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Douglas XB-42 Mixmaster
par Mucray Mer 07 Juil 2010, 21:16
Le XB 42 de Douglas sur Wikipedia version anglaise :
[Vous devez être inscrit et connecté pour voir ce lien]
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The [Vous devez être inscrit et connecté pour voir ce lien] XB-42 Mixmaster was an experimental [Vous devez être inscrit et connecté pour voir ce lien], designed for a high top speed.
The unconventional approach was to mount the two engines within the [Vous devez être inscrit et connecté pour voir ce lien] driving a pair of contra-rotating propellers mounted at the tail, leaving the wing and fuselage clean and free of aerodynamics-reducing protrusions.
Two prototype aircraft were built, but the end of [Vous devez être inscrit et connecté pour voir ce lien] changed priorities and the advent of the jet engine gave an alternative way toward achieving high speed.
[Vous devez être inscrit et connecté pour voir ce lien]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
The [Vous devez être inscrit et connecté pour voir ce lien] XB-42 Mixmaster was an experimental [Vous devez être inscrit et connecté pour voir ce lien], designed for a high top speed.
The unconventional approach was to mount the two engines within the [Vous devez être inscrit et connecté pour voir ce lien] driving a pair of contra-rotating propellers mounted at the tail, leaving the wing and fuselage clean and free of aerodynamics-reducing protrusions.
Two prototype aircraft were built, but the end of [Vous devez être inscrit et connecté pour voir ce lien] changed priorities and the advent of the jet engine gave an alternative way toward achieving high speed.
Mucray- CLUB
- Messages : 678
Re: Douglas XB-42 Mixmaster
par Mucray Mer 07 Juil 2010, 21:20
The aircraft mounted a pair of [Vous devez être inscrit et connecté pour voir ce lien] liquid-cooled V-12 engines behind the crew's cabin, each driving one of the twin propellers.
Air intakes were in the wing leading edge.
The undercarriage was [Vous devez être inscrit et connecté pour voir ce lien] and there was a long fin under the tail to prevent the propellers from striking the ground.
The pilot and co-pilot sat under twin [Vous devez être inscrit et connecté pour voir ce lien], and the bombardier sat in the extreme front behind a plexiglass nose.
Air intakes were in the wing leading edge.
The undercarriage was [Vous devez être inscrit et connecté pour voir ce lien] and there was a long fin under the tail to prevent the propellers from striking the ground.
The pilot and co-pilot sat under twin [Vous devez être inscrit et connecté pour voir ce lien], and the bombardier sat in the extreme front behind a plexiglass nose.
Mucray- CLUB
- Messages : 678
Re: Douglas XB-42 Mixmaster
par Mucray Mer 07 Juil 2010, 21:22
Defensive armament was two 0.50 in (12.7 mm) machine guns each side in the trailing edge of the wing, which retracted into the wing when not in use.
These guns were aimed by the copilot through a sighting station at the rear of his cockpit.
The guns had a limited field of fire and could only cover the rear, but with the plane's high speed it was thought
unlikely that intercepting fighters would be attacking from any other angle.
These guns were aimed by the copilot through a sighting station at the rear of his cockpit.
The guns had a limited field of fire and could only cover the rear, but with the plane's high speed it was thought
unlikely that intercepting fighters would be attacking from any other angle.
Mucray- CLUB
- Messages : 678
Re: Douglas XB-42 Mixmaster
par Mucray Mer 07 Juil 2010, 21:24
Two more guns were fitted to fire directly forward. Initially ordered as attack aircraft (XA-42) in the summer of 1943, this variant would have been armed with 16 machine guns or a 75 mm (2.95 in) cannon and two machine guns.
Mucray- CLUB
- Messages : 678
Re: Douglas XB-42 Mixmaster
par Mucray Mer 07 Juil 2010, 21:25
Operational history
The first XB-42 was delivered to Army Air Force and flew at [Vous devez être inscrit et connecté pour voir ce lien] on 6 May 1944.
Performance was excellent, being basically as described in the original proposal; as fast or faster than the [Vous devez être inscrit et connecté pour voir ce lien] but with defensive armament and twice the bombload.
The first XB-42 was delivered to Army Air Force and flew at [Vous devez être inscrit et connecté pour voir ce lien] on 6 May 1944.
Performance was excellent, being basically as described in the original proposal; as fast or faster than the [Vous devez être inscrit et connecté pour voir ce lien] but with defensive armament and twice the bombload.
Mucray- CLUB
- Messages : 678
Re: Douglas XB-42 Mixmaster
par Mucray Mer 07 Juil 2010, 21:26
The twin bubble canopies proved a bad idea as communications were adversely affected and a single bubble canopy was substituted after the first flight.
Testing revealed the XB-42 suffered from some instability as excessive yaw was encountered, vibrations and poor engine cooling - all problems that could probably have been dealt with.
The [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien] underneath the fuselage.
Careful handling during takeoff and landing was going to be required on account of the limited ground clearance.
Testing revealed the XB-42 suffered from some instability as excessive yaw was encountered, vibrations and poor engine cooling - all problems that could probably have been dealt with.
The [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien] underneath the fuselage.
Careful handling during takeoff and landing was going to be required on account of the limited ground clearance.
Mucray- CLUB
- Messages : 678
Re: Douglas XB-42 Mixmaster
par Mucray Mer 07 Juil 2010, 21:31
In December 1945, Captain [Vous devez être inscrit et connecté pour voir ce lien] and Lt. Col. Henry E. Warden set a new transcontinental speed record when they flew the XB-42 from [Vous devez être inscrit et connecté pour voir ce lien] to [Vous devez être inscrit et connecté pour voir ce lien] in [Vous devez être inscrit et connecté pour voir ce lien] (c. 2,300 miles) and in just 5
hours, 17 minutes, the XB-42 set a speed record of 433.6 mph (697.8 km/h).
hours, 17 minutes, the XB-42 set a speed record of 433.6 mph (697.8 km/h).
Mucray- CLUB
- Messages : 678
Re: Douglas XB-42 Mixmaster
par Mucray Mer 07 Juil 2010, 21:34
The record-breaking XB-42 prototype had been destroyed in a crash at Bolling Field attributed to a failure of the landing gear, but the other was used in flight test programs, including fulfilling a December 1943 proposal by Douglas to fit uprated engines and underwing [Vous devez être inscrit et connecté pour voir ce lien] 19XB-2A axial-flow [Vous devez être inscrit et connecté pour voir ce lien] of 1,600 lbf (7.1 kN) thrust each, making
it the XB-42A.
In this configuration, it first flew at Muroc (now [Vous devez être inscrit et connecté pour voir ce lien]) on 27 May 1947.
In testing, it reached 488 mph (785 km/h).
it the XB-42A.
In this configuration, it first flew at Muroc (now [Vous devez être inscrit et connecté pour voir ce lien]) on 27 May 1947.
In testing, it reached 488 mph (785 km/h).
Mucray- CLUB
- Messages : 678
Re: Douglas XB-42 Mixmaster
par Mucray Mer 07 Juil 2010, 21:37
After 22 flights, the lower vertical stabilizer and rudder were damaged in a hard landing in 1947.
The XB-42A was repaired but never flew again, and was taken off the AAF inventory list 30 June 1949.
The XB-42A was repaired but never flew again, and was taken off the AAF inventory list 30 June 1949.
Mucray- CLUB
- Messages : 678
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