Curtiss P-36 P-40 series drawings
H81-A2 Modeling Note
A long-awaited new tool 1/48 P-40B kit was released from Airfix. I'd built it as AVG Flying Tigers Hawk H81-A2 flown by Charles Older.
Prior to the construction, I made drawings of P-36 and P-40 Series. When I made my drawings, I used a set of Curtiss's factory drawings and the Structural Repair Instructions manual. I carefully read factory drawings and manual, checked photos of actual aircfart, then I translated them into my drawings.
As for P-40 series - as well as other aircraft for example Wildcat -, total lengths described in existing reference books are not reliable. See the list below. Even the official EMI manual made a mistake.
Total Length (inches)
D&S : Details & Scales, WA : Walk Around, IA(1) : In Action 1026, IA(2) : In Action 1205, EMI : Erection And Maintenance Instructions, FD : Estimation by Factory Drawings from AirCorps Library
(*) : P-40K
Lengths in the column FD of the table are based on factory drawings, and I believe these lengths are the nearest to the truth. Well, I'd explain the reason. The most reliable length is the short body model of P-40D/E/K. Each length written in general three view drawings, cowl assembly drawing, fuselage assembly drawing of factory drawings are equivalent. Values are 118-3/8" from the firewall (sta 0) to the tip of the spinner, 262-11/32" from the firewall to the rudder rear end, totaling 380-23/32" = 380.72" = 9,670 mm. The short body K model is the same as the D/E model.
It is certain that M/N model of long body Warhawk is just 20" longer than the short body model judging from the fuselage assembly drawing (the station value of the ladder hinge). Thus the total length is 400-27/32". However,the general three view of factory drawings made a mistake as total length 399-27/32". The individual lengths in this figure are correct but the total sum are not match. And I guess that the EMI manual quoted from this general drawings.
Next, as for Merlin model F/L, general three view are not included in the factory drawing. However, there are cowl assembly drawings which clearly shows that the cowl of F/L model is 1/4 "shorter than the Allison model D/E. The total length after spinner and fire wall are the same. Thus, the total length of Merlin model should be 0.25" shorter than Allison model.
Subsequently, P-36 (or H-75, both are the same). There is the general three rview in the factory drawings, and the total length including the spinner is described. However, it is slightly different when superimposed with the side view photo of the actual aircraft.I guess the spinner may be the reason of this diference. The rear fuselage after the fire wall is confirmed to be the same length as P-40D/E by the fuselage structure drawings. Thus the rear fuselage of P-40B is also the same as P-40D/E.
Finally, the total length of P-40B. Actually, factory drawings from "AirCorps Library.com" don't include any B/C model drawings. But according to the factory drawings of B model nose from other source,the rear end of the spinner station is -92-13/16". The length of the spinner can be calculated from side view photos. Then the station of the spinner tip is estimated -119.0". The fuselage length after the fire wall is 262-11/32" = 262.34". Thus, the total length is estimated 381.3" (rounded to significant figures). In fact, the value in "D&S" and "In Action" are around 381".
I will try to overlap with actual photographs. The photo is from airliners.net. Some portions don't mutch when you look closely. Well, I guess some of them are individual differences. The windscreen of this aircraft is more upright. It might be restoration mistake. (Note that the overlaid drawings are not the latest version.)
B and E side view are overlaped. This kind of comparion is unique to the WEB site, isn't it? Looking at individually, B model seems to be somewhat short because of the deep fuselage, but you can see that it is an illusion of the eye. Also, there are many common portions. The rear fuselage lower half and the main wing framework are the same shape from P-36 to P-40N. (Note that drawings are not the latest version.)
I think that reproducibility of the cross section shape is highly important in modeling.
The front view was checked with side, top and bottom view drawings.
The basic structure of the fuselage and the wing is the same as P-40B. P-36 is used in the USAF. The export version is named differently, and it is confusing because there are two variant of P&W Twin Wasp engine and Wright Cyclone. So I tried to sort out as below.
P&W Twin Wasp R-1830 valiant
P-36A fuselage guns 0.50x1 0.30x1, no wing gun, 178 production
P-36C wing guns 0.30x2 wad added 32 production
P-36G wing guns was changed to 0.30x4. renamed from H75A-8 30 production
H75A-2 fuselage guns 7.5mmx2, wing guns 7.5mmx2, originally orderd by France, obtained by the RAF when France fell and named Mohawk II 100 production
H75A-3 fuselage guns 7.5mmx2, wing guns 7.5mmx4, originally orderd by France, obtained by the RAF when France fell and named Mohawk III 135 production
H75A-6 fuselage guns 7.5mmx2, wing guns 7.5mmx4, deliverde to Norway, Thirteen captured by the Germans who provided eight to Finland 24 production
Wright Cyclone R-1820 valiant
H75A-1 fuselage guns 7.5mmx2, wing guns 7.5mmx2, originally orderd by France, obtained by the RAF when France fell and named Mohawk I 100 production
H75A-4 fuselage guns 7.5mmx2, wing guns 7.5mmx4, originally orderd by France, obtained by the RAF when France fell and named Mohawk IV 284 production
H75A-7 fuselage guns 7.5mmx2, wing guns 7.5mmx4, orderd by Holland, but Holland fell before delivery, provided to the Dutch Indies 20 production
H75A-9 fuselage guns 7.5mmx2, wing guns 7.5mmx4, diverted to RAF as Mohawk IV, then transferred to India 10 production
* quoted from D&S
The P-36A which was first deployed on the USAF has 0.50 (starboard) and 0.30 (port) fuselage guns. There is no wing machine gun. This model was encountered Pearl Harbor attack. Only one aircraft of P-36B was producted. The following P-36C added 0.30x2 guns to the wing. P-36A and some C model had no exhaust fairing. Some C model has the fairing. It is unknown whether it is retrofitted, or removed, or introduced at the middle production of C. The spinner is step type. P-36G was ordered by Norway as H75A-8, and taken over to the US by the surrender of Norway and sent to the training unit. There are slits on the fuselage machine gun panel which is a feature of export model H75A.
Export model is different from USAF model such as fuselage gun slits, pitot tube, antenna, gunsight and so on. France was ordered H75A-1 to -4. H75A-1 and -4 equipped Wright Cyclone, -2 and -3 equipped P&W Twin Wasps. Each model had different wing guns. H75A-2 had no fuselage gun slits. Due to the surrender of France, part of them was handed over the RAF and was named Mohawk. The spinner of them was mostly step type. Some late model has shell shape spinner. Part of H75A-6 was sent to Finland. Cyclone engine model was also seen in the Finnish air force but its history is unknown.
The engine cowl top view shape was drawn as to take the necessary clearance from Twin Wasp R-1830 engine (diameter 1,220 mm). When it was drawn as the coordinate table of the factory drawing, the side line from the engine cowl to firewall did not connect smoothly.
The horizontal stabilizer rear end line is different from P-40. The hinge position is the same, the elevator of P-36 is extended forward. There are two curved stays that support the hinge tube of the elevator.
Six exhaust holes of Allison engine are not equally spaced. The space between the third and fourth is a little wide. If you carefuly look at photos of actual aircraft, you can notice the exhaust pipe interval is different. It is not only B model, but also D and subsequent model. On the other hand, Merlin engine is equal intervals of 6-1/16 @ 5. Well, it is about 0.01" in 1/48 scale.
Port Aileron tab of the RAF Tomahawk including Flying Tigers's H81A-2 is fixed type. On the other hand, the USAF model is movable. In the late production of C model, the tail gear legs is longer, and the rear end is cut off.
Next drawings are Cyclone engine models. But there was not enough data to make the accurate drawing. Although there is a reasonable good aerial photo showing side profile, there is no good photo of top view, details (especially the lower side). So my drawings are close to imaginary figures. There are many unknown parts on the underside. So I didn't make bottom view drawing to prevent from misunderstanding.
Perspective errors of side profile aerial photo are corrected, then it was traced. Thus I think the outline of side view drawings is and the outline of the side view adequately accurate.
The maximum diameter of the engine is in front of the cylinder and the rear half is narrow.
The diameter of Cyclone R-1820 engine is 1,378mm. There are spaces of air ducts at the top and bottom. The machine gun should pass between the cylinders.
It is compared with Twin Wasp P-36 in the side view. The total length due to engine differences is not so different as Wildcat.
I guess that the accessory cowl must be wider than P-36.
I'd show side view photo which was errcorrected perspective error. Sources are reference -39. The step of the silhouette is not the step of the fuselage but the gear fairing. Don't make a quick judgment. I'd also try to overlap with FM-2.
Expansion of front view. Bulletproof glass fits into a metal frame. The metal fixture is omitted in this drawing.
There is not enough material to make the correct drawing. So these drawings of the fixed gear are almost the imaginary picture. There is a reasonable good photo for the side view of the gear fairing. But, there is no picture from the front. So, the front shape and the location of the gear fairing are not so accurate but imaginative.
Anyway, I list up fixed gear Hawks below.
H75M fuselage 0.50x2 wing 0.30x4 ordered by China 30 production
H75N fuselage.50x2 wing 0.30x2 ordered by Thailand production number unknown, some aircraft mounted 23mm gun under the wing
H75O fuselage.50x2 wing 0.30x2 ordered by Argentina 29 production, additional 20 built in Argentina
H75H, Q are both only 2 were producted. H has different shape gear fairing, curved windshield. Some references describe that H75Q has retractable gear.
Black lines are fixed gear model, red lines are a retractable Cyclone model, grey is a Cyclone R-1820 engine of fix gear model.
The shape of the windscreen composed of flat glasses is determined as follows. First of all, I considered a triangle (light blue) with extending the front, back, and bottom sides of the side window. The angle of inclination of the front window is the same angle as the curved glass type. It can be seen from the photo of the actual aircraft. Then I confirmed with a supplementary line of 45° so that three vertices of the triangle do not contradict each other in each drawing. Since the shape of the windscreen rear frame is the same as the slide hood, the two points of the triangle are fixed, and forward point is moved and searched where the shape of the front window looks like photo of actual aircraft. The result is shown below. It should not be "drawings which can not be built". Since the side window is narrowing forward, the top view shape of the lower fairing is also different from other models. The fixed gear type might be planned knockdown production and easy to manufacture.
First of all, I review these models. There is almost no difference between F and L model. F-1 has a short tail, F-5 and subsequent models have a long tail. L model is a lightweight variation, the external differences from the long tailed F are that machine guns are reduced four and small windows are attached to the port side of the windscreen. However, there are various parts in internal details, and there are also uncertainties as to the timing of introduction. So you had better to confirm in actual aircraft photos when you build your model. My drawings show early F model as the starboard side and late L model as port.
P-40N is a lightweight model like P-40L. It is named Kitty Hawk IV in the RAF. N-1 has the same canopy as M, has four guns and is reduced the inner weight. From N-5, the canopy and the seat are changed, the tire is reduced from 30 "to 27", guns are returned to six (according to D&S, it's from N-15, but 6 guns can be seen on N-5 in original ww2 photos, but there is possibility of retrofit). The lower side navigation light is changed to three color lights.
The wing and fin is basically the same as F/L. The top view shape of the engine cowl is basically the same. However, the bottom view shape of the radiator cowl and panel lines are different from F/L. There are many unclear points as for details of the lower surface.
The port side view is the early production of K model(the late production of K has the long tail), the starboard is the early production of E model.
|1||Erection And Maintenance Instruction P-40E/K/M/N model||-||-|
|2||The World Famous Airplane of the World No.39 P-40 Warhawk (New Eddition)||-||Bunrin-Do|
|3||The World Famous Airplane of the World P-40 Warhawk (Old Eddition)||-||Bunrin-Do|
|4||Curtiss P-40 In Action aircraft no.26||0-89747-025-7||Squadron/Signal Publications|
|5||P-40 Warhawk In Action aircraft no.205||0-89747-537-2||Squadron/Signal Publications|
|6||Walk Around P-40 Warhawk Walk Around Number 8||0-89747-361-2||Squadron/Signal Publications|
|7||D&S Vol.61 P-40 WARHAWK PART 1 Y1P-36 through P-40C||1-888974-14-1||Squadron/Signal Publications|
|8||D&S Vol.62 P-40 WARHAWK PART 2 P-40D through XP-40Q||1-888974-15-X||Squadron/Signal Publications|
|9||P-40 Warhawk In Color Photos from World War II||0-87938-928-1||Motorbooks International|
|10||Eagle Files 4 Tigers Over China The Aircraft of the A.V.G.||0-966076-7-4||Eagle Editions|
|11||Flying Tigers American Volunteer Group||3-912749-03-04||DTU|
|12||Miniatury Lotnicze 22 112 Sqn "Shark Squadron" 1942-1945||83-89088-75-4||Kagero Studio|
|13||Miniatury Lotnicze 28 AVG "Flying Tigers" 1941-1943||83-89088-28-2||Kagero Studio|
|14||Monografie 36 Curtiss P-40 vol.1||978-83-60445-27-3||Kagero Studio|
|15||Monografie Lotnicze 61 Curtiss P-36 Hawk cz.1||83-7237-036-2||AJ-Press|
|16||Monografie Lotnicze 62 Curtiss P-36 Hawk cz.2||83-7237-037-0||AJ-Press|
|17||Monografie Lotnicze 63 Curtiss P-36 Hawk cz.3||83-7237-038-9||AJ-Press|
|18||Monografie Lotnicze 64 Curtiss P-40 cz.1||83-7237-039-7||AJ-Press|
|19||Monografie Lotnicze 65 Curtiss P-40 cz.2||83-7237-040-0||AJ-Press|
|20||Monografie Lotnicze 66 Curtiss P-40 cz.3||83-7237-041-9||AJ-Press|
|21||Aircraft of the Aces 35 P-40 Warhawk Aces of the CBI||1-84176-079-X||Osprey Publishing|
|22||Aircraft of the Aces 38 Tomahawk and Kittyhawk Aces of the RAF and Commonwealth||1-84176-083-8||Osprey Publishing|
|23||Aircraft of the Aces 41 American Volunteer Groups Colours and Markings||1-84176-224-5||Osprey Publishing|
|24||Aircraft of the Aces 43 P-40 Warhawk Aces of the MTO||1-84176-288-1||Osprey Publishing|
|25||Aircraft of the Aces 55 P-40 Warhawk Aces of the Pacific||1-84176-536-8||Osprey Publishing|
|26||Aircraft of the Aces 86 P-36 Hawk Aces of World War 2||978-1-84603-409-1||Osprey Publishing|
|27||Aircraft of the Aces 117 Aces of the 325th Fighter Group||ISBN 978-1-78096-302-0||Osprey Publishing|
|28||Aviation Elite 14 49th Fighter Group Aces of the Pacific||1-84176-785-9||Osprey Publishing|
|29||Aviation Elite 31 23rd Fighter Group 'Chennault's Sharks'||ISBN 978-1-84603-421-3||Osprey Publishing|
|30||Aviation Elite 39 57th Fighter Group 'First in the Blue'||978-1-84908-337-9||Osprey Publishing|
|31||Osprey Duel 8 P-40 Warhawk vs Ki-43 Oscar||978-1-84603-295-0||Osprey Publishing|
|32||Osprey Duel 38 P-40 Warhawk vs Bf109 MTO 1942-44||978-1-84908-469-7||Osprey Publishing|
|33||Checkertails The 325th Fighter Group in the Second World War||0-89747-316-7||Squadron/Signal|
|34||49th Fighter Group||0-89747-221-7||Squadron/Signal|
|35||The Curtiss P-36 and P-40 in USAAC/USAAF service 1939 to 1945||0-9539040-5-9||Guideline Publications|
|36||Red Series 5112 Curtiss Hawk-75 in French Service||978-83-61421-07-8||Mushroom Model Publications|
|37||Red Series 5104 Fighters Over France and the Low Countries||83-916327-1-7||Mushroom Model Publications|
|38||Les Ailes de Gloire No.6 Curtiss Hawk H75||2-914403-08-9||Editions d'Along|
|39||Curtiss Hawk 75||-||Ducavia|
|40||Suomen Ilmavoimien Historia 5 Curtiss Hawk 75 P-40M||951-98751-9-0||Kari Stenman Publishing|
|41||RAAF Camouflage & Markings 1939-45 Vol1||-||Kookaburra Technical Publications|
|42||RAAF Camouflage & Markings 1939-45 Vol2||0-85880-037-3||Kookaburra Technical Publications|
|43||The P-40 Warhawk, Mustang and Kittyhawk in Australian service||0-9587978-1-1||Aerospace Publications|
|44||Aircraft Pictorial No.5 P-40 Warhawk||978-0-9817931-1-5||Warships Publishing|
|45||Aviatic WWII Aircraft No.1 Curtiss P-40F Warhawk||-||Aviatic|
|46||Air Vanguard 8 Curtiss P-40 Long-nosed Tomahawks||978-1-78096-909-1||Osprey Publishing|
|47||Air Vanguard 11 Curtiss P-40 Snub-nosed Kittyhawks and Warhawks||978-1-78096-912-1||Osprey Publishing|
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