1/72 MPM XP-56 'Black Bullet'

Gallery Article by Carmel J. Attard on Dec 31 2015

 

      

XP-56 ‘Black Bullet

History

The XP-56 was built out of a new construction process known as Heliarc welding, better known as TIG welding. It was built out of, then, new material magnesium, which was welded using a special welding torch for this process. Tailless in design configuration the XP-56 also known as ‘Black Bullet’, was an attempt to radically improve fighter aircraft performance using an unconventional, near all- wing, airframe design. 

The first prototype flew on the 6th September 1943 being powered by a Pratt Whitney R-2800-29 double wasp engine that drove two three-bladed contra rotating propellers. The XP-56 was the winner out of three designs that competed for the Army’s request for Data R-40c document of November 1939. The army specifically mentioned in R-40c that they would consider aircraft with unconventional configuration. The other contenders were Vultee who submitted a twin boom pusher the XP-54, and Curtiss with the offer of a canard pusher, the XP-55Ascender.

The XP-56 had a wide track, tricycle undercarriage. The lateral and directional control was made by means of a pair of spoilers flush on the upper and lower surfaces of the drooped wing tips, with pitch control came by means of elevators mounted inwards of drooped wing tips. The Black Bullet was quite heavily armed with 20mm cannons and four 0.5 calibre machine guns in the nose. There were two prototypes which were built and flew:41-786 and 41-38353, the latter had a dorsal fin in addition to the ventral one.

The first XP-56 was ready in April 1943 and was shipped to Muroc Dry Lake (the place which later was renamed Edwards AFB after the pilot who flew the flying wing bomber YB-49 that was lost with all crew members on it) During the initial ground handling trials it was found that the aircraft tended to yaw sharply and dangerously while taxiing at high speed, it was then thought that faulty wheel brakes caused the problem. In effect this delayed the first flight until September 30th 1943, when test pilot John Mayers took the XP-56 into the air for the first time. During this flight the aircraft maintained a height of only five feet which it appeared to fly normally, which was very encouraging. Nose heaviness was a persistent problem and lateral control was difficult to maintain during flight. Before these problems could be addressed the port main wheel blew out during a high seed taxiing run and the aircraft somersaulted over onto its back and was totally wrecked.

To correct deficiencies encountered with the first prototype the second XP-56 (42-38353) underwent some major changes. These included a major increase in the upper vertical surface size, fitting a new form of rudder control; the centre of gravity was moved further forward. On March 23, 1944, test pilot Harry Crosby took the second prototype up for the first time. Crosby found that it was impossible to lift the nose wheel off the ground at speeds below 160mph and the test flight lasted only a few minutes. In a later flight it was found that the nose wheel problem went away after the landing gear was retracted. Still the aircraft was found to be underpowered for its weight and only low speeds could be attained which was far short from the projected 454mph at 25,000 feet. 

Further test flight trials were undertaken and on the tenth flight the pilot complained of extreme tail heaviness on the ground, low power, and excessive fuel consumption. The second prototype was finally declared un-airworthy, following unsatisfactory reports of poor handling in the air and too dangerous to continue flight tests with it. Shortly there after the project was abandoned since the age of jet propulsion was nearing the time to bring the era of propeller-driven fighters to a close. The failure of this project however was not a total loss for Northrop learned a lot about flying wing designs where the data gained was put to good use in design of XB-35 piston engined bomber and the YB-49 jet-powered bomber, and the B-2 Stealth bomber.

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The kit
It is not a common choice to have a prototype produced as an injection moulded kit and the XP-56 Black Bullet was such type. MPM has produced the kit to a scale of 1/72 and I am glad to see it in view of its unique shape. There are two colour options, which are an overall silver/metal finish as the aircraft appeared for the first and second flight in September 1943. The other scheme is for a camouflaged olive drab upper surfaces and neutral gray lower surfaces which was worn by Black Bullet during pre-flight testing and high speed taxi trials conducted five months prior to first flight.

Construction
This is an interesting aircraft with a unique design which is injection moulded in light grey plastic with two injection moulded cockpit canopies included. The fuselage, which was stubby and rounded with its unpressurised cockpit situated well forward is well represented in two plastic halves with detailed parts for the cockpit that includes bulkheads, instrument panel, seat and headrest and also a rollover bar. The short stubby dorsal fin comes in two halves which fit on the fuselage in one piece. The very large ventral fin, which very nearly scrapes on the ground when the aircraft stood on its landing gear, is integrally moulded with the two fuselage parts.

The cantilever mid-mounted wings come into four main parts and two accurately shaped wing tip components. There are two very intricate shaped air ducts for cooling of the radial engine. These are made in resin and are to be located in wing leading edge. Each of these have very thin vertical fins which otherwise could not be produced by injection technique. These intake duct details, part 43 and 44 need to have the corners that come adjacent to the roots a little proud and therefore are trimmed down to foul with the two wing parts 38 and 41.

The kit also includes two very tiny fairings, also in resin. These are to be mounted on the nose and the position of these could be estimated from the clear photo that comes on the box cover depicting the second prototype during ground trials. There is a slight inaccuracy concerning the landing gear doors mounted under the wing. The bottom plan view on the instruction sheet is showing no inboard landing gear doors. However the shape of the wheel wells, that are covered by the missing doors is correct on the drawings provided with the kit. In this case the drawing can be used as a guide to re-scribe the shape of the closed doors to replace those incorrectly scribed lines provided in the kit. Like the modern day F-104 and Mirages, the inner doors were open only whilst the landing gear was in transit up or down.

Colour and markings
As mentioned earlier there are two colour options and the decals provided are well registered and of high quality, for the olive/grey aircraft these consist of four stars. The alternative decal for the all silver finish XP-56 there are four star and bars outlined in red along with a small serial number to go on the small vertical fin.

Conclusion
This was an interesting and unique release by MPM at this scale and shows the extent of prop driven aircraft design and shape evolved before the advent of the jet engine.

Ref: 
Warplanes of the Second World War. Fighters volume 4 by William Green.

Carmel J. Attard

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Photos and text © by Carmel J. Attard