steve@uspm650.Dayton.NCR.COM (Steve Bridges) (12/06/90)
From: steve@uspm650.Dayton.NCR.COM (Steve Bridges)
In article <1990Nov27.044525.3091@cbnews.att.com+ ntaib@silver.ucs.indiana.edu (Nur Iskandar Taib) writes:
+
+*>Both P-47s and P-51s, with drop tanks, had the range to escort
+*>bombers all the way in and back to German targets. The later
+*>P-47s with the bubble canopy were in perpetual contest with the
+*>P-51D as highest-scoring American fighter type.
+
+*>The P-38 with drop tanks had the range, but were not considered
+*>competitive against later Luftwaffe fighters. Most P-38s were
+*>assigned to North Africa and Italy anyway.
+
+*>It's not that the P-38J-LO wasn't all that good...it's mostly
+*>that earlier variants couldn't turn with the Germans, and being
+*>as big as they were, could be spotted from quite a bit further
+*>out than single-engined fighters. This last was a real disadvantage.
+
+
+Well, actually, earlier in the war, the P-47s
+and P-38s didn't have the range to escort bom-
+bers all the way into Germany. The later model
+Jugs were probably a little better as far as
+range was concerned, but accounts of the frus-
+trations felt by allied fighter pilots watching
+as German fighters waited just beyond their
+range are numerous. Of course, this does not
+begin to compare with how the bomber crews
+felt. (!)
I seem to remember reading that the later model P-38s (with the
bigger internal tanks and bigger drop tanks) had the ability
to escort the B-17s anywhere in Europe.
+
+The P-38 eventually did turn into a fantastic
+fighter when used properly. It could (in some
+situations) turn inside german fighters by
+using its maneuvering flaps - a button, when
+depressed, would lower the flaps to a pre-de-
+termined setting.
This was simply lowering the flaps to an 8 degree setting. Produced
a little drag, but more than made up for it in additional lift.
+It was mostly deficient in
+roll rate.
This was true in the early models. Remember, the P-38 was designed
as an interceptor, to be used to shoot down bombers. They (the
Army) wasn't demanding a turn-on-a dime airplane. So, the
aileron control forces were high. When the P-38J-25 came out,
it had hydraulically boosted ailerons, and the roll rate was one
of the fastest.
The biggest problems early on were
+reliability (those Allisons kept blowing up
+and were a real pain to repair)
Yep, a real problem. The early models had no cowl flaps, and the turbo
intercooler ducting ran all the way from the turbo to the wingtip and
back.
Since the '38 was designed for use in the US, where temperatures
at altitude were higher than the ETO, the lack of cowl flaps wasn't
deemed a problem.
However, in the ETO, with temperatures at altitude were 40 below or
better, the engines never warmed up enough for proper lubrication,
octane and lead separated out of the fuel, and the result was
Allisons swallowing valves, backfires through the intercooler
ducting, throwing rods, and making life miserable for the
mechanics.
With the '38J, the entire engine system was re-designed. An
oil cooler (with cowl flaps) was added below the spinner, and
the intercooler ducting was eliminated/re-routed. The failure
rates of the Allisons went down after that.
+and the lack
+of the compressibility flap fitted to later
+models - the airplane would, in a dive, sudden-
+ly lock its controls solid and tuck its nose
+under, often tearing the wings off.
Not too far off. The compressibility effects were related to
how high up in the transonic region the airplane was. At
altitude in a high speed dive, the airplane was fairly high up
in the transonic region. Shock waves formed by the wing would
prevent the elevator from moving. Eventually, the airplane's nose
would start to tuck under (the start of an outside loop).
There were 2 possible solutions -- avoid the high-speed high-altitude
dive ---
or -- hang on until you reached a lower altitude (where the airplane,
while indicating a high airspeed, was lower in the transonic region),
and make use of the elevator trim tab to pull out of the dive.
The compressibility flaps changed the characteristics of the wing
to offset the formation of the shock waves.
--
Steve Bridges | NCR - USG Product Marketing and Support OLS
Steve.Bridges@Dayton.NCR.COM | Phone:(513)-445-4182 622-4182 (Voice Plus)
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