YP-80A "the skunkworks sylph"

[vanir]

For those who got a slapping for thread hijacking with a P-80A vs Me-262 debate.

Little extra info on the X/YP-80A, we usually hear more about the 262.




Lockheed was selected in mid43 for a contract to develop a combat worthy jet fighter to succeed the XP-59A. The design requirement was to use the De Havilland H-1B turbojet to be license produced, a centrifugal design completely different to the German Jumo. Another requirement was a test airframe ready to fly in 180 days.

Kelly Johnson completed the prototype, named Lulu-Belle in 143 days. January 9, 1944 the XP-80 flew at Muroc with Milo Burcham at the controls and the De Havilland motor (same as the kind used in the Vampire and MiG-15).

Max initial climb rate was 3000fpm, maximum level speed reached 502mph at 20,480ft and usable ceiling reached 41,000ft.

But the license producer of the De Havilland jet were encountering engineering difficulties and the USAF wanted an alternate engine. General Electric was working on its own license produced axial thrust engine called the I-40, production designation J33. They authorised Lockheed to build a prototype with this engine.

The second prototype, designated XP-80A and called Gray Ghost for its paint scheme was completed in 132 days. It was similar looking but bigger and weighed 25% more than Lulu-Belle, plus was fitted with rudimentary cockpit pressurisation. Tony Le Vier flew it on June 11, 1944.
He noted it was longitudinally unstable without gun/ammunition ballast, this issue haunted the production series as all P-80 become unstable when the ammo runs out, it's one of the only aircraft which are ferried with guns/ammo.
There was a lot of bugfixing to do like sorting cockpit air conditioning, temperatures reached 180F and blistered Le Vier's skin. It was fixed by combining it with a refrigeration system.
And a faulty tachometer had almost caused an accident due to incorrect engine settings.
Le Vier was also identifying new phenomenae peculiar to jet flight, such as "inlet rumble" caused by boundary layer air around the engine inlets, which can induce directional snaking of the aircraft.
Engine flameouts at high or low altitudes were also commonplace.

A second XP-80A prototype in a bare metal finish was made, called the Silver Ghost. Wingtip fuel tanks were tested on this airframe.
Following this a preproduction series were built to the same configuration for service testing, the YP-80A.

Over the course of testing, using the GE-J33 max initial rate of climb leapt to 5000fpm, top speed an easy 550mph and usable ceiling passed 45,000ft with ballast for war armament loadouts.

Then the YP-80A started killing pilots. Milo Burcham died in one when a fuel governer failed (overspeeding the turbine at about 50ft above ground on take off, it was messy).
Dick Bong, a Pacific ace was flying a new YP-80A when a similar engine failure claimed his life.
Then one tried to kill Tony Le Vier, destroying the Gray Ghost XP-80A testbed (he had a reputation for roaming around the aerodrome at speeds exceeding 575mph in it). Nobody could figure out why it suddenly shed its tail following a mechanical shudder in flight.
Then Army pilot Van Nuys managed to bring a YP-80A to a belly landing after experiencing another engine failure.

Investigators found substandard manufacture of turbine blades were causing the failures, which was due to the industrial processes used to make them in the US. The turbine shed blades and the blades buzzsawed through tailplanes and fuselage sections during flight.

This took time to find, and fix. It would've precluded successful use of the type during the war years, if it was put in front line service in 1945, the P-80A would've been dropping like flies to turbine failures.

By 1947 the P-80 was sorted and a specially prepared P-80R set an airspeed record of 623.738mph over Muroc.

 

[Siegfried]

For those who got a slapping for thread hijacking with a P-80A vs Me-262 debate.

Investigators found substandard manufacture of turbine blades were causing the failures, which was due to the industrial processes used to make them in the US. The turbine shed blades and the blades buzzsawed through tailplanes and fuselage sections during flight.

This took time to find, and fix. It would've precluded successful use of the type during the war years, if it was put in front line service in 1945, the P-80A would've been dropping like flies to turbine failures.

By 1947 the P-80 was sorted and a specially prepared P-80R set an airspeed record of 623.738mph over Muroc.

I think the engine MTBO at the time was 50 hours, about twice that of the Jumo 004B. I also believe the alloy was not nimonic as used on the British engines but the following:

100 years of Aircraft engines | Machine Design
"When the Army Air Corp wanted a more powerful jet engine, GE produced the I-40 (J-33). It powered the P-80 Shooting Star. It used a host of alloys, including Inconel for the combustion system, Stellite for the turbine nozzles, and Hastelloy B for the turbine bucket."

ie traditional US turbo charger materials.

When the BMW tried to use turbo charger techniques (ie welding of turbine blades to the disc) they found that this didn't work on upscaled turbines.

The German alloys were essentially just stainless steels or Iron alloys: tinidur, cromidur and sicromal but in very selected areas only: turbines, turbine buckets. Combustion chambers were passivated steel.

The task of controlling jet engines so that they are protected from mommentary fuel surges was grossly underestimated by all combatents: its not particularly difficult.

Speed of combat equiped P-80A seems to be 530mph not 550mph.

 

[FLYBOYJ]

The P-80A would have killed a few pilots had the USAAF really wanted them pumped out, but remember, these failures occurred during production test flight, the point where you wanted to identify problems like this. Unfortunetly these failures killed an excellent test pilot, the American top ace and almost killed Tony LeVier. BTW, Bong's accident was due to the same condition that killed Burcham.

"At the time of the crash, Bong had accumulated four hours and fifteen minutes of flight time (totaling 12 flights) in the P-80. The I-16 fuel pump was a later addition to the plane (after an earlier fatal crash) and Bong himself was quoted by Captain Ray Crawford (another P-80 test/acceptance flight pilot who flew the day Bong was killed) as saying that he had forgotten to turn on the I-16 pump on an earlier flight"

I interviewed Tony back in 1990 when I was writing for a small newspaper part time. Tony told me he didn't think Bong ever got a thorough briefing/ check out in the P-80 and felt that if he had an opportunity to meet with him Bong would have never had his accident. Wreckage of Tony's aircraft can still be found along Serria Highway just noth of Lancaster Ca.

The X-Hunters - Aerospace Archeology Team

 

[vanir]

Thanks FlyboyJ, always welcome your posts and like your point of view. I'm still picking up things in life, I look to others still as a guide. Sad to hear Tony's regret.

 

[FLYBOYJ]

Thanks Vanir, Tony was quite a guy - I also an opportunity to meet Milo Burcham Jr. when I worked at Lockheed. Didn't mention the accident, just the legacy of his dad.

 

[nuuumannn]

Hi Guys,

Just a few points about the de Havilland engine, the Halford H.1B as it was known after its designer, the brilliant Frank Halford, responsible for the DH Gipsy inline family, also the Napier H series of engines, including the Sabre, was later known as the de Havilland Goblin. The Goblin was a centrifugal flow gas turbine with a single compressor wheel and 16 combustion chambers, with a straight-through flow from these to the turbine section, which Halford reasoned would be more efficient than the 'S' bend design of Frank Whittle's early Power Jets engines.

On carrying out engine runs of the XP-80 prototype on 17 November 1943, the aircraft's intake skins buckled under the strain and got sucked into the bifurcated engine intakes, damaging the engine. This was because the aircraft's intakes were too lightly manufactured and had nothing to do with the design of the engine, as is sometimes claimed. In order to continue the programme, a second Halford H.1 was sent to Lockheed; this had been originally intended for the second prototype de Havilland D.H.100 Spider Crab, eventually renamed Vampire.

One minor point; the MiG-15 was powered by a copy of the 5,000 lb thrust Rolls Royce Nene as the Klimov RD-45, a far more powerful engine than the DH Goblin. A derivative of this engine also powered the MiG-17. In 1946, in a bizarre move, the British government supplied the Russians with examples of the Rolls Royce Derwent and Nene jet engines, from which they developed the Nene beyond what Rolls Royce ever did, since the British firm was convinced that the axial flow Avon was the way ahead, despite the real potential the engine offered. The Nene was licence built in the USA as the Pratt Whitney J-42.

Waaay off topic, now. I bet your conversations with those guys were fascinating, Flyboyj; I'd be hanging on every word they said.

 

[pbfoot]

Also manufactured by Orenda in Canada and used to power the 650+ Canadian built version of T33

 

[FLYBOYJ]

Waaay off topic, now. I bet your conversations with those guys were fascinating, Flyboyj; I'd be hanging on every word they said.

No worries, but yes, it was exciting to meet them, I cherish my years at Lockheed. Got to hear Kelly Johnson speak at a Lockheed Management Club dinner one night, he talked about the U-2 development.

A comment about the Soviets and the Nene - although they were given the engines, they did not have manufacturing rights nor were they privy to proprietary detailed information about the engine. That information was flat out stolen by agents who were able to visit the RR factory and walk up on some of the machines manufacturing engine components. The Soviet agents wore rubber soles that picked up the metal chips left on the floor by the machines. These chips were analyzed and the metallurgy was able to be copied.

 

[Matt308]

The P-80A would have killed a few pilots had the USAAF really wanted them pumped out, but remember, these failures occurred during production test flight, the point where you wanted to identify problems like this. Unfortunetly these failures killed an excellent test pilot, the American top ace and almost killed Tony LeVier. BTW, Bong's accident was due to the same condition that killed Burcham.

"At the time of the crash, Bong had accumulated four hours and fifteen minutes of flight time (totaling 12 flights) in the P-80. The I-16 fuel pump was a later addition to the plane (after an earlier fatal crash) and Bong himself was quoted by Captain Ray Crawford (another P-80 test/acceptance flight pilot who flew the day Bong was killed) as saying that he had forgotten to turn on the I-16 pump on an earlier flight"

Interesting. Perhaps I'm recalling a different person other than Bong, but I have a book on Korean War Aces (name escapes me, but can cite it if needed) that notes Bong crashed on takeoff and the suspected cause was a habit from his prop time of throttling back right shortly after takeoff, which starved the turbine engine in the P-80. I'll have go back and re-read that section.

 

[FLYBOYJ]

Interesting!

 

[nuuumannn]

No worries, but yes, it was exciting to meet them, I cherish my years at Lockheed. Got to hear Kelly Johnson speak at a Lockheed Management Club dinner one night, he talked about the U-2 development.

That would have been real mouth watering stuff. I imagine Kelly Johnson to be a great orator. I've read only part of Ben Rich's book on the Skunk Works, and thoroughly enjoyed what I read. Those would have been good days.

That information was flat out stolen by agents who were able to visit the RR factory and walk up on some of the machines manufacturing engine components. The Soviet agents wore rubber soles that picked up the metal chips left on the floor by the machines. These chips were analyzed and the metallurgy was able to be copied.

Yep, I've heard similar stories too, those crafty Russkies! Still, you have to wonder what on Earth Clement Attlee's government was up to giving them examples of British jet engine technology. Attlee was a socialist; I have read that the move was made as a friendly gesture. His government did, however give the British people one of the best things to happen to British society, the National Health Service - free access to medical assistance for all.

 

[Matt308]

Yep, I've heard similar stories too, those crafty Russkies! Still, you have to wonder what on Earth Clement Attlee's government was up to giving them examples of British jet engine technology. Attlee was a socialist; I have read that the move was made as a friendly gesture. His government did, however give the British people one of the best things to happen to British society, the National Health Service - free access to medical assistance for all.

Oh how lovely.

 

[Matt308]

Matt308 any more political outbursts and we will remain you to a nice spot on the beach for a few days.

 

[Matt308]

Apologies to the forum. I will refrain in the future. Carry on.

 

[nuuumannn]

Also manufactured by Orenda in Canada and used to power the 650+ Canadian built version of T33

Yep; there was plenty of potential in the Nene; there was a Nene Vampire planned and Britain's best chance at developing a direct competitor to the MiG-15 was powered by the Nene; the Hawker P.1081 and P.1087 (although these were designed to be powered by the RR Tay). RR's decision to go straight to the Avon hampered airframe development in the UK; especially since the Avon was a bit of a dog to begin with; it suffered severely from compressor stall, which led to inevitable delays with a/c into service. The Armstrong Siddeley Sapphire was a far superior design, not having any of the issues of the Avon. It wasn't until the Sapphire's compressor section was copied and grafted onto the Avon did it become the engine it should have been.