Post by Peter StickneyPost by Geoffrey SinclairPost by Peter StickneySo, having sorted through nearly 60,000 Accident Reports for all types
from 1943-August 1945, here's what falls out.
These numbers are all for Continental US-based aircraft, so any losses
are due to normal activity, and not somebody makng holes in the
airplane with intent.
The first P-61s listed as "On Hand - Accepted by the USAAF and
available for issue was in October 1943. The number On Hand in CONUS
(Continental US) began at squadron level numbers in January 1944, and
built up to a nominal level of about 150 (Remember, these aircraft are
the ones used for training and being prepped for deployment overseas,
so it does bounce around a fair bit.
Flying Hours/month averaged at 1000 Hrs in 1944, and roughly 4000-5000
hrs/month in 1945 - Until August, after which the urgency had worn off.
Total P-61 accidents, ranging from a dinged wingtip from a line truck,
to crashing into a schoolhouse full of nuns, was 61.
Class A accidents, where the aircraft was writted off, or someone was
killed, was 23.
Fatal accidents were 7.
Total Flight Hours were 45,000 So, here are the numbers in standard
Flying Hours Total Accidents Class A (Destroyed Aircraft) Fatal
45,000 61 23 7 Which
gives rates per 100,000 flying hours (The standard measurement for
Accidents / 100K Hrs - 136 Percentage of total accidents: 100%
Class A / 100K Hrs - 51 Percentage of total accidents: 38%
Fatal / 100K Hrs - 16 Percentage of total accidents: 11%
Here are the corresponding numbers from the USAAF Statistical Digest
for the P-38 and A-20, which are roughly equivalent in size and
Aircraft Accident Rate Percent Class A Percent Fatal P-38
139 55% 24%
A-20 131 45% 23%
P-61 136 38% 11%
Some things to consider on the aggregate numbers - They will always
start high, with a small number of aircraft and flight hours, a single
accident can skew the rates significantly. These numbers tend to go
down as the Learning Curve is climbed, and mechanical/design, training,
and general familiarity issus are encountered and resolved, So the P-38
and A-20 numbers had 4-5 years to stabilize, and the P-61 was still in
the initial stage.
Given that, we can see that the overall accident rate is what would be
expected for a single pilot twin engine fighter, the severity of the
accidents was significantly lower, and the chances of ketting killed in
an accident are shout half.
So, taken in context, the P-61, despite the novelty of many of its
features, was less likely to be written off, and much less likely to
kill its crew.
Nice analysis, I have a reservation in that average accident rates were
trending down 1942 to 1945, the USAAF Statistical Digest has the rates
as all accidents, fatal accidents, fatalities, aircraft wrecked,
1942 the figures are 71, 8, 17, 17 Jan to Aug 1945 are 43, 5, 14, 12
From now on 1945 is January to August.
So the P-61 was arriving in a more flight safety environment.
I considered that aspect, and it gets rather murky. While it's true that
the "Safety Culture" of the USAAF had improved with experience,
particularly with high performance multi-engine training. (As someone who
has flown a number of light Twins, such as the Piper Aztec and Beech
Baron, and also a high performance twin - The Mu-2, I can tell you that
there's a big step in the discipline and attention required to be safe.)
But - there is also the fact that an aircraft entering service will have
a higher rate of incidents - with small numbers in service, and low
number of flight hours, a single incident can skew the numbers a great
deal. Add in that not only the students, but instructors having little or
no experience in the aircraft, there's going to be a high rate at the
beginning of service, that will, at some point, level out.
The P-38 and A-20 had that benefit. The P-61 hadn't really had a chance
for that.
So - I took the quick way out and used the aggregate numbers.
The relationship between Accident, Wrecked (Class A), and Fatal seems to
be pretty consistant.
Yes, I saw the 1942 figures in particular and thought they needed to be at
least noted and probably omitted, given how much higher they were,
agreed simply reporting 1944/45 figures would make any new type seem
worse for the reasons given.
(snip)
Post by Peter StickneyPost by Geoffrey SinclairThe RAAF, after much effort, put a Vengeance wing into the field in new
Guinea, a few weeks later they were pulled out as not worth the airfield
space etc. they required. Shortly after they started arriving in
numbers in 1943 target towing modifications were being trialed.
Meantime the RAAF Helldivers were sitting on the US West Coast for a
while awaiting shipment, they were railed to the East Coast as there was
cargo space available there. For the 1945 invasion of Japan the US
trans continental rail links could not handle the amount of cargo
required, so ships were loaded in the East Coast ports and sent via the
Panama Canal.
Something that I'll bet the RAAF was eternally grateful for, having then
to make do with Mustangs, Beafighters and Mosauitos.
They wished.
In the end RAAF wartime aircraft supply was roughly a third local, a
third US and a third Britain. The local industry deserves credit when
you allow for the fact that until mid 1939, taking out an early 1930's
RAAF order for 32 DH.60, plus a later order for 6 more, all time total
Australian aircraft production was not far out of single digits.
They were at the end of a long supply chain, had low priorities, had
MacArthur and his attitude to anything non US Army and had a high
level internal feud going on the US local authorities at least were
well aware of.
Beaufighters usually came from Britain in reasonable numbers at the
agreed rates, beginning in March 1943, same for Spitfires, beginning
October 1942, (6 had arrived in August, then a pause). Understandably
enough the US in 1942 to early 1943 had the more erratic supply, after
also understandably being more reliable than Britain in 1940/41. And
everything arrived later than in the original plans.
The administrative mayhem of the early P-40 arrivals, RAAF order,
USAAF order, Dutch Order, assembled by RAAF or USAAF units
based on who had capacity on the day, transferred to and from and
to and from the RAAF and USAAF, compounded by the loss of 14
RAAF order P-40 en route.
The orphan single squadrons of A-20 and Kingfisher from ex
Dutch orders, the Buffalo and P-43 photo reconnaissance, the
almost single squadron of P-39, the single (Dutch aircrew/RAAF
ground crew) B-25 squadron and so on made for spare parts
and training problems.
The inevitable problems of small allocations from current production,
which meant for example, P-40E, P-40K, P-40M, then P-40N with
associated spare parts etc. issues, as production lines were
continually updated. Leading to things like conversion of all Allison
-73 to -81 engines, then stepping up to trying to convert -39 to -81.
Local metal covered aileron trials for P-40. The problems of local
manufacture of spare parts, starting with supply of things like the
relevant alloys. Silver lead bearings for Hercules engines for example.
The 150 Helldivers on order ended up being 10 delivered in
November 1943, versus the 342 Vengeances out of 400, the RAAF
cancelled the order in March 1944. I am not sure but I suspect the
Helldiver order was more cancelled in the US than Australia, it
was gone by end January 1944, in December 1944 five were
transferred to the USAAF, then 5 more the next month. The
Vengeance were harder to shift, 238 still on strength at the end
of June 1946.
The Vengeance squadrons largely became B-24 units.
The remainder of the pre/early war Hudson orders and the locally
built Beaufort were the bomber force in mid 1943, 93 and 279 out
of 412 on strength. Fighters were 200 P-40, 138 Spitfire, 100
Boomerang and 81 Beaufighter.
Wartime imports, 840 Kittyhawk, 656 Spitfire, 210 Beaufighter,
246 Hudson, 73 Mosquito.
The first local production Mosquito flew on 23 July 1943, but it turned
out the wings had not been made correctly, then when they thought
the problem had been fixed there was at least one more crash that
delayed production, so first official local production was in March
1944 and only 28 by the end of the year. The unused wings were
later put through the first "all of wing" fatigue testing experiments.
Local Beaufighter production started in May 1944, did well, 112 built
by year's end.
The Mustang plans were of course victim of the sudden urgent demand
for the type in 1944/45, despite the order for 350 local production being
lodged in mid 1943, local delivery of the first of 80 kits supplied by North
American did not start until May 1945, a month after the first of 262
imports from the US began arriving. A couple of Mustang squadrons
were forming in Australia near the end of the war but were disbanded,
Mustangs replaced Kittyhawks in the 3 squadrons sent to Japan as
part of the British Commonwealth Occupation Force
Mid 1943 transport/communication fleet, 8 C-47, 5 ex Dutch Dornier,
4 Douglas Dolphin, 83 mostly locally made DH.84, 2 Empire flying boats
(about to be returned to Qantas), 2 Fox Moth, 2 C-60 and 5 DC-2.
452 Spitfire squadron had equipped with the local G-Suit design in mid
1943, with plans to do the entire wing, the suit required air conditioned
ready rooms as it was so warm, but it gave adequate floatation in sea
water without a life jacket. Trial installation in Kittyhawks had been
done.
Post by Peter StickneyPost by Geoffrey SinclairPost by Peter StickneyAnd, I must say, that while the Allison Mustangs weren't the absolute
world beater that the 2-stage Merlin Mustangs were, it equalled or
exceeded the contemporary Fw-190s
Down low especially.
Post by Peter StickneyPost by Keith WillshawThe He-177 was a disaster all round mainly because of the coupled
engines. When the same technique was tried with the Avro Manchester
the result was the redesigned Avro Lancaster. Its other main problem
was that it was supposed to do everything from tank busting as a dive
bomber to maritime attack with torpedoes and be a strategic bomber. It
did none of them well and the resources used would have been better
spent on conventional bombers such as the Ju-88 series.
I've often wondered whether the RLM got hold of the Specification for
the Manchester. About the only thing they didn't duplicate was the
ability to be launched by catapult. (The Manchester, in addition to
being a coupled-engine Heeavy Bomber, was also supposed to be capable
of dive and torpedo bombing.
Doubt it, the comments on the He177 being fragile, not something
Lancasters have been accused of.
True, but that's more the execution than the spec. Of course, a lot if
it probably had to do with the fashions of the time - All fighters had to
have inline engines and pointy noses, large bombers were to have the
least number of engines possible, thus the attempts by Rolls, Daimler-
Benz and Allison to make 2000 HP engines by merging 2 smaller motors
together.
Yes, no one seems to have had much trouble moving to 1,500 HP class
engines, everyone had trouble with 2,000 HP class ones.
Bolting two lower power engines together was a nice shortcut that
apparently eventually largely ended up working, but only after the
engines had acquired such a bad reputation they were taken out
of production.
(snip)
Geoffrey Sinclair
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