JL McClellan: FW-190 draft Copyright 2005 p 1 of 36

Editors note:The   Design   Analysis   article   was   originally

published   in   the   October,   1944   issue,   Volume   43,number  10,  and   the  Gear  Retracting Unit  was   in   theMarch, 1945 issue, Volume 44, Number 3, of  Aviationmagazine,   published   by   McGraw­Hill   PublishingCompany   of   New   York,   NY,   USA.   Supplementalillustrations are from the 1942 volume.

This reconstruction is derived from microfilm. Thesource   is   University   Microfilms   International,Publication   No.   364   (Aviation   Week   and   SpaceTechnology),  Reel  No.  18 (January 1942 – December1942), Reel No. 20 (January 1944 – December 1944)and Reel No. 21 (January 1945 – December 1945).  Thesource was from tightly bound volumes, so that there issome   distortion   of   the   images,   especially   near   thebinding.     It   has   not   been   practical   to   remove   orcompensate   for   all   the   distortions,   so   none   of   theillustrations in this reconstruction should be consideredreliable sources as to fine details of shape, proportion orspatial   relationship.     The   distortions   are,   in   general,small,   and   should   not   detract   from   a   generalappreciation of arrangement and relationship.

The   editor  has   attempted   to   represent   the  originallayout   of   the   article,   but   there   are   some   exceptions.Limitations in the compositing tools cause a differencein the text flow relative to the illustrations, compared tothe original, so that some changes have been made, tocompensate partially for that effect. Tabular informationhas been consolidated at the end of the article, and an

enlarged copy of the cockpit instrument panel layout hasbeen added at the end of the article.

The Design Analysis article was one in a  series  ofdesign  analyses  published   in  Aviation  during   the  waryears,  between  May 1943 and November  1945.    Thesubjects   were   the   Bell   P­39  Airacobra,   Curtis   C­46Commando,  Fleetwing  BT­12,   Douglas   A­20  Havoc,Bristol  Beaufighter  (British),  deHavilland  Mosquito(British), North American P­51  Mustang, Lockheed P­38  Lightning,  Focke­Wulf FW­190 (captured German),Boeing   B­17  Flying   Fortress,   North   American   B­25Mitchell  (specifically,   the  B­25H  and  B­25J  models),Mitsubishi   “Zeke   32”  Hamp  (captured   Japanese),Consolidated  Vultee  B­24  Liberator,   Fairchild   C­82Packet, and Messerschmitt Me­262 (captured German),with one article dealing specifically with the Me­262'sJumo  004   jet   engine.     Some   of   the   analyses   wereauthored by senior members of the design teams at theoriginal   manufacturers,   while   others   were   written   bystaff editors of Aviation magazine.

The   original   articles   were   copyright   to   theirrespective   sources:  the   employers   of   the   authors,following general practice of the time.

This   reconstruction   is   compilation   copyright   JLMcClellan, 2005.

JL McClellan: FW-190 draft Copyright 2005 p 2 of 36

DESIGN ANALYSIS NO. 9

THE FOCKE-WULF 190

By JOHN FOSTER, Jr., Managing Editor, Aviation, and

CHESTER S. RICKER, Detroit Editor, Aviation, who also drew the field sketches.

Here is the most comprehensive engineering report ever published

on the Luftwaffe's top-ranking fighter, revealing for the first time

many structural features and Nazi design theories. Presented with

AVIATION'S inimitable wealth of detail and on-the-spot sketches.

ERMANY'S  FOCKE­WULF   190presents   an   apparentlystrange   combination   of

simple,   yet   sturdy,   construction,paralleled   by   highly   complexcomponents.    Analysis   of   the   craftreveals,   however,   that   is   has   beendesigned for  the pilot  and the fieldmaintenance   man.     What   oftenappears   initially   to   be   anunnecessarily   complex   small   unitturns out to be a well­designed, self­contained,   and   quickly   removablecomponent.

G

Underlying   theory   of   the   entiredesign appears to be to reduce fieldmaintenance time to a minimum, asthough   the  plane  had  been   createdwith the idea that it's quicker to getparts off the plane replaced than torepair the parts themselves.

Then, too, the design is such thatthe   craft   can   be   built   throughwidespread use of subcontracting ordispersal  plants.    The   fuselage,   forexample, is comprised of two majorcomponents,   the   fore   sectionextending from the firewall, or whatthe Germans call bulkhead No, 1, tobulkhead No. 8 aft of the pilot's seat,and   the   aft   section   extending   frombulkhead 8 to the empennage.

The   fore   fuselage   section   is   theheart of the plane and is, in effect, adouble­deck box type structure, withthe top section making up the pilot'scockpit   and   the   lower   sectionserving as the fuel tank bays.

The firewall, or No, 1 bulkhead, isbuilt  up  of   light  sheet  steel  backedby sheet  aluminum alloy riveted tobuilt­up flanges extending from thetwo top forged engine mount fittingsdown to forged fittings which  serveas   attaching   points   for   both   lowerside   engine   mounts   and   the   frontwing spar.

Longerons run aft from these fourpoints to No. 8 bulkhead, where theyare spliced to lighter ones in the aftsection.   Top longerons are 1­3/4 in.wide U­sections made up of 3/16­in.thick   aluminum alloy  and   serve   astracks  in  which  the cockpit  canopytravels.   One hat­shaped stringer oneach side, 10­1/2   in.  below the toplongerons,   make   up   the   onlyhorizontal   stiffeners   in   the  top  partof   the   fuselage.     Aluminum   alloysheet, riveted to the lower longerons,forms the cockpit floor, separating itfrom the fuel tank bays.

Bulkheads   in   the   upper   forefuselage   section   are   not   uniformly

JL McClellan: FW-190 draft Copyright 2005 p 3 of 36

ACKNOWLEDGEMENTThe editors of Aviation are deeply grateful to Brig. Gen. K. B. Wolfe, Commanding

General of the Army Air Forces Materiel Command and members of his staff forassistance in preparation of this article.

For unstinting cooperation and help, special thanks to: Major D. L. Hancock, Lt. J. E.Arnoult and Mr. M Llacera of the Technical Data Laboratory; Capt. Howard M. Spickler,chief, and Lts. Joseph Becker, W.H. Wilson and A. J. Shank of the Captured EquipmentUnit, AC/AS, Int. W.D.C. And Lt.Col. G. R. Johnston, Chief, Public Relations Section andMr. D. P. Kelly.

spaced, nor are they all of the sameconstruction.  No, 2, of conventionalstamped flanged construction, is 12­1/2 in. aft of No. 1; No. 3 some 6­5/8 in. farther aft is directly beneaththe   front   windshield   base.     No.   4,also of conventional construction, is10­5/8 in. farther aft.  No, 5, directlyunder   the   rear   end   of   the   fixedwindshield and above the  rear sparfitting,   is   angle   shaped   against   theskin,   and   extends   above   the   flooronly to the stringer.  It is braced by a3/4­in.   tubular   section   flattened   ateach end for riveting to the bulkheadand cockpit   floor.    No.  6   is  an  A­frame structure, the base of  the forepart being 12 in. aft of the  No. 1  5bulkhead,   the  top 18­1/2  in.  fartheraft.     The   sloping   fore   part   is   achannel section in which the pilot'sadjustable   seat   is   supported.     Thevertical member, set 5 in. aft of thetop,is conventional stamped, flangedconstruction, riveted to the fore partat   the   top   by   a   web   plate   ofaluminum   alloy.     No.   7   isconventional construction, set 12 in.aft of the rear part of No. 6, and No.8   is   a   built­up   stamped   flangedmember extending the full depth ofthe fuselage,  and  forms the  joiningpoint  of   fore  and   aft   fuselagesections.

The   lower   fore   fuselage,   or   fuel

JL McClellan: FW-190 draft Copyright 2005 p 4 of 36

Fore and aft sections of fuselage. Fore section, which is heart of plane,extends from firewall aft to bulkhead No. 8, which is shown in detail A.This section is divided into upper and lower sections, separated bycockpit floor, which is indicated by dotted lines 1. Lower sectioncontains fuel tank bays which are covered by single skin panel 2. Thisis quickly detachable by loosening nine screws along each side and fivein each end. Rear spar fuselage attachment fitting is shown at 3.

Details of fore fuselage section between firewall-bulkhead No. 1 and bulkhead No.8,with top longerons cut away. This detail shows how bulkheads are unevenly spacedand vary in construction. Forged rear spar attachment fitting, shown in detail drawing,is attached to build-up web tie-through member, which also serves to separate two fueltanks

bay section, has but six bulkheads. No.   1   forms   the   front   end,   being

JL McClellan: FW-190 draft Copyright 2005 p 5 of 36

Cut-away view of aft fuselage section, from point where it is attached tofore section by double row rivets, aft to bulkhead No. 14, where empennageis bolted to it. Bulkheads 9 and 10 are built up in three sections, rivetedtogether. Tops of bottom sections are flat to accommodate camerainstallations. Fabric panel in set in No. 12 to prevent dust from seepingforward into fuselage. Tube mounted in No. 13 provides for lifting bar.

FW-190 fuselage with cockpit canopy,fairings and doors in place. “Waffle” typeconstruction, in which two skins are rivetedtogether by one rivet in each dimple, bringscowling weight to about 1.75 lb. per sq. ft.(compared with 1.25 for American andBritish cowling's), but reflect German designphilosophy of keeping fairings attached andin place for hurried locking. Fairings hingedat bottom of engine mount, giving access toaccessory compartment, serve as workstands. Top fairing, seen folded back overwindshield, covers two 7.9-mm. Machineguns firing through propeller arc; those justaft of engine-mount cowlings give access toinboard gun ammunition boxes. Door in aftfuselage gives access to radio, camera, andcompass.

right aft of the front wing spar.  No.2, which is in reality a contour rib, is10   in.   aft   and   is   a  continuation  ofNo.   3   from   the   upper   section.Lower No. 3, set 5­78 in. farther aft,is   also   a  contour   rib   and   joins   thelongeron  between  Nos.  3  and  4  ofthe upper section.  No, 4, of built­upweb construction,  is the tie­throughmember  between   rear   spar   fittings,and separates the two fuel tank bays.No. 5 is set below the forepart of theA­frame No. 6 of the upper sectionand, like lower No. 6,  which is set11 in. aft, is contour­rib type.

One belly skin panel, attached tolongitudinal   and   transverse   angleshaped stiffeners,   is attached to thelower   fuselage   section   by   ninescrews along each side and five oneach end, thus giving quick access tothe   two  self   sealing  fuel   tanks,which   are   suspended   from   thecontour rib­bulkheads by heavy webstraps.

On   the   upper   fore   fuselagesection,   immediately  aft   of   the   topengine  mount   fittings,   the   fuselagestructure   is   flat,   forming a   shelf   towhich are bolted mounts for the twin7.9   mm.   machine   guns   that   firethrough the propeller.   Back of thisgun mount  shelf   the   fuselage  sidesextend up to form the  base  for   thewindshield, the front panel of whichis 1­3/4 in. bulletproof glass.

At the base of this front panel ishinged the fairing to cover the guns

JL McClellan: FW-190 draft Copyright 2005 p 6 of 36

Field sketch showing details of heavy toggle latches which hold cowlingand fairing in place. They are strong enough to spring fairing into placeeven if it is distorted. Tension adjustment, with small flat bar lock, isshown at left. Center sketch shows toggle in closed position, and slot inmating piece is at right. Sketches at upper right reveal details of lock.Locking plate has two depth slots, so center indicator pin sticks up whenlatch is unlocked; it is flush when locked.

Heavy toggles are also used on engine cowling, this sketch showingthem at top. Piano-type hinges, with eye for easy removal andinspection, are used at bottom.

Three adjustable air outlet flaps, mounted in doors hinged at bottom, are set on eachside of engine cowling. To operate them, a screw-and-nut mechanism is attached toforward side of firewall and is connected to each side door by tubes. Latter areconnected to linkage on doors by levers and bell cranks so arranged that they do nothave to be removed or adjusted when doors are opened..

just mentioned.   This fairing, whichhinges up and back for access to theguns,   is   of   “waffle”   typeconstruction,   with   the   two   skinsbeing fastened together by one rivet

in each inner  skin dimple.    Threeheavy   locking   toggle   switches   –typical   of   those   installedthroughout the plane – are used oneach   side   to   hold   the   fairing   in

place.Such heavy cowling – and easily

removable hinges to keep it in place–   naturally   adds   what   seemsunnecessary weight.   It is, however,in keeping with the apparent designtheory; the cowling is always on thecraft ready for  locking and a quicktakeoff.  It is heavy enough to standhard   wear,   in   fact,   the   side   panelsswinging   downward   around   theengine   mount   are   used   as   workplatforms.  Too, in case the cowlingis bent a bit,   the toggles are sturdyenough to pull it into place for quicklocking.

Cowling on the FW­190 averagesabout 1.75 lb. per sq. ft.,  comparedwith 1.25 for British and Americancraft, but the German's persistent useof the type indicates their belief thebeatings   it  can  take   and   the   speedwith which it can be locked in placemake it worth the added weight.

The cockpit  cover and its fairingare built as an integral unit.  Base ofthe   structure   is   a   5/8­in.   tubularmember bent   into an  inverted U atthe  front   to fit   into  the windshield.The   plastic   glass   of   the   cover   ismounted between two strips of bunaand  a   flat   aluminum strip,  held  byscrews driven into self­locking nutsin the tube.  At the rear of the plasticglass  a stamped,   flanged  aluminumA­frame sets between the tube­frameends,   and   is   riveted   to   aluminumalloy   fairing   mounted   on   a   3/4­in.tube   extending   aft.     The   wholestructure rides on three ball bearingrollers; one on each side at the frontof the plastic glass section in the topfuselage longerons, and one attachedto   the   tube,   running   in   a   channelsection   (which   serves   as   top

JL McClellan: FW-190 draft Copyright 2005 p 7 of 36

DIAGRAMMATIC COCKPIT LAYOUT

Cockpit canopy details, showing method of fastening plastic glassto tubular frame. Entire canopy slides on ball bearing rollers intracks formed by upper fore fuselage longerons and in trackformed by upper aft fuselage longerons. Canopy can be operated

only from inside cockpit, by crank on right side attached tosprocket engaging pin ratchet (seen at left above) attached to frontend of tubular frame. Note silhouette armor plate mounted incanopy frame; it slides forward to just behind pilot's head.

longeron)   set   in   the   fuselage   turtledeck.

The cockpit cover can be operatedonly from inside by a crank attachedto  a  sprocket  which  engages  a  pinratchet  attached to  the front end ofthe  tubular frame.   Emergency exitcan be effected by pushing down ona   small   handle   located   near   thecrank.  This disengages the sprocketand   then,   through   a   series  of   rodsand shafts,   releases a   latch holdingthe firing pin.   A cartridge explodesand blows the rear end of the canopybackward far enough to let the slipstream get  under  and  pull   it   away.The   explosive   charge   –   about   thesize of a 12­gage shotgun shell – islocated aft of a silhouette of 1/4 in.armor plate back of the pilot's head.This armor is attached to the cockpitcover   tubular   member   by   linksattached   to   studs   welded   to   thearmor plate.

An interesting angle of the cockpitcover is its connection with the radioantenna,   which   leads   in   from   thevertical fin to and over a pulley setin   the  plastic  glass   just  behind   thearmor plate, then over another pulleyset in the aft end of the cover fairing,then   forward   again   to   an   insulatedlead­in   to   the   radio   mounted   justbehind   No.   8   bulkhead.   Thus,regardless   of   whether   the   cockpitcover   is   open   or   closed,   the   radioantenna has the same tension.  

While  the cockpit   itself  does notgive   the   appearance   of   beingovercrowded  there  is,   nevertheless,no waste  space.    Flight  and engineinstruments   are   arranged   on   twopanels   beneath   the   windshield   andon horizontal panels on each side, asshown   in   the   accompanyingdiagrammatic   layout.     The   pilot'sseat,   the back of which is made ofarmor   plate,   is   only   adjustable   upand down 4­in.  and is designed forseat pack parachutes.

The aft fuselage – from bulkhead8  through  14 – is  semi­monocoqueconstruction,  and is  attached to   thefore   section   by   a   double   row   ofrivets   through   both   skins   and   theflanged section of bulkhead 8.    Anexamination   of   several   differentcraft,   including   more   than   onemodel, indicates these two sectionsare   not   jig­drilled   prior   to   mating.Apparently   the   two   sections   arebrought together in a mating jig andboth drilling and riveting done there,for  variations  in  rivet  locations are

readily apparent.  This same type ofassembly is rather widely used, aswill  be  noted  in  the  discussion ofother components.

Bulkheads No,  9  and  10 of  theaft fuselage section are built up inthree   sections,   the   bottom   onesbeing heavy  channel sections  withflat   tops   to   support   camerainstallations.     Upper   portions   ofboth   are   conventional   stampedflanged   construction,   rivetedtogether and to the bottom sections.

Numbers   11,12,   and   13   are   oflighter   construction   and   followconventional   practice,   being   builtin halves and riveted together at topbottom.    No.  13   contains   a   crosstube for lifting the fuselage.  In No.12   there   is   set   a   fabric   panel   tokeep dust from seeping forward tothe   radio,   camera   and   mastermagnetic compass with its contact

for   control   of   the   repeater   on   theinstrument panel.

Bulkhead No. 14 is heavy flangedconstruction   for   bolting   theempennage to the aft section.

There are two upper side channel­shaped   longerons,   riveted  to   thosefrom   the   fore   fuselage   by   6­in.splices   and   they   extend   to   aft   ofbulkhead No. 11.  A channel­shapedtop longeron extends the full lengthof the aft section, between bulkheads8   and   11   serving   to   support   thecockpit   cover   fairing   track.    Thereare   six   Z­shaped   stringers   withrolled   edges   on   each   side   of   thissection  of   the  fuselage  and   five   inthe bottom in addition to two heavyU­shaped   stringers   where   side   andbottom sections are joined.

The aft fuselage skin – like that inthe fore section –  is slightly lighterthan our 24ST,  but  no evidence  of

JL McClellan: FW-190 draft Copyright 2005 p 8 of 36

Here are details of mechanism which blows canopy away for emergency release.Mounted in aft tube (behind armor plate) which rolls in aft fuselage section top longeron,it is operated by lever at pilot's right hand. A safety (1) is provided in firing block.Explosive charge(2) looks like ordinary shotgun shell. Firing pin is shown at (3) andrelease at (4).

Accessories in Focke-Wulf 190 fuselage section. (1) Is hot air supply to cockpit; (2) iscover over fuel pumps and electric junction boxes; (3) is handle moving canopy; (4) isarmor and bulletproof glass; (5) is battery; (6) is explosive canopy release; (7) is cameramount; (8) step which telescopes up into fuselage; and (9) fabric panel in bulkhead No.12 to protect instruments located in aft fuselage section.

wrinkling was  found  in  the  severalcraft studied.   Flush riveting is usedon every surface of the craft.

One of  the outstanding examplesof   simple,   yet   sturdy   constructionfound in the  Focke­Wulf  190 is theempennage.   It is attached to the aftfuselage  section  at  bulkhead 14 bymating, flanged bulkheads through aseries of closely­spaced bolts.

Leading aft   from this  bulkhead,some 5 in. form the top skin,  is astamped flanged rib with lighteningholes,  extending from side to  sideand seven and three eighths incheslower is another full­width rib.  Thestabilizer goes through the fuselagebetween these ribs.

Both   ribs   intersect   a   diagonalmember  which   is   the heart  of   the

empennage, for it carries tail wheelloads  on   the  ground  and,   once   thecraft   is   airborne,   carries   both   fin­and­rudder   and   stabilizer­and­elevator loads.

Starting at the bottom skin 18­3/4in. aft of the attaching bulkhead, thismember   extends  up  and  aft  63­1/2in. to the top vertical fin rib (whichextends aft to support the top rudderhinge) at the base of the detachablevertical   fin   tip.     Nine   inches   formthis member's  lower  end, on the aftside, is riveted a fitting to which isattached   the   front   end   of   the   tailwheel drag yoke.  On the front face,between   the   two   horizontal   ribspreviously noted, is riveted a forgedhexagonal   fitting   to   which   thestabilizer rear spar attaches.

Above   the  top horizontal   rib,  onthe aft face is riveted a 20­in. doublechannel   member   which   forms   theguide   rails   for   the   tail   wheelretracting   unit,   which   will   bedetailed later.   The channel memberis surmounted by a  plate  bearing apulley which is part of the retracting

JL McClellan: FW-190 draft Copyright 2005 p 9 of 36

Cut-away view (left) of empennage and integral vertical fin.This section bolts to aft fuselage section at bulkhead 14.Diagonal structural member is heart of this section, for itsupports tail wheel loads when craft is on ground andsupports fin, rudder, stabilizer, and elevator loads when shipis airborne. Two skins, extending from the bottom of fuselageto top horizontal rib at base of fin tip, are riveted together attop along a vertical flange. Aft of diagonal member and abovemiddle horizontal rib, skins are of “waffle” construction.

Hinged inspection door ─ 30 in. high by 15 in. across base –is locked in place by special screwdriver-operated fasteners.Piano hinge and springs are protected by fabric covering.Field sketch (above) gives detail of fin leading edge, showinghow two skins are riveted together along vertical flange.Single formed aluminum alloy fairing is fastened over flangeby flush screws driven int diamond-shaped safety nuts rivetedbetween flange. Same method is used for leading edge ofstabilizer.

Detail field sketch showing construction of door latches. Forged bracket A, is riveted todoor. Operating bell crank is made in two parts. Stop B, which limits throw; and latchpiece C, which drops into slot in bracket when locked. Latch is turned with screw driver atE. Spring keeps screw head flush when in locked position. It must be pressed inward torelease. Guide bracket D is soft enough so that it can be beat with pliers to tighten lock.

unit, and the top fin rib.The topmost of the two horizontal

ribs   extends   aft   of   the   diagonalmember   16­1/4   in.,   the   middlerudder   hinge   being   mounted   at   itsend.  The other horizontal rib, aft ofthe  diagonal,   extends  downward  atapproximately 28 deg. from the baseof the stabilizer fitting to the bottomof the tail cone to support the lowerrudder hinge.   A vertical web plateof   stamped   flanged   alloy   connectsthe two ribs at their aft ends.

Below   the   two   horizontal   ribs,three   Z­shaped   stringers   on   eachside   run   from   bulkhead   14   to   thediagonal   member,   and   a   similarnumber are employed above.

At the leading edge of the fin, theskin is crimped and riveted together,with a series  of 5  diamond­shaped,self locking nuts inserted and rivetedbetween the crimping.   The leadingedge skin, a single sheet of formedaluminum   alloy,   can   then   befastened in place with flush flat headscrews driven into the diamond­nuts.Drilling of the two fin skin surfacesapparently is not a jig operation, forstudy   of   several   craft   showeduneven   spacing   and   lack   of   rivetalignment.  In one plane, as a matterof   fact,   even   a   difference   in   rivetsizes was evident.

Skin aft of the diagonal member –between it and rudder hinge points –is   of   the   familiar   double   skin“waffle”   construction,   eliminatingthe need for stringers.   A triangularinspection door – 30 in. high by 15in. across the base set in the left sideof the fin gives quick access to thetail wheel retracting unit and top ofthe   oleo   shock   strut.     Two   screwdriven   locks   are   used.     The   pianohinge  springs   to   keep   the   doorclosed.     These   and   the   hinge   aresealed in fabric.

Apparently   deterioration   of   pilotquality,   well­prepared   airports,   orsome other  causes  have resulted  infailures   in   the   empennage,   forexamination  of   later  models  of   the190   reveals   that   additional   webplates  have  been   installed  betweenthe horizontal ribs behind and belowthe   stabilizer   fitting   to   betterdistribute the stabilizer­elevator andtail wheel loads.

The  dynamic  and  mass  balancedrudder is built around a single sparof   stamped   flanged   aluminum   towhich   are   riveted   the   three   hingefittings.     Leading   edge   is   flush

riveted   to   the   spar,   and   ribs  haverounded   gusset   plates.     Trailingedge   is   also   of   metal,   with   theentire   unit   being   fabric   covered.Unlike   most   modern   fighters,   the190's  rudder  trim tab is adjustableonly   on   the   ground.     It   consistssimply of a 15 x 1 in.  metal stripriveted into the trailing edge, with aseries   of   perforations   to   facilitatebending   to   the   desired   degree.Two types of tabs are used; somewith   slotted   perforations,   some

with round holes.The   stabilizer   is   full   cantilever

single   spar   all­metal   construction,built   as   one   unit   except   fordetachable   tips.     There   are   sevenfloating ribs on each side.  Stabilizerattaches   at   the   aft   edge   to   thediagonal member of the fin throughforged fitting previously noted,  andhinges   on   pins   that   go   into   selfaligning  trunnions,   for vertical   trimof craft is effected through adjustingthe stabilizer.

JL McClellan: FW-190 draft Copyright 2005 p 10 of 36

Fabric-covered rudder is built around single spar (shown in detail at right). Top, center,and bottom bearings are shown in details at left. Rudder operating cables are attachedto outer holes shown in middle bearing detail. Note how hinge pins are tapered tofacilitate assembly. Rudder is secured by bolt on lower hinge pin. Trim tab is adjustableonly on ground. It consists simply of 15 x 1-in. Metal strip riveted into trailing edge, withrow of perforations to facilitate bending to desired angle.

JL McClellan: FW-190 draft Copyright 2005 p 11 of 36

Focke-Wulf 190 stabilizer is single-spar full cantilever structure built in two halves andbolted together at center line. Top and bottom skins are flanged and riveted together toform front spar. Leading edge is attached like fairing on vertical fin. Three ball bearingsupports for elevators are provided on each side (shown in detail in sketches at top).Formed tips are screwed into place with flat-head screws in countersunk washers.Captured nuts in flange of outer rib hold them in place.

Stabilizer angle of attack is adjusted by electric motor-driven screw jack mounted inleading edge of vertical fin, with hinge point along spar at trailing edge. Electric indicatoris attached to stabilizer so that its position is shown on instrument panel. This fieldsketch shows adjustment marks on fuselage and fairing.

Elevators are built around single spar(shown in center) with metal leading edge,ribs, and trailing edge. Whole unit is fabriccovered, fabric being stitched in place withwire loops. Even though stabilizer isadjustable in flight, right elevator (shownhere) has perforated trailing edge trim tab –adjustable only on ground – similar to thatfound on rudder.

Stabilizer adjusting unit, with ball-and-socketat top for attaching to inside of fin leadingedge and fitting at bottom for attaching tostabilizer. Electric motor runs at 14,000 rpm.And, through six gear trains with 533-to-1reduction gear, moves stabilizer over fulladjustment arc in about 20 sec. Magneticbrake keeps it from over-running whencurrent is turned off. Bellows type rubbersleeve at bottom of screw jack keeps itclean.

JL McClellan: FW-190 draft Copyright 2005 p 12 of 36

Full cantilever wing on Focke-Wulf 190 is built around frontspar, which extends through plane from tip to tip just belowfirewall. It carries bottom engine mount support, shown herein detail sketch. Inner section of leading edge is built asseparate unit having its own ribs. Outer section, withconventional D-type ribs, is attached to lips extending outfrom front spar by flush screws

Front spar at center line is 16¾ in. deep, with triple web construction extendingout beyond inboard gun ports and double web to point beyond outboard bunports, from which point it is conventional single web I-beam. Lower skin, withribs, stringers, and inspection panels, is made up as separate subassembly andattached as unit to spar. Joggle in spar is deep enough so that landing gearwheel is in front of it when retracted.

On   the   center   of   the   stabilizer'sleading edge is a fitting attached to ayoke   which,   in   turn,   fastens   to   ascrew   jack   and   electric   motorsuspended by a ball and socket jointfrom the leading edge of the verticalfin.   This motor,  which turns up to14,000 rpm., has six trains of gearswith 533 to 1 reduction.     It  movesthe stabilizer leading edge 4.1 in. permin.,   or   over   the   full  arc  ofadjustment   in   about   20   sec.     Amagnetic   brake   is   provided   toprevent   motor   overrunning   whencurrent is cut off.

In the stabilizer, as in the leadingedge of  the vertical fin,   the upperand   lower   skins   are   crimped   andriveted   together   and   the   leadingedge screwed in place via six of thediamond­shaped nuts.   In this unit,too, rivet alignment and spacing areboth   irregular   along   the   crimpedskin.

Elevators,   like   the   rudder,generally   follow   conventionalpractice  with   a   single   spar,  metalleading   edge,   metal   ribs   with   thefamiliar   rounded   gusset   plates,metal   trailing   edge   and   fabric

covering.    Despite  the fact   that   thestabilizer   is   adjustable,   the   rightelevator   has   a   perforated   trailingedge trim tab like that on the rudder.

The   elevator   hinges   to   thestabilizer   at   three   points   and,although   all   three   fittings   aredifferent,   each   hinge   has   an   selfaligning ball bearing unit.

A   departure   from   conventionalconstruction   shows  up   in   the   190wing, for it  is built as a single unitfrom   tip   to   tip.     Thus,   if   it   isdamaged   structurally   any   placebetween   the   detachable   tips,   theentire   unit,   rather   than   say,   onepanel, must be replaced.

The integral center section of thetapering front  spar   is  a very heavymember,   for   it   takes   the weight  ofthe   two   lower   side   and   bottomengine   mounts,   fuselage   fittingattachments,   four   20­mm.   cannon,and main landing gear.  At the centerline it is a built­up triple­web I­beam16­3/4   in.   deep,   reinforced   by   aheavy   vertical   channel­shapedmember embracing, at its lower end,a forged fitting for the lower enginemount structure, a combined tubular­and­channel truss unit.  Between thecenter  line  and side engine mounts,set   24­in.   out,   are   two  vertical   hatshaped   stiffeners.     Engine   mountmembers   themselves   are  of   similarshape,   but   are   heavier   and   areriveted rather than bolted to the spar.

At   these   side  engine  mounts   thespar   is   bent   forward  14  deg.,  withthis   angle   being  maintained   64­1/2in. to the main landing gear fittings,from   which   point   it   parallels   thecenter section.  The bend permits thelanding   gear   to   retract   in   and   upahead of   the spar.    This  section ofthe   spar   has,   in   addition   to   thecannon  ports,   three   lightning   holesand three vertical angle stiffeners.

The   triple­web   constructioncontinues   beyond   the   bend   to   justoutboard of the port for the barrel ofthe   inboard   cannon.     Immediatelyoutboard of the landing gear fittings,where   the   spar   again   bends,   it   is

JL McClellan: FW-190 draft Copyright 2005 p 13 of 36

Wing ribs of FW-190 vary in construction and only six are attached to both top andbottom skins. Top detail sketch A shows rib adjacent to fuselage, with reinforcementforgings; B is outboard-most “solid” rib; C and D are typical floating ribs; E is outboard ribto which formed tips are attached with flush screws. F illustrates construction of sparfrom outboard cannon port to wingtip, showing forward-extending lips, to which leadingedge is screwed.

reinforced by a heavy riveted gussetextending   some   12   in.   beyond   theoutboard   cannon   port,   from   whichpoint   to   the   tips   the   spar   is   singleweb I­beam with 1­1/2 in. lighteningholes.     For   the   full   length   of   thisouter  portion   the   spar  has  lips   topand bottom to which th leading edgeis screwed.

The   leading   edge,   form   enginecowl outboard to the landing gear, isbuilt as one unit and is attached byscrews   to   the   spar.     The   mainmember,   just   outboard   of   the   gunport,   is   a   double,   stamped   flangedrib with cutout for the landing gearstrut.  Two feet farther out is anothercontour   rib   of   I­beam   constructionand between them a stamped flangedcontour rib.   Tip­end of this sectionalso has a stamped flanged rib withcutout   for   the   landing   gear   strut.Remainder   of   the   leading   edge   isbuilt   as   one   unit,   consisting   offormed   aluminum   sheet   reinforcedby conventional stamped flanged D­type nose ribs.

Only   five   'tween   spars   ribs   oneach   side,   besides   those   at   thewingtips,   are   attached   to   both   topand bottom skins.   Of conventionalstamped,  flanged  construction,   theyare   located   just   outboard   of   theinboard cannon; on either side of thelanding gear fittings to form a torquebox; on either side of  the outboardcannon ports; and at the outer end ofthe   reinforcing gusset   around   theseports.

The   rear   spar,   a   conventionaltapering   I­beam,   extends   from   topand   bottom   forged   fuselageattachment   fittings   to   the   tips,   andcarries both flaps and ailerons.   It isdouble   web   for   32   in.   from   thefuselage fittings, single from there tothe tips.

It would appear that the rear sparand   the   top  skin  panel   (forward   tothe front spar) are built as an integral

JL McClellan: FW-190 draft Copyright 2005 p 14 of 36

At top is shown inverted view of centralwing leading edge subassembly, withdetails of its major ribs given below.

Top skin, with its floating ribs and stringers,is made up as complete subassembly andriveted to rear spar and, finally, skin abovesplit-type flap with its ribs is attached torear of spar. Aileron brackets (shown in thedetail sketches) are also riveted to aft faceof rear spar. Note that space is left for thefew ribs fastening to both top and bottomskins; they are attached to this top skin byblind riveting.

JL McClellan: FW-190 draft Copyright 2005 p 15 of 36

Flaps are built around metal monospar andare constructed in two halves rivetedtogether at the middle hinge, with inclusionof actuating arm. This hinge – unlikeinboard and outboard hinges – is welded tospar and carries a dial with readings from 0-60 deg. Numbers show through a hole intop skin (as illustrated in top detail sketch)so that pilot has exact reading of eachflap's position at all times. Flaps areelectrically operated with their individualmotors connected through relay control boxso that neither will get more than 3 deg. Outof line with other.

This field sketch shows detail of flap fromabove, with top fabric covering removed toreveal how ribs are formed from cutoutsections of top face. Shown on trailingedge are two of ten rubber bumpers whichabsorb vibration when flap is closed upagainst top skin.

Complete details of aileron are shownbelow. From top to bottom: Unit withoutfabric covering; lower leading edge skin;unit with fittings and fabric covering inplace. At left is exploded view of inboardball-bearing mounting and at extreme rightis exploded view of outboard hinge slotribs.

JL McClellan: FW-190 draft Copyright 2005 p 16 of 36

Field sketch (right) of inboard end of aileronwith bottom fabric removed. Intercostals (but .012-in. Thick) only serve to hold fabric whichis stitched in place with continuous wirefastening poked through the slots punched inframe. These slots are in a groove so thatwire will be buried beneath fabric surface.Also clearly shown is perforated trim tab,similar to those used on rudder and elevator.

Main landing gear (below), showing howwheels are hinged from front spar. Retractinggear arms (1) and (2) are attached to electricmotor-driven drum (3) to which are attachedmechanical position indicator (4) and dash pot(5). Fairing (6) is pulled up into place whenlanding gear strikes arm (7). A steel cable (8)running from retracting gear arm in over pulleyat center line straightens arm (7) to holdfairing in open position when wheels aredown. Switch (9) between retracting geararms cuts power off when wheel s are down.When retracted, gear is secured by latchshown at bottom of detail sketch (10). Thisunit also carries switch to cut off power whenwheel is latched up. A cable attaches to lever(11) to release latch in case of power failure,when wheels go down by gravity as motor isdisconnected when power is off.

unit,   with   blind   riveting   beingnecessary   only   for   attaching   thefive top­and­bottom or “solid” ribspreviously   mentioned,     Threestamped,   flanged   contour   ribs   are

located between the “solid” ribs andsix   are   utilized   between   the   outerflap hinge and the tip rib.   All theseribs   have   cutouts   for   Z­shapedspanwise  stringers,   of   which  thereare   nine   outboard  of   the   flap,   andeleven between the “solid” ribs. Skinaft of the rear spar, above the flap, isa separate subassembly attached byten contour  ribs  riveted to  the sparweb,   with   one   continuous   stringerbetween the spar and trailing edge.

Also built as a unit is the bottomskin   panel,   which   screws   to   frontand rear spars.    One contour rib  islocated   at   the   fuselage   attachmentfittings, one between the cannon andlanding gear ports, and five betweenthe outer “solid rib and the tips.  Allthese ribs have diagonal cutouts forZ­shaped stringers similar to those inthe upper panel.

An interesting development foundon later 190 models is the additionof aluminum strips, .032­in thick and3/4­in. wide, riveted to the ribs andskin,   much   like   diagonal   bracesbetween joists in a house to preventside sway.    This  addition has beenmade   to  both   top   and  bottom skin

JL McClellan: FW-190 draft Copyright 2005 p 17 of 36

Detail field sketch showing pressure indicating marks on main landing gear fairing.Lower part of vane moves with wheel; upper part is attached to oleo cylinder. Scale isgraduated in atmospheres, 25-30 being range.Phantom view from pilot's cockpit looking

toward leading edge of wing, showinglanding gear position indicator. It is entirelymechanical, like a bayonet oil gage. Itslides through slotted ball in top wing skinand disappears when landing gear is fullyretracted.

Main landing gear retracting motor and reduction gear, a unit but 14 in. long and 7 in. india. at ring, with bolt holes where it is attached to front t spar. Motor runs at 14,000rpm., has 3.3:1 reduction from armature shaft then safety centrifugal clutch, then 53:1and 60:1 gearless reductions for over-all reduction of 10,494:1. One such unit isprovided for each wheel.

JL McClellan: FW-190 draft Copyright 2005 p 18 of 36

Phantom view showing how tail wheel is automaticallyretracted with main gear. As right wheel moves up, it tightenscable A, which goes up over pulley, inboard to right side offuselage, then aft through conduit to vertical fin diagonalmember, up over it to pull up on yoke attached to top of oleo.As left wheel moves up it tightens cable B to open slidingdoor C under cameras.

Here is phantom view of vertical fin, showing tail wheelassembly. Wheel fork is set in front end of figure-eight castingto give castering action, but oleo strut is in direct line withwheel hub. Loads of both front end of drag yoke and top ofoleo strut are taken by diagonal member. Stabilizer goesbetween horizontal ribs extending aft from front bulkhead todiagonal member.

JL McClellan: FW-190 draft Copyright 2005 p 19 of 36

These field sketches show details of tail wheelretracting gear and roller locking device. Atleft is track (with oleo and lock removed)which is riveted to aft face of diagonalmember of assembly. Oleo would extend upthrough the dust-catching fabric with bellowattached to the top. Also shown is metal tubeto prevent coil spring from injuring enclosingmaterial. Sketch at right shows gear in placeand locked in down position, and in upperright method of locking is showndiagrammatically. A is direction of load thrust,B is direction of pull by coil spring. This pullstrigger roller C down into locking position,forcing large roller D – which takes landingload thrust from top of oleo – int its downposition.

Aileron control is via tube from control stick, leading forward to bell crank attachedto front face of front spar, then outboard through idler to compensate for 5-deg.dihedral, to point directly ahead of flap operating motors. Here bell crank changesdirection back to front face of rear spar, where direction is again outboard to bellcrank attached to aileron itself.

panels,   and   appears   to   be   amodification   made   in   productionrather than in the field.

Split   type   flaps   followconventional   practice,   with   themonospar being made up of a rolledsection with beaded stiffeners.   Topskin section is cutout in the familiarrounded   gusset   pattern;   ribs   arenormal   stamped   flangedconstruction.     Top   and   bottomsections   are   riveted   together   at   theleading  edge,  and   the  whole   fabriccovered.   With a total span of 7 ft.10 in. each, the flaps are built up inhalves,   the   two   sections   beingriveted   together   adjacent   to   themiddle of three ball bearing hinges.Atop the trailing edge are ten 1/2­in.dia.   rubber   bumpers   to   absorbvibration   between   the   flap   andtrailing edge.

Inboard   and   outboard   hingefittings   are   castings   riveted   to   theflap   spar.     The   mid­fitting,   whichalso forms the flap actuating arm, isof   built   up   welded   construction.Attached   to   this   fitting   is   a   dialreading 0­60 deg., visible through ahole in the top skin panel, so that thepilot   can   get   an   exact   reading   ofeach flap position.

Electrically  driven  by  gear   trainsthrough   a   nut   to   a   screw   jackattached   to   the   motor   mounted   onthe   front   face  of   the   rear  spar,   theflaps move down 60 deg.   The twomotors   are   connected   through   arelay control box so that neither flapcan   go   more   than   3   deg.   withoutstopping   to   wait   for   the   other   tocatch up.

Fabric­covered Frise­type aileronsare   as   light   in   weigh   as   they   arereported to be on controls.  They arebuilt   around   a   channel   monosparwith   beaded   vertical   stiffeners   towhich  are   riveted  upper   and   lowertwo­layer metal  leading edge skins,the   inner   ones   having   beadedstiffeners.   Aft of the spar there are10   conventional   ribs,   with   thefamiliar   rounded   gussets,   and   10intercostals of stamped flanged lightaluminum alloy.  These light­weightintercostals are provided to contourthe fabric and allow it to be stitcheddown with wire.

Ailerons are mounted on three selfaligning ball  bearing  hinges  at   ribsNo. 1, 5, and 9.   The inboard hingeat   rib   No.   1   is   a   cast   aluminumfitting   into   the   bottom   of   whichscrews a lug and ball bearing collar,

running on a  tapered  pin assemblythrough the bracket attached to therear spar.  The screw bearing collaris split and the taper jambs it tightwhen   the   lock   nut   is   tightened.This   makes   it   possible   to   getperfect   alignment   between   thehinge,   bracket   and   wing   fairingwithout   the   necessity   of   matingparts   in   jigs.     Mid   and   outboard

fittings are cast angle brackets, withroller   bearing   collar   screwing   infrom  the  bottom and   running  on  apin   through   a  bracket   in   the   samemanner as the other hinge.   In eachcase,   curved   shims   between   thebearing   collar   and   bracket   areutilized to eliminate side play whileretaining alignment.  Balance weightwashers are fastened into the hinge

JL McClellan: FW-190 draft Copyright 2005 p 20 of 36

Phantom views showing rudder and elevator controls. Push-pull rods go direct fromrudder pedals to differential linkage located just ahead of bulkhead No. 14 in aftfuselage. From this linkage cables go inside vertical fin to ruder connecting points.Elevator controls go from stick via tube to right side of fuselage, then via push-pull rodto bulkhead No. 8, from which point two double cables lead back to differential unitlocated below stabilizer adjusting motor. Bell crank and push-pull rods lead fromdifferential to elevator horn. Both rudder and elevator differential units are shown in thedetail sketches.

JL McClellan: FW-190 draft Copyright 2005 p 21 of 36

slots   with   a   bolt   and   captured   nutriveted to each side rib of the slots.

On   the   inboard   end  of   the   rightaileron is a 19­14­in­long trim tab –adjustable   only   on   the   ground   –similar to those on the stabilizer andrudder.

Main landing gear is a single­strutoleo   shock   unit,   with   conventionaltorque scissors, attached to a forgedsteel   tapered   roller   bearing   spindleassembly.     The   front   face   of   themounting   is   flanged   to   bolt   to   thefront   spar.     Fairing   is   in   threesections;   one   attached   to   bracketsextending up from the hub, anotherbolted to the oleo strut and the thirdhinged at the center of the fuselage.A scale painted on the two fairingsattaches to the landing gear tells at aglance  if   proper   pressure   –   about1,300 psi. ­­ is being maintained inthe shock strut.

Retraction   is   electric,   with   aseparate  unit   for  each  wheel.    The

JL McClellan: FW-190 draft Copyright 2005 p 22 of 36

Indicative of lavish attention to design, andwide use of ball bearings, are details shownin these field sketches. At top is seen openand closed position of wind-up device onstraps which hold hydraulic lines on landinggear. Note ratchet locking device. Centersketches show how ball bearings used onbrackets are peined in place, then protectedby felt washers and held by simple metalclamps. All elevator hinges, for example,use this type. In many places, as shown inlower sketches, ball joints are provided. Anotched ball bearing race is pressed intoplace, then ball shaped ring is slipped in.When rotated into operating position itcannot fall out; it provides a self-aligningconnection. This type unit is used on rearspar attachments, lower engine mountattachment to front spar, on all jacks, shockabsorber connections and other pointswhere stresses might be raised by fixedfittings.

Engine mount ring is attached to engine mount at four points, loads being distributed tofour corners of fuselage and to bottom of front spar at center line. Also shown are throttlecontrol linkage – leading from left to right side of craft before going forward throughengine mount ring. Detail at lower right depicts throttle itself. Pulling lever back into rearslot kills engine; pushing forward and across quadrant gives double boost for shortperiods. Thumb switch on end of throttle handle controls propellor pitch electrically.

Here is Kommandgerat or “brain box.” Located just ahead of engine mount ring, it isconnected to throttle linkage. When pilot moves throttle lever this hydraulic-electric unitautomatically adjusts fuel flow, fuel mixture, propellor pitch setting, ignition and , atproper altitude, cuts in second stage of supercharger. It is 16-in. High, 16-in. long, and12-in. wide.

motor which turns up 14,000 rpm.,is   mounted   back   of   the   front   sparweb, with a 3.3:1 reduction from thearmature   shaft,   then   a   safetycentrifugal  clutch,   followed by  twogearless  reductions,   one   53:1   theother 60:1,  giving a   total  reductionof 10,494:1 in three steps in a unit14 in. long and, at the front end, 7in.   in diameter.    The last  reductionstage – at the front face of the sparweb – drives a 1­3/8 in. thick forgedsteel   ring   to   which   is   yoked   atapered   aluminum   alloy   I­beam   of

13­3/4   in.   length.    This   in   turn   isjointed   to   another   tapering   beaminto   the   lower   end   of   which   isscrewed a ball and socket joint thatattaches   to   the   oleo   strut.     Theforged ring turns outward to lowerthe   wheels   and   the   arms,   due   totheir toggle action, lock the landinggear  down.    When   turned   towardthe   airplane   center   line,   the   jointbetween the I­beams or toggle armsbreaks   to  pull   the oleo and wheelup and inward.

  It   is   interesting   to   not   that   in

down  position   the  oleo   struts  havenot   yet   reached   the   perpendicular,but   there   is   no   down   lock   on   thegear.     The   two   I­beams   form   astraight line when the gear is downand this straight thrust, coupled withthe  high   reduction  from the  motor,appear   to   suffice   for   gear   downlocking.  

Small metal contacts through fiberinsulation on the faces of the I­beamjoints   automatically   shut   off   themotor when the landing gear is fulldown.    On  the  rotating  member  ofthe landing gear mechanism there isa small scaled rod which projects upthrough a ball joint in the top of thewings as the gear goes down so thatthe pilot can tell the exact position ofeach wheel.

As gear retracts, the oleo strut justabove the wheel contacts a coupling(set   in  a  box­structure  mounted  onthe   front   face   of   the   front   spar)which   snaps   into   place,   locks   thegear in up position and automaticallyshuts  off   the  retracting gear motor.The   lock   is   held   closed   by   anelectrical   latch   and   releaseselectrically when the power is turnedon to lower the wheels.   Unlockingcan be done manually, however: thepilot pulls a knob (on the left side ofthe   instrument  panel)  attached   to  aflexible cable which, atop the centerof the front spar, is yoked to similarcables   leading   out   to   each   landinggear up­lock box.

The   tail   wheel   is   retractedautomatically   with   the   main   gear.At  the  joint  of  the  two I­beams onthe   right  main  wheel   is   attached   acable that runs over a pulley set justabove   the   gear   spindle,   thenceinboard   to   the   right   side   of   thefuselage – in a conduit through thecockpit  –   back  to   a   pulley  on   thefront of the diagonal “heart” memberin the fin, then up over a pulley atopit and down to a yoke set at the topof the tail wheel oleo.  Thus, and it'snot   as   Rube   Goldbergian   as   it

JL McClellan: FW-190 draft Copyright 2005 p 23 of 36

Group assembly showing all oil lines for power plant. All lines going through to fuselageare attached to permanent fittings installed in firewall. A tape at edge of fuselage carriesnumber of each connection; corresponding number is on line itself on encircling tape justbehind union nut.

Oil cooler of FW-190 is set behind armor plate in nose of engine cowling. (Also seeAVIATION for Nov. and Dec., 1942 – “Design Details of the BMW 801 Engine.”)Exploded view at left shows (left to right) armor plate, oil cooler, armor plate, andcowling.

sounds, as the main gear joint starsto move up, tension on the cable istransmitted   back   to   the   tail   wheelretracting mechanism and the wheelis   pulled   up.     A   similar   cablearrangement   is   used   to   pull   thecamera  protecting  door  open  whenthe   landing  gear   is   retracted.    Thecenter wheel fairings are held tightlyopen   by   a   cable   system   when   thelanding   gear   is   down.     They   areclosed   by   the   wheel   when   it   isretracted.

The   tail  wheel itself  is mountedin   a   steel   fork   which   fits   into   thefront   end   of   a   heavy   steel   figure­eight casting which places the centerof the yoke 6 in. ahead of the wheelcenter to permit  castering.   The tailwheel   drag   yoke   attaches   to   thediagonal empennage member and tothis figure­eight casting just ahead ofthe bottom of   the oleo strut, whichfits into the aft portion directly overthe wheel center.

At   the   top  of   the  oleo   strut   is  ayoke   containing   four   rollers;   twoload carrying larger ones set on eachside   of   the   center,   two   smallerlocking ones just aft.   These rollersrun   in   the   channel   member(previously  mentioned in discussionof the empennage) on the aft face ofthe diagonal member, and are part ofthe   yoke   to   which   the   retractingcable attaches  and to which is alsoattached   a   coil   spring   going   downand aft to the rib holding the lowerrudder   hinge.     This   spring  –   andgravity – pull the unit down.  At the

bottom   of   the   channel   the   trackleads forward,   just  enough for thelarger rollers to fit into the resulting“pocket” so that loads from the tailwheel   are   transmitted   up   throughthe   oleo   directly   against   –   andtoward the front – of the diagonalrib, thus locking the wheel in downposition.    When  tension  is put  onthe   cable   from   the   main   gear   it

starts   the   smaller   rollers   up   thechannel   and   they   in   turn   pull   thelarger  ones  out  of   the  “pocket”,   tounlock   the   gear,   and   then   up   thetrack

The   tail  wheel  moves  up 20  in.,and   rubber   pads   on   the   axle   justoutside the fork fit snug against thebottom the fork fit snug against thebottom   fuselage   skin   when   it   is

JL McClellan: FW-190 draft Copyright 2005 p 24 of 36

Complete fuel tank and line arrangement. Electric pumps are used in each tank andelectric measuring gages are also employed. Filler openings are on right side of fuselageinside quickly detachable cover plates. Forward self-sealing tank holds 61.2 U.S. gal.;aft tank holds 76.8. Tanks are separated by rear spar tie-through member.

This wiring diagram shows: (1) Electric fuelpumps in tanks; (2) battery; (3) radioantennae; (4) radio motor-generator; and(5) master compass which operates electricrepeater head on instrument panel.

JL McClellan: FW-190 draft Copyright 2005 p 25 of 36

These two detail sketches show armament arrangement on Focke-Wulf 190. At top are two 7.9-mm. machine guns with electricsynchronizing unit just below muzzles; two lines leading down go toinboard 20-mm. cannon (also shown in lower sketch) are locatedjust outside propellor arc.

retracted.  A spring loaded “V” camcenters the wheel as soon as the loadis released.

An   interesting   detail   of   the   tailwheel castering unit is this: the pivotis a hollow steel forging, welded tothe   fork   and   the   hollow   space   isutilized   as   a   grease   reservoir   forlubricating   the   swivel   surface,   thegrease   coming   out   through   a   3­in.long   slot   which   also   serves   as   thetail wheel lock.

Main landing gear tires are 700 x175   mm.   smooth   contour   and   tailwheel   tire   is   350  x  135  mm.,  alsosmooth contour.

Stick­and­rudder   controls   aregenerally the conventional push­pullrod and cable  type,  except  that   theelevator and rudder controls embodydifferential bell cranks which give ahigher   control   surface­to­stick   orrudder   ratio   near   neutral   position,thus   tending   to   smooth  out  controlaction at high speeds.

Rudder   pedals   are   stirrup   typewith heel plates, with the hydraulicbrake   cylinder   an   integral   part   sothat exerting  toe pressure energizesthe   system.     Distance   of   rudderpedals   from  the  pilot's   seat   can  beindividually   adjusted   by   turning   aknurled knob set in the push­pull rodon each side of the cockpit aft of thepedals   themselves.    There   are   also

four positions for the pedal fulcrumpoint.     Rudder   pedal   units   aresuspended   from   brackets   attachedto fuselage bulkhead No. 2.   Push­pull  rods   lead directly aft   throughthe   fuselage  up   to   the  differentialbell crank which is suspended fromthe   top   longeron   at   bulkhead   13.From   there   cables   lead   aft   insidethe  empennage  skin  and  attach  tothe rudder spar, which is 4 in. wideat the middle hinge.

The 21­1/4­in. long control stickis   mounted   in   a   cast   base   in   thefuselage   floor   center   betweenbulkheads   3   and   4.     Elevatorcontrol is via a tube leading to the

right   side   of   the   cockpit,   then   viasingle push­pull rod to just aft of thepilot's  seat   to   a   bell   crank   fromwhich two double 1/4­in. cables leadback   to   a   differential   bell   crankmounted   in   bulkhead   14,   whereanother   short   single   push­pull   rodleads  back   to   a  bell   crank  directlyunder the stabilizer leading edge anda   vertical   pus­pull   rod   attached   tothe elevator horn on the center of theelevator spar.

Aileron control  consists  of a tuberunning   forward   from   the   controlstick base and actuating a  push­pullrod and bell  crank set  on the frontface of the front spar center.   From

JL McClellan: FW-190 draft Copyright 2005 p 26 of 36

Use of FW-190 as fighter-bomber brought installation of this electrically-operated rackbeneath fuselage center for carrying one 500-lb. bomb. Note long light aluminum fairingextending aft from bomb rack itself.

Bottom view of control switch junction box located at left of pilot'sseat. Note how all lines leading out at right have been grouped

into seven quick-disconnect plugs, each one of which is ofdifferent shape so that wrong connections cannot be made.

here push­pull rods extend outboardthrough   an   idler   hinge   to   changedirection corresponding to the 5­deg.dihedral  to a point  directly in frontof the  flap operating  motor where abellcrank changes direction aft to thefront   face   of   the   rear   spar.     Hereanother  bellcrank changes  directionalong   the   rear   spar   to   the  inboardend of the aileron where still anotherbell crank and push­pull rod attachesto the aileron horn.   All hinges andconnections   are   mounted   on   selfaligning   ball   bearings.     The   bellcranks   are   all   mounted   on  widelyspaced ball bearings so that there islittle   lost   motion   even   when   thebearings get loose.

The   German's   extensive   use   ofball  bearings  is particularly evidentin the Focke­Wulf 190 controls, forfinely   built   ball   bearing   units   areused   not   only   throughout   thecomplicated differential bell cranks,but   wherever   moving   parts   arejoined   and   in   all   the   electricreduction gears and motors.

Aileron stick gearing is 3.2 deg. tothe inch; elevator stick gearing is 4.1deg.   to   the   inch;   and   rudder  pedalgearing is 6 deg. to the inch.

Outstanding control on the craft isthe   throttle   quadrant   and   itsKommandgerat,   or   “brain   box”.Only one lever, mounted on the leftside of the cockpit is used.  From it apush­pull   rod   leads   forward   anddown  to a  bell  crank attached  to arod  which   runs   across   to   the   rightside of the fuselage to a second bellcrank   and   push­pull   rod   going   upand forward through the firewall toanother push­pull rod­bell crank andthe   tube   unit   which   takes   themovement   to   the   left   again   a   fewinches (to a point inside the enginemount  ring) and another bell crank

and  push­pull   rod  which  connectswith the “brain box”, a finely builtcomplicated unit measuring 16 x 16x 12 in.

As   the  pilot  moves   the  throttle,and   the   movement   is   transmittedthrough  the  bell  cranks  and  push­pull   rods,   the   “brain   box”automatically makes compensatingadjustments  for   fuel   flow,   fuelmixture,   propeller   pitch   setting,ignition,  and  cuts   in   second  stagesupercharger at proper altitude.   If,however, the pilot desires to makea   propeller   pitch   change   withoutchanging other settings, he may doso   “manually”   by   pushing   arocking   lever   switch   set   in   thethrottle.     Further   details   of   the“brain box”  cannot  be  revealed atthis time.

Another interesting detail  of theFocke­Wulf's  design  is   the enginemount   ring,   a   hollow   tubularstructure  which  also serves  as   thereservoir   for   the   hydraulic   fluidused   in   the   “brain   box”.     TheBMW­801   engine   itself   wasdiscussed   in   detail   in  AVIATIONfor Nov. and Dec., 1942, and thusis not included in this discussion ofthe craft.

All   the   190's   fuel   supply   iscarried   in   two   self­sealing   tankssuspended   by   fabric   straps   in   thelower fore fuselage section with thefore   tank,   between   spars,   holding61.2   U.   S.   gal.   and   the   aft   tankhaving a capacity of 76.8 U. S. gal.

Both   tanks   are   filled   from   theright side of the fuselage, the fillerpipe   cover   plates   being   quicklydetachable flush units.    Each tankcontains   a   sealed   electric   pump.Gages   are   all   electric;   the   fuelwarning   light   and  pump   indicatorlights  being  arranged vertically   in

the   center   of   the   lower   instrumentpanel; the fuel supply gages for eachtank just to their right; and selectorgage   to   their   right.     Manually­operated   fuel   selector   valve,however,   is   on   the   left   of   the   topinstrument panel.   Lines from tanksto engine go through the firewall.

Majority   of   the   highly   complexelectric   system   components   arelocated   to   the   right   of   the   plane'scenterline.     On   this   side,   forexample,   are   the   distributor,   twogenerators,   battery   and   mainjunction box with its ground supplyconnecting   plug,   this   latter   unitbeing   located   in   the   aft   fuselagebetween bulkheads 8 and 9.

Wires leading from the removabletop instrument panel – containing sixflight  instruments – go out   throughthree  quick disconnect plugs  to  theright for power or, as in the case ofthe   dash   repeater   compass,   to   themaster compass in the aft section.

Two   control  switch  junctionboxes are required, one on each sideof   the   cockpit.     That   on   the   leftcontains   the   throttle   quadrant,propeller   pitch   control,  ignitionswitch,   flap   and   landing   gearindicator   lights,   starter   mixturecontrol,   stabilizer   trim   switch   andindicator,   flap   and   landing   gearswitches,   primer   pump   switch   andradio.  It is built as a removable unit,and  wires  going  out   from  its   frontend   are   led   through   three   quick­disconnect plugs, those out the backend to the main junction box throughfive lines in two similar plugs.

The   right­hand   panel   containsforward   and   rear   circuit   breakers,external   battery   indicator,   fuelbooster   pump   switches   and   enginestarter.  Four quick­disconnect plugsare installed in the front end; even inthe rear leading to the main junctionbox.

JL McClellan: FW-190 draft Copyright 2005 p 27 of 36

Quickly detachable flight instrument panel with, left to right, altimeter, bank and turn andairspeed indicators, tachometer, compass and manifold pressure gage. Note use ofquick-disconnect plugs.

The   electric   system   is   furthercomplicated by the fact that four ofthe   six   guns   –   the   two   7.9   mm.machine  guns  and  the   two  inboard20­mm.   cannon   –   must   besynchronized   to   fire   through   thepropeller.    The  synchronizing unitsare   mounted   behind   the   engine.Electric leads from them go to each

gun.Wherever   possible,   wires   are

grouped   when   leading   from   onepart   of   the   airplane   to   anotherthrough   generous   use   of   quick­disconnect  plugs.    In general,   too,the   Focke­Wulf   190   follows   theGerman   practice   of   having   wiresleading from one part of the plane

to another   in   the  same location,  sothat   mechanics   working   on   oneaircraft   will   not   have   to   becomecompletely   indoctrinated   beforebeing  assigned   to  another  make  ortype.

JL McClellan: FW-190 draft Copyright 2005 p 28 of 36

Phantom view illustrates general arrangement of wiring in fuselage, extending from propellorpitch control and distributor at extreme left to stabilizer adjusting motor in vertical fin. Notehow all wires are led to right side of fuselage, those from junction box at pilot's left reachingthat side through conduit in back of pilot's seat before entering main junction box on right sideof aft fuselage section. Outside battery connection is in this box with connecting plug flushwith fuselage skin.

HE   FOCKE­WULF   190   hasindependently   operated   mainlanding wheels, each of which

is carried by an arm pivoted at rightangles to, and mounted on, the frontmain   spar.     It   is   held   in   landingposition   by   a   hinged   link   securingthe wheel  by a   toggle action whendown.

T Upper half of the hinged link issecured to a rotatable member by afork and pin joint, and the axis ofthis   member   is   approximatelyparallel to the wheel arm pivot.

Rotatable  member   is   the   frontend of  the electric  retracting gear.Each   wheel   retracting   unit   is   acomplete assembly held to the front

face  of   the  main   spar  by   ten boltswith  castellated  nuts.     Removal  ofthe connecting pin and the ten nutsand   breaking   of   two   electricalconnection   plugs   is   all   that   isnecessary  to   remove  this  unit   fromthe fuselage.

Outstanding   features   of   theretractor   are   its   compactness,   lightweight,   and   unusual   method   ofgetting a very high gear reduction ina small  space.    The unit,   includingthe   motor,   measures   13­1/2   in.   inlength   and   8­5/8   in.   over   themounting   flange.     There   are   onlythree   reductions  needed   to  give   anover­all   of   10,500   to   1   fromarmature shaft  to the rotating head.

JL McClellan: FW-190 draft Copyright 2005 p 29 of 36

Design and Operation

Of FW-190 Gear Retracting Unit

By CHESTER S. RICKER, Detroit Editor, "Aviation"

Unusually compact–—measuring only 8-5/8 x 13-1/2 in.—it has over-all reduction of 10,500 to 1. And specialdesign eliminates gear cutting so that production canbe accomplished with grinder, lathe, and drill press.

Cross-sectional assembly drawing of Focke-Wulf 190 landingwheel retracting gear. Note that ball bearings are used onintermediate reduction eccentric and roller bearings for finalreduction. Details of centrifugal clutch between electricmotor and reduction gearing are also shown.

With a 10,000­rpm. 27v. motor thismeans a full rotation of the operatinghead   in  one  minute.    Since  only aquarter revolution is enough to raisethe landing wheel,  retraction time isabout 15 to 20 sec.

There   is   a   3.3­to­1   reduction   inthe   motor   head   so   the   shaftextending from the motor runs about3.200 rpm.  On this are mounted twocast iron shoes, driven by a cross pinand  held   in  place  by   a   continuouscoiled spring band.  The latter is stiffenough to hod the shoes in place andto   resist   centrifugal   force   so   as   toallow   the   motor   to   attainconsiderable speed before the shoesengage a surrounding drum of steel.This   gives   an   automatic   clutcheffect.

The   drum   is  attached  to   theintermediate   reduction   mechanism.Giving a final over­all  reduction of3,180 to 1, the last two mechanismsare compacted into a space of 4 in.axially  and  of  7­1/2   in.  dia.    Bothreductions are also coaxial with theunit,  and the casing head rotates inthe  final  reduction.    Apparently nostandard   spur   gear   train   of   equalratio   could   be   crowded   into   thissmall space.

The last two reductions, while ofthe same  type,  are attained withoutgears of the tooth type, instead beingenabled   through   shallow   scallopsground in the edge of hardened steeldisks   and   engaging   hardened   steelsleeves that float on pins fixed in thesurrounding housing.

Principle   employed   is   similar   tothat   sometimes   used   with   toothedgears where an internal gear mesheswith a spur gear having one or moreteeth less than the internal gear, thespur   gear   being   oscillated   by   aneccentric at its center, but preventedfrom rotation by a pin.   The axis ofthe  eccentric  shaft  must  be  coaxialwith the internal gear.  Then fro eachrotation   of   the   eccentric   shaft   theinternal  gear  will   be  advanced  onetooth by the spur gear.   This designwas used at one time for operatingvariable pitch propellers.

Only   difference   between   theabove gear reduction and that of theFW­190 design is   that   in   the   latterthe   gear   teeth   are   eliminated   fromboth members.   The aforementionedsemi­circular scallops ground in theedge   of   the  disks   replace   the   spurgears, and the internal gear teeth arereplaced  by   the  pins  on  which   the

hardened steel sleeves are mounted.In each reduction two disks  are

used   so   as   to   give   a   continuousdrive at  all   times.    The eccentricsare   also   arranged   diametricallyopposite one another so as to keepthe   two   disks   balanced   whenrunning.

Another   unusual   feature   of   thedesign   is   the operation  giving   thetwo   reductions.     For   theintermediate one, the outer memberis   secured   so   that   the   oscillatingdisks   rotate   slowly,   making   one

complete   rotation   every   53oscillations.

Eight pins engage these oscillatingdisks   and   thus   rotate   with   them.These pins are mounted in a flangeon the end of the eccentric shaft togive the final reduction.   The latterreduction mechanism is mounted onthe   flanged   forging  which  supportsthe   entire  reduction  gear   and   isbolted   to   the   front  main   spar.    Onthis member are eight heavy sleevedpins   that   pass   through   the  finalreduction­oscillating   disks   and

JL McClellan: FW-190 draft Copyright 2005 p 30 of 36

Parts of Focke-Wulf 190 retracting gear. At left is electric motor with half of centrifugalclutch and its retaining spring removed. Next is housing containing intermediatereduction mechanism. Clutch drum is clearly shown on this unit. In foreground ismounting plate with its stationary pins, which carry hardened steel sleeves, two of whichhave been removed. At right is final reduction head with operating fork. Retainer platehides oscillating members. This plate, mounted on stationary pins, carries a ball bearingto support outer end of eccentric shaft. (AAF photo)

Reduction mechanism of retracting gear. At left are oscillating disks of intermediatereduction; center, final reduction oscillating disks, with flanged eccentric shaft carryingpins which engage intermediate reduction disks; right, pin and sleeve internal gearmechanism that is attached to wheel lifting arm. (AAF photo)

prevent   them   from   rotating.Therefore   they   force   the   internalgear  or   retracting  gear  head  whichencloses them to rotate one turn forevery 60 oscillations of the disks.

The head is the member which ispinned to the arm that lifts or lowersthe landing gear.  To take the liftingload,  the outside member is carriedon   two   roller   bearings   located   oneach side  of   the  internal  gear pins.These bearings have 64 rollers,   1/4

x 1/4 in.Outer   member   is   held   in   place

endwise by a plate secured by eightcap screws engaging the pins usedin attaining the final gear reduction.A cover plate attached to the frontof   the   rotating   outer   memberencloses the entire mechanism.

Design   of   the   mechanismeliminates gear cutting by enablingprocessing   of   the   parts   with   agrinder, lathe, and drillpress.

JL McClellan: FW-190 draft Copyright 2005 p 31 of 36

JL McClellan: FW-190 draft Copyright 2005 p 32 of 36

DIAGRAMMATIC COCKPIT LAYOUT

ENLARGED

THE   FW­190A3,   newest   and“hottest” German fighter plane, is anextremely good craft, but it does notlive up to the claims made for it byNazi   officialdom.   In   fact,   bothBritish and American planes can, ashas   been   proven   in   combat,   morethan hold their own against it.

Nevertheless,   many   points   ofinterest   and   value   to   the   designer,the   production   man   and   themaintenance   chief   have   beenbrought out by inspection and flighttests   of   British   engineers,   whosereports   have   recently   been   madeavailable. This close study was madepossible  when  a  German  pilot  wasforced  down   in   England   andcaptured before he could destroy theplane.

Created by Kurt Tank, builder ofthe Focke­Wulf  Condor, long rangefour­engine   bomber   and   the   FW­189,   short   range   reconnaissance

plane,   the   190   was   designed   forquantity   production   and   extensivesubcontracting.

It   is  a   low­wing,   full   cantilevermonoplane with a 34­ft. 5­in. spanand   length   of   29   ft.   4   in.   Wingconstruction   is   of   conventionaltwo­spar type, with the wing beingbuilt   in  one  piece.  While   this  haseffected   a   material   saving   inweight,   it   has   made   maintenancemore difficult.  Wing trim tabs aresmall   perforated   plates   on   theailerons and are adjustable only onthe ground.

Split   flaps   are   electricallycontrolled by push buttons to threepositions: closed; down 10 deg. fortakeoff,   and   down   60   deg.   forlanding.

Unlike   modern   Allied   craftwhich   have   elevator   and   ruddertrim tabs, the Focke­Wulf stabilizeris   adjustable,   making   it   morevulnerable   to   concentrated   firepower.

The fuselage is also built in onepiece and is very well streamlined,narrowing vertically practically allthe way back from the engine. The

entire cockpit cover, including ratherlong fairing, slides back but it cannotbe opened in flight. Emergency exitin   flight  can  only  be  accomplishedby pushing a button which detonatesa   cartridge   which   breaks   thesupporting  member,   allowing   theentire cover to be blown away.

All  the   fuel   is  carried  in   thefuselage   in   two   self­sealing   tanks,one  of  64  gal.   immediately  behindthe   pilot's   seat,   another   of   51   gal.under the seat.

The   electrically   operated   fullretracting landing gear has a tread of12 ft., apparently made necessary bythe   high   landing   speed  —approximately 110 mph. It is also setwell   forward   to   permit   heavybraking   without   nosing   over.   Aninteresting   feature   of   the   landinggear   is   the   tail   wheel   retraction,   acable   attached   to   one   of   the   frontwheels automatically pulling the tailwheel up into its well.

Power PlantPower   is   supplied   by   a   BMW

801D  14­cylinder   radial,   air­cooledengine   developing   slightly   under1,600 hp.  at 2,700 rpm. for takeoffand just over 1,750 hp. at 3,000 rpm.at  18,000   ft.  Cowling   is   extremelyclose­set, the diameter being but 52in.,   necessitating   installation   of   alarge   fan   set   just   behind   thepropeller. The oil radiator is set justinside   the   nose   of   the   cowling,cooling being effected by a reverseflow   through   the   radiator   and   outthrough   a   narrow   opening   at   itsfront.  Extensive  baffling  distributesthe air to all   the cylinders with  theheated   air   bing   exhausted   throughlong   louvres   cut   in   the   cowlingsides. Unlike the BMW 801A, thereare no facilities for sliding the nosering  or  cowling   at   the  back  of   the

JL McClellan: FW-190 draft Copyright 2005 p 33 of 36

The right side of the inward retractinglanding gear of the Focke-Wulf 190 isshown at left. The locking mechanism at “A”is electrically operated, as is the retractinggear itself, which pivots the rod “B” in andup to pull the gear into the well. Travel ofthe rod tightens the cable “C” which retractsthe tail wheel, thus eliminating the need fora separate power unit for that part of thelanding gear. “D” is the line from the cockpitto the hydrayulic brake. Not that the fairing“E” comes only a little way below the hub ofthe wheel; another piece on the fuselagemoves in behind the retracting wheel tocomplete the underclosure. )For otherdetails of the Focke-Wulf 190 see Aviation,October, 1942, p233.)

JL McClellan: FW-190 draft Copyright 2005 p 34 of 36

Structural details of Focke-Wulf 190A3 revealed in this cut­away illustration, re­drawn from The Aeroplane, include following: Aileron hingebracket and open­end shroud are at “A.” with aileron tab—adjustable only on ground—at “B” and aileron control at “C.” “D” is one of two 20­mm.cannon firing outside propeller arc. Landing gear radius rod break hinge is at “E,” operating tail wheel retracting cable “F.” Landing gear retractingpower is delivered by electric motor “G,” with position being checked by indidcator “H.” “J” is on of two 20­mm. cannon firing through propellerarc. “K” is armor=plated couling enclosing oil cooler. Two 7.9 machine guns are at “N.” Throttle is at “O,” while “P” is 14­mm. armor plate toprotect pilot from tear. Adjusting mechanism for pilot's seat is at “Q.” Fuel tanks of 64 and 51 gal. are sown at “R” and the plane's battery is at “S.”Tail wheel retracting cable is at “T” and compass at “U.” Tail wheel lock is at “V” and shock leg guide and block are at “W.” “X” is tail incidencemotor and “Y” shows elevator and rudder tabs. (Also see Aviation, Oct 1942, page 233, and Nov., page 157.)

motor to adjust the flow of air.The   electrically  operated,   three­

blade,   constant   speed   VDMpropeller is of rather small diameter— due   to   landing  gear   restrictions— but the blades are of long chordalmost all the way to the tips.

Armament and Armor

Armament   consists   of   two   7.92mm. machine guns mounted atop thefuselage firing through the propeller;two   20   mm.   Mauser   cannonmounted   in   the   wings,   also   firingthrough   the   propeller;   and   two   20mm  Oerliken  cannon   also   in   thewing but firing outside the propellerarc. Despite the fact that four of thesix   guns   fire   through   th   propeller,the   fire   power   totals   about   3,500rounds per minute — 1,200 for   themachine guns; 1,400 rounds for theinboard   cannon   and,   strangelyenough,   but   900   for   the   outercannon.   Effectiveness   of   the   firepower   is   curtailed  due   to   the  shortrange of the machine guns and lowmuzzle velocity of the Oerlikens.

Provision   is   also   made   forattachment   of   a   550­lb.   bombbeneath   th   fuselage   for   very   shortrange operations.

The plane is well  armored.  A 5­mm. plate protects the oil radiator inthe   nose   ring   cowling   and   the   aftportion for the cowling is fitted with3­mm. plate. Cockpit windshield has2¼­in. thick bullet­proof glass and abulkhead behind the pilot's seat is 8­

JL McClellan: FW-190 draft Copyright 2005 p 35 of 36

FOCKE-WULF

FW-190A3 International News Photo                    

RIGHT: Flight tests of this Focke-Wulf190A3, captured intact by the British, revealmany unusual design and constructionfeatures but show that the “pride of theLuftwaffe” leaves much to be desired. Notethe wide tread of the landing gear—12 ft.—

made necessary by a landing speed of 110mph. LEFT: This close-up of the Focke-Wulf 190 shows the extremely closecowling around the BMW 80iD 14-cylinderengine, the first radial air-cooled engine tobe mounted in a German fighter. Note the

cooling louvres through which cylinder-cooling air and exhaust are dissipated. Notealso the 20-mm. cannon, set in the leadingedge of the wing; fires through the propellerarc.

Cut-away and diagrammatic views of the BMW 801A engine, forerunner of the Model D installed in theFocke-Wulf 190, the main difference being that on the D the nose ring and motor cooling air regulatorrings are not adjustable. These illustrations, redrawn from “The Aewroplane”, show the large cooling faninstalled just behind the propeller and point up the reverse flow of air.

mm. thick. A 14­mm.­thick panel isfitted behind the pilot's head in themovable cockpit cover.

Performance Not OutstandingPerformance   range  of   the  190   is

limited,   its   most   effective  altitudesbeing   above   15,000   ft.   and   below25,000 ft. Its top speed at 4,500 ft.,for   example   is   but   326   mph.compared with 375 at  18,000 ft.   Itcan,   however,   do   390   mph.   at20,000 ft. for one minute by meansof a booster. Reports from Americanbomber   crews   indicate   the   Focke­Wulf does not perform well near itsreported service ceiling of 37,000 ft.British fighters are understood to beable to turn inside the 190, even atits most efficient altitudes.

Specifications   and   performancedata are as follows:

Wing span.............................. 34 ft. 5 in.Length......................................29 ft. 4 in.Wing area.................................203 sq. ft.Wing loading......................42.2 lb./sq. ft.Power loading..........................5.3 lb./hp.Gross weight..............................8,580 lb.Weight empty.............................6,240 lb.Maximum speed (18,000 ft.).....375 mph.Landing speed...........................110 mph.

JL McClellan: FW-190 draft Copyright 2005 p 36 of 36