The XP-52 and XP-59

[Wuzak]

In 1939 Bell produced a proposal for a fighter with a pusher layout, twin booms and swept back wings. It was to be powered by a Continental IV-1430, and was known as the XP-52. The radiator was mounted in a duct in the nose.

Estimated performance was 425mph (684km/h) at 19,500ft (5,944m);

This aircraft was superseded by a new proposal, where the liquid cooled Continental was replaced by the air cooled Pratt & Whitney R-2800, the aircraft being redesignated XP-59. The nose intake was continued, presumably with the air ducted around to the R-2800.

Estimated performance was up to 450mph (725km/h) at 22,000ft (6706m).

A picture of the XP-59 wind tunnel model on Wiki:
http://en.wikipedia.org/wiki/File:Bell_XP-59_wind_tunnel_model_060913-F-1234P-012.jpg

This too was cancelled, and an order for a jet aircraft prototype was ordered from Bell, using the designation XP-59A.

The XP-59A was completely different to the XP-59. The XP-59 design seems to lend itself to a jet engine installation, with an intake already in the nose for the engine(s) and the main modification to the airframe required would be to lift the tailplane clear of the exhaust.

Baugher speculates as to why Bell was chosen to make the first jet prototype, but perhaps one reason was the apparent suitability of the XP-59 to jet power. Surely developing the XP-59 had already had quite a lot of work done on aero and structural design, which would have made life simpler for them.

The XP-59A contract also required work to be done quickly - perhaps another case that the USAAC/F saw the XP-59 as the perfect vehicle for the jet, but forgot to tell Bell?


http://home.att.net/~jbaugher1/p52.html
http://home.att.net/~jbaugher1/p59.html
http://en.wikipedia.org/wiki/P-59_Airacomet

[Red Admiral]

The XP-59 would be severely down on power with only 1 jet giving around 1600lbf. I'd imagine that was the main reason behind the redesign. I think Bell was probably chosen from their light workload as well which meant they were easily able to take on another project. They just managed to create a plane that can only be described as poor.

With a more powerful engine like the H.1 then the single engine version is more of a proposition. You've got something pretty similar to the Vampire. The problem was that the H.1 wasn't yet available, and when it was it was used for the P-80.

[ChrisMcD]

Hi Folks,

I remember reading that Bell were very concerned about loss of power due to overlong ducting - both intake and exhaust. There seems to have been a lot of concern about this at the time that influenced a lot of the layouts chosen (ie 262, Meteor, Vampire).

Compared to the 262 and Meteor - where asymmetric thrust problems were a major problem, the Bell layout looks like a superior design.

I remember that the 262 had a lethal reputation for single engined failures at takeoff.

Then there is the Zurabatic Cartwheel!

http://www.avroarrow.org/AvroArrow/JanZurakowski.html

[Wuzak]

The XP-59 would be severely down on power with only 1 jet giving around 1600lbf. I'd imagine that was the main reason behind the redesign. I think Bell was probably chosen from their light workload as well which meant they were easily able to take on another project. They just managed to create a plane that can only be described as poor.

With a more powerful engine like the H.1 then the single engine version is more of a proposition. You've got something pretty similar to the Vampire. The problem was that the H.1 wasn't yet available, and when it was it was used for the P-80.


Any reason why they couldn't modify the rear fuselage to take two Jets?

[Red Admiral]

Any reason why they couldn't modify the rear fuselage to take two Jets?

Space I imagine.

An R-2800 engine is 53" diameter whilst the J31 was around 45" (I think) You'd have to make some drastic alterations to the wing centre section in order to widen the fuselage to fit two engines in and it rather negates the nose inlet.

http://i25.photobucket.com/albums/c84/AviationImages/MBproj001-1.jpg

Another solution is this one from Martin-Baker with a Derwent in the nose and tail and a good quantity of ducting.

[Wuzak]

Space I imagine.

An R-2800 engine is 53" diameter whilst the J31 was around 45" (I think) You'd have to make some drastic alterations to the wing centre section in order to widen the fuselage to fit two engines in and it rather negates the nose inlet.

True enough.

Looking at the P-59A's contemporaries, it was, according to Wiki*, but not other sources I have, faster (413 mph/664 km/h) than the MkI Meteors (410 mph/660 km/h), which had similar engines.

Interestingly the single engine jets (The Vampire and the P-80) proved to be much faster, with top speeds in excess of 500 mph/800 km/h. The jets they used had more thrust than those in the Meteor and P-59A.

The Meteor also first flew with Halford H1s, which was to be developed into the Dh Goblin.

*Reading the text it specifies that the F MkI Meteor had a top speed of 417 mph/671 km/h but the in teh specifications it is listed as 410 mph/660 km/h.

[Kutscha]

A book considered to be an excellent reference source by some has the top speed of the P-59 as 376mph/605kph @ 5000'/1525m and 409mph/658kph @ 35000'/10670m. (could the P-59 actually reach 35k'?)

[Red Admiral]

Service ceiling was quite high for the P-59 at around 46000ft because of the large wing. Of course, the large draggy wing and draggy airframe meant that speed was considerably limited. Instead of achieving best speed at around 8000ft like other early jets (being Mach limited) it achieved it at 30,000ft+ as there was so much skin friction drag. Bell then developed the P-59 into the P-83 which was much larger and heavier and possibly more of a turkey.

[GregP]

There were 3 XP-59As and 13 YP-59As. All were hand made. Just becuase you made somethuing for the left side ... didn't mean that the item on the right side was a mirror image.

The GE I-A engines (1,400 lbs S.t nominally) and the GE I-16 / J31-GE engines including both the -3 (1,650 lbs s.t.) and -5 (2,000 lbs s.t.) units had different performances.

So, their maximum speeds were quite variable among the population.

The 3 XP-59As had side-opening canopies. The YP-59As and onward had sliding canopies that were a bit taller. That added drag but made exit from a failing airframe easier.

Yes, they had BIG wings and yes, they could fly HIGH for the times. So could the F-89 Scorpions that used a very similar wing.