Twin Mustang… getting close to flying

Hmm. Maybe there is something to my theory.
Thrust line of the Hornet is below the wing like the ’82.
Prop rotation works best inward at the top. Am I a genius? (please don’t answer that)

Andy

Here’s a little snippet from the Wickepedia page

“Like several versions of the P-51 Mustang, the first two prototype XP-82s as well as the next 20 P-82B models were powered by British-designed Rolls-Royce Merlin engines, built under license by Packard. These provided the fighter with excellent range and performance; however, the Army had always wanted to give the Twin Mustang a purely American and stronger engine than the foreign-designed P-51’s V-1650 (built at Packard plants, dismantled after the war). In addition, the licensing costs paid to Rolls-Royce for each V-1650 were being increased by Britain after the war. It therefore negotiated in August 1945 with the Allison Division of the General Motors Corporation for a new version of the Allison V-1710-100 engine.[1] This forced North American to switch subsequent production P-82C and later models to the lower-powered engines. It was found that Allison-powered P-82 models demonstrated a lower top speed and poorer high-altitude performance than the earlier Merlin-powered versions.”

The engines on the prototype were originally set up like the P-38 with the tips rotating outward at the top.
As you say Oxcart, it wouldn’t fly.
They quite literally switched the engines to the opposite sides and ended up with a world beater.
The P-38 suffered from the opposite problem. With the prop tips turning in at the top, it didn’t fly worth a darn.

I wonder if the reason is because the thrust lines of each A/C were different. That is P-38 below the wing mean chord whilst the ’82 has the thrust line above.
Just my observation.

Andy

There was a bit of a problem on the prototype. The prop rotation caused the centre wing section to stall and it wouldn’t fly!

As ever, one lives and learns!

The XP.22 Twin Mustang was fitted with a Packard Merlin V.1650-21.

This was a fully reverse rotation engine with the Carb fitted with a Speed Density Pump.

Mark

Not the XP.

Some of the production models were Merlin powered as well.
I can’t list them off the top of my head.

The project was incredibly lucky to find a very rare opposite rotation Merlin.

I thought the P-82 had Allisons?

dcollins wrote

“Does this have counter-rotating props, ie. one being a left hand tractor, and the other being a right hand tractor, in the same way as the Hornet’s 130 series Merlins?

If it does, are they rotating down towards the centre (like the Hornet) or upwards at the centre?”

Yes David. Props rotate inwards at the top. The project was incredibly lucky to find a very rare opposite rotation Merlin.
(Sorry, I don’t know the designation off hand, but It would be fairly easy to find by looking through the rebuild diary)

http://xp-82twinmustangproject.blogspot.ca/

It’s a pretty good read. Hope that helps.

Andy

1987, Dazdaman. The CAF’s ‘B’ model. But it landed very heavily and ended up at the Air Force Museum after they tried to sell it and the Air Force said they couldn’t do that because it was on loan and claimed it back.

Very impressive.

When was the last time one of these flew?

Impressive achievement.

Does this have counter-rotating props, ie. one being a left hand tractor, and the other being a right hand tractor, in the same way as the Hornet’s 130 series Merlins?

If it does, are they rotating down towards the centre (like the Hornet) or upwards at the centre?