Navalized P-38 Lightning?

Scott Peterson wrote:

Guy Alcala wrote:

Certainly. I'll have to use the figures for the PBJ-1H, essentially the
marine version of the B-25H. With a bombload of 6 x 500 lb bombs plus the
75mm cannon and ammo, at a t/o weight of 35,106 lb. (considerably heavier
than Doolittle's B-25Bs), the t/o runs are as follows (note, this is for a
field not a carrier deck):

0 wind, 1495 feet.
15 knots, 1064 feet.
25 knots, 813 feet.

Nice of you to use a version that's almost 7000 pounds heavier.

The discussion was about the ability of a P-47 to make a free-running t/o from a
CVE. I used the heaviest weight B-25 data I had to show that even _that_
version only needed between 2/3rds and 3/5ths of the t/o run that a clean but
fully fueled and armed P-47 does (2,220 - 2,540 feet). Hell, the PBj-1H's power
on stall speed at that weight was only 93 knots (see Hornet WoD below).
Naturally, lighter B-25s like Doolittle's (about 31,000 lb. was the predicted
weight, or about 4,000 lb. less than the above -- see

http://www.ibiblio.org/hyperwar/AAF/...B-Special.html

have even shorter t/o runs, given them an even more significant advantage over
the P-47.

Please note that the Hornet was worked up to just about full speed, i.e.
30+ knots, and there was a considerable natural wind blowing when Doolittle
& Co. took off.

Glad it wasn't an unnatural wind. But so what? From what I remember
they were anticipating and trained based on about 40 knots over the
bow when they took off. That they got more was a bonus.

Here's so what. 40 knots WoD (combination of 'unnatural' wind, i.e. ship speed,
and natural wind) is considerably more than an 18 kt. CVE is likely to be able
to supply in the generally warmer and calmer tropics, while a 30+ kt. CV in the
North Central Pacific can almost guarantee it. Actually, checking Hornet's
after action report at

http://www.ibiblio.org/hyperwar/USN/...cv8-Tokyo.html

it seems that the Hornet was steaming at only 22 kts, as there was 40+ knots of
natural wind (see para. 1(j). of the above), for a WoD of 62kts or better. And
the lead a/c (Doolittle's) had a 467 ft. deck run available (para 1(g), same
ref.), i.e. 25 feet more than the_total_ length of a Bogue's flight deck (442
feet) and only 10 feet less than the total length of a Casablanca (477 feet). A
ferry carrier would have to catapult its entire deck load off first, before it
had anywhere close to that much t/o run available.

In point of fact, the Navy conducted flight tests using a slightly
modified P-51D (I think) on USS Shangrila in 1944. The plane was
easily able to take off using the same space as Navy fighters

And how, pray tell, was it able to "take off using the same space as a navy
fighter," when (even assuming the '1,185 ft.' figure for the P-51D's t/o
run given in "America's Hundred Thousand," is _not_ a typo) the
contemporary F6F-5 and F4U-1D only required t/o runs under the same
conditions of 780 ft. (405 feet less than the P-51D) and 840 feet (345 feet
less) respectively?


Apparenttly very easily. If you read the rest of the report you quote
below it mentions that they had deck left when they lifted on all the
takeoffs.

Not sure which report you're referring to. It's not in Brown's account which I
quoted. But how long was the deck run, exactly, what were the WoD conditions,
what did the P-51s weigh, and what were they loaded with (and where was the
Cg)? I'd be kind of surprised if the rear tank was filled.

and no
catapult and easily landed using a hook fitted for the tests. The
results were quite favorable but not compelling enough to continue.

'Quite favorable' is an interesting way of putting it. Eric Brown's
comments are rather different:

"Landing the Mustang required concentration, for at an approach speed of
105 mph the view was bad, and high-rebound ratio landing gear made a
three-point landing tricky, This state of affairs was exacerbated by the
aircraft's lack of directional stability, on the landing run. The U.S.
Navy abandoned the Mustang's deck-landing trials on an aircraft carrier for
these reasons."

It just shows you're taking material out of context. The problems
were because they had made so few modifications for the initial tests.
Had they continued, modified landing gear and modified tail were among
the anticipated changes.

Sure, they could maybe have made the a/c work, about as well as the Seafire
eventually did, and probably considerably less well than the Corsair (and look
how long that took to get right), which had, after all, been designed for the
job.

The view was bad, but certainly no worse than the Corsair. And until
strut changes were made to the Corsair it had the same bouncing
problems.

Uh-huh. and look how long it took to get those fixed (and the slow-speed control
problems, and the stall, etc.). If you haven't already read it, I can recommend
Boone T. Guyton's "Whistling Death: the Test Pilot's story of the F4U Corsair,"
as he was Vought's project pilot for the a/c.

And tests were not abandoned because of poor results. The results were
quite good. They were abandoned because the P-51 did not show any
significant advantage over the naval aircraft it would have replaced.

Sure. Why go to all that trouble to modify the a/c (adding lots of weight),
when you've got the F4U-4 available that has equal or better performance.

All of which makes the later Corsair sound like a great deck-landing a/c by
comparison.

Why should it? The Corsair was notorious for bad visibility during
landing.

Until they raised the seat 7" and bulged the hood, which is why I specified the
'later' Corsairs, i.e. -1A and subsequent. Still not great, but much improved.

But what, exactly, does this digression have to do with the
ability of a P-47 to make a non-catapult take off from a Casablanca or
Bogue class CVE that's only allows roughly half the t/o run, and is 15
knots slower than the Shangri-La?

P-51's were mentioned in the discussion and you posted those
meaningless numbers which had nothing to do with getting a plane off
of a carrier..

I posted the t/o numbers for context, during a discussion of the ability of the
P-47 (and for that matter, most army fighters) to get off a CVE unassisted,
which (barring unusual circumstances), it couldn't. And I'm curious as to why
you think a/c t/o run distances, whether relative or in this case absolute, are
meaningless and have nothing to do with getting a plane off a carrier. Which
numbers do you think would be more relevant?

Guy