XP-86 Early Straight-wing design

[ACResearcher]

I'm working on a project involving mid-to-late WWII U.S. jet fighter projects/proposals and need a good example of the above. Can anyone help me?

AlanG

 

[overscan (PaulMM)]

Poor quality but a start. KRIS HUGHES AND WALTER DRANEM - NORTH AMERICAN F-86 SABREJET DAY FIGHTERS (Warbirdtech, 1996)

 

[overscan (PaulMM)]

Aviation Classics 09 - North American F-86 Sabre

 

[overscan (PaulMM)]

AAHS Journal - Volume 51 Issue 1 "Mach 1 and the North American XP-86" looks possibly interesting.

https://www.aahs-online.org/journals/journal_template.php?vol_no=v51n1

 

[Zizi6785]

Here:
https://www.britmodeller.com/forums/index.php?/topic/235021672-north-american-xp-86/

 

[overscan (PaulMM)]

Thats an early FJ-1. Not quite the same.

 

[hesham]

Wow,amazing pictures my dear Paul.

 

[Johnbr]

Hope this helps.

 

[kitnut617]

The model I built of it last year. The third pic is supposedly the only known photo of the straight wing XP-86, but I've seen another although it's not the primary aircraft which was having it's photo taken. The caption said 'notice the XP-86 in the background', I pretty sure it's in one of my AeroMilitaria quarterlies I get from Air-Britain.

In the latest edition of Squadron/Signal's book F-86 in Action, the first chapter has a 3-View of it plus some history.

I also used the wind tunnel model in the photo Paul posted as a reference.

D'oh! Johnbr beat me to it ---

 

[Tailspin Turtle]

AAHS Journal - Volume 51 Issue 1 "Mach 1 and the North American XP-86" looks possibly interesting.

https://www.aahs-online.org/journals/journal_template.php?vol_no=v51n1

Excellent article but no illustrations of the straight-wing XP-86

 

[Sabrejet]

Thats an early FJ-1. Not quite the same.

Just joined and was surprised to see that the drawings I posted wayyyy back on Britmodeler had found a place here. I marked them up to show the main dimensions/differences etc (in red). I have a lot of other XP-86 data which I can post if of interest.

 

[overscan (PaulMM)]

Sure!

 

[Sabrejet]

Here are a few evolutions of the design from first swept-wing version with non-swept tail surfaces and two wing aspect ratios, to a more defined design.

Dimensions are rather fluid during this period, with vertical tail height officially given as 15.3 ft until 28 March 1946, when Master Change Request MCR P-17-2 increased the vertical fin height by 8 inches.

 

[T. A. Gardner]

The original XP-86 was North American's "Jet Mustang." The straight plank wing version that used P-51D wing and tail surfaces mated to a new fuselage. It was dropped in favor of the swept wing version shortly after the war. The USN picked up the design as the FJ Fury for an attack / ground support aircraft and continued its development.

 

[Sabrejet]

The original XP-86 was North American's "Jet Mustang." The straight plank wing version that used P-51D wing and tail surfaces mated to a new fuselage. It was dropped in favor of the swept wing version shortly after the war. The USN picked up the design as the FJ Fury for an attack / ground support aircraft and continued its development.

The FJ-1 pre-dates the XP-86 and flew a year before the XP did. The XFJ-1 was NAA model NA-134 while the XP-86 was NA-140. There is a great deal of confusion regarding the XP-86 for sure!

 

[Caravellarella]

So, the original straight-wing XP-86 (NA-140) design didn't have the same "Mustang-style" wing as the FJ-1 Fury (NA-135)? I was trying to visualise the differences between the FJ-1 and the original straight-wing XP-86 designs; they look related a little bit...

Terry (Caravellarella)

 

[Sabrejet]

Visually the straight-wing NA-140 and NA-134 (XFJ-1) were similar, but whereas the NA-134 mounted its mainplanes onto trunnions that were part of the fuselage carry-through structure, the NA-140 wing was more like the P-51 in that it was joined along the aircraft centreline and then mounted onto the fuselage from beneath. The production F-86 wing was a natural extension of the P-51 wing attachment architecture (via a central wing box) rather than being an evolution of the XFJ-1 method.

 

[Caravellarella]

Visually the straight-wing NA-140 and NA-134 (XFJ-1) were similar, but whereas the NA-134 mounted its mainplanes onto trunnions that were part of the fuselage carry-through structure, the NA-140 wing was more like the P-51 in that it was joined along the aircraft centreline and then mounted onto the fuselage from beneath. The production F-86 wing was a natural extension of the P-51 wing attachment architecture (via a central wing box) rather than being an evolution of the XFJ-1 method.

Dear Sabrejet, is it safe to assume that the NA-140 isn't actually derived from the NA-135; but possibly more of a parallel development then?

Terry (Caravellarella)

 

[Sabrejet]

NA-134. Yes, more of a parallel development.

 

[Justo Miranda]

On 14 October 1944, North American proposed the NA-134 jet fighter to the US Navy. Three prototypes were ordered on 1 January 1945, under the designation XFJ-1. On 28 May 1945, the US Navy approved a contract for 100 production FJ-1 Fury jet fighters. It was hoped that the new aeroplane would be available in time for the invasion of Japan—Operation Olympic—planned for May 1946. The Allies expected to suffer a high number of casualties caused by second-generation suicide jet bombers Kawanishi Baika (740 kph/460 mph) and Kugisho Ohka 43 (596 kph/370 mph). The US Navy needed fast interceptors to protect the invasion fleet.
The XFJ-1 prototype was flown on 11 September 1946, powered by one General Electric GE-2 (TG-180) axial flow turbojet rated at 1,730 kgf (3,820 lbf) thrust. The aeroplane’s wings and tail surfaces were very similar to those of the P-51H. The thin wings, which lacked a folding system, had been designed with retractable slatted airbrakes (developed in 1942 for the A-37 dive bomber) mounted on the upper and lower surfaces. The first production FJ-1, with fuselage speed airbrakes and an Allison J-35 turbojet, was delivered in October 1947. On 10 March 1948, the aeroplane performed the first carrier landing on USS Boxer (CV-21).
Five months later, the Fury entered service with the VF-5A (VF-51) naval squadron for a jet familiarisation programme. In May 1949, the VF-51 started an operational training trip aboard USS Princeton (CV-37), the results were not good, one of the aircraft was destroyed and all the others were damaged. The US Navy determined that slower acceleration by jets during the take-off was not recommended and catapult departures became standard practice. The manoeuvrability at low speeds of the FJ-1 was regarded as mediocre and the Fury was soon eclipsed by the McDonnell F2H Banshee. By July 1949, all the aeroplanes were transferred to the US Naval Reserve units.

FJ-1 Technical Data Wingspan: 11.64 m (38 feet 2 inches) Length: 10.5 m (34 feet 5 inches) Height: 4.5 m (14 feet 10 inches) Wing area: 25.5 sq. m. (275 sq. feet) Max. weight: 7,076 kg (15,360 lb) Max. speed:769 kph (478 mph) Ferry range: 2,415 km (1,500 miles) Ceiling 9,754 m (32,000 feet) Armament: six 0.50-cal M-2 heavy machine guns.

The operational debut of German jet fighters in July 1944 made the Mustang obsolete. On 11 September 1944, the USAAF issued a general operational requirement (GOR) calling for a day fighter with a top speed in excess of 600 mph (965 kph), a range of 850 miles (1,368 km), and eight 0.5-cal. M3 or six 0.6-cal. heavy machine guns.
To meet the specification, eight days after the publication of the GOR, the firm Republic Aviation Corporation proposed the AP-23 design, with an estimated top speed of 611 mph.
On 4 October 1944, the North American design team envisaged the study of the NA-140 jet fighter, with nose air intake, wings, and tail surfaces similar to those FJ-1. To avoid compressibility shock, the NA-140 had laminar-flow straight wings with a 10 per cent thickness/chord ratio and a very slim fuselage with a high fineness ratio. The wings have ‘fence’ airbrakes on the upper and lower surfaces, a folding system, and two 170-gal. (644-l) wingtips fuel tanks. To save drag, the aircraft had one curved windshield and one teardrop canopy with 64 cm (25 inches) width only, 17 cm less than that of the P-51 D. The critical Mach number (the speed at which it can fly without encountering control problems due to compressibility) of the NA-140 airframe was 0.9, higher than 0.8 of the Lockheed XP-80 and 0.76 of the P-51 D.
The proposed engine was one General Electric GE-2 (TG-180) axial flow turbojet rated at 1,730 kgf (3,820 lbf) static thrust, circular air intake, and a ‘S’-curved air duct to pass under the cockpit. NA-140 (4 October 1944)
Technical Data Wingspan: 12.17 m (39 feet 11 inches) Folded wingspan: 5.39 m (17 feet 8.5 inches) Length: 11.53 m (37 feet 10 inches) Height: 4.65 m (15 feet 3 inches) Estimated max. speed: 925 kph (575 mph) Armament: six 0.50-cal. MG 53-2 heavy machine guns.
In November 1944, the GOR was modified calling for six 0.5-cal. only; that same month, the USAAF ordered three Republic AP-23 prototypes under the designation XP-84.
North American improved the original design of the NA-140 to gain some speed. In the proposed 15 August 1945 version, the weight and dimensions of the aircraft had been reduced, but aerodynamic tests carried out with wind tunnel models only indicated a top speed of 582 mph. The proposed aeroplane had a pressurised cockpit, boosted controls, and an AN/ APG-5 radar rangefinder. The antenna was mounted in the extreme nose and it was necessary to design a new air intake, with an oval section, for the Allison J 35-A-15 turbojet with 250 lb static thrust more than the J 35 GE-2. NA-140 (15 August 1945 Project).
Technical Data Engine: one Allison J 35 A-15 axial flow turbojet rated at 4,000 lb (1,812 kgf) static thrust Wingspan: 11.64 m (38.2 feet) Length: 10.82 m (35.2 feet) Height: 4.02 m (13.2 feet) Wing surface: 23 sq. m (255.3 sq. feet) Estimated max. speed: 937 kph (582 mph) Estimated max. weight: 5,210 kg (11,500 lb) Estimated ceiling: 14,177 m (46,500 feet) Armament: six 0.50-cal M3 heavy machine guns.
On 18 May 1945, the USAAF ordered two prototypes of the NA-140, under the designation XP-86. The mock-up was approved on 20 June 1945, four months after the XP-84 mock-up. The North American officials knew that the NA-140 programme would be cancelled by the lack of speed, but there were only two possible solutions: reduce drag or use a more powerful turbojet. Using the materials available at the time, it was physically impossible to reduce wing thickness without dangerously degrading its structural strength, and the new Allison turbojet would take too long to become available.
On 28 February 1946, the Republic XP-84 prototype was flown, powered by one J 35-GE-7 rated at 3,750 lbf (1,700 kgf) static thrust; a maximum speed of 573 mph (922 kph) was attained.

On 29 April 1945, a company of US infantry occupied the Messerschmitt research centre at Oberammergau and captured the Messerschmitt P.1101 prototype, an experimental fighter with swept-back wings and tail surfaces, designed to fly at 612 mph (985 kph). The P.1101 was powered by one Heinkel-Hirth HeS 011 turbojet rated at 2,649 lbf (1,200 kgf) static thrust only. Fortunately for North American, the German research data on swept-wing flight was available in July 1945. On 14 September 1945, wind tunnel tests were performed with a 1/23rd NA-140 scale model, with 35-degree swept wings. These trials were extremely promising and the USAAF approved the modification, entitled RD-1369, on 1 November 1945. On 23 April 1946, North American proposed a new design that could use two new types of swept wings but retained the fuselage and tail surfaces from the previous 102 Ultimate Allied Fighters of the Second World War version. The 5AR type had 37 degrees swept, 5 aspect ratio, and a 37.07-foot (11.3 m) wingspan to provide for better stability. The 6AR type had 39 degrees swept, 6 aspect ratio, and a 40.8-foot (12.44 m) wingspan to provide for better range.
At that time, there were doubts about the ideal configuration because the wings of the Messerschmitt P.1101 had been built with a variable swept that could be adjusted, on the ground, between 35 and 45 degrees. The prototype had been captured before performing its first flight, which was planned for June 1945. The data captured from the Germans were only theoretical estimates. On 15 October 1946, the NA-140 had 36-degree swept wings, 38-degree swept tailplane, 40-degree swept tailfin, and a circular air intake. The wings were fitted with automatic slats in 90 per cent of the leading edge to provide stability at low speeds. NA-140 (15 October 1946 Project).

Technical Data Engine: one Chevrolet J 35-C-3 axial flow turbojet rated at 4,000 lb (1,812 kgf) static thrust. Wingspan: 11.34 m (37.2 feet) Length: 11.44 m (37.54 feet) Height: 4.4 m (14.49 feet) Estimated max. speed: 1,046 kph (650 mph) Armament: six 0.50-cal M3 heavy machine guns The prototype XP-86, with 35.2-degree swept wings, was rolled out on 8 August 1947, performing its first flight on 1 October 1947. The wing thickness/chord ratio was optimised at 11 per cent inboard and 10 per cent at the wingtips; the airbrakes were moved to the rear fuselage sides and the canopy width was enlarged 30 cm (11.7 inches) to allow the ejection seat operation.

On 26 April 1948, the XP-86 went supersonic, in a shallow dive, powered by one J 47-GE-3 axial flow turbojet rated at 5,200 lbf (2,356 kgf) static thrust. XP-86 (1 October 1947) Technical Data Engine: one Chevrolet J 35-C-3 axial flow turbojet rated at 4,000 lb (1,812 kgf) static thrust Wingspan: 11.44 m (37.54 feet) Length: 11.31 m (37.12 feet) Height: 4.5 m (14.79 feet) Wing surface: 25.45 sq. m (283 sq. feet) Max. speed: 1,020 kph (634 mph) Max. weight: 7,446 kg (16,437 lb) Ceiling: 13,260 m (43,500 feet) Armament: six 0.50-cal M3 heavy machine guns.

 

[Sabrejet]

There are a few errors in the above:

1. "Three prototypes were ordered on 1 January 1945, under the designation XFJ-1" - original Navy designation was XF-4J-1.

2. "The thin wings, which lacked a folding system, had been designed with retractable slatted airbrakes (developed in 1942 for the A-37 dive bomber) mounted on the upper and lower surfaces" - I’d disagree with ‘slatted’ – the retractable dive brakes were plain surfaces, described rather disparagingly by NAA aerodynamicist ‘Mac’ Blair as , “four by two’s”. They were simple in design and operation and not slatted.

3. "11 September 1944, the USAAF issued a general operational requirement (GOR) calling for a day fighter with a top speed in excess of 600 mph (965 kph), a range of 850 miles (1,368 km), and eight 0.5-cal. M3 or six 0.6-cal. heavy machine guns" - NAA’s initial proposal was for six, 0.5-cal or six 0.6-cal.

4. "The proposed engine was one General Electric GE-2 (TG-180) axial flow turbojet" - The XP-86 prototypes were designed to accept two versions of the J35 engine: the Chevrolet-built J35-C3 (TG-180-A5) or the Allison J35-A5 (TG180-A7); both were GE designs.

5. "On 14 September 1945, wind tunnel tests were performed with a 1/23rd NA-140 scale model, with 35-degree swept wings. These trials were extremely promising and the USAAF approved the modification, entitled RD-1369, on 1 November 1945." - This isn’t quite correct: the USAAF to approved a research and development grant on 18 August 1945 to investigate the swept-wing XP-86 under design study RD 1369. The following month a wind-tunnel model of the new design was tested, and NAA published its initial findings on 10 October; a presentation to the AAF resulted in a decision on 1 November 1945 to proceed with the swept-wing XP-86.

6. "The wing thickness/chord ratio was optimised at 11 per cent inboard and 10 per cent at the wingtips; the airbrakes were moved to the rear fuselage sides and the canopy width was enlarged 30 cm (11.7 inches) to allow the ejection seat operation." - Ejection seat requirements, including airframe mods, were settled as far back as April 1946 when it was agreed to change from a GFP seat to one designed specifically by NAA.

7. "On 26 April 1948, the XP-86 went supersonic, in a shallow dive, powered by one J 47-GE-3 axial flow turbojet" - This isn’t correct; none of the XP-86s received the J47 engine; first confirmed supersonic flight was with the #2 XP-86, on 27 April (not 26 April); none of the XP-86/P-86/F-86 series could go supersonic in anything but a very steep dive. #2 went supersonic with an Allison-built J35. First J47-powered aircraft of the Sabre series was the #1 P-86A-1 (F-86A-1), which flew for the first time on 20 May 1948.