Subject: Number Thirty-Eight in the Series--Lockheed P-38 Lightning (5 of 11)

From: [email-masked] (Joseph F Baugher)
Date: 25 Nov 92 17:44:41 GMT

>From Joseph F Baugher <[email-masked]>

Through all the modifications leading from XP-38 to P-38H, the basic 
contours of the engine nacelles of the Lightning had remained 
virtually unchanged.  The P-38J version, which first began to appear 
in August of 1943, introduced some appreciable differences in the 
geometry of the engine nacelles which make this and later versions 
easily distinguishable from earlier versions of the Lightning.  

Earlier P-38s had passed the compressed air from the 
turbosuperchargers through a hollow passageway lying along the leading 
edge of the wing all the way from boom to wing tip and back in order 
to cool it down before it entered the carburetor.  There were problems 
encountered with this arrangement.  The difficulty in controlling the 
superchargers caused frequent engine backfires, some of which actually 
caused changes in the shape of the wing leading edge.  The large area 
of these wing intercoolers also make them vulnerable to gunfire.  The 
P-38J (known by the Lockheed company as the Model 422) introduced a 
revised powerplant installation, with the intercooler being changed to 
a core-type radiator located below the engine.  The air intake for the 
intercooler was sandwiched between the oil radiator intakes in a 
deeper, lower nose.  The core-type radiator took cooling air through 
the central duct behind the propeller and exhausted it through a 
controllable exit flap, thus permitting a considerable amount of 
control over the the temperature of the air entering the carburetor.  
The leading edge tunnels were eliminated and were replaced by 
additional self-sealing fuel cells in the outer wing panels.  

This modification was initially tested on P-38E Ser No 41-1983.  The 
P-38J also had redesigned Prestone coolant scoops on the tail booms.  
All P-38Js retained the V-1719-89/91 engines of the P-38Hs, but their 
more efficient cooling installations enabled military rating at 27,000 
feet to be increased from 1240 to 1425 hp, while at that altitude war 
emergency rating was 1600 hp.  

The revised beard radiators produced some additional drag, but it was 
more than adequately compensated for by the improved cooling which 
made the Allison finally capable of delivering its full rated power at 
altitude.  Consequently, the P-38J was the fastest variant of the 
entire Lightning series--420 mph at 26,500 feet.  Maximum speed at 
5000 feet was 369 mph, 390 mph at 15,000 feet.  Range was 475 miles at 
339 mph at 25,000 feet, 800 miles at 285 mph at 10,000 feet, and 1175 
miles at 195 mph at 10,000 feet.  Maximum range was 2260 miles at 186 
mph at 10,000 feet with two 250 Imp gall drop tanks.  An altitude of 
5000 feet could be attained in 2 minutes, 15,000 feet in 5 minutes, 
10,000 feet in 7 minutes.  Service ceiling was 44,000 feet.  Weights 
were 12,780 lbs empty, 17,500 lbs normal loaded, 21,600 lbs maximum.  
Wingspan was 52 feet 0 inches, length was 37 feet 10 inches, and 
height was 9 feet 10 inches.  Wing area was 327.5 square feet.  
Armament consisted of one 20-mm Hispano M2(C) cannon with 150 rounds 
plus four 0.50-inch Colt-Browning MG 53-2 machine guns with 500 rounds 
per gun.  In addition two 500, 1000, or 1600-lb bombs or ten five-inch 
rockets could be carried on underwing racks.  

The 1010 Model 422-81-14s included three production blocks.  The first 
block consisted of ten service test P-38J-1-LOs.  These were quickly 
followed by 210 P-83J-5-LOs with two 55-US gallon additional fuel 
tanks in the leading edge space previously occupied by the 
intercoolers and thus restoring maximum internal fuel capacity to 410 
gallons (1010 gallons with drop tanks).  Modifications, including the 
addition of stiffeners, were required to prevent deformation of the 
new wet wing leading edge.  The last production block consisted of 790 
P-38J-10-LOs with flat windshields with the bulletproof glass panel 
being incorporated into the windshield.  

These were followed by Model 422-81-22s in two blocks.  The first 
block consisted of 1400 P-38J-15-LOs with revised electrical systems.  
The second block consisted of 350 P-38J-20-LOs with modified turbo 
regulators.  

When earlier J-series Lightnings went into a high speed dive, their 
controls would suddenly lock up when a certain speed was reached and 
the nose would begin to tuck under, making recovery from the dive very 
difficult.  The problem would begin at Mach 0.65 to 0.68, accompanied 
by vigorous buffeting and a strong nose-down pitch.  As speed 
increased, it became progressively more and more difficult to recover 
from the dive, larger and larger stick forces being required for a 
pullout.  At Mach 0.72, dive recovery became for all practical 
purposes impossible, and runaway dives that got this far out of hand 
usually had fatal results.  The onset of severe buffeting would, of 
course, usually provide adequate warning for a pilot in a diving P-38 
that he was about to encounter a problem, but it is easy to get 
distracted while in the stress of combat.  This dive recovery problem 
was so severe that the Lightnings found it very difficult to follow 
German fighters in a dive, allowing many Luftwaffe fighters to escape 
unscathed.  

The problem was eventually traced to a shock wave that formed over the 
wings as the Lightning entered the transonic regime, the shock wave 
preventing the elevators from operating.  In order to counteract this 
problem, starting with the P-38J-25-LO (Model 422-81-23) production 
block, a small electrically-operated dive flap was added underneath 
each wing outboard of the engine nacelles and hinged to the main spar.  
These dive flaps would change the characteristics of the airflow over 
the wing, offsetting the formation of the shock wave and permitting 
the elevators to operate properly.  This innovation largely solved the 
problems encountered by diving P-38s.  

The P-38J-25-LO production block also introduced power-boosted 
ailerons.  These consisted of ailerons that were operated by a 
hydraulically-actuated bell-crank and push-pull rod, making it easier 
for the pilot to maneuver the airplane at high airspeeds.  This 
boosting system was one of the first applications of powered controls 
to any fighter, and required only 17 percent of the previous stick 
forces.  The hydraulic aileron booster system vastly improved the roll 
rate and thereby increased the effectiveness of the P-38 in combat.  
P-38Js with power-boosted ailerons proved to have the highest 
roll-rates of any fighter.  

210 P-38J-25-LOs were built.  

In March of 1944, Colonel Benjamin Kelsey reached an indicated speed 
of more than 750 mph during a high-speed dive in a P-38, which would 
have made the P-38 the first supersonic fighter.  However, it was 
later discovered that compressibility effects on the airspeed 
indicator at about 550 mph had given a greatly exaggerated reading.  
Nevertheless, the Lightning handled quite well at high speeds, and its 
strong airframe withstood the excessive aerodynamic loading produced 
by these high-speed dives.  

With the increased use of the Lightning as a light bomber, the type 
was modified to carry in place of the forward-firing armament either a 
bombardier with a Norden bombsight in a glazed nose enclosure, or a 
"Mickey" BTO (Bombing Through Overcast) bombing radar in the nose with 
an operator station between the radar and the pilot's cockpit.  These 
modifications were developed at the Lockheed Modification Center in 
Dallas, Texas.  These so-called "droop-snoot" Lightnings were used to 
lead formations of P-38s each carrying two 2000-lb bombs which were 
released on instructions from the lead bombardier.  

Two P-38J-20-LOs (serials 44-23544 and 44-23549) were modified in 
Australia during the autumn of 1944 for use as single-seat night 
fighters, carrying AN/APS-4 radar in a pod underneath the starboard 
wing.  These modifications were tested in New Guinea and the 
Philippines.  

A P-38J-5-LO (serial number 42-67104) was tested at Wright Field and 
Orlando, Florida as an experimental night fighter with a radar 
operator sitting on a jump seat just aft of the pilot.  The AN/APS-4 
radar was initially mounted under the fuselage in a pod just aft of 
the nosewheel.  This pod proved to be rather easily damaged by stones 
thrown up by the nosewheel during takeoffs and landings, so it was 
repositioned beneath the starboard wing, but this resulted in 
interference from the adjacent engine nacelle.  

Beginning in September of 1944, a P-38J was used to test a unique 
method for extending the range of escort fighters by having the 
fighter engage a hook trailed from a B-24H bomber.  Attached to the 
hook was a standard drop tank.  After contact, the tank was 
automatically attached to standard external tank fittings beneath the 
fighter's wing.  The method proved to be basically feasible, but it 
required considerable skill on the part of the Lightning pilot in 
order for it to work.  Consequently, this innovation was not pursued 
any further.  

A number of P-38Js were modified in service as TP-38J-LO two-seat 
"piggyback" trainers with a jump seat aft of the pilot.  Some of these 
aircraft carried an AN/APS-4 radar pod underneath the starboard wing 
and were used to train P-38M crews.  

At least one P-38J was successfully flown with skis.  P-38J-1-LO Ser 
No 42-13565 was fitted with an experimental retractable ski 
installation.  

The initial photo-reconnaissance version of the P-38J was the 
F-5B-1-LO (model 422-81-21).  It had the same camera installation as 
did the earlier F-5A-10-LO (equivalent to P-38G-10-LO), but had an 
airframe and engines identical to those of the P-38J-5-LO.  The 
F-5B-1-LO introduced a Sperry automatic pilot, which became standard 
on all subsequent reconnaissance versions.  Two hundred of these 
photographic aircraft were built, serial numbers being 42-67312/67401 
and 42-68192/68301.  This was the last of the Lockheed production of 
the reconnaissance version of the Lightning, subsequent F-5 versions 
being modifications of standard P-38 fighter airframes performed after 
delivery.  

The F-5C-1-LO was the designation given to P-38J airframes converted 
at the Dallas Modification Center to a standard basically similar to 
that of the F-5B-1-LO but with improved camera installations.  A total 
of 123 aircraft is believed to have been so modified.  The serial 
numbers of the P-38J aircraft so modified are not known.  

A total of 200 P-38J-15-LO fighter airframes were converted in Dallas 
to F-5E-2-LO reconnaissance configuration.  These were produced to a 
standard similar to that of the F-5C-1-LO.  The designation F-5E-3-LO 
was given to a similar conversion of 205 P-38J-25-LO airframes.  
Again, any record of the serial numbers of the P-38J aircraft modified 
to F-5E-2-LO or F-5E-3-LO standards seems to have been lost.  

One F-5B-1-LO (42-68220) was modified with a revised camera 
installation and was redesignated F-5F-LO.  

The few surviving USAAF P-38J aircraft were redesignated F-38Js in 1948 
when the USAAF became the USAF and the P designation was changed to F. 

P-38J-10-LO Ser No 42-67762 is currently held in storage at the Paul 
Garber Preservation, Restoration and Storage Facility at Suitland, 
Maryland.  I saw it there on November 2 of this year.  It is more or 
less intact, but needs some restoration work before it is really 
presentable.  

Serials of the P-38J/F-5B were as follows: 

42-12867/12869 		Lockheed P-38J-1-LO Lightning 
42-13560/13566 		Lockheed P-38J-1-LO Lightning 
42-67102/67311 		Lockheed P-38J-5-LO Lightning 
42-67312/67401 		Lockheed F-5B-1-LO Lightning 
42-67402/68191 		Lockheed P-38J-10-LO Lightning 
42-68192/68301 		Lockheed F-5B-1-LO Lightning 
42-103979/104428 	Lockheed P-38J-15-LO Lightning 
43-28248/29047 		Lockheed P-38J-15-LO Lightning 
44-23059/23208 		Lockheed P-38J-15-LO Lightning 
44-23209/23558 		Lockheed P-38J-20-LO Lightning 
44-23559/23768 		Lockheed P-38J-25-LO Lightning 

Sources:

  Lockheed Aircraft Since 1913, Rene J. Francillon, Naval Institute Press,
  1987

  The P-38J-M Lockheed Lightning, Profile Publications, Le Roy Weber
  Profile Publications, Ltd, 1965.

  War Planes of the Second World War, Fighters, Volume Four, William Green,
  Doubleday, 1964.

  Famous Fighters of the Second World War, William Green, Doubleday, 1967.

  The American Fighter, Enzo Anguluci and Peter Bowers, Orion Books, 1987.

  Wings of the Weird and Wonderful, Captain Eric Brown, Airlife, 1985.

  United States Military Aircraft since 1909, Gordon Swanborough and Peter
  M. Bowers, Smithsonian Institution Press, 1989.

Joe Baugher       AT&T Bell Laboratories    2000 North Naperville Road 
		  Naperville, Illinois 60566-7033.   (708) 713-4548