By David C. Copley
2000 - 2001
Mr. Sharpsteen, thank you for this opportunity to interview you regarding the P-38. I have been working on a computer model of the P-38 for Microsoft Flight Simulator. I have many reference books on the P-38, its production, use, and pilots, but I have not been able to find much information on its dynamic characteristics during flight, etc.
I am not a pilot, so please forgive me if I do not use the correct terminology. In cases where I am a little uncertain, I have tried to re-phrase the question for clarity.
Here are my questions. If you can't answer some of them, that's OK, since I realize it has been many years since you last flew the P-38.
First, could you tell me your rank and the fighter group to which you were attached?
I retired as a lieutenant colonel from the US Air Force. But at the time back on Guadalcanal, I was in the 339th fighter squadron, which was a part of the 347th fighter group and they operated headquartered in New Caledonia, and our combat flying was done on Guadalcanal in the Solomons.
We would fly up there from New Caledonia to Espirito Santos, about half way up to the Solomons. We would refuel there and then fly on up to Guadalcanal. We operated first off of the fighter strip 1 there, which had been started there by the Marines after the Marine ground force landed and took over.
Then they set up this landing field about 3,000 feet long of grass and the Marines with their F4U4s and the SPDs were flying out of there. We came in there first with the F-39s we flew on Henderson Field, which was where the transports and bombers landed and then of course we got shelled from back inland there. We had to move over with the Marines on fighter strip 1. And then when we got our P-38s we flew fighter strip 1, which was as I say about 3,000 foot grass field which had a little hump at one end, which we would clear by about 15 feet. The coconut trees at the other end were sort of a barrier too.
Then we moved over to fighter strip 2 where the Air Force/Air Corps first, we had our own flying strip there where we flew from there and some P-40s came in later and flew from there also.
1) Which production variant did you fly (F, G, .. J, etc.)?
I flew the P-38G-15-LO. The LO just stands for Lockheed.
2) Are you familiar with any of the others, such as the L?
Well, I got a chance to fly, I think it was a J model. The big
difference for the J model over the older ones up to the H was that
the older ones did no have a hydraulic boost for the ailerons and
the J and on up had the hydraulic boost with variances also in the
engine dash number. [editor's note: he would be referring to
the J-25 and L, which had the hydraulic boost]
3) What was the roll rate? (How many seconds did it take to spin the
aircraft 360-degrees about its longitudinal axis?)
I can’t really say what the roll rate was. I never did check it. The roll rate on the older ones, such as the G that I flew was quite slow. It took a lot of muscle to hold the wheel. We had a wheel, and not a stick for the aileron control and it took a lot of beef to hold that wheel over for a roll. And for a slow roll it required quite a bit of down elevator when you were inverted. That is the down elevator was then the up elevator. So there was a lot of nose drop when you were inverted with the old model without the hydraulic boost and the ailerons, but with the later model, with the boost, you could do a roll, an aileron roll, in just about the way you could later on with the F86 Saberjet and they had a real nice roll rate.
4) Could a roll be accomplished without losing altitude? At what
speed?
Earlier I mentioned variances between the G and the later model J and up. The big changes were in the hydraulic boost for the aileron and the change of the super charger intercooler from the wing leading edges to under the engine making it look like the P40. It lost its real nice streamline look with the intercooler down under the engine with the oil cooler. The prestone coolers were on the booms and they were also a little larger in the later models.
When talking about our rolls, that was around cruising speed, say around 230 knots and that usually would then be as I said. You would have to make corrections all the way around with the one I flew, the G model, in order to keep from losing altitude. Whereas, as I said with the J and up models, the roll rate was faster and you would go around the inverted position fast enough so that you wouldn’t lose any altitude.
5-6) Under extreme circumstances, such as combat, how long did it take
to turn the aircraft 180-degrees? How was this accomplished? (What
combination of aileron, rudder, flaps, throttle, etc. was required?)
Did the controls respond quickly? How much physical effort was
involved?
Well, there again, I never did really check it out, time it in seconds, but there again with the later models with the boost you would be able to go to a steep bank faster and pull around then again a little faster. With the twin engine airplane, if you slow the inside engine a little bit, and you boost the top engine a little bit, that would help you to get around in your turn some also. But you could do it in real fast, if you did it in the maximum rate.
Normally with that airplane we would use the rudder and the
aileron so that they would be synchronized there together. Of
course, also, if you wanted to help some there, we could have as
part of our full operation, we had a maneuver flap, in which the
flaps because just a split flap. And then I forget just what the
number of degrees that was, but that would enable you to make it all
just a little bit faster. Of course the maneuver flaps were limited
to cruising speeds or not much above. They shouldn’t be used at a
high speed dive. So, but the controls, the rudder and elevator were
all responded rapidly. It was just in the older ones where the
aileron required an extra bit of muscle. But as I said, after we
got the boost ailerons, that was just took hardly any effort at all.
7) Were there any hazards to performing this maneuver (other than
the combat risks)? (In other words, would the aircraft become
unstable, or stall, etc.?)
The only hazard you would have in any of them
would be in a high speed stall, that is if you pulled that elevator
back too much, too fast, you could get a high speed stall, in which
case, of course, you would lose airspeed and possibly control of the
airplane.
8) When taking off, did you have to pull back pretty hard, or did
the aircraft just float off the ground on its own (once up to
speed)?
No, I didn’t have to pull back hard.
The airplane was in really a climb position on take-off and
we normally used the maneuver flap position for take-off.
And then once we got up to oh, around 100 miles per hour or
around there then it would come off quite easily and pick up speed
quite rapidly. Once you
lifted, retracted, your landing gear.
The landing gear on the P-38 was really imposed about 1/3 air
drag for the airplane so getting that landing gear up on take-off
was real important. As
soon as you got off the ground, up the gear, and then once that was
up and then the airplane would pick up speed quite rapidly and then
you would get up to climb speed and you wouldn’t have to use any
elevators. It was all
quite easy.
9-10) On approach with full flaps and gear down, did you need a lot of throttle to keep it from falling too quickly? Please describe how the aircraft performed with partial flaps, full flaps, etc.
Normally, we would be coming around from base leg into final you
would have power off and with the fowler flaps which the P-38 had.
Now they give you increased wing area as well as in the flap down
position, greater lift. And so they were a big help there. So
there would be no problem about falling too quickly, of course
unless you let your airspeed get below the correct speed. Normally,
with full flaps down we could come in around 100 miles per hour
without any trouble at all. But once I had the flaps refused to go
full flap, and I just had maneuver flap, there I had to come in
about 115 miles per hour. With it there I just had the split flap
effect and not the full fowler flap effect, so there was quite a
difference there between those two positions.
Normally with regular airplanes you put the flaps down and there
is a tendency for the airplane to nose over, so it requires that you
use the elevator trim to give you a neutral feel on the controls.
And of course it would slow you down, so either you add power to
maintain level flight or you wanted to, if you were in your landing
approach, you nose the aircraft down to keep up your recommended
speed. Like I said, with partial flaps it took around 115 miles per
hour to come in, with full flaps around 100.
11) How did the gear deploy? (In what order?, Did the nose gear come
out first and then the main gear? )
Well, in normal extension I seem to recall that the main gear
started down first and then they would be down quite a ways before
the nose gear would come down or start down and get the main gear
fully extended and then the nose gear.
12) Did the main gear deploy/retract simultaneously or did one lag
behind the other, say, due to mechanical reason or hydraulic reason?
They never do on any airplane unless it happens to be one that
has electric motors for retract, like the old Leech C45, but some of
those would all come up roughly together. But with the hydraulic
gear, one main gear will start up and get most of the way up, and
then the other will come up, and then the nose gear will start up.
13) How long did the gear take to fully deploy? Retract?
I couldn’t say. It could vary. In the tropics it would be faster than say if the planes were up in the arctic area where everything was cold. They had to move a lot slower than when everything is up to room temperature. It could take a full 30 seconds or maybe even a minute to get all the way up. If you picked up too much speed that would add some load on it and that would make it a little slower.
14) How long did it take for the flaps to fully deploy?
Well, then again, speed is a factor.
If you try to deploy, extend the flaps at maximum speed, they
will come out much slower than at the normal traffic pattern speed.
Retraction, well, there again, the airspeed will help getting
the flaps up from the full extended position.
15) Did you ever fly a P-38 with the dive recovery (compressibility) flaps (on late J's and all L's)? (If so, please comment on how they were used generally and in combat situations. How did they affect normal flight..., etc.)
No, I never did try the dive flaps. Although I did fly an airplane with them, I didn’t have occasion to try them out. But they were a blessing to the P-38 pilot in knowing that he could roll over and put it in a dive straight down and be able to pull out. Whereas with the ones we flew there would be a problem, then the elevator in the up position, it would have a tendency to do just the opposite. So that wasn’t very good.
16) I see in some books a reference to ‘combat flaps' being added to late model F's. Can you explain these? Are these different from the standard four flaps that extend from the inner wing and just outboard of the engine nacelles?
They were part of the regular flap system, and they were just split flaps, that is most flaps on small airplanes, they would be hinged at the front and then just drop down. And then when according to the fowler flap condition, the whole flap would move back on rails to extend the wing area and also add some more flap to the condition.
Well, as I said the maneuver flaps were just used to give the
wing added camber, or increase the lift, and then the maneuver flaps
were part of the main flap system. Being just split flaps at first
and as maneuver flaps or take-off flaps, and then when you took the
flap control leaver around the detent and to the full down position,
and then the flap system would slide back on rails and give the
added wing area, and also more increased camber.
17) What was the effect on the aircraft of dropping ordnance and/or
fuel tanks? (Could you tell a difference? Did the plane tend
upwards?)
We didn’t carry any bombs, although we could. We had hard points between the pilots in the south and the engine in the south there. And we carried normally 50 gallon, that would be one hour for the engine, one tank on each side of the airplane so that would give you another hour of flight and then they did have some bigger ones that would give you more, as the fellas used when they went from Guadalcanal up to Bougainville and managed to get Admiral Yamamoto flying down to the Zero base at Balalae at the south end of Bougainville.
Now in dropping the tanks we had a problem sometimes. The tank
would not drop away. We would hit the switch and the hooks wouldn’t
move. The load on the hooks would be too much. We would have to
try various maneuvers, mainly give it a little negative G forces to
take the weight of the tank off the hooks and then sometimes, most
of the time that would allow the tanks to drop. But sometimes, just
nothing would let the tank drop away so you were really in trouble
there.
18) How was ground steering accomplished? Did the control wheel move the nose wheel
for steering? Were there separate brakes for the main gear for
differential braking?
Well, normally in taxiing, you would use the brakes. Each main
wheel had a brake in it that was controlled by one of the rudder
pedals. The left rudder pedal controlled the left and the right
pedal controlled the right main wheel. Of course, also there was
differential engine power and so if you were moving real slowly then
you would have to use the throttle in order to get some movement
there. And the nose wheel didn’t do a thing for the ground
steering. So there was the main wheels, as I said, a separate brake
for each one, and you could do the differential braking. Now on
some airplanes like the F86, that had a little control that the
pilot could depress and that would give taxi control left and right
to the rudder pedal. In this case the rudder pedals controlled the
nose wheel for easy steering.
19) What was the affect on the aircraft when firing guns? Could you
feel any recoil?
Yes, you really felt the recoil in the cockpit there. The 20 mm
had quite a bang and the four 50s gave you a jolt too.
20) As a flight progressed, could you sense any significant change
in the center of gravity due to fuel consumption?
The fuel tanks were very close to the CG and so
there really wasn’t too much change there, and also with the hard
point for the drop tanks, was right there around the CG, and so it
wasn’t really that noticeable.
21) How quickly did the aircraft ‘right itself' after a shallow turn?
Well, the airplane did have some dihedral, but as to righting itself, well, it would do that in a shallow turn. It would have a tendency to come back up. Although I don’t recall ever relying on that. And of course, as with any airplane, where you have it trimmed in flight for level flight, and you put the nose down, it will, after oscillating up and down, return to level flight. But that I don’t recall, ever relying on the airplane to come back from a bank all by itself.
22) During extreme combat maneuvers, did the aircraft have a tendency to stall (during rapid climbs, turns, etc.) If so, what was done to recover?
During rapid combat maneuvers I never did have it stall. Of
course, if you were up there at 35,000 feet you could get into a
stall real fast. But at 10,000 feet it would take quite a pull on
the controls to get yourself into a stall. Or if you pulled up too
steeply, and did stall it, there if you weren’t in full power
already you would put it up to full power and drop the nose so that
you could recover from the stall.
23) Under what conditions would the aircraft oscillate (if any)? What was the most common oscillation? (Up and down, side to side ...)
Well, as I said, it would under the right conditions, but I never had anything come up like that while I was flying them so I really can’t say as to just how it would go without doing it, how it would feel.
24) When aiming at a ground target, either strafing or bombing, was it easy to hold on target or did it drift (under relatively calm weather conditions).
All I did was strafing, never any bombing with it, although it would carry a 500 pound bomb. But the P-38 was very different from any of the single engine airplanes in that there was no problem with torque or any tendency for it to want to drift off one side or the other. With the counter rotating props it eliminated all tendency to want to go one way or the other. So when you put the B on your target it stayed there. There was no tendency like in the P-39, P-40, it took real flying to hold it right on there straight. This made shooting the guns on the P-38 just like later flying in the jet F86. That also had no tendency to want to torque one way or the other, and so there again it would go where you aimed it, and the bullets would go where you were aiming. Or course under rough air conditions where you had some rough air, that would tend to throw the airplane around. Although not quite as much as on the smaller, like the P-39 or P-40.
25) How did it handle (generally) in bad weather?
The P-38 was of course was very nice airplane to fly on instruments. It was very stable. No problem at all. It was just like any other twin engine airplane, if you lost an engine, then you would really have to get busy and tend to the bad engine and make corrections in trim. But ordinarily flying along on instruments in the soup did very well.
26) On take-off, what was the relative ground acceleration with a full tank?
With full drop tanks, of course it accelerated more slowly than a clean airplane would. And as far as how long, I never really checked that. You would usually stop at the end of the runway before take-off, and load up your engines, check the magnetos, and turn around into the runway compass heading and let her go. But the actual time it took for that was a lot like the F86, a little bit slower in starting but as you picked up speed it would accelerate faster and then it going to take-off speed, well rotation speed, so that the nose would drop just a little and get into a slight climbing position, and it would lift just off the ground automatically that way and then it would be going right up into climb, gear up, and then get up a little more speed, flaps up, and up you go.
27) How effective were the brakes? Was the aircraft easy to stop after landing?
The P-38 had Lockheed multiple disk brakes and I thought they were very good. Of course, like any other brake system, if you used them too much they would get hot and lose their efficiency. The airplane slowed down quite rapidly by itself on the ground and you would only use the brakes after you got towards the end of your landing row and were ready to leave the runway onto a taxi strip.
28) When flying along at cruising speed and altitude, how long would
it take to accelerate to top speed while maintaining same altitude?
I’m not sure of that. I don’t recall that I ever had to do that sort of thing. If you did put it up to full throttle, and as you picked up speed, you would have a tendency to climb, so you would have to use the down elevator to maintain the same position.
29) When applying full throttle, how long would the engines take to respond and come up to full manifold pressure?
The engines would get right up to full pressure right away. Of
course, at 10,000 you would put your throttle levers up to the
detent and the engines would zip right up to 3,000 rpm. I forget
just whether it was 35 or 38 inches of manifold pressure for that
position. Then as you went on up to altitude you would start
dropping your manifold pressure would start to decrease and when it
got down to a little more down below your ground pressure then you
would go around your detent to use your throttles on up to the
proper pressure. Now you couldn’t go on up to full throttle
position because then you would exceed your manifold pressure in the
engine and you could blow out your turbocharger. So you were
limited to how you used your turbocharger and didn’t exceed the
recommended pressures for the different altitudes.
30) Please describe how the aircraft flew with one engine out / prop
feathered.
On one engine, no problem, it flew right along nicely. As one of the Lockheed test pilots would do, I never did, but he would get going on take-off, and when he got to what was considered single engine speed, he would feather, pull the throttle back on one engine, feather that engine and take on off. So you can see, the airplane was a single engine airplane, as well like all the other current commercial jet airplanes had to do, they have a go/no go location position on take-off. You reach a certain point, if one engine fails, they can take off on one engine but pulling the throttle back and abort. That’s the way it was on the P-38 too.
31)
Finally, I am curious about the P-38's sound (I am an acoustical
engineer). At cruising speed, how loud was it inside the cockpit? Did
pilots wear hearing protection? (I have flown in turbo-props, such as
ATR's or Saab's. They can get pretty loud during take off. Was the
P-38 louder than these?)
The P-38 noise, with the turborcharger, with the manifold going all the way from the engine back to the turborcharger position, it acted like a muffler. So there was a muffled sound.
I remember the first time I flew a P-38 and I had my left window down and idling along taxiing at about 1,000 rpm. And to me that purr of the exhaust on the Allison engine was the sweetest sound I’d heard. I’m a lover of the nice exhaust on regular engines, but this, that powerful purr, that just, you knew you had something there. It was very quiet, and yet a powerful purr.
The engine was much quieter than in the P-39. Well, the P-39 wasn’t as bad as the P-36 or the P-40 where the engine was in front of you. The P-39 engine behind you helped. The P-38 with that long manifold gave it, as I say, a muffling effect and it was very quiet and we didn’t need to use a little tuft of cotton in the ear on the old P-36 and P-40s. I don’t know about the ATRs or Saabs, but I don’t think I’ve been around them on take-off so I can’t compare. Although you could compare it with the turbo prop airplanes and comparing them with regular reciprocating airplanes, the turbo prop is much quieter than the regular reciprocating engine or the turbo jet engine. So the 38 was a quieter engine.
After retiring from the US Air Force, Mr. Sharpsteen was employed at the Boeing Company. My father worked with him for several years and arranged our correspondence in 2000 and 2001.
At the time, I was researching the flight characteristics of the P-38 for my Flight Simulator models. While I found a lot of material in books describing and enumerating the specifications and ratings of the plane, I found little information on some of the handling and performance from a pilot's perspective.
The interview was accomplished by correspondence, as he lived in the Pacific Northwest and I in the Midwest. I wrote a series of questions and then he made an audio tape recording of his answers.
The transcribed and published interview on this page contains my questions and his answers in edited form, as though I was interviewing him in person.
I obtained his permission to use his name as a technical reference for my models, and also to eventually publish the interview. Several years ago, I was saddened to hear that Mr. Sharpsteen passed away. I offer this interview to the public now to honor his memory and service to his country.