Ernie P.

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The Stearman XA-21 t is, Hydro Junkie. And you're up. Now 'fess up; you've known the answer for a while, haven't you? Thanks; Ernie P.

What warbird do I describe?



Clues:

1. There was only one ever built.

2. It was built by one of four aircraft companies which competed in a competition for a contract to build a new warbird.

3. It was the only one of the four which did not eventually enter production in some form.

4. The other three aircraft were all produced in large numbers.

5. This aircraft was the only multi-engined aircraft produced by the company.

6. And, although it wasn’t selected for production, it was a fast aircraft for the day.

7. Despite this failure, the name of the producing company is one well known to almost everyone on this forum.

8. It was initially produced with a large “greenhouse” cockpit area, intended to provide lots of visibility for its pilot and bombardier.

9. Unfortunately, the high visibility cockpit restricted forward visibility for the pilot.

10. So, the company installed a more standard cockpit area; but performance remained about the same.

11. Twin engine; crew of three.

12. Nine machine guns.

13. Bomb load over 2,500 pounds.

14. A little over 50 feet in length.

15. Wingspan around 65 feet.

16. Dry weight was over 12,000 Lb.

17. Loaded weight was around 18,000 Lb.

18. The cockpit arrangement was similar to that used on most German WWII bombers.

19. The revised cockpit arrangement was similar to that used on many WWII American medium bombers.

20. Maximum speed was just over 250 MPH.

21. It could cruise at 200 MPH.

22. Machine guns were all .30 caliber.

23. The other three aircraft, all of which ultimately found their way into production (although perhaps after extensive changes), were used in a variety of roles.

24. These roles included attack, reconnaissance, intruder, light bomber, night fighter, medium bomber, patrol and trainer.

25. The other three were all produced in large numbers.

26. And all three were used by other countries.

27. Ironically enough, one of those foreign countries wound up using one of the aircraft to attack the armed forces of the manufacturing country.

28. The specifications for the aircraft were released in late 1937 or early 1938 (sources differ).

29. The competition in which our subject aircraft failed to attract any orders was held in 1939.

30. All three of the aircraft in competition with our subject aircraft attracted interest from the French Air Force.

31. And all three of them, in their final forms, ultimately served with the French.

32. Our subject aircraft did not.

33. The specifications, and the competition itself, were from the USAAC.



Answer: The Stearman XA-21



The Stearman XA-21 (Model X-100) was a competitor in a United States Army Air Corps competition for a twin-engined attack aircraft which (after redesigns) led to the Douglas A-20 Havoc, Martin A-22 Maryland and North American B-25 Mitchell.

Design and development

The X-100, designated XA-21 following purchase by the Army Air Corps, was a twin-engined high-winged monoplane of all-metal construction. It featured an unusual cockpit arrangement, much like those on most German World War II bombers designed during the war years, with a streamlined greenhouse canopy enclosing both the pilot and bombardier stations.

Operational history

The XA-21 was first tested with the streamlined cockpit but this configuration was found to restrict the pilot's forward vision, and the aircraft was rebuilt with a conventional (stepped) nose and cockpit structure. Although this change in the cockpit did not significantly affect performance, the XA-21 was not ordered into production.

The sole XA-21 had serial number 40-191.



General characteristics

• Crew: 3
• Length: 53 ft 1 in (16.18 m)
• Wingspan: 65 ft 0 in (19.81 m)
• Height: 14 ft 2 in (4.32 m)
• Wing area: 607 ft² (56.39 m²)
• Empty weight: 12,760 lb (5,789 kg)
• Useful load: 5,560 lb (2,520 kg)
• Loaded weight: 18,230 lb (8,269 kg)
• Powerplant: 2 Χ Pratt & Whitney R-2180-7 Twin Hornet radial engines, 1,400 hp (1,030 kW) each

Performance

• Maximum speed: 223 knots (257 mph, 414 km/h)
• Cruise speed: 174 knots (200 mph, 322 km/h)
• Wing loading: 30.0 lb/ft² (147 kg/m²)
• Power/mass: 0.15 hp/b (250 W/kg)

Armament

• Guns:
  • 4Χ wing-mounted 0.30 in (7.62 mm) M1919 Browning machine guns
  • 1Χ nose-mounted 0.30 in machine gun
  • 4Χ aft-firing 0.30 in machine guns
• Bombs: 2,700 lb (1,200 kg)

The Douglas A-20 Havoc (company designation DB-7) is an United Statesattack, light bomber, intruder and reconnaissance aircraft of World War II. It served with several Allied air forces, principally the United States Army Air Forces (USAAF), the Soviet Air Forces (VVS), Soviet Naval Aviation (AVMF), and the Royal Air Force (RAF) of the United Kingdom. Soviet units received more than one in three (2,908 aircraft) of the DB-7s ultimately built. It was also used by the air forces of Australia, South Africa, France, and the Netherlands during the war, and by Brazil afterwards. In British Commonwealth air forces, bomber/attack variants of the DB-7 were usually known by the service name Boston, while night fighter and intruder variants were usually known as Havoc. An exception to this was the Royal Australian Air Force, which referred to all variants of the DB-7 by the name Boston. The USAAF referred to night fighter variants as P-70.In the autumn of the same year (1937), the United States Army Air Corps (USAAC) issued its own specification for an attack aircraft. The Douglas team, now headed by Heinemann, took the Model 7A design, upgraded with 1,100 hp (820 kW) Pratt & Whitney R-1830 Twin Wasp engines, and submitted the design as the Model 7B. It faced competition from the North American NA-40, Stearman X-100, and Martin 167F. The Model 7B was maneuverable and fast, but did not attract any US orders. The model did, however, attract the attention of a French Purchasing Commission visiting the United States seeking aircraft for the modernization of the Armee de l'Air in the wake of the Munich Crisis. The DB-7s were shipped in sections to Casablanca for assembly and service in France and French North Africa. When the Germans attacked France and the Low Countries on 10 May 1940, the 64 available DB-7s were deployed against the advancing Germans. Before the armistice surviving planes were evacuated to North Africa to avoid capture. Here, they fell under control of the Vichy government and briefly engaged the Allies during Operation Torch the Allied invasion of French North Africa in November 1942.



The Martin Model 167 was an American-designed medium bomber that first flew in 1939. It saw action in World War II with France and the United Kingdom, where the latter named it the Maryland. In response to a United States Army Air Corps light bomber requirement issued in 1938, the Glenn L. Martin Company produced their Model 167, which was given the official designation XA-22. Martin's design was a twin-engine all-metal monoplane, capable of around 310 mph (500 km/h) with a crew of three. The XA-22 was not adopted for operational service in the U.S., as the contract was won by the Douglas DB-7, which became the A-20 Havoc, but Martin received foreign orders, and about 450 of these fast, twin-engined bombers were built.

The North American B-25 Mitchell is an American twin-engine, medium bomber manufactured by North American Aviation (NAA).The design was named in honor of Major General William "Billy" Mitchell, a pioneer of U.S. military aviation. Used by many Allied air forces, the B-25 served in every theater of World War II and after the war ended many remained in service, operating across four decades. Produced in numerous variants, nearly 10,000 Mitchells rolled from NAA factories. These included a few limited models, such as the United States Marine Corps' PBJ-1 patrol bomber and the United States Army Air Forces' F-10 reconnaissance aircraft and AT-24 trainers.The Air Corps issued a circular (Number 38-385) in March 1938 describing the performance they required from the next bombers — a payload of 1,200 lb (540 kg) with a range of 1,200 mi (1,900 km) at more than 200 mph (320 km/h). Those performance specifications led NAA to submit their NA-40 design. The NA-40 had benefited from the North American XB-21 (NA-39) of 1936, which was the company's partly successful design for an earlier medium bomber that had been initially accepted and ordered, but then cancelled. However, the company's experience from the XB-21 contributed to the design and development of the NA-40. The single NA-40 built flew first at the end of January 1939. It went through several modifications to correct problems. These improvements included fitting 1,600 hp (1,193 kW) Wright R-2600 "Twin Cyclone" radial engines, in March 1939, which solved the lack of power. In March 1939, North American delivered the substantially redesigned and improved NA-40 (as NA-40B) to the United States Army Air Corps for evaluation. It was in competition with other manufacturers' designs (Douglas 7B, Stearman X-100, and the Martin Model 167F) but failed to win orders. The aircraft was originally intended to be an attack bomber for export to the United Kingdom and France, both of which had a pressing requirement for such aircraft in the early stages of World War II. However, the French had already opted for a revised Douglas 7B (as the DB-7). Unfortunately, the NA-40B was destroyed in a crash on 11 April 1939 while undergoing testing. Although the crash was not considered due to a fault with the aircraft design, the Army ordered the DB-7 as the A-20.

Hydro Junkie

Actually, I didn't. I was just staying away from answering since I was HOPING someone else would answer this one. What gave it away was the cockpit revision, crew size, being multi-engine, the number of weapons and the date it flew. After that, it was just deductive reasoning to figure it out.
If I don't put up something by tomorrow night, it's open floor

Ernie P.

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All; per the above, the floor appears to be open. If anyone has a question they would like to post, feel free. If no one posts anything by tomorrow, I will do so, but I'd prefer a new poster take this one. Thanks; Ernie P.

Snoopy47

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I hope this counts but can anyone name the item in the picture? Should be pretty easy for you experts.

What is the aircraft?

Ernie P.

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Now that's interesting! I have an idea, but let me go check before I answer. Thanks; Ernie P.

Ernie P.

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Sir; I can't find a photo with sufficient detail, and it is difficult to judge scale in the photo; but my guess is it is an aluminum surround for one of the turbochargers on the P-38 Lockheed Lightning. Thanks; Ernie P.

FlyerInOKC

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I thought it looked like a landing light bezel.

Ernie P.

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But a landing light bezel from what aircraft? Thanks; Ernie P.

FlyerInOKC

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II'm still working on that part!

Hydro Junkie

I'm thinking more like an exhaust outlet fairing for a radial engined plane, maybe a Wildcat

Ernie P.

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Snoopy47; thanks for the question, but we need a response to our guesses as well. And, at least one new clue every 24 hours. Please respond. Thanks; Ernie P.

Ernie P.

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Snoopy47, unless you provide an answer to the guesses posted, and a new clue to your question, we will have to move on. Please do so today. Thanks; Ernie P.

Snoopy47

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Sorry guys, been away from the computer lately.

Clue...... It's from a P47. That will probably give it away, haha.

Ernie P.

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Sir; thanks for the clue. It looks as though Hydro Junkie was on the right track. Thanks; Ernie P.

Hydro Junkie

DAMN IT ERNIE, DON'T SAY THAT!!!!!!!!!!!!!!!!!!!!!!!!!!
I was hoping I was someplace beyond the left field fence!

Ernie P.

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<Chuckle> Well, I suppose it still could be a landing light bezel, as FlyerInOKC suggested. Thanks; Ernie P.

Snoopy47

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Hahahaha, Yep Hydro Junkie so definitely on the right track.

Hydro Junkie

Okay, since I'm on the right track, maybe an exhaust pipe heat shield?

Ernie P.

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Sir; at least one new clue per day, please. And please respond to all guesses. Thanks; Ernie P.

Ernie P.

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The P-47 has two flanges, one on each side of the fuselage, just below and in front of the leading edge of the wing. They look very similar to the photo provided. But they aren't exhaust outlets.;I just remembered the exhaust is in the tail, with the turbocharger. Hmmmmm... Wonder what those flanges are? Fuel fittings, maybe? Thanks; Ernie P.

Hydro Junkie

Is it possible it's for an oil cooler intake?
Okay, Ernie, this shot clearly shows an exhaust in front of and below the leading edge of the wing:

I think this shot answers the question on what kind of exhaust that is. It's definitely an oil or hydraulic fluid cooler on both sides below the engine

and the part being asked about is a fairing around the cooler exhaust

Hydro Junkie

Here's a shot that really shows that fairing:

Ernie P.

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Yeah, and you'll notice there is a flap on that (apparent) exhaust port. So I'm agreeing it is probably an oil or hydraulic fluid cooler exhaust. BTW; there's a mockup of the P-47 exhaust system on display at Uvar-Hazy; and it's available online. So both the exhaust and turbo system piping were at the rear of the aircraft. Thanks; Ernie P.

proptop

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G'mornin'...been a while fer me here...
Anywayze...IIRC the P-47 had a butterfly in that short exhaust stack, right behind the cowl...it would open or close to direct or redirect the exhaust depending on altitude and boost requirements...(not sure if I'm wording this adequitely, but ...) At lower altitudes, the butterfly would be open, allowing some of the exhaust to go straight out that pipe...effectively bypassing the turbo...to prevent over-boosting the engine at high power settings at low altitude.

At higher altitudes it would close and direct all of the exhaust back to the turbo...

Not sure about "iffy" memory here, but IIRC it is barometrically controlled and regulated automatically (bellows?) and connected to the throttle quadrant...MAP lever...???

Ernie P.

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Well, proptop; I don't know if you're correct or not; but your answer sounds very plausible. I hadn't thought about the necessity of bypassing the turbo at lower altitudes. Good work! Now if we can just get Snoopy47 to respond.

Snoopy47; please post at least one new clue each 24 hours and please respond directly to all answers. Thanks; Ernie P.