army aviation digest - feb 1960

8/12/2019 Army Aviation Digest - Feb 1960

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lIHiteJ gta,t,u ,Q m fVI TION DIGEST

EDITORIAL STAFFCAPT JOSEPH H POOLEFRED M MONTGOMERYDIANA G WILL IAMS

FEBRUARY 196VOLUME 6NU MBER 2

RTI CLESHIGH, LOW, WHAT S THE GAME?

Lt J arne M. Knowlton, CELEARN AND LIVEFUNDAMENTALS OF TWIN-ENGI E FLIGHT

Jame R. PaulMOUNTAIN OPERATION

Lt William A. Kilpatrick, InfSTRAP THAT TIGER DOWNGerald M. BrugginkDO WE NEED AN AVIATION BRANCH?CENTRALIZATION IS THE ANSWER

Capt Larry . Mickel, InfNOT BRANCH, BUT BALANCE

Capt Roger M. Pezzelle, InfSTATISTI S IN A CIDENT PREVENTIONDEVELOPMENT OF THE GAS-TURBINE ENGINE

CWO Paul J. Chauvin, TC

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THE T-53 GAS TURBINE AJames E. Mize EEN BY MAINTENANCE 29

PUZZLERCRASH SENSE

DEP RTMENTS1233

U. S. ARMY AVIATIO SCHOO LMaj Gen Ernest F. EasterbroCommandantCol Delk M. Odenssistan t Commandant

SCHOOL STAFFCol Robert H. SchulzDirecto r of Instruct ionCo l Edward N. Dahls tromSec? etaryLt Col Jack BlohmCO, US VNS RegimenLt Col J ohn W. OswaltCombat Development Offi

DEPARTMENTSLt Col Ritchie GarrisonTacticsLt Col James B. Gregorie, JA dvanced F ixed W ingLt Col Raymond E. J ohnsonRotary WingLt Col Harry J. KernMaintenanceLt Col Thomas J. SabistonPublications andN on-Resident InstructionLt Col G. W ilford J aubertPrimary Fixed Wing

The U. S. ARMY AVIATION DIGESTan official publication of the Departmentthe Army publiRbed monthly undersupervision of the Commandant, U S. ArA v i l ~ t i o n School.

l he mission of the U S. R ~ I Y AVI1 101- DIGES r is to provide informationan operational or functional nature conceing slIfety and aircraft accident preventitraining. maintenance, operations, researalld development. aviation medicine aother related data.Manuscripts. photographs, and other illtrations pertaining to the above subjectsinterest to personnel concerned with ArAviation are invited. Direct communicatis authorized to: Edit


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WHAT S THELieutenant James M Knowlton CE

W ITH THE ADVENT ofgreater mobility largerdispersion of forces and nuclear capabilities by our Army,a great deal of thought hasbeen given to the role of ArmyA via ion on the ba tlefield ofthe future . This role includesnot only the type of tnissionsbut also the methods we willuse to accomplish these missions.One of the most pressingproblems is the determinationof the altitudes that we will usein the accomplishment of missions. Articles have been written concerning the pros andcons of flying at our high andlow altitudes. The purpose ofthis article is to examine theadvantages and disadvantagesof high and low altitudes withemphasis that selection of oneor the other should have a di-

tK nowlton is with the Formsand R ecords Branch of the D -partment of Maintenwnce H e isi xed win g qualii ed and in strtt-ment rated

rect bearing on our training ofpilots and observers. Whetherit be a surveillance observation,or fire adj ustment mission different methods must be used totrain personnel for high or napof-the-earth altitudes. This determina ion will also provideResearch nd Developmentwith a direction in which towork towards devices that willaid in the accomplishment ofthese missions as well as togive certain performance considerations to keep in mindwhen planning for f u t u r eArmy aircraft.I would like to examine theadvantages and disadvantagesof both types of flying in termsof five general areas: pilot endurance; navigation; radio communication; detection recognition and location of targets;and vulnerability. There areother factors, but these are themain areas and deserve themost consideration.

PILOT ENDURANCEThe first area is that of pilot

GAME?

endurance. At high altitudes,let's say over 5000 feet abovethe terrain, this endurancecould be as high as 6 or 7 hoursa day per pilot. I t would depend partly on the physical condition and training of the pilotsbut would be governed more byi rcr f t endurance maintenance capabilities and logistical support.On the other hand the lowlevel nap-of-the-earth flying

where the pilot is following thecontours of the terrain, overor around hills and high treesand down through gullies necessitates a higher degree ofconcentration and reflex action.He must be ready for a steepturn, a climb or a letdown instantaneously. A pilot who hasflown an hour of this type offlying will be ready for a cigarette and a chance to ca chhis breath. His mission or flying time per day dependingalso on preparation time, mightonly be 2 hours a day Froma standpoint of continuous reconnaissance or surveillance


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server will see nly a verysmall percentage of targets athigh altitudes. Then he willn t be able t o make positiveidentification between, for instance, a 155 self-propelled anda medium tank.

The low flying observer hasmany advantages in recognitionof targets. It is almDst impos-

Only smaller areas can be surveyed, but missions can beplanned to include most likelytarget areas. Target locationand fire adjustment will be difficult, but some possible solutions will be discussed later.

VULNER BILITYThe last area is that of air-

HIGH, LOWany aircraft that is keepingthem under observation or calling in fire missions.Slow flying, relatively speaking, Army aircraft are also vulnerable t o any high-performance aggressor aircraft thatthe pilot does not see. The napof-the-earth aircraft will encounter only sm II rm s

but w ll he be able to identify machinegun emplacements camouflage equipment etc.?sible to hide or camouflageguns, vehicles, r even personnel from an observer flying 100feet over the ground. Detection is instantaneous; it mustbe, due to the rapid passageover the ground. This infDrmation is also much more complete and accurate but observers must be trained in IDw-Ievelscanning methods and splitsecond recognition of ta.rgets.

craft vulnerability, perhaps themost important consideration.The aircraft flying its missionhigh in the air will not Dnlyhave to cope with machinegunand antiaircraft fire but alsowith guided rockets, heat-seeking rockets, noise-seeking rockets radar-controlled fire, andprobably other weapons stillunder development. The aggressor will attempt to destroy

manned and fired by aggressorpersonnel. They may hear anaircraft coming, but localization of sDund will preventtheir telling exactly from whatdirection. Then they m u s traise, aim, and fire their weapons in the 2 or 3 seconds thatthe aircraft is visible. Radarcontrolled guns will be ineffective against it due to interference by the ground. Heat-

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FEBRUARY 1960seeking missiles will be dangerous to the aggressor because ofthe danger of their homing inon his own tanks or sternostoves. Noise-seeking missileswill be confused by the echoesand reverberations of the engine exhaust from the ground.Of course in the event of engine trouble or damage causedby enemy fire the pilot will justabout have time to set up anapproach to an area almost immediately ahead. There will beno gliding back behind friendly lines by damaged low flyingaircraft.These are some of the problems associated with high orlow altitude flying. What aresome of the techniques or developments that would aid theArmy Aviator in the performance of his mission?PERFORM NCE TECHNIQUES

The only way to increasepilot endurance is to train aviators to fly and navigate at lowaltitudes. This. would decreasehis reaction time his uneasiness and the time required toplot plan and memorize a lowaltitude mission. He may usea combination of a plannedcourse with a combination ofheadings, ETAs, and checkpoints or perhaps a system ofdirections given by high altitude aircraft. Improvementsin radar or a drone-carried TVmight enable persons miles tothe rear to follow and issue directions to a low flying aircraft.This control of the preplannedcourse will also enable battlefield air control to anticipatehis departure and return andmake the necessary clearancesand alerts.R d i communication byhigh altitude aircraft would beimproved by automatic codingand decoding radios. The lowaltitude aircraft could relay in-4

formation that necessitates immediate countermeasures bythe commander to a high altitude relay aircraft. Perhaps ahelicopter with exceptional acceleration might climb to sufficient altitudes to transmit ona high - frequency radio anddrop back on the deck. Thedevelopment of an improvedlow-frequency radio that is notrendered useless by the maskings of the earth, or adverselyaffected by range and atmospheric limitations would be advantageous.

Observation at high altitudeswould be improved by the development of a magnifyingface plate that would not restrict the observer's field ofvision as binoculars do. A recording device would enablethe observer whether at highor low altitudes, to gather information without stopping hisscanning. A camera mountedon the low flying observer'shead and controlled to take pictures when he pushes his microphone button to describe detected targets would save thetime and expense of studyingpictures that contain no targets.Training in flying a definitelow altitude flight path at aconstant airspeed might helpin target location. The flightpath would be known to the artillery or be tracked by radar.By knowing the time lapsesince passing a certain checkpoint a call tanks 250 yardsto left, would enable the firesupport to plot the target inrelation to the aircraft path.Fire adj ustment by the helicopter with exceptional acceleration that could climb up andobserve the round just as i tfalls each time from a different direction might be a solution. Fixed wing aircraft flyingat low altitudes might have to

call in fire and then returnlater to observe damage or thelack of it.Wha can be done to decreasethe vulnerability of an aircrafat a high altitude. Not muchexcept to increase its speed

and then missiles rockets andhigh performance enemy aircraft will always be fasterAdded armor protection fopilot and observer would be effective at high and low altitudes. The low flying aircrafmust fly right over the treetops and be exposed to groundfire for as short a period aspossible. Increased maneuverability would enable the piloto have a greater safety factoin case objects such as treesor wires come up unexpectedly

From the different problemand possible solutions associated with high or nap-of-theearth flying it is apparent thathese are two different distinct types of flying and havetwo definite indications. Pilotand observers must be trainedwith emphasis on the problemsassociated with the high- olow-altitude flying. This decision as to what type of flyingwill be done on the modern battlefield must be made to aidResearch and DevelopmentTactics and training in establishing a direction towardwhich to work. Pilots and observers must be trained differently in at least these fiveareas; aircraft and devices wilalso v r y according to theheight above the ground awhich they will be used. Testand studies indicate that iwill be necessary to fly bothhigh and low altitudes depending on the situation. Trainingand research should be directedtowards these distinct problems encountered in both typeof flights.


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earn

T HE TECHNIQUES of Armyflying are not difficult tolearn. Procedures, however,m u s t be followed slavishly.Good j udgmen and experienceare necessary, especially whenflying in hilly or mountainousterrain.

nd ive

The factors of downdraftsand air turbulence in mountainoperations are complicated andvery important. The best advice is to f o r ego mountainflight until you have made aspecial study of the hazards orbeen thoroughly indoctrinatedin the techniques. Insufficient room to turn

Complete mastery of an air-craft in the flatland will notprovide insurance for safe operation in mountain flying. Con-sider this Shawnee H-21) pilotwhose m SS On was to photo-graph a e a v e r that had

Theme song for mountain fliers: "Don't Box e In "

crashed in rugged, woo d e dmountain country. He had atotal of more than 700 hoursand was considered exceptionally proficient in the Shawnee.Let the pilot tell his story:We circled the wreck clockwise, with the Beaver on ourleft so the photographer couldtake pictures from the air . . .We were making our second low reconnaissance of thearea at approximately 35 knotswhen the aircraft started tosettle.I increased rpm to 2700 andmanifold pressure to 45.5 inches of Hg (maximum) and dived

This article was prepared by theU S rmy Board for viationAccident Research


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ountains ever fence youin,?the aircraft to regain flyingspeed but the ship continuedto fall through. There was notenough room in the box canyonto re'gain effective lift, so atthe last moment I executed aflare and landed on the steepslope with a near zero airspeed.The ship slid backwards shearing the right main gear. Itthen rolled on the right side,shearing the blades, and slidapproximately 100 feet downthe mountain w h e r e rocksbrought it toa halt.Flight path prior to the

crash was from east to westinto a box canyon surroundedby high j a g g e d mountainpeaks. The wreckage of theai rcraf t being photographedwas about 6,100 feet above sealevel. The pilot had judged thewind to be light and variable,generally from the west southwest.

The first low reconnaissancewas successfully completed.The climbout was made overthe canyon rim and a peak thatcircled to the north. The crashoccurred on the second lowpass.

Downdrafts and turbulenceare caused by air-mass movements against the mountainrange. In general, moderate,smooth updrafts will be on thewindward side of the range. Onthe leeward side, very turbulent air and strong downdraftswill exist below the level of themountain crest. In some casesthis area can get so violentthat an aircraft becomes unmanageable.In this case the pilot made aserious error in judgment. Hehad two safe courses open tohim and chose neither. Hecould have made the low passat an altitude high enough tokeep out of the box canyon. Ifhe felt he had to descend below the canyon rim, he shouldhave made the pass in the opposite direction, toward theopen end of the canyon.

Even under ideal weatherreporting conditions, forecastsare notoriously unreliable inmountainous terrain. Win dconditions may vary unpredictably. Knowledge of thisshould keep an aviator vigilantand, more important, sharpenhis planning.Undoubtedly the type of mission affects the probability ofan accident. Hazards are in-

curred under a variety of conditions such as instrumentformation, and low-level flyingparticularly low-level flying inmountainous terrain. This typof flying demands mastery ocertain techniques. Appraisina situation in low-level operations is something for the pilot's judgment. Descriptions ian article cannot begin to provide adequate substitutions fopractical experience.

EXPE T THE UNEXPE TEDTwo first lieutenants in twL-19As were on an authorizeVFR flight to resupply an infantry patrol. Weather had

been marginal all morning buby noon had cleared sufficiently to make the scheduled dropHere's what happened as viewed through the eyes of the participants:

COMPANY COMMANDER(of infantry pa t ro l : Mcompany was in column on thsouth slope of the mountain aapproximately 1,500 feet elevation. The aircraft madedry run over the drop zone todetermine the best spot to drothe rations. I was in radio contact with the passenger of thfirst plane. After the dry runit was determined the bestsition for the drop was at thtail of the column, because oclouds higher up the slopeBoth planes then circled inpreparation for the final runand the ration drop. The leaplane made an accurate droin the marked area. After thdrop the plane turned left ian attempt to get over thmountain. The area availablfor climbing in relation to thelevation of the mountain wavery s m a and the plancrashed into the side of thslope.ENLISTED MAN (passen


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ger in lead plane): We madea good ration drop and it appeared that everything wasnormal; however, the pilot toldme we were in trouble and going to crash. He made a leftturn, raised the nose of the aircraft and touched down on asteep incline to the left of ouroriginal path.P ILOT OF S E C O N DPLANE: As we both enteredthe canyon I was at 1,500 feetindicated, and the lead planeslightly lower. I climbed to2,000 feet to check the cloudheight, and at this altitude Iwas just at the bottom of theclouds. From this I estimated

we had about 500 feet to workin. We made one dry run overthe troop area, and on this firstpass neither I nor my observerspotted the troops; however,on the second trip up the canyon we saw them. I again triedto m a k e radio contact butcouldn't, so I tried to cut inside him. Because of the tur-

bulence I was forced to makea shallow turn; however, Igained on him and was 200 to300 yards to his rear, and maybe 200 feet higher. He droppedhis bundles and started a leftturn toward the ridge line,then his right wing dropped,and I thought he was going toturn away from the hill. Almost immediately the aircraftturned left again and struckthe mountain.I dropped my bundles fromabout 200 feet and switched toemergency f r e que n c y andstarted calling MAY DAYPILOT: At abo u t 1300hours I started my descent toward the west in order to passacross the ridge on which thedrop was to be made.

When approaching the areaI noticed that slightly to myleft it appeared that the terrain was much more suitablefor the drop so I swung leftto pass directly over it. I wasat an altitude of about 75 feetabove terrain when I releasedust prior to impact th pilot pulled th nose up

LEARN AND LIVEthe rations. I applied powerand started to make a climbingturn to the right and at thesame time realized I could notmaintain a steep enough climbto clear the ridge to the westof the drop area. I elected toturn left in order to crash landgoing directly uphill I maintained as steep a climb as possible and told my passenger wewere going to crash. Just priorto impact I pulled the nose ofthe aircraft up to slow my forward speed as much as possibleand to touch down in a threepoint attitude.

OPERATIONS OFFICER: Iam the operations officer forthe Aviation Company and, assuch, my office accepts andevaluates missions and assignspilots and aircraft to the mission.

Even though relatively newto the area, this aviator hadmade four flights into the samegeneral area of the proposed airdrop.I had no qualms about assigning him to this resupplymission. The only alternativewould have been to cancel outthe resupply mission. This mission had already been delayedfor one day because of weatherand the patrol needed the ra tions. Aerial resupply was theonly method to supply them.The Army Aviation Schoolp ro v i de s for and formallyteaches all phases of ArmyAviation operations. Resupplyby aircraft (including parachute supply drops) is one ofthe phases of the school. twas the opinion of the company commander and mine thatofficers awarded the MOS ofArmy Aviator were trained inall phases

ACCIDENT INVESTIGATION BOARD: havingcarefully considered the evi-


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Flight path that faileddence finds that the accidentwas due to pilot error.What do you think?FLIGHT P TH TH T F ILED

Admittedly, Army Aviatorsare well-trained and upon graduation are equipped for almostany eventuality - except forjudgment and experience. Onederives from the other. Thesedesirable traits come only intime, with painstaking observation, self-development, unittraining, and analysis.Before that hoped-for levelof experience is reached errorsare made all the time. As j udgment is developed with experience, the tendency to err lessens. But let's face it: perfection is never attained.If you ve never been subj ected to a certain experience,you cannot h a v e developedjudgment in that area. If youhave never flown in rugged ter..rain, you may find it difficultto believe the dangers really

exist. But they do. Maybe thispilot's experience will help enlighten others.8

A civilian aircraft had beenreported missing. An ArmyAviator had been briefed forthe air search mission. TheBird Dog had been preflightedcarefully and the flight to thesearch area was uneventful.The pilot throttled back toslow cruise (70-75 mph), set15-20 flaps while he and hisobserver began scanning theterrain from 1,000 feet above.The direction of search wasgenerally upslope and altitudewas gained as they flew inland.Proceeding up the river Inoticed the cloud bases were2,500 feet and I seemed to beabout 200 to 300 feet belowthem. The fork of the river Iwas following ended in a dishshaped valley and the mountains ahead and to the rightwere cloud covered. A ridgeto the left was open and I sawthat I was high enough to clearit by 200 to 300 feet. Approaching the ridge I addedpower, anticipating a downdraft. Approximately one-halfmile or less from the ridge, Ientered a downdraft and applied full power and made an

effort to gain more altitudeRealizing the engine wasn't reacting fast enough and I wasgoing in, I left the full poweon and gained as much altitudeas I could in a power-on stallAs stall speed was reached, Iaimed at a large tree and started adding flaps. When I hit thetree, all forward speed stoppedand vertical motion was smallWe paused momentarily on thetreetop and rolled over on theright wing. The aircraft pivoted 90 to the right in fallingand struck the right wing andcontinued rolling over on itsback.

I t was the opinion of the accident investigation board thathe pilot was dividing his timebetween searching and flyingand was not conscious of losing altitude until it was toola e to take action.

If the pilot had been flyingto one side of the valley in themanner of mountain-wise aviators, it is possible he could haveturned away from the ridgeand avoided the crash. Thereare tricks to all trades. Trad-

he ird Dog crashed in dense jungle and was never recovered


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Flight path o H 19C prior to crashing punches with a mountainisn't the way to learn them.

OWNWIN L NDINGIf you're still not convincedof the hazards of mountainflying, consider the case of the28-year-old aviator with morethan 2,000 hours flying time inhis log book. This age and ex

perience level should have re-moved him from this type ofaccident, but the mountain hazard tripped him.

speed was 35-40 knots, leavingplenty of clearance for a leftturn in case of a downdraft.Nearing the ridge line the air-craft started to settle and fullleft pedal and sufficient leftcyclic was used for a left turn.Feeling no control response,full power was applied but theaircraft continued to settle andgo straight ahead. The air-craft was then headed for asmall draw in the ridge lineand to the left of the drop zone.Noticing several people stand-ing in the aircraft's flight path

LEARN AND LIVE

who would be hit if it crashedon the ridge line, we flaredshort of it and the initial pointof impact was approximately20-30 feet below the ridge line.The aircraft turned to theright after crashing and hit on

the right side and top, losingtwo blades and breaking theleft windshield. t continued toroll to the right and came torest about 100 feet below, withthe nose pointing up the ridge.The accident investigationboard learned that actually thewind was opposite what thepilot had estimated. In makingthis error he brought the air-craft into the pad on the ridge

in a downwind condition. Theaircraft was loaded 400 poundsbelow gross. While the densityaltitude wasn't given in the accident report, the midsummer,midday temperature probablyhad some bearing on the air-craft settling with power.

But the big bugaboo herewas topography. Mountain flying requires special alertnessto avoid the hazard of terrain.If a thorough basic knowledgeof mountain flying is lacking,even alertness won't help. Getthe word. Learn and live.

(Editor's Note: See ountainOperat ions page 13.)He was assigned an H-19Cresupply mission to a mountainoutpost. Let him tell whathappened: The aircraft hit below the ridge and rolled downslopeWe followed the ridge lineup to the pad. Passing overthe pad at about 200 feet we

made a climbing left turn andapproached from the south fora low pass at 50-100 feet tocheck the feasibility of airdropping. The air was not veryturbulent and the wind wasblowing up the ridge from theor th t approximately 10knots. The low pass was start-ed, descending to 50-100 feetover the drop zone for a lowreconnaissance. A p pro a c h

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ITH THE prospects oflarger, faster, safer, andmore efficient multiengine aircraft appearing on the ArmyAviation horizon, it might beappropriate for single - enginepilots to start considering themany facets of safe multiengine flying in preparation forfuture training. Those who arepresently twin-engine qualifiedmay find it worthwhile t review basic safe operating procedures.Modern twin-engine aircraftin the Army s present inventory deliver excellent flight performance, reliability, and safety, provided they are properlyhandled by pilots who know

Mr Paul is a civilian instructorin the Instrument Division of theDept of dvanced Fixed WingTraining H e is presently on TDYwith the Caribou project at the

viation Board10

ames R Paul

how to use them. It is generally felt that any reasonably proficient single-engine pilot in theArmy can, in a few hourstransition, take off, circle thefield, and land any of theArmy s multiengine aircraft.However, should an emergencyoccur, such as the loss of anengine on takeoff before at taining s a f e single enginespeed, the aviator may findhimself riding a completely unmanageable monster, with little recourse except t ride herdown.

For safety in twin-engineaircraft, familiarity with twospeeds is vital:

1 ENGINE-OUT MINIMUMCONTROL SPEED Vmc) isdefined as the minimum airspeed at which the aircraft iscontrollable when the criticalengine is suddenly made inoperative, with the remaining en-

gine at takeoff power. Sincthe power output increases alower altitudes, the engine-oucontrol loss is more critical otakeoff, especially ro m airports at low elevations. (Thleft engine is considered thcritical engine, since, all Ubuilt engines turn props clockwise, with the resultant torquto the left.)

In the event of a sudden engine failure at an airspeed below the engine-out minimumcontrol speed, the operating engine must be throttled bacimmediately to achieve an airspeed at which flight controcan be maintained. If this power will not prevent a loss of altitude, an immediate landinm u s t be effected. Bankinslightly (not more than 5toward the operating enginwill assist in maintaining flighcontrol without appreciable losof lift.


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fteran engine failure at cruising METO power should be applied immediately

2. ENGINE - OUT B ESTCLIMB SPEED (Vy) is definedas the airspeed which deliversthe best rate of climb, or slowest descent, with one engineout with the remaining engineat takeoff power. This may bevery close to vmc; Vmc and Vyspeeds are published in theflight manual for each particular series of aircraft.When operating an aircraftout of confined areas or overobstacles, the pilot will obviously obtain the steepest angle ofclimb possible. However, if anengine should fail under theseconditions, 10 knots or belowvmc, and in a steep climbingattitude, he is immediately inserious trouble. The only recourse is to reduce power onthe good engine, level off, andattempt to regain vmc or land.Never attempt a takeoff overan obstruction without firstconsidering and formulating adefinite plan in the event anengine should fail.When testing for an unknown minimum control speed,set the plane up at some relatively high speed, close thethrottle on one engine withtakeoff power on the other, andslow down to the speed atw h i c h you can just holdstraight flight with full rudder.

This speed is actually a littlebelow Vmc for sudden and com.plete loss of power on the takeoff, since to have control of theaircraft the pilot should be ablet turn into the good engine.Some aircraft can be controlledto the stall and recovered onone engine. In such cases thevmc should be established at asafe speed above the stallingspeed even though it can becontrolled at a slower speed.

When testing for engine-outbest climb speed, set up takeoff power on one engine, closethrottle on the other, and flythe plane at different airspeedsfor a predetermined time (5minutes) at each speed. Thendetermine at which speed thebest rate of climb is obtained.Three important principlesto remember in the operationof twin-engine aircraft in orderof importance are these:1. Altitude is more valuableto safety after takeoff than airspeed in excess of the best rateof climb speed. A number oftakeoff and climb-out procedures are available; let s analyze the extremes. First, weleave the ground, hold herdown, and go over the end ofthe runway at cruising speed,but at only 30 feet high, thenwe lose an engine. (An FAA

publication tells us at 123 mphthe drag on the windmillingpropeller is 2 times that at100; at 200 mph drag is 4times that at 100.) The pilotsuddenly discovers that he converted all the energy producedby the engines into speed andthe speed deserts him immediately. By the time he has control of the situation, he findshimself down to about thespeed he should have been allthe t ime-but still at 30 feet.From here he will have to climbto an altitude to clear the obstructions and get back to theend of the runway.In other words, we havefound that speed cannot readilybe converted to energy to helpyou around the field. If theenergy has been converted toheight above the field elevationto permit you to clear all obstructions in level flight, theproblem is much simpler. Using the same reasoning we usein single-engine aircraft, extraheight can be traded for energy.2. Climb or continued levelflight is impossible with gearextended and a propeller windmilling in present Army multiengine aircraft. When a pilotassumes the responsibility fora twin-engine a i r c r a f t he


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FEBRUARY 1960should determine in what configurations of gear, flaps, andpropeller the aircraft will maintain altitude with full load andan engine out. Several fatalaccidents have resulted fromattempts to pull up and goaround with the gear downwhen the aircraft was actuallyincapable of climbing in thisconfigura ion.3. After an engine failure atcruising, METO* power shouldbe applied immediately to establish single-engine flight. tis a recognized practice to apply maximum allowable powerto the operating engine untillevel flight is definitely established. If the aircraft is foundto be capable of level flight orclimb with the existing load,altitude, and temperature, anappropriate power reductioncan then be made. In no caseshould the airspeed be allowedto fall below the engine-out bestclimb speed, even though altitude is lost, since this speedwill always provide the bestchance of climb or the least al-

*METO - The maximum poweravailable from the engine for continuous operation.

T I S SITUATION, eventhough it is hypothetical,

will pertain to both fixed androtary wing aircraft.

At 12 :34 :59 an aircraft isslowly flying in front of a groupof Army Aviators at an indicated airspeed of 45 mph, at analtitude of 100 feet, with a 45mph headwind on his nose, us-12

titude loss. The ability to climbat approximately 50 fpm incalm air is necessary to maintain level flight for prolongedperiods, even in moderate turbulence.A pilot with single-engine

training and experience who aspires to fly twin-engine aircraft should study all availabletechnical information on itsperformance and the operationsof its components and emergency equipment. He shouldfamiliarize himself with thefollowing general proceduresfor use in event of a sudden engine failure:1 FAILURE DURING TAKEOFF OR CLIMB-OUTa. If airspeed is below vmc,reduce power to maintain flightcontrol and gain speed, by lossof altitude if possible.

b. If airspeed is below engineout best climb speed, attainthat speed before attempting toclimb.c. If airspeed is at or aboveengine-out best climb speed,keep maximum available power on good engine and hold engine-out best climb speed. If

ing whatever power needed.Altitude-100 feetAirspeed-45 mphWind-45 mphManifold Pressure-as necessaryN ow for the hypotheticalpart: At 12 :35 there is a dropin the wind to 0 mph. If thesame attitude were held and

climb results, maneuver care. fully for a landing back at thairport; otherwise prepare toland at nearest available areaKeep gear and flaps retracteduntil you are sure of reachingdesired landing spot.d. If sufficient runway iavailable, land straight aheadregardless of airspeed.

2. FAILURE DURING CRUISING FLIGHTa. Increase power on good

engine to METO.b. Maintain engine-out besclimb speed.c. Reduce power only whenunneeded altitude is gained.d. Proceed to a landing at thefirst adequate airport or landing area.

SUMM RYThe above information musbe considered as fundamentalof flying our Army s multiengine aircraft. To satisfactorilyand safely operate a particulatype or model, a careful reviewof the 1 must be accomplished

wi t h appropriate transitiontraining covering this vital subject.

the same manifold pressurwere held: 1) What will theairspeed be at 12 :35? 2)What will the groundspeed bat 12 :35? 3) What, if anything, would happen to the altitude? 4) Would there bany danger of ground contactThe recommended solutionto the PUZZLER may be foundon page 14.


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ountain OperationsLieutenant William A. Kilpatrick, Inf

o THE UNINITIATED, operations f ro m strips inelevations are a subjectf respect, and in some inawe. Mountain operapresent many proband different techniques

required from those usedt sea level. Mountain operaare not inherdangerous if approachedplanning and foreugh t, regardless of theor ruggedness of theIf war should come, Armywill be expected toits mission regardless ofterrain, and we should allprepared to fulfill that mis

of us fortunateto have been stationedt po s t s near mountainousshould be in good stead.extensive checkoutsrequired before the pilots

r e declared operational inLt K ilpatrick is presently s-gned to the 9th viation Com-any F ort Carson Co orado.

s u c h areas. Unfortunately,many posts have neither theterrain nor the necessity forsuch checkouts. Consequently,we often meet seasoned pilotswho have mistaken ideas aboutthe proper techniques in thisfield.Since the elevation of thestrip was about 5,000 feet, Iheld 10 miles an hour excess

airspeed on final.So there I was in this valleywith the canyon walls about2,000 feet above me on bothsides when suddenly the wallscame together.Pilots experienced in mountain flying always breathe asigh of relief when they hear

statements like these, becausethey figure that at least onemore pilot has learned his lesson about mountain operationswithout the necessity of havingthe story put together by theboard of aircraft accident investigators. Incidents such asthose could have been avoidedby following a few simple rulesconcerning mountain opera-

tions. We learned those rulesin basic flight training, butwe've forgotten about them because of disuse.Just in case you have forgotten them too, here are a fewthings to think about beforetaking off on that cross-coun

try tha will take you overmountainous terrain for thefirst time.1. Be aware of the effects ofmountainous terrain on the existing wind. There will normally be an updraft on the upwindside of a hill or ridge line anda downdraft on the downwindside, the severity of which isnot necessarily dependent oneither the velocity of the windor the actual height of the terrain. Although this can varyif the wind is quartering to theterrain, it is important to remember when flying aircraftnot equipped with 0 x y g e nwhich may require you to flyclose to the terrain.So, unless you are holding altitude that you are certain willallow you to clear, regardless

3


16/40

FEBRUARY 1960of the downdraft, approach atan angle of approximately 45 Be prepared to turn away if itshould become necessary. Tryto avoid tight turns, but beready to use flaps if necessary;they will reduce the turningradius of the aircraft considerably without standing it onits wing.2. Weather in the mountainsis considerably more unpredictable than at lower levels. Except for scattered air massthunderstorms, we usually associate clear skies and unlimited visibility with high pressure systems. he existingweather can change and oftendoes change far more rapidlyin the mountains. Instead offlying off with a quick look atthe teletype and glance at theweather map, get a good weather briefing from the man whohas experienced it.3. Navigation in the mountains is normally more difficultdue to lack of usual checkpoints. This is true whetheryou are flying with groundchecks or radio aids. In themore desolate areas, even thehighways and railways are sowinding and hidden by terrainthat they are useless. So getback to the system taught inschool of checking rivers, lakes,

The Puzzler questions wereanswered by the National Aeronautics and Space Administration, Langley Field, Virginia.

1. The airspeed at 12 :35, after the 45 mph headwind subsides, would be approximatelyo mph.2. The groundspeed at 12: 35is apprDximately O3. The aircraft will be unableto de vel p an aerodynamic

i4

valleys, mountains, and othernatural features. Keep a clO secheck on your exact position;you'll be amazed hO W muchalike all mountains can lookonce you're a little disoriented.Flying a valley in unusuallyhigh country can be a verygood system, but be sure it'sthe right one and the canyonwalls don't "suddenly come together." With the limited ra dios available in the L-19, airways are usually few, far between, and indirect. When youdo find one, the MRA may beconsiderably above the 10,000-foot level.4. The stalling speed of anyaircraft is the same indicatedairspeed regardless of the altitude. Many times when coming into an airport at an elevation of 4,000-5,000 feet for thefirst time, the pilot used to flying at sea level sets up landingapproach that would do justiceto aI). F-I04, only to reach theroundout point, float half thelength of the runway, thendrop it in from about 15 feet.Naturally your true airspeed ishigher, but your indicated gliding speed is the same as at sealevel.Another thing, one of thefirst points you r instructormade when you started flight

force sufficient to support itsweight. Stall or separation offlow about the wing will occuras aircraft begins drop withnegligible forward speed.4. Since the aircraft is notdeveloping a lift equal to' itsweight, the acceleration due togravity will cause the aircraftto fall toward the ground. Propeller thrust for the assumedaircraft would have only a secondary effect during the fall.

training was "always knowhere you're going to set tplane down if the engine failThis point is particularly trin mountains because forclanding areas are few and fbetween. Although you mayindicating a lot of altitude, tground may be much toO cloto consider the parachute asmeans of transportation. Tasome sort of survival gear wyou, a regular kit if possibIf not, at least carry a fematches in a waterproof band several candy bars; adress warmly. The very thithat caused YDU to go in, suas weather, might precludeimmediate search and rescoperation. And it may belong walk to the nearest farhouseScare rules? If approachwith knowledge, respect, aby simply applying these fesimple points, Army Aviatocan operate as safely and sucessfully in the mountainsanywhere in the world.Remember, although expeence may be the best teacher,can alsO be the deadliest, so a little preflight planning, aof inflight thinking, and mDutain operations can be as pleaant and gratifying as anyyour experience.

Ground contact could be epected.The aircraft will have no foward momentum with respeto the ground at 12 :34 :59.Inertia will have the effeof seemingly resisting moti

as in Newton's Law: If a bois at rest, it will continuerest; and if it is in motion,will continue in motion wiconstant velocity unless theis a net force acting on it.


17/40

STR P THAil ~ G R DOWN

H WAY some pilots treattheir shoulder harness re

of what the actressone of her revolutionary

remarked to the bishop:Sometimes I wonder. Are gir

necessary evil or doesmake them necessary ?

more pilots would beif they had beenmeticulous about their shoul-American wom-

are about hip harness. Ifsounds like a bold statewe remind you that it isthe evidence of hun-

Mr Brugg ink is an accidentwith viation Crash

njury Resea;rch of Flight Safetyoundation

Gerald M Bruggink

dreds of aircraft accident reports. We do not believe it nec-essary to use the gory detailsof some of these reports toconvince you of the importanceof the shoulder harness.

WHY USESHOULDER HARNESS?

Basically, we use a shoulderharness to keep our faces fromramming into the instrumentpanel or other solid objectsduring he a v y decelerat ions.Personally, we think very highlyof anything that safeguardsour bodies. And so does af r i end of ours, after hesmashed his jaw against thecontrol wheel during a mostunfortunate encounter wi t htrees. He had a shoulder harness in his aircraft, but a fancy

d

seat cover prevented his usingit. Besides this basic function ,a properly used shoulder harness ha s other advantages,such as preventing injury inturbulent weather and reducing the chance of vertigo underinstrument conditions.

HOW TO USETHE SHOULDER HARNESSHave you ever seen the com-

pletely in t a c t cockpit of acrashed aircraft and been surprised to hear that although hedid not have a scratch on hisface the pilot received seriousspinal or internal inj uries? Didyou ask yourself how thesethings happen? If you are notallergic to numbers, you canfind an answer in the followingdiscussion.

5


18/40

FEBRUARY 1960Suppose you are drivingalong comfortably in a 40 gstressed cockpit. M a k e youfeel pretty safe, those 40 g's,don't they? It will take somebeating before that protectiveshell around you collapses. But

what about your own designstrength? If you are :MotherNature's standard e d i t onyou:ll probably take about 40hOrIzontal and 25 g vertical dec e l e r ~ t i o n be for e developings e rIO u s aftereffects. Thismeans that the engineers haveput you in a wheelhouse thattakes approximately as muchpun.ishment as you do in longitudInal decelerations and evenmore in vertical decelerations.Let's now suppose that youare faced with a situation thatonly happens to the other guy :a forced landing in extremelyrugged terrain. You t 0 u c hdown at 112 mph with an impact angle of 18 0 ; the aircraftstarts horizontal decelerationat 35 g's. (All figures quotedare based upon actual N ACAtests. *) Just as you begin to

~ o n d e r when this thing is goIng to hurt, you become completely unconscious. What hashappened ? Very simple: although the aircraft was decelerating at a ~ o l e r b l e 35 g's,you were subjected to a peakload of 45 g's because you hadnot taken all the slack out ofyour shoulder harness.

WH T ABOUT THEINERTI REEL

Sure, that inertia reel worked exactly as it was supposedto. But it did not take intoconsideration your negligenceto take all the slack out of the*NACA Research MemorandumRME 57 G 11, Accelerations inFighter-Airplane Crashes.Note: The aspects of the verticaldeceleration will not be disCUSSQdhere.

16

harness and a few other thingssuch as: the stretching of theshoulder harness under tremendous loads and the elasticityof your body and clothing. We'llgo a little deeper into this.ANALYSIS OF A BIG KICK

When the seat, as part of theaircraft structure, and yourhips, which were well securedby the safety belt, started decelerating at 35 g's, your uppertorso was thrown forward witha force 35 times its own weight.The shoulder harness locked atthe first onset of the g-loadsbut between the c o m f o r t b l ~a?j ustment by the spring tenSIOn of the inertia reel only andthe hard manual pull on thestraps in the lock position,there are always a few inchesto spare. Add to this the unavoidable give of the shoulder harness material itself andthe elasticity of your body plusclothing and it becomes obviousthat you had a certain amountof freedom of forward travel.The result was that your rateof slowing down, momentarily,was less than that of the aircraft.. This would be a desirablesItuation if it would last indefinitely. Unfortunately, it cameto an abrupt end when thes.houlder harness, reaching itslImits, became as taut as asteel cable and reduced thatspeed differential to zero in theform of a snapload on yourtorso.

Assuming that the aircrafthad slowed down to 90 mphwhile your upper half was stillgoing at 95 mph, this speeddifferential would only be 5m ~ ~ ~ u t if your catchingup WIth the aircraft tookplace in approximately 1/ 50 ofa second, this would result ina g snapload on your body.(ThIS is a simple demonstra-

tion of the axiom that it is nspeed that hurts but ratechange of speed.) Add these 1extra g's to the 35 the aircrahad already and you have45 g peak, which will answthe question about the ill-feeing Ppot in the good-lookinCOCkPIt In addition, these pealoads sometimes have the naty habit of exceeding the tidown strength of your seashoulder harness, or safety be(in which case you have odeepest sympathy).Summarizing, we arrive athealthy conclusion: to avodangerous snaploads (load-amplification) during heavy deceerations a pilot should take thlast inch of slack out of hshoulder harness. What whave said in no way reflects othe ingenuity and workmaship of the inertia reel manfacturer. Actually he'll be thfirst to admit that the inertreel does not allow for carelesness. He'll also admit that yocan obtain maximum tightnesof the shoulder harness manu ~ ~ l y only and in the lock pSItIon, for reasons explainepreviouslyI t is a proven fact that thautomatic features of the inertia reel will provide adequaprotection under severe impaconditions, if the shoulder haness is properly adjusted.We have been discussing aextreme case in which you anyour aircraft went to the limiof structural integrity. ThNACA tests proved that yousurvival such a borderlincase may well hinge on thlengt? of the loose strap-endflapPIng carelessly in front oyou.

TTENTIONLIGHT AIRCRAFT PILOTSThe foregoing might creatthe impression that we ar


19/40

STRAP THAT TIGER DOWN

as it is in a 707.ainly concerned about theheavy-stuff drivers. This ispurely accidental; and we'llconclude with a few points ofspecial interest to the light aircraft pilot.

2. Several t y pes of lightplanes with a shoulder harnesslack an automatic locking device, which makes proper manual adj ustment more critical.

in the form of a good shoulderharness.4. Since the t i e - dow nstrength of seat, belt, and harness in light planes is often lessthan that in heavier aircraft,snaploads can easily contributeto tie-down failures. There isnothing funny about becominga human missile in an aircraft.

1 The g loads a pilot can beexposed to during a crash aremore a function of impact angle, speed and terrain, and other unpredictable circumstancesthan of the type aircraft he isflying. Consequently, the proper use of the shoulder harnessis as important in a Tri-Pacer

3. Experience has shown thatduring severe impacts in singleengine light aircraft, the engineis often pushed back into the instrument panel. This decreasesthe distance between the pilotand possible lethal objects infront of him and indicates theneed for a face-saving device

VVe agree that the shoulderharness makes a dull subject.All it does is help you keepalive when you know how touse it.

STORM EV SION BY OMNIf you do not have radar, your omni receiver might offer interim assistance in theavoidance of areas of hail and heavy precip.At least that's the opinion of one airline captain.when airborne radar is not available,good use can be made of the VHF navigationreceivers by keeping one tuned to the stationahead. The short wave signals used by VORgive evidence of not readily penetrating hailshafts or areas of heavy precipitation. I havemade successful use of this 'theory' during thepast three thunderstorm seasons

For exampleAt the time of takeoff from point A to destination B there were no thunderstorms reportedon course, but there was a line of storms parallelto and north of the course that were forecastto hit the course in little over two hours.Flying at 6,000 feet IFR and on instruments,I had my omni receiver turned to the VOR immediately ahead of me, on course and aboutmidway between point A and my destination.About halfway to the site of this VOR and some

10 minutes before reaching a river that bisected the course, the omni course needle beganto oscillate badly. I called in and was told thata severe thunder and hail storm had strucksuddenly. Almost at once we hit heavy turbulence and rain which necessitated our turningsouth in search of smoother air. Finding it, weflew a course parallel to the original one, butthe course needle did not steady until we weresouthwest of the VOR station to which we'dbeen tuned.

VVe then letdown to 4,000 feet, but couldn'tpick up our destination or talk to it for another10 minutes. In the meantime, however, wecould see heavy lightning to the west. Notuntil we were about 50 miles out from our destination could we tune them in, and then withsevere oscillation of the needle. e were toldour destination had a severe thunderstorm andhail. But being short on fuel, we decided tocontinue on in and ask the tower for radarassistance. . . ClutterConfirmation of what our oscillating courseneedle was saying came when we were told theirscope was completely cluttered with precipitation and they could not see us.A VOR station beyond our destination camein steady so we obtained ARTC permission todetour and stayed on that course until we weresome 15 miles south of destination B. Gettinga steady course needle at that point (220 0 fromdestination), we turned toward destination Band went on in through heavy rain but relatively smooth airAnd the captain added, Of course, it willnot tell you which way to turn, but a goodknowledge of current conditions usually willprovide this information. Also, some commonsense has to be used, such as knowledge thatyou are at a normal position for reception, etc.

t will not take the place of radar, but it is anaid that we now have and should be using. Thusused, it is my belief that the addition of oneADF set to 150 kc can save many bumps andmuch damage (Flight Safety Foundation)17


20/40

DoCentralization s the nswer

A branch is the sure8t means of integrating aviation spotential into the total ground elfort.

Captain Larry S Mickel Inf

FORECASTING THE shapeof future wars is a continuing process. Perhaps the mostval u a b I e contribution suchthought can make is in pointing out deficiencies in our current organization and equipment. We like, for instance, topicture the aerial vehicle asdeploying hard - hitting troopformations to the f r thestreaches of the battlefield withunparalleled s p e e d. S u c hthoughts are healthy and stimulating, but they conceal thesimple fact that Army Aviationas organized today c n n o tachieve these mobility goals.An examination of the facts isrevealing.Army Aviation is presentlyorganic to s ev e n branches.Each of these branches claimsto have definite need for integrated aerial support. Each is

A graduate of the USAIS Advanced Course, Capt Mickel s nowa member of the Air MobilityGroup of the Airborne-Air Mobil-ity Department, Fort B enning,Georgia.18

vitally interested in its growthand development, but for separate and distinct purposes.This splitting of effort has permitted numerous organizational and operational concepts toarise. These concepts have generally become separated intotwo schools of thought.

On one hand we find theservice branches - primarilyt h e Transportati0 n Corps -which consider Army Aviationto be logistical in nature and,theref0 re, subject t0 control ofthe services. On the otherhand the combat arms desirean air capability subject to immediate operations and contingent only on the requirementsof t r 0 0 P commanders. Theservice branch concepts havepredominated presumably because of the status of the Chiefof Transportation at Department of the Army level. TheChief of Transportation directly responsible to Deputy Chiefof Staff for Logistics, has nocounterpart in the com b tarms. Army Regulations dictate the Chief of Transporta-

We Need

This article was repr1 ntedpnblished at the U. S. Arm

tion s responsibility for doctrine procedures n d techniques relating to aviationwhile the combat arms aregiven a similar mission without equivalent status at theChief level.An examination of aviationmanagement shows a c0 nfusionof responsibility, though theDirector of Army Aviation,within the office of DeputyChief of Staff for Operations,is responsible for over-all staffsupervision and c00 rdination ofArmy Air effort. Army Regulations dictate that the Commanding General, USCON ARC,has specific responsibility toward aviation units and personnel in CONUS, except foractivities directly assigned theChief of Transportation. Yet,the Transportation Corps hasidentical responsibilities for alltransportation u n i t s exceptArmy transportation helicopterunits. Further the Chief ofTransportation has a responsibility to advise the Army Aviation School on all matters reIat -Continued on page 20


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22/40

FEBRUARY 1960

entralization s the nswer ng to avia ion - a r a t he rsweeping coverage in view ofthe functions of aviation whichare entirely unrelated to theTransportation Corps mission.Then, the Aviation School rep-resents all seven of the ArmyAviation user branches; fur-thermore, user branch schoolsrepresent themselves in mat-ters concerning branch air doctrine.

This muddle closely approximates the situation which existed in the Army Air Corpsprior to the establishment ofthe United States Army AirForce in 1941. From the period1935 to 1941, the responsibilityfor air activities in the UnitedStates Army was divided between the Air Corps and GHQAir Force. This responsibilitywas shared with nine corpsareas (later called Service Commands), established on a geographical bas i s In theory,GHQ Air Force had operationalcontrol, wi t h administrativesupport the responsibility ofthe Air Corps, while the corpsareas assisted both. A resultof this divided responsibilitywas an inadequate system ofsupply, maintenance and train-ing.

The words of the War Department Special Committee onthe Army Air Corps, publishedon 18 July 1934, are true today. The normal position ofthe Air Corps in the administrative organization of t h eArmy should correspond to itsfunctions, (1) as a combat armand (2) as a procurementand supply service. This wasthe lesson of experience in theWorld War and the lesson embodied in the National DefenseAct of 1920. In other words,2

aviation must be accorded abranch status.Among the problems whichbranch status would eliminatefor Army Aviation is the unusual policy for officer aviatorscalled dual proficiency. Asdescribed in AR 600-105, Ar-my Aviation Career Program,an aviator is required to main-tain ground proficiency consist ent with his nonrated contemporary.

The announced obj ective ofdual proficiency is to pro-duce and develop qualified andexperienced commissioned officers for the professional andtechnical phases of Army A viation. Yet, it is true that anaviator entering the best qualified echelon of promotionmust have a high degree ofbranch proficiency to competewith the nonrated officer whoseentire time is spent in branch-material assignments.During those periods whenan aviator is on a ground as-signment attempting to retainhis branch proficiency, his flying proficiency will suffer, sincein most cases he is able to accumulate only the minimum of80 hours flying time per year.Thus, the program defeats thefirst priority task for the aviator: achieving the maximumcombat performance from hisaircraft.A recent survey of aviatorsat Fort Benning shows that 18percent of the 150 aviatorsquestioned had transferred, orintended to transfer, from theInfantry to the TransportationCorps. Aviators see in theTransporta ion Corps a unifying Chief and an opportunityfor a full-time aviation job,with a wide variety of aviationassignments and command op-

portunities. Infantry p i l o t sfurther note that TC is the procurement agency for ArmyAviation, that TransportationCorps is authorized a largerpercentage of field grade v i ~tors than any of the combatarms, and that TransportationCorps assignment means an opportunity to fly large aircraft.As a consequence, the Trans-portation Corps will becomethe aviation branch unlesssweeping changes are made inthe aviation organization.

Already the TransportationCorps' very strong hold on aviation has had some undesirableeffects. Arm y Aviation hascost $900,000,000 in the lasteight years, the majority ofthese funds going to procurement of freighter aircraftthat are too large to be concealed in the combat zone andtoo expensive to be risked forward of the FEBA. The battlegroup has not one single air-craft.

Under a branch system, coordination of aircraft procurement by the Chief of ArmyAviation would insure the necessary balance between heavytransport and frontline air-craft. Establishment of an aviation branch as a combat armwould further guarantee thatdevelopment and procurementare consistent with Army A viation's mission: To augmentthe capability of the Army toconduct prompt and sustainedcombat, incident to operationson land.Establishing a n a v ia t ionbranch, which is within thestatutory authority of the Secretary of the Army, would provide a solution to the majorityof growing pains now sufferedby Army Aviation. t wouldinvolve m a j r changes, andwould encounter strong oppo-

ont ml ed on page


23/40

otBranch but Balancespecially designed. Even then,

though, it was clear that versatile light aircraft had an important role in close support,and that such aircraft wouldfulfill this role especially wellif placed directly under the control of the ground commander.In 1942, for instance, light aircraft were authorized to theArtillery as aerial observationplatforms.

This b r 0 a d separation bytypes and functions clarifiedthe role of aircraft in warfare,and contributed to the generalefficiency of air support. On theone hand, large, fast, heavilyarmed aircraft would have strategic and certain tactical functions, and on the other small,slow, lightly armed or unarmedaircraft would have only immediate tactical functions. Byestablishing an Army Aviationbranch we would be destroyingthis useful specialization whichhas developed as a result of theoriginal separation. By repeating the original separationwe would only be confusing it,and we would be seriously impairing the capabilities for closesupport that now exist.Only very recently the regimental commander had organicto his unit-and therefore immediately responsive to h i scommands-two light aircraft.Now he has none. At a timewhen clO se air support has assumed great importance for reconnaissance, cO'mmand n dliaison transport, delivery oftrO'ops and supplies and, insome cases, as a weapons platform, we have made that kindof support less available. Eventhe pooling concept, which resulted from the great and various demands made upon Army

Aviation, is a step in the wrongdirection, simply because theground commander has had tobeg for whatever air supporthe gets. Because aviation hasi t s e l f an argument against

branch. On the O ne h n d ,branch is predicated on thebasis of use, and not equipment.That is why we did not create aseparate missile branch, butintegrated our new missilesw i t h i n appropriate existingbranches. We gave the missilesto the people who would usethem. Similarly, we must givethe aircraft to the people whowill use them-Infantry, Artillery, or whatever, must haveorganic aircraft. On the otherhand, aviation, if left to itselfin a branch organization, would,precisely because of its difference, tend to acquire trappingsof mystery n d witchcraftwhich do not contribute to efficiency. Airplanes are in every sense air vehicles, andthere is nothing exotic aboutthem. As vehicles, they mustbe controlled by the user, theground commander.

Furthermore, with the advent of the zero ground-pressure device, a separate aviationbranch would not only be inadvisable, but impracticable. Thispiece of equipment, presentlyin the developmental s t g e ,may soon be as common as thejeep is now. Plainly enough,the logical direction O f ArmyAviatiO'n is nO t tO'wards moresophisticated aircraft but towards equipment which is easyto operate, simple to maintainand econO'mical to prO'duce -and which, moreover, will beavailable and appropriate forsustained tactical use O n an unprecedented scale. We must

not allO w branch proponents toimprisO'n Army Aviation within the 1959-1960 time frame,for branch and A V are incompatible. Imagine, for example,how absurd it WO uld be to talkabout a jeep branch, and yetbranch eXPO'nents are in effecttalking about the same kind O fthing. When zerO grO'und pressure vehicles are a dime a dO z-en, then obviO'usly the domainof the air must be common toall branches.If officers continue to pilotArmy aircraft, the branch concept would also create prohibitive personnel difficulties. Therole of Army Aviation is sodefined by law and conventionthat though at the lower echelons a considerable number O fpersonnel are required, at thehigher echelons O f commandand on staff levels there simply would be no room fO r placement within a branch. Evennow, field-grade, air-qualifiedO'fficers must be employed inother duties than Army Aviation. When expanded aviationrequires expanded numbers O flieutenants n d captains aspilO'ts of light aircraft, thenhigh-level command room willbe even scarcer. A profusiO'nof A V s would complicate theprO'blem, and adding branch O ntop O f these elements wouldcreate an inoperable system.Frequent assignment O f Army Aviation personnel of O nebranch to air support dutieswith another has already takenits tO ll in efficiency of operation and gO od personnel management. Infantry O'fficers whOshO'uld be flying with Infantryunits are flying with separateArtillery battalions, and Artillery officers are flying for Infantry battle groups. SituatiO ns like this contribute to alack of effective support. If,

ontinued on page 321


24/40

FEBRUARY 1960

entralization Is the Answer ,.sitiDn as it has since 1954 whenfirst recDmmended by ArmyAviation representatives in theDepartment of the Army. ThisoppDsition has developed as aresult f a fear that the ArmyAvia ion Branch wDuld developan Army Air CDrps attitude,thus separating itself from thegrDund combat echelons f theArmy, and on the Dther hand,that constituting an aviatiDnbranch would provide the AirFDrce with an argument forassimilating that organizationinto its structure.

The first f these fears stemsfrom the historical backgroundof military aviation. Now thatthe Air Force has assumed thestrategic aviation roles, thereis no reaSDn to suppose that thepropDsed aviation branch wouldfDllow the example of the ArmyAir Corps, which grew to havemissions so independent of thegrDund arms that it ceased toprDvide t h e m with effectivesuppDrt. Army Aviation's mis-siDn is clear enough and thepre-existence of the Air Forcewill effectively discourage anydeparture from it.

The fear of assimilation bythe Air Force is also ground-less. It need only be pDinted Utthat the Air Force has con-stantly treated those missiDnsnow assigned Army AviatiDn asa thorn in its side. The use ofsupersonic aircraft in ground

22

support roles indicates an ap-parent lack f interest in aviatiDn aspects f the ground fight.The Army is n W authDrized bylaw to engage in aviation ac-tivities and a reorganization ofArmy Aviation in the interestof efficiency would be of nomDre concern to the Air Forcethan any Dther internal activity of the Army.

The Army A viatiDn Branch,although primarily a combatbranch , would function as bothan arm and a service, as fDrexample does the Corps of Engineers. The responsibilities fordevelopment, procurement, Dr-ganization, maintenance ndtraining would then logicallycome under one office for di-rection and coordination, theoffice of the Chief f Aviation.Aviation units would be assigned within the combat armsand technical services as re-quired. Here they would re-spond to Dperational requirements f the ground command-er under the same commandrelationship as found betweenthe Infantry DivisiDn and theInfantry Division engineer battalion.

Many advantages would ac-crue from an aviation branch.These include: central cDntrolof responsibilities for aviation,centralization of career management for Army aviators,elimination of the need for

dual proficiency, eliminationof the present struggle forpower between the branches,and provision of a basis fDrrapid mDbilization expansiDn.Further, an aviation branchwould insure that proper rec-ognition is given to the growthof all Army Aviation functions.The Army must recognizethat Army Aviation is a full-time profession. As a cDrol-lary, the Army must alsO rec-Dgnize that a prDperly devel-oped and vigorously executedSChODI, unit and combined armstraining program is the surestmeans f achieving effective,integrated performance f avi-ation and combat arms on thebattlefield. The Infantry andother combat arms must finallyrecognize that the ultimate Dr-ganizatiDn for Army Aviationis an aviation branch-a com-bat arm and service so organ-ized that it centralizes all avia-tion effort n W fractionalizedbetween seven arms and serv-ices.Army A viatiDn has come tohave a variety of rDles, some ofthem conflicting. To fulfill themefficiently under all conditions,Army air must be balanced andadaptable. An aviation branchis the best and mDst equitableway of insuring that we giveevery role the emphasis it re-quires, that we develop theequipment needed to fulfill eachrDle in the best manner possi-ble, and that we make maxi-mum use of Army's aviationpotential.


25/40

Not Branch but alance f. thowever, an aviation branchwere adopted, it is likely thataviation personnel would become even more disoriented.Whereas there is at the presenttime some incidence of branchuniformity between aviator andsupported ground forces, underthe branch concept, of course,there would be none.

Perhaps one of the most compelling considerations actingagainst the branch concept isalso one of the least mentioned.The fact is that the countrysimply cannot afford a fourthair force. The Army doesn'tneed, doesn't want a privateair force. We don't feel possessive about aerial warfare. Whatwe do want is an Army air thatwill help us to do the Armyjob. What we need is an integrated air capability that allows an Army which is thinking in three dimensions to' actin three dimensions - to perform its unique Army missions.For the Army's sake, as wellas the country's, we need organic air and not a separatebranch.

Nevertheless, problems doexist in Army Aviation and, ifan aviation branch is no answer to them, neither is thepreservation of the status quo.But a separate aviation branchis by no means the only alternative. There- are certain logical revisions of the present aviation program which wouldsolve these problems withoutcreating new ones.Generally speaking, ArmyA viation grew in response toshort - range necessity ratherthan long-range planning. I tis not surprising, then, that theprogram is out of joint and hasmajor defects, and that rather

sweeping changes are indicated.Among these is a concentration of budgetary responsibilityin an overall aviation authority.

The Director of Army Aviationshould, in coordination withusing branches, be given research, procurement and doctrine responsibility for ArmyAviation. In this way, the requirements which g r 0 u n dforces have for air supportwould be developed by air personnel, adj usted by ground personnel and supervised within asingle framework of cO'ntrol.The Chief of Transportationwould in this case no longerhave total responsibility for aircraft procurement, and equipment design would be equitably coordinated among all theusers. The ground forces wouldobtain a direct, balanced voicein Army Aviation. No longerwould there exist the unfortunate situation which has Infantrymen operating on the FEBAin aircraft better suited to carry bulky cargo in rear areas.No longer would essential reconnaissance wait upon complicated maintenance. No longer would aircraft arrive toO lateto carry too little toO short adistance. Aviation would bewhat i t has not yet been-andwould not be under the branchconcept--Arrny Aviation.

In addition, Army Aviationshould be completely integratedwithin the combat arms andservices in supports. Only inthis way will we forestall thefascination with branch, withpooling and with centralizedcontrol of operations - and,more important, only in thisway will we remove once andfor all the borrower basis n

which field commanders mustoperate at this time. Poolingof aircraft at higher and higher levels may, indeed, decreasemaintenance problems. I suggest that this decrease occurspartially because pooled aircraft are less frequently usedthan they would be were theyorganic. But the point to remember is that fewer n1aintenance prO'blems must not become an end in itself. We arenot primarily concerned withincreasing maintenance ease,but with providing effectivesupport. And organic aircraftare the only ones that can giveus effective support. In addition, while centralized controlof administration and procurement is fine, when applied tooperations centralization is distinctly harmful. We wan tequanimity, not unanimity, andthere is a difference betweenthe two.One further alteration willsolve what is among the mostpressing difficulties now facingArmy Aviation: the dual proficiency req uirement. hewhole dual proficiency problemarises from the fact that commissioned officers pilot Armyaircraft, for dual proficiency it self is by no means an extraordinary requirement. The jeepdriver is also a radio-telephoneoperator. The NCO tank commander combines the functionsof a communicator, an Artilleryman and an Ordnance shopforeman. It is only becausecareers are at stake that dualproficiency in Army Aviationhas assumed its present proportions, that there have come tobe major personnel difficulties.Even though it may be unreasonable to require of the officeraviator a performance of competitive quality in two fields,the concept of dual proficiencyin itself is not unreasonable.

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Not Branch but alanceThe obvious solution, therefore, is to substitute for theofficer aviator a noncommis

sioned officer aviator. Afterall, the tradition of the officerpilot is nothing but a vestige ofthe days of the leather helmet,the white scarf and EddieRickenbacker's Hat-in-the-RingSquadron. We have demandedand successfully-a high degree of technical competencefrom the modern NCO. Thereis no reason why we cannot apply the NCO technical potentialto Army Aviation by assigningNCOs as aviators. In fact, theNCO is likely to develop a sustained excellence in the technical aspects of Army air whichis beyond that allowed by thepresent system.

Actually, this transition fromofficer aviator to NCO aviatoris not one of choice. The aerialvehicle-designed for operationby enlisted men-will unavoidably change the face of ArmyAviation. Just as the A V invalidates the branch concept,it invalidates the commissionedpilot custom. With expandingArmy Aviation, it is quite likely that, even disregarding the

HE AVIATION ELEMENTof the U. S. Army Transportation Environmental Opera tions G r 0 u p (TREOG) returned to Fort Eustis fromGreenland w he r e the groupspent the summer of 1959 onexploratory m i s s ion s . Thelatest in cold weather transportation, equipment, and technique we reuti l ized by theTREOG group.24

A V, we would soon need morepilots than our officer-procurement program could provide.Because Army Aviation will always have an auxiliary role, wecannot afford to divert to Armyair sufficient resources to support a continuing officer-pilotprogram. Clearly, a change isin the offing. To prevent thelack of consistency and systemwhich has sometimes characterized the development of ArmyAviation in the past, we shouldaccept the NCO pilot conceptnow, and we should begin a coordinated program of planningand training.

We can do this without wasting the valuable reservoir ofknowledge and experiencewhich is represented by officerpilots. This knowledge and experience would, in fact, be demanded by the type of aviationprogram described above. A viation-trained officers would beused as air officers on thestaffs of the units they supported. They would be used inresearch and development programs in the office of the Director of Army Aviation. Theywould be used as instructorsfRIOG

Three major operations wereaccomplished during this period. OPERATION LEAD DOGwas the farthest north penetration of the Arctic by surface mechanized equipment;OPERATION TOP DOG explored the feasibility of usingsea ice as a long range avenueof transportation for logisticalsupport of military operation;OPERATION FLYING FROG

in aviation - training. And, ofcourse, they would be used tosupervise, guide and direct theprogram as a whole.If there is any impetus within the Army to extend ArmyAviation into the area of legitimate Air Force operation, thenit is not the result of Army ambition. We must not, however,seize upon the failure of theAir Force to provide the kindof support to which it is committed by law as an excuse forfalling into the aviation branchtrap. The branch concept promises a great deal, but in realitywould operate with only thesame efficiency - and sometimes with considerably lessefficiency - than the presentsystem.What we really need is a sensible revision of this system,which creates an Army Aviation that is less than an airforce or branch, but substantially more than an uncoordinated and unbalanced stepchildof necessity. Such a revisionis the only way we will obtainpractical responsiveness to thetactical commander's will, refinement of the equipment development process, effective useof personnel and an equitableemphasis within the Army onspecific air functions.

resulted in the farthest northlanding and the longest flightover the permanent icecap byU. S. Army aircraft.The TREOG group also madean altimetry s u r v e y, established as t r 0 positions, andproved the reliability of theOverland Train. The Train supported 437,000 ton miles ofcargo at an average speed of4.2 mph.


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Ji'EBRUARY 1960defines an Army aircraft accident as an unexplained eventinvolving damage to an aircraftin the Army inventory equal toor n excess of the criteria forthe repair of damage listed inTable A, which occurs betweenthe time the engine or enginesare started for the purpose ofcommencing flight until the'time the aircraft comes to restwith all engines, and propellersor rotors, stopped upon completion of flight, regardless ofresponsibility.If we combine the two anddisregard the damage clause,we find that an Army aircraftaccident is an unintended interruption in a planned sequenceof events involving the operation of Army aircraft.Let's see how this affects thestatistical picture.

An Army Aviator takes offfrom a tactical strip in a BirdDog. His mission is to reconnoiter an aggressor column re ported on the move. Shortlyafter takeoff, he discovers hiswindshield is fast becomingcovered with a film of oil. Theaviator aborts the mission andreturns to his field. He makesa normal landing. He finds thathis preflight failed to disclosethat the mechanic had neglected to replace the locking pin inthe oil filler cap. Is this an accident? Certainly not withinthe meaning of AR 385-40.he mission, however, was

aborted. The interruption wasunintended. If we're going tomisuse statistics then surelythis must be an accident.Then there was the installation that had hangar space foronly half the number of aircraft in its inventory. Windand hail damages to the halfthat could not be placed undercover totaled $500,000. A survey team wrote these aircraftoff and no accident report was26

made. Was this an accident?According to the survey teamit was not; yet this same thinghappened time after time, until the damages totaled morethan 3 million.This shows part of the problem. In one case the missionwas aborted but no damage wasincurred to the aircraft or injury to personnel. The othercost the Army $3,000,000. Inneither case was an accidentcharged. Statistics do not reflect such situations.The term safety is negativein that it connotes danger andat the same time desire for removal of danger. Corrective

action could well be negativealso. For instance, if the commander desires a low accidentrate, all that is necessary is tocancel all flying. This immediately gives a zero accident rate.Another negative aspect isin the concept of safety. Tosome people it means safetyfor safety's sake. This can leadto an inhibited frame of mindwherein a pilot may be concen

trating so much on safety thathis thinking becomes restricted and he does not utilize hisaircraft to its maximum. Themilitary goal for aviation is theaccomplishment of the missionwith minimum hazard.In an imperfect world therecan be no absolute safety; hazards are faced daily. One canonly speak realistically of degrees of safety and danger.There are various ways ofmeasuring safety and danger.If there is one losing card in adeck of 100, for everyone draw,the hazard of losing is .01; thedegree of safety against losingis .99.Accident prevention also canbe learned from experience.Records may show that out ofm traffic movements in a cer-

tain area, n have led to accidents. It can be said that thehazard of an accident in oneflight to this area is : and similarly the degree of safety ism-n . Hazard and safety canbe looked upon as probabilities,which are mutually complementary and add up to unity.

Another important conceptin the philosophy of safety isthat of the acceptable hazard, and conversely the required degree of safety or thesafety standard. This standardcan be debated politically orphilosophically but not scientifically. It is a matter of individual or public opinion, andin the Armed Forces one ofpolicy. The Army, Air Forceand Navy have departmentsstaffed by competent physiologists and psychologists, aircraft performance engineers,and statistical experts whoscientifically formulate flightoperational limitations and double checks. Using facts fromprior accidents, these expertsdesign the limits and doublechecks in such a way that pilotsmay safely operate within theirinherent weaknesses and within the design limits of the aircraft. When these limits aredisregarded, accidents 0 c cu rand statistics accumulate.

Such statistics are measuresof the aviation hazard experienced and represent probabilities of an accident occurringper unit exposure. But they donot represent the true effectiveness of an accident prevention effort. If attention is focused on the causes of accidents, wherever and whateverthey may be, the rates and statistics will fall into proper perspective. The goal must be areduction of aircraft accidentsand not that accident rates beadministratively lowered.


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Here s a CloserLook into thDevelopment of th

Gas Turbine ngineTH MODERN gas-turbineengine is based on the principles of jet propulsion knownfor over 2,000 years, but firststated as a law of physics bySir Isaac Newton. His third lawof motion states that for everyaction upon a body, there is anequal and opposite reaction.This law explains rocket thrust,one form of jet propulsion, buta full explanation requires hissecond law of motion also: therate of change of momentumof a body measures in directionand magnitude the force actingupon it.

The rotating water sprinklerin your own yard is a commonapplication of the principle ofjet propulsion. Water entersthe hollow shaft of the sprinkler under pressure, w h i c hserves as an axis for the rotating sprinkler head. The pres-

CWO Paul J Chauvin, TC

surized water flows to the nozzles and is ejected at high ve- .locity. Consequently, thrustforces developed at each nozzlecause the sprinkler head to rotate.While the refinement of thegas-turbine engine is a 20thCentury accomplishment, thereare intermittent historical references of men experimentingwith devices based on the jetpropulsion principle.As early as 120 B.C. Hero of

Alexandria, Egypt, skilled inmathematics and physics, invented a device known as theAeropile. t consisted of a hollow sphere mounted on an axlebetween two supports. Whensteam under pressure was pipedinto the sphere and allowed toescape through nozzles on itssurface, the reaction caused the

sphere to spin between the supports. Weare not sure of howit looked, but it could have beena primitive form of the gasturbine.The discovery of gunpowderfurther advanced the idea ofjet propulsion and opened a

new field of experimentation.When or where gunpowder wasfirst used is uncertain, but wefind mention of it in writingsas early as 846. Chinese records reveal that in 1232 flyingfire arrows were used to defend a walled city. These wereprobably rockets mounted onarrows for flight stability.Leonardo da Vinci in 1550sketched a device to be placed

CW O Chauvin is an instructorin the Department of Mainte-nance US VNS . H e is qualifiedin the Sioux Raven and Shawnee27


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FEBRUARY 1960in the chimney to use the hot seems that experiments and degases from the fireplace to turn velopments have continued cona spit for meat. This, too, used currently by individuals andthe jet propulsion principle. nations. However, the first air-

In 1629 an Italian engineer plane propelled by a gas turbineGiovanni Branca, invented was flown by the Germans onsteam turbine. A jet of steam August 27, '1939. This aircraftwas applied to drive a spindle was designated as a researchvery rapidly. Using cogwheel plane with no intended militarygearing, its rotational speed application. Later German jetwas reduced to drive a stamp development reached 1,300 airmill. Perhaps the use of reduc- craft during World War II.tion gearing and high rotation- Practical development in jetal speed in our modern turbojet propulsion was accelerated inengines originated in Branca s the prewar years. Britain didearly turbine. much of the pioneering workMost of these early applica- in developing a gas turbine andtions. used steam for propulsion, kept the secret for severalbut In 1791 John Barber an years, but gave full informaEnglishman, patented a p o ~ r tion to the U. S. in July 1941plant consisting of a gas pro- under the Mutual Aid Agreeducer and receiver, air and gas ment, then in effect. Unawarecompressors, a com bus t ion of the German development,chamber, and reduction gear- the British had made their firsting. This was not a jet propul- flight of a gas-turbine airplanesion engine; however, it fore- May 15, 1941.* The U. S. didshadowed the turbojet engine, not make their first jet flightand many credit Barber with until October 2 1942.the invention of the gas tur- No discussion of the gas tur-bine. bine is complete without in-Today we regard our jet- eluding the contributions of Sirpropelled helicopters as mod- Frank Whittle to the field ofern inventions. Yet in 1903, an British design. While still aartist proposed the use of steam student in the R.A.F. Academyjet propulsion to drive a heli- in 1928, he wrote papers oncopter, using a rotary engine both the gas turbine and jetdesigned by a man n arne d propulsion. Two years later heA very. . was granted a patent for a tur-

Between 1905 and 1920 num- bojet design. His was the guiderous gas turbines were built ing hand in British gas-turbinein Europe for driving air com- development.pressors. In 1902 the first gas Both Whittle s and the Gerturbine was built in the U. S. man aircraft flown two yearsunder the direction of Sanford earlier used the turbojet deA. Moss, who used it to obtain sign. The rocket and the turboinformation for his doctor's jet both obtain propulsive forcethesis at Cornell University. by a rearward directed jet ofIts earliest application was to hot gases. The rocket carriesdrive a supercharger for re- both the fuel and oxidizerciprocating engines. while in the airplane onlyEven though there has been fuel element of combustion iscontroversy over who or what carried.nation should be credited withthe development of the firstsuccessful turbojet engine, it28

*Powered .by two turbojet enginesBritish fighter.s ,were.first used againstthe German V-I flying bombs in 1944.

J T NGIN SThere are two basic types ofjet engines: self-contained engines which carry both oxygenand fuel (rocket); thermal airengines, which take their oxygen from the atmosphere. Ther

mal air engines are further divided into four types: Athodyd,or con t in u 0 u s - firing - duct;pulse-jet, or intermittent-firingduct; turbojet, or gas-turbineengine; turboprop, a variationof turbojet using a conventional propeller. Various jet powerplants use a combination oftypes.The postwar years have seenmuch progressive work in thegas turbine in America bymany different companies, someu n d e r government contract.The first turbine specifically designed for the helicopter wasdeveloped by Lycoming Division of Avco Corporation in1951--the T-53. In 1953 General Electric entered the fieldand developed and produced theT -58. The T -53 is used in present Army aircraft, while theT -58 is used in some experimental aircraft.The performance of our ad-vanced types of turbine-powered aircraft maintains developmental interest. Today weare standing on the thresholdof scientific progress which willcarry man into space.References:Casamassa, Jack V., and BentRalph D. JET AIRCRAFT POWERSYSTEMS, 2nd Ed. New York: McGraw-Hill Book Company, Inc., 1957.Chapel, Charles Edward. JET AIRCRAFT SIMPLIFIED. Los Angeles:Aero Publishers, Inc., 1954.Driggs, Ivan H., and LancasterOtis E. GAS TURBINES FOR AIRCRAFT. New York: The RonaldPress Company, 1955.Smith, M.B.E., G. Geoffrey. GASTURBINES AND JET PROPULSION . London: liffe Sons, Ltd.;New . York; Philosophical Library1955. .


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The T 53Gas TurbineAs

Seen y aintenanceUSE OF THE T-53 in theHU-1A helicopter and AO 1aircraft presents a new type ofpowerplant for the Army. Fa-miliarization with the (shaft)gas turbine, its systems, andoperating principle is a mustfor flight and maintenance per-sonnel if acceptable results areto be obtained.Gas-turbine engines run toofast; the pressure is too high;operating temperature is toogreat; life of the engine is veryshort - these and many otherstatements have been made byso m e maintenance personnel.Some of these statements canonly be answered as m r eknowledge of the engine andits components is gained.Suppose we take a look atthe speed of the T -53 and compare it to that of the R-985

Mr. Mize has been a supervis01Ytraining instructor

army aviation digest - feb 1960

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