symptomatic pilots averaged 30.2 years.Certain other factors were considered to explain the variancefrom expected figures. All sevenaviators smoked. Each consideredhimself to be in good physical condition, though none found the timeto exercise regularly. No aviatorwas obese. There was no statisticalheight-weight difference betweensymptomatic and nonsymptomaticaviators. None had engaged inSCUBA (self-contained underwaterbreathing apparatus) diving prior toflying and none remembered previous injury to an involved joint.Cooling of an extremity maypredispose the occurrence of bends .Indeed, one pilot associated the onset of joint pain with a cool drafton his knee. No others made thisassociation. Neither side was assodated with pain in a particularknee, as one might expect from adraft.

The constant finding was that ifpain developed in one knee on aflight, during the next flight itwould occur more intensely in thesame knee without regard to theseat in which the aviator sat.The length of exposure and therepeated nature of exposure are thelast and perhaps the most significant factors producing an increasein evolved gas dysbarism in thesemen. Most series reflecting the incidence of bends are based on exposure of 2 hours or less. The average duration of flight for these menwas 4 hours. Two or four aviatorsexperienced symptoms only in thelatter stages of flight , well after 2hours had elapsed.Evolved gas dysbarism also occurs more frequently in those whohave experienced it previously.When it recurs it is usually in thesame joint. Air Force and Navyregulations wisely medically restrict

pilots for a defined period afterthey experience evolved gas dysbarism to minimize this risk of recurrence. All symptomatic aviatorsin this series continued to fly afterinitial difficulty. Each experiencedmore profound symptoms in thesame joint, which occurred soonerand often involved adjacent jointson reexposure. In every case thereexposure was within 36 hours ofthe initial flight.

f not all of these aviators , or ifindeed none of them had dysbarism. . . then what are the alternativediagnoses? Certainly hysteria wouldexplain all the symptoms. However,two facts are not satisfactorily explained by hysteria: First, the involved aviators were stable andhighly motivated and completedevery mission often in the face ofconsiderable pain. Second, becauseof scheduling, other duties and alternate flights , each was unaware ofthe others difficulties until just before the final mission. Each had attributed his pain to muscle cramps,arthritis or the aging process. Onlywhen they compared notes did theyrealize a common problem was involved.

Another possibility is that ofmusculo-skeletal pain occurring ina cold cramped cockpit. The difficulty with this hypothesis is that itdoes not explain why symptoms didnot appear in the numerous otherflights below 24,000 feet in thesame cold cramped cockpit.Although a diagnosis of evolvedgas dysbarism cannot be absolutelyconfirmed in these cases, it is evident that bends did occur in thefour symptomatic aviators. Thevariance from expected incidenceare best explained by the length ofexposure and the repeated nature ofthe exposure. Hysteria and musculo-skeletal pain as an alternatediagnosis fail to explain certain aspects of the case. Thus this is believed to be the first reportedoccurrence of the bends amongU S Army aviators.U S ARMY AVIATION DIGEST


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hitherThe r t ontinued from page Navigational systems and procedures, instrument approach procedures and radio communicationprocedures. Meteorology (including thecharacteristics of air masses andfronts and the weather associatedwith them) and the availability,evaluation and use of meteorological reports. Instrument procedures contained in pertinent military directives. The written examination isadministered subsequent tcfthe formal ground school. f such a school

is not available, the command towhich the naval aviator is assignedis responsible for administering theexamination.Unless a pilot s instrumentcheck ride coincides with the administration of the NATOPS written examination, his written examis prepared locally, along with theground school, by the instrumentflight board.The unit NATOPS officer inconjunction with operations personnel also develops a programedtraining schedule for the unit whichoutlines the general subjects to becovered by the NATOPS and instrument examinations. t may beonly a schedule for study but couldbe in the form of a programed textor study guide depending on thecomplexity of the aircraft and thelevel/mission of the unit.Other Navy regulations also impact on written examinations fornaval aviators. These include: Those naval aviators not currently on fiying status or flyingother than Navy aircraft do nottake the NATOPS or instrumentexaminations. This is essential because the NA TOPS program is ori-

u S. Navy and Air Force pilots discusstraining of their services during an airtactics training program, NAS, Oceana

FEBRUARY 1973

ented to the aircraft an aviator iscurrently fiying. The Navy extends under certain circumstances the expirationdate for instrument ratings. In suchcases the aviator must complete aformal course within 90 days of theend of the extension period. In theevent of failure on the part of anaval aviator to successfully complete one of the written examinations, his commanding officer willreview the individual s case anddetermine whether an extension begranted or board action initiated.The NATOPS program is an integral part of Marine Corps aviation. No deviations from the Navyprogram are authorized. The Marine Corps operates a few aircraftnot flown by the Navy, but theseaircraft are part of the Navy inventory. As such, their operations aresubject to all NATOPS regulations.

The Marine Corps has its ownretraining air groups called U. SMarine Corps Combat ReadinessTraining Groups. There are two ofthese-one on each coast-for allfixed wing Marine tactical aircraft.Other Marine aircraft crews C-130s, helicopters, etc.) are handledby separate training squadrons alsolocated one on each coast. Thegroups and various squadrons function much the same as the Navy sreadiness squadrons. The MarineCorps uses the NATOPS manualsfor all aircraft it operates. [Note:While it is true that the MarineCorps makes the bulk of the inputsto NATOPS manuals governing theaircraft it alone operates, thesemanuals remain NATOPS manualsin every sense.] ,A formal training syllabus is alsorequired for the Marine pilot uponreassignment; however, except forMarine pilots exchanged with theNavy, the training is conducted at

U. S Navy photo

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the appropriate Marine traininggroup or squadron.The Marine aviation unit NA-

TOPS officer is certified for 1 yearby the appropriate Marine traininggroup or squadron (with the excep-tion of Marine aviators on dutywith the Navy). He has the sameresponsibilities and qualifications ashis Navy counterpart.As stated, the Marine Corps usesNATOPS manuals for all aircraftit operates. The written examina-tions are prepared based on thesemanuals but, unlike the Navy, theNATOPS exams are prepared lo-cally (squadron level) and approvedby either Fleet Marine Force Pa-cific FMFPAC) or Fleet MarineForce Atlantic FMFLANT). Theexams are similar in content andformat to the Navy NATOPS ex-ams for the NATOPS flight man-uals specifically outline the areasto be tested for each aircraft. In-strument written examinations areprepared at group level, approved

20

U. S Navy photo

by FMFPAC or FMFLANT as ap-propriate, and are administered atwing level normally.The Marine Corps, as the Navy,conducts annual NATOPS evalu-ations of each Marine aviation unit.

The team generally comes fromwithin one of the three Marine airwings and the commander, execu-tive officer, NATOPS officer andoperations officer, as well as oneair crew, are usually flight checked.The program is coordinated withthe appropriate combat readinesstraining group or squadron.The Corps also conducts peri-odic unannounced unit checks whenteams from group or wing adminis-ter aNATOPS written examinationto an entire unit (it will be theNavy s exam for those aircraftflown by both services). This isdone even if the unit recently com-pleted a locally prepared NATOPSexamination.The duties of the unit NATOPSofficer in the Marine Corps are the

Retraining air groups implement theNATOPS program. One RAG checksantisubmarine aircraft such as thesein formation near the U Ticonderoga

same as those in the Navy. He con-ducts the balance of the flightchecks within his unit and may, asa member of the instrument flightboard, conduct instrument renew-als. He also may be responsible forthe preparation of the NA TOPSexamination and/or the instrumentexamination depending on the levelof his unit.The same regulations apply toMarine aviators with regard to tak-ing the NATOPS examinations,maintaining a valid instrument rat-ing, renewal of the instrument rat-ing, extensions and actions in theevent of failure or noncompliance.While preparing the researchpaper which led to this article, asurvey regarding the future of theArmy s annual writ was conducted.t addressed 21 specific points withregard to the writ and space wasprovided for comments on eachpoint. Responses were receivedfrom 171 field grade aviators aver-aging 10.5 years as Army aviatorsand 3,100 hours, and 50 warrantofficers averaging 11 years ratedand 4,100 hours.No attempt was made to solicitcomments from the newer genera-tion of Army aviators for it was feltthat aviators who had been exposedto the writ for 8 to 10 years wouldprovide more meaningful answersand that many of the newer avia-tors, as most aviators, were exempt

from taking it during Vietnam serv-ice . . . thereby reducing theirexperience level.The group surveyed representsonly 1 percent of all Army aviators-active, Reserve, National Guardand DA civilians. However, it iscloser to 5 percent when only avia-tors rated for more than 7 years areconsidered. This fact, coupled withthe very selection of the aviatorsU. S ARMY AVIATION DIGEST


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for the courses they were attending,must be weighed carefully in evaluating the conclusions drawn. The19 most significant conclusionsmade as a result of the specificpoints queried n the survey arecontained in the accompanyingfigure.Opinions of field grade officersand warrants were surprisingly consistent and were in substantial variance only in three areas. Specifically, 75 percent of the field gradesfavored addressing all questions onthe exam versions n the studyguide but only 52 percent of thewarrants agreed. Further, the warrant officers liked the current format of the study guide better 86percent vs 63 percent) but wereless enthusiastic about its becominga programed text 30 percent vs.48 percent). Lastly, only 73 percent of the field grades supportedthe administration of the writ primarily by examiners as comparedto 88 percent of the warrant officers.Over 2,000 comments were received on the various questions aswell as areas not specifically queried by the survey. Some of themost thought-provoking commentswere: Couldn t the U S ArmyAgency for Aviation Safety (USAAA VS) provide experience data onaccident cause factors falling intothe general purview of the exam scoverage? The administration of theexam has been poorly managed inthe past at some installations andin some units.

Current regulations regardingthe annual writ are confusing, outof date in some areas and not rigidly enforced in many cases. Valuable feedback could beobtained regarding the writ by surveying all or part of the Army aviation community in conjunction withits administration. The study guide is not used atall by many aviators whose only

FEBRUARY 1973

time spent on the writ is the fewhours required to take an examination version. Many teaching points,i.e., new regulatioos and procedures, are not really learned orunderstood.In view of the brief overview ofthe background of the writ, programs of the other services and thesurvey s results, three options appear to be available regarding thefuture of the writ.Option 1. Do away with the an-nual writ altogether There are twovalid reasons why this option,which would place the responsibility for updating and evaluatingaviators at unit level, should be rejected at the outset. First, the need

for annual review and updating ofArmy aviators is greater than everbefore.This is due to the increased em-

phasis on an all rotary wing force,the transition from a wartime to apeacetime Army, the large numberof tactical ticket holders aspiringfor standard cards, the ever-increasing complexities of instrumentflight and the large number of aviators that will be placed n an excusal status. Second, the survey sresults clearly indicate that mostexperienced Army aviators supportand recognize the requirement forsome type of ,annual writ; as, ofcourse, do the Air Force, Navy andMarine Corps.Option 2. Continue withoutchanges This option does havethe advantage that the current writis an established, if not entirelyproven, system. Further, there issufficient flexibility within its current structure to offset some of itsdisadvantages as indicated by the

Survey Conclusions95 percent favor some type of annual written examination.69 percent support coverage in the study guide of each teaching point in theexamination versions.68 percent favor the current programed text format of the study guide.A plurality, but not a majority, favors the preparation of the study guide asa programed text (44 percent for; 28 percent against; and 28 percent did not

answer).83 percent favor the length and composition of the current study guide.64 percent prefer an examination made up of most, if not all, self-containedquestions.88 percent favor the areas currently covered by the writ and the respectiveemphasis placed on each.90 percent support the current multiple choice format used.Of three choices-Vietnam, CONUS or rotated worldwide-51 percent favorthe latter option with regard to the area for the VFR portion of the exam.62 percent favor the inclusion of International Civil Aviation Organizationrules and Federal Aviation Administration procedures in some manner in theannual writ.76 percent favor the provisions of AR 95-1 regarding the action to be takenif an aviator fails to complete the annual writ.81 percent favor the provisions of AR 95-63 which require the aviator tocomplete the annual writ within 9Q days of reporting into a flying job after atour where the exam requirement was waived.77 percent support administering the exam open book to both instrumentand non instrument rated aviators.81 percent favor 80 percent as the passing score.,80 percent favor continuing with two fixed wing and two rotary wing versionsof the examination.78 percent support the current retake policy in the event of failure (AR95-63).85 percent favor the current procedure of administering the exam to allaviators except those with waivers or returning to flying duty from assignmentswith waivers in the last 3 months of the fiscal year.76 percent favor the administration and control of the annual writ wheneverpossible by instrument examiners.78 percent oppose incorporation of any type of aircraft dash 10 test as partof the annual writ.81 percent agree with the references used as the basis for the writ.

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survey results. For example, problem areas such as poor administration, the fact that many aviators donot look at the study guide and theapparent lack of adherence to pertinent regulations could be eliminated by increased command emphasis and interest at all levels.There are, however, some goodarguments for not continuing withthe writ's present structure. Theshift to rotary wing operations andthe excusal program are significantchanges within Army aviation andmust be evaluated. The survey results tend to support the premisethat the current writ, which haschanged little in over a decade, isnot now accomplishing its statedpurpose. The problems associatedwith its administration cannot besidestepped any longer. And lastly,the professionalism and no-nonsense approaches of the otherservices with regard to standardization and proficiency programs,specifically annual written examinations, and the success of theseprograms cannot be ignored.

Option 3. Change certain as-pects o the annual writ The optionis not whether to change the writbut rather what changes can andshould be made. Nineteen specificconclusions fell out of the surveyand several other considerationswere surfaced. Not all of theseareas require change nor are someof these areas significant issues(though the conclusions should beof interest to those charged with thepreparation of future writs). In theinterest of brevity this article addresses the five areas consideredmost important as a result of thesurvey and the analysis of the program of the other services. The recommendations offered at the endof this article deal with these areasonly.When should the examination beadministered? The Army is the onlyservice that schedules its annualwritten examination during a specific time period rather than in con-22

nection with instrument rating renewal. Yet, with the waiver of theexam during service in Vietnamand the new excusal policies, theexam is now being administered ona year-round basis to meet the requirements generated by aviatorsreturning to flying positions fromwaivered status. There is a real advantage in administering the examat the time of instrument renewal,particularly if it can be given bythe examiner who also will conductthe flight check. This change shouldnot create a significant burden forthe various airfield operations andaviation units in view of the largenumber of aviators programed forexcusal status. I agree with the survey's comments that favor all aviators taking the writ. But this is notnow the policy. t is recognized thatif aviators in excusal status are required to take the writ, a programadministering the exam at the timeof instrument renewal (birthday)could impact adversely on someairfield operations and units. However, it should be noted that thesurvey results support the continuance of the current policy of administering the exam to the majority of Army aviators in April, Mayor June.

Format of the study guide. Thesurvey's results and the success ofthe Air Force program suggest thepublication of the study guide as aprogramed text. The Air Forceprogramed text also includes extracts from various references andserves as its own reference databooklet. Based on my experienceI believe that the study guide andreference data booklet could bereadily combined into such a programed text. Certain hard-to-getreferences used in the preparationand administration of the currentexamination, such as the variousARs, TMs and FM 21-26, couldbe readily extracted for inclusionin such a document (as could applicable ICAO and F procedures). A programed text published

every few years and updated onlyas required would be cheaper thanthe current procedure of annuallypublishing a new study guide andreference data booklet.The actual taking of an examination, however, could require ad

ditional reference material. Suchreferences might be the FLIP documents, ARs, TMs, etc., themselves; or could be published aspart of the examination booklet(s);or be incorporated into a separateRDB distributed in limited copiesto various installations or unitscharged with administering theexam. The introduction of mandatory ground school training (discussed below) prior to taking thewrit would virtually negate problems in this area.With any programed text, as withthe current study guide, the problem would remain as to how to getthe aviator to take it or use it forreview. One solution would be tomake its completion mandatoryprior to taking the exam. But, if itwere to be published every fewyears, this would not be feasible. Asecond solution would be to combine this study guide/programedtext with mandatory ground schoolinstruction as a supplement or complement to it (similar to the AirForce program). The completion ofthe text would then be requiredonly of those aviators whose attendance at such a ground schoolwas not possible. The documentshould be a part of the aviator'sprofessional library and therebyavailable to him for both reviewand use in conjunction with themandatory training.Mandatory classroom training.This would not have been feasiblein the past perhaps because itwould have been difficult for manyaviators to attend such training.Still, these are the aviators nowexempt from taking the writ underthe excusal program. Only thoseaviators flying . . . not excusedfrom meeting proficiency mini-

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Crewmembers of some Marine aircraft such as these C-130 crews arechecked by separate Marine trainingsquadrons located one on each coast

mums are now required to takethe exam, as well as those (thoughexcused) serving in aviation relatedassignments.Such a ground school conducted(as the Air Force's) for 2 days toinclude the administration of theexamination, monthly or bimonthly,should not be a problem orburden for aviation units and/orairfield operations in view of theexcusal program. The benefits thatwould accrue are truly significant:standardized training covering notonly examination subjects but alsorelated material; virtual eliminationof the problems now associatedwith the administration of theexam; economical use of referencematerials; and facilitation of thereturn to fiying of aviators comingoff excusal status.Number and format of examination versions. This depends primarily on if the mandatory classroomtraining concept is adopted. f itwere, then one (or at the most two)versions of 50-to-100 questionswould suffice, similar to the AirForce's program. The passing scorealso would depend on such achange. But, it is unlikely that anything but the current, multiplechoice format could be employed.In event of failure the aviatorwould either retake the same examination after further training orthe other versions if appropriate.Most of the aviators surveyedfavored four versions two fixedwing and two rotary wing but responded without any considerationof the impact of a mandatoryground school.Combining the writ with dash 10type testing. NATOPS does this butthe Air Force does not. The NATOPS program, as fine as it is forthe Navy and the Marine Corps,FEBRUARY 1973

does not have significant application to the Army due to its emphasis on the particular aircraft.The survey results also did not support any combining of the two typesof testing. Further, the Air Forcehas had considerable success withits program, which staggers instrument proficiency testing and aircraft proficiency testing at 6-monthintervals.Of course there are many alternatives with regard to the future ofthe writ, but the issues discussedhere can best be considered in thelight of the three basic options nowavailable. Option 1 doing awaywith the writ, was rejected at theoutset. Option 2, that of essentiallymaintaining the status quo, doesnot fully satisfy t