McDonnell XP-67 Moonbat

[johnbr]

 

[johnbr]

 

[Wurger]

 

[johnbr]

 

[Wurger]

 

[fubar57]

That was a great looking aircraft

 

[Old Wizard]

 

[johnbr]

The engine.
In 1932, the Army contracted with Continental for development of a cylinder with high specific power. Using the resulting Hyper No. 1 cylinder, the Air Corps instructed Continental in 1934 to develop what became the horizontally opposed O-1430 to be buried in the wings of large aircraft to improve streamlining for higher speed. However, by this time, the Air Corps decided that 746 kW (1,000 hp) engines were obsolete for bombers, and that fighter wings were too thin for a submerged installation.

By 1939, the Air Corps decided that an inverted vee was needed for improved visibility, and instructed Continental to drop the 0-1430 and begin work on the inverted I-1430. Following development problems, it was decided in 1943 that the engine could not possibly be used in the war, and only eight engines were built for experimental use. This Continental I-1430-11 was test flown in a modified Lockheed P-38 testbed aircraft.
Physical Description

• Type: Reciprocating, V-type, 12 cylinders, water-cooled
  Only 23 I-1430 series engines were delivered. Although more powerful and lighter than the nearest competitor, the engine was not produced because tooling capacity for large scale production was not available.
  TECHNICAL NOTES:
  Model: Continental I-1430 Hyper
  Type: 12-cylinder, liquid-cooled, inverted Vee
  Displacement: 1,430 cu.in.
  Horsepower: 1,600
  RPM: 3,200
  Weight (dry): 1,615 lbs.
  
• Power rating: 2,386 kW (3,200 hp) at 3,200 rpm
• Displacement: 23.4 L (1,426 cu in.)
• Bore and Stroke: 140 mm (5.5 in.) x 127 mm (5 in.)
• Weight: 732.6 kg (1,615 lb)

 

[wuzak]

This Continental I-1430-11 was test flown in a modified Lockheed P-38 testbed aircraft.

Would that have been the XP-49?

 

[wuzak]

The story is that when installed in the XP-67 or XP-49 the engine barely made over 1000hp.

And that the XP-67 pilot deliberately destroyed the engine by overheating it.

 

[johnbr]

The final McDonnell design, the McDonnell XP-67 "Bat" or "Moonbat", was powered by a pair of engines in wing-mounted nacelles with 4-bladed propellers in a tractor configuration. However, the design was quite ambitious; the design team tried to maintain a true airfoil section through the center fuselage, merge the rear portions of the engine nacelles with the wing, and radically fillet all edges of the fuselage and nacelles into the wings in an effort to reduce drag. The design used laminar airfoil sections throughout. The production aircraft was intended to have a pressurized cockpit, a novel innovation at the time. Although the design was conceptually advanced, it was beset by numerous problems and never approached its anticipated level of performance. The project was cancelled after the sole completed prototype, which first flew on January 6, 1944, was destroyed by an engine fire.

 

[Wurger]

 

[johnbr]

The McDonnell Moonbat was a prototype interceptor aircraft. Upstart aerospace parts manufacturer McDonnell Aircraft was eager to begin manufacturing its own aircraft. The advanced design never approached its anticipated level of performance. The project was cancelled in September 1944 after the sole completed prototype was destroyed by an engine fire. Its first flight was in January 1944.

On 30 September 1941, McDonnell received a contract for two prototypes, a wind tunnel model, and associated engineering data. The Model IIa was designated as the XP-67.

Photos are of Project #85 in February 1942.

 

[johnbr]

Xp-67 engine
https://crgis.ndc.nasa.gov/historic..._with_Continental_XIV-1430-17/19_Hyper_Engine

 

[Wurger]

 

[Old Wizard]

 

[johnbr]

 

[johnbr]

 

[johnbr]

Type: Long Range Fighter​

Origin: McDonnel Aircraft Corporation​

Crew: One​

Model: XP-67​

First Flight: January 6, 1944​

Production: 1 Prototype​

Engine:​

Model: Continental XI-1430-17/19​

Type: 12-Cylinder inverted-Vee aircooled engine​

Number: Two Horsepower: 1,350 hp​

Dimensions:​

Wing span: 55 ft. 0 in.​

Length: 44 ft. 9.25 in.​

Height: 15 ft. 9 in.​

Lifting Surface Area: 414 sq. ft.​

Weights:​

Empty: 17,745 lb.​

Loaded: 22,114 lb.​

Maximum: 25,400 lb.​

​

Performance:​

Maximum Speed: 405 mph at 25,000 ft.​

Maximum Speed: 357 mph at 10,000 ft.​

Maximum Climb Rate: 2,600 ft./min.​

Service Ceiling: 37,400​

Maximum Range: 2,385 miles​

Armament: Proposed​

Six 37mm M4 cannon mounted in wing roots​

Ammunition: 45 rounds per gun.​

 

[johnbr]

The XP-67 was the first attempt by the McDonnell corporation to build a fighter for the United States Military. The same corporation would go on to built the superb F-4 Phantom II, F-15 Eagle and F-18 Hornet air superiority and strike fighters would initially see some bumps in the road, led by none other than James S. McDonnell himself.

McDonnell had acquired a substantial amount of aeronautics education in his schooling (Princeton), having served with the Army Air Service and ultimately various aircraft manufacturers. With one successful design under his belt (stalled by the arrival of The Great Depression), McDonnell sought to earn his own wings under his own banner. Thusly, the McDonnell company was born and looked to make some quick connections with the US Military.

The XP-67 was such a connection. A very ambitious design in every sense of the word, the fighter was intended to be the Allied answer to killing enemy bombers in the sky. The formidable aircraft would undertake a radial design that saw the entire aircraft visually flattened from end to end. The twin engine system would have its engines forged straight into the large wing area generating a stable about of air flow, drag and lift. The single-seat cockpit was planned to be pressurized and the aircraft was designed to reach top speeds close to 500 miles per hour. Alas, the final product would not come close to matching those specifications - a project too ambitious for the time.

Armament of the XP-67 initially consisted of a 6 x 12.7mm machine gun array with an additional 4 x 20mm cannon. This was later upgraded to a 6 x 37mm cannon system with speculative designs also featuring a single massive 1 x 75mm cannon. In any respect, the XP-67 would have been the consummate bomber-killer that McDonnell and the US Military had envisioned from the beginning. Unfortunately, the intended armaments were never added to the prototype system itself.

With the first prototype rolling out in December of 1943, it quickly became apparent that the engines would be prone to catching fire. With the engines held deep in the nacelles, the fire would have already begun to spread uncontrollably before being noticed, adding an unacceptable element of danger to the design. Cooling of the engine also became an issue throughout testing and the turbo chargers never lived up to expectations.

By 1944, with Germany's air force concentrating mostly on its fighter designs, the need for a true dedicated bomber-killer was no longer. As a result, the Army saw fit to cancel the XP-67 project. A second XP-67 - this one with a jet powerplant in the rear along with the two propeller engines - was almost complete when the cancellation call came in.

With the effective death of the XP-67 and lessons learned, the McDonnell corporation would turn its attention to the arrival of the jet age and begin a production run of very successful aircraft. Had the XP-67 been allowed to fly, had its engine issues ironed out and had Germany still maintained a bomber force to be reckoned with, the XP-67 would have quite possibly been the Allied answer to combat the Reich in this fashion.
Dimensions:
Length: 44.78ft (13.65m)
Width: 54.99ft (16.76m)
Height: 15.81ft (4.82m)

Performance: (About MACH)
Maximum Speed: 270mph (434kmh; 234kts)
Maximum Range: 2,384miles (3,836km)
Rate-of-Climb: 2,600ft/min (792m/min)
Service Ceiling: 37,999ft (11,582m; 7.2miles)
Structure:
Accommodation: 1
Hardpoints: 0
Empty Weight:17,749lbs (8,051kg)
Maximum Take-Off Weight:25,399lbs (11,521kg)
Powerplant:
Engine(s): 2 x Continental XIV-1430-17/19 radial engines generating 1,600hp each.

Armament Suite:
Original:
6 x 12.7mm machine guns
4 x 20mm cannons
Updated Design:
6 x 37mm cannons

Planned:
1 x 75mm cannon
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