P-38 vs P-51

[pbehn]

Dan - do you know that a CRITICAL ENGINE is? Do you know what ENGINE OUT PROCEDURES are? Go do some homework and come back because once again and as always you speak from deep bovine fecal cavities.

The fact that there is a critical engine undermines the case of twin aircraft being safer than single ones, in combat they have twice as many engines to hit, easier to see, easier to hit and twice as much fuel to hit. This is a forum where the mods are more abusive than the participants and worse in their ignorance and partisan views. I will join Drgondog in exile, and we all know how that happened, don't we?

 

[FLYBOYJ]

The fact that there is a critical engine undermines the case of twin aircraft being safer than single ones, in combat they have twice as many engines to hit, easier to see, easier to hit and twice as much fuel to hit. This is a forum where the mods are more abusive than the participants and worse in their ignorance and partisan views. I will join Drgondog in exile, and we all know how that happened, don't we?

Don't let the door hit you in the arse on the way out!!!!

And yes, we all know how that happened!!!!

Oh - and you need to learn what a critical engine is as well!

 

[DerAdlerIstGelandet]

The fact that there is a critical engine undermines the case of twin aircraft being safer than single ones, in combat they have twice as many engines to hit, easier to see, easier to hit and twice as much fuel to hit. This is a forum where the mods are more abusive than the participants and worse in their ignorance and partisan views. I will join Drgondog in exile, and we all know how that happened, don't we?

Woah? What the heck did I do to you?

I did not attack you, and never have. I have nothing but respect for you, and shown you nothing but respect.

 

[DerAdlerIstGelandet]

Early P-38s only had one set of accessories (pumps, generator, etc) later ones got two generators but I am not sure about a full duplicate set of pumps. I believe P-38s used electric propellers, having the battery go dead means some pretty tricky work to adjust the pitch on props and you better get it right the first time.

I did not get what you were referring to. My apologies.

 

[DerAdlerIstGelandet]

Never had a problem with pbehn. I don't know what or why this happened.

 

[FLYBOYJ]

Well, where were we.....

 

[BiffF15]

The P-38 could easily fly on one engine (to include the early ones) and it did fly well. The P-38 did not have a CRITICAL engine so ENGINE OUT procedures were the same whether the left or right engine failed. Yes - early P-38s had the issue with one generator but in the end each engine had 2 magnetos which meant the aircraft kept flying. (DAN ARE YOU READING THIS)

The P-38 is one of the only twins I know of where you had to REDUCE power on the good engine if you had an engine failure during take off. (Wes, if you read this chime in on other GA or Corp twins with the same characteristics.)

"Another issue with the P-38 arose from its unique design feature of outwardly rotating counter-rotating propellers. Losing one of two engines in any twin engine non-centerline thrust aircraft on takeoff creates sudden drag, yawing the nose toward the dead engine and rolling the wingtip down on the side of the dead engine. Normal training in flying twin-engine aircraft when losing an engine on takeoff would be to push the remaining engine to full throttle; if a pilot did that in the P-38, regardless of which engine had failed, the resulting engine torque and p-factor force produced a sudden uncontrollable yawing roll and the aircraft would flip over and slam into the ground. Eventually, procedures were taught to allow a pilot to deal with the situation by reducing power on the running engine, feathering the prop on the dead engine, and then increasing power gradually until the aircraft was in stable flight. Single-engine takeoffs were possible, though not with a maximum combat load."

Lockheed P-38 Lightning Airplane Videos and Airplane Pictures

FBJ,

I'm pretty sure that the P38 had two critical engines, which meant the engine out procedures were the same.

IIRC from Tony Leviers book that the P38 brought about some performance innovations, IE a V1 or SETOS (single engine take off speed). I think the initial performance calculations came from a SWP 38 Squadron.

Cheers,
Biff

 

[DerAdlerIstGelandet]

And for the record, Bill's self imposed exile has nothing to do with anything that happened on this forum. It was because of a private political spat he and I had on Facebook. I have apologized for offending him, as it was not my intent. That is why I do not care for political discussion on this forum. It tears relationships and friendships apart. Bill was a great loss to this forum, is a good person, and he is missed here. I hope one day he is will to set this aside and return.

I don't know what happened with pbehn here, nor why he brought up the Bill fiasco. I have always considered him a good and valued contributor. If he would want to return, I would have no problem with that. I however do support Joe in his decision to remove him.

Now hopefully we can get back on topic.

 

[FLYBOYJ]

FBJ,

I'm pretty sure that the P38 had two critical engines, which meant the engine out procedures were the same.

Or no critical engine! LOL - I Interviewed Tony about 30 years ago and we laughed about the same thing. His feelings were that the older P-38s with the generator on one side WAS the critical engine, but when the later models came out with everything paired it was more semantics.

IIRC from Tony Leviers book that the P38 brought about some performance innovations, IE a V1 or SETOS (single engine take off speed). I think the initial performance calculations came from a SWP 38 Squadron.

Cheers,
Biff

Yes - and He used to do a single engine aerobatic demo on one engine and with the landing gear down. I was trying to find that one on YouTube

 

[XBe02Drvr]

Never had a problem with pbehn. I don't know what or why this happened.

I think he was feeling unsupported by the rest of the forum after his little set-to with Schweik, and you gotta admit you guys did get on Dan's case kinda hard. Some of us have thinner skins than others, and I think Pb may have been feeling a little self-conscious about being under-informed about the fine points of engine out procedures in high powered twins.
You know the old saw about: "If ya ain't a pilot, ya ain't sh$t!". I think we "high and mighty" aviators sometimes get a little too full of ourselves for the comfort of our less fortunate shipmates. Mea maxima culpa. Et tu, Brute`?
Cheers,
Wes

 

[FLYBOYJ]

I think he was feeling unsupported by the rest of the forum after his little set-to with Schweik, and you gotta admit you did get on Dan's case kinda hard. Some of us have thinner skins than others, and I think Pb may have been feeling a little self-conscious about being under-informed about the fine points of engine out procedures in high powered twins.
You know the old saw about: "If ya ain't a pilot, ya ain't sh$t!". I think we "high and mighty" aviators sometimes get a little too full of ourselves for the comfort of our less fortunate shipmates. Mea maxima culpa. Et tu, Brute`?
Cheers,
Wes

Agree Wes - but then again it's hard to fill brain cavity when the outflow valve is stuck! But then again we're old sailors so this rolls off some of us

 

[XBe02Drvr]

but then again it's hard to fill brain cavity when the outflow valve is stuck!

If you service the wiffie by dumping it through the outflow valve, well, what do you expect? S - - t happens when you put a new guy out on the floor before he's fully trained! No wonder it's stuck!
Cheers,
Wes

 

[Shortround6]

I am not a pilot and may be reading too much into somethings (sometimes a little knowledge is a dangerous thing) but I think it is hard to apply generalizations to some planes.

Like the old saying that a twin just gives your choice of where to crash.
This might very well be true with old low powered private or commercial aircraft, especially those without constant speed, full feathering propellers in the 30s and 40s.
Some twins would not hold altitude with full power on the remaining engine ( this was true for a number of WW II military aircraft) because of the lack of a feathering propeller.
On private planes in the 50s two 160-200hp engines really weren't a good replacement for a single 240-300hp engine.

However single seat fighters and fast bombers are another catagory. The difficulty in landing may go up but with enough power (and fuel) hundreds of miles could be covered and a proper (but high speed) approach made to the runway.

I just googled it and one reason small twins gpt a bad rap was the FAA and training requirements.

What's wrong with piston twin pilots? | Air Facts Journal

Maybe he is wrong but if 1/3 of your total accidents were while training in one aspect of flying a twin out of all the hours flown, training and non training something is wrong.
That is like killing firefighters on the training ground because you are trying to make it "realistic.

A P-38 had power to weight ratio of around 15-16lbs per hp when flying on one engine at max continuous (not military of full power) and that should be plenty of power to keep the plane in the air as long as the fuel lasts and do any needed maneuvers.

Apparently the USAAF didn't get the memo about the P-38 crashing with one engine because they prepared flight operation instruction charts in the manuals for most models (at least P-38 D &E , F, G telling pilots recommended speeds/altitudes for different ranges depending on fuel while flying on one engine.
maybe they were just trying to keep up morale

 

[DerAdlerIstGelandet]

I think he was feeling unsupported by the rest of the forum after his little set-to with Schweik, and you gotta admit you did get on Dan's case kinda hard. Some of us have thinner skins than others, and I think Pb may have been feeling a little self-conscious about being under-informed about the fine points of engine out procedures in high powered twins.
You know the old saw about: "If ya ain't a pilot, ya ain't sh$t!". I think we "high and mighty" aviators sometimes get a little too full of ourselves for the comfort of our less fortunate shipmates. Mea maxima culpa. Et tu, Brute`?
Cheers,
Wes

He shouldn't have. I made it clear I was not taking sides, and that both should tone it down. It wasn't even him who got the thread temporarily closed.

 

[Zipper730]

Regarding the P-38

Advantages

1. Performance
   • The earlier P-38's (E/F) had a superior rate of climb to the unlettered P-51's; against the P-51A it was superior from 0-5000 and from around 20,000 feet up
   • The earlier P-38's (F/G) seemed to be able to out accelerate earlier P-51 models (P-51/P-51A) in level flight from 0-250 mph and probably a bit above that
   • I would not be surprised if it would out-accelerate the P-51 in a dive initially due to it's greater mass -- I wouldn't do it long though (mach tuck is a bitch).
   • The P-38's seemed to have better zoom climb performance all the way up to the P-51B at least, while close -- it'd hang on a bit longer.
   • The P-38J's long-range wing-tanks didn't upset the CG as much as the Mustang's did, so it didn't require as much burning of internal fuel before switching to drop-tanks.
2. Armament
   • The armament centered in the nose provides a greater range of, well, ranges where it can accurately hit other aircraft
   • The 20mm cannon also provides substantial hitting power over the P-51's all 0.50 armament
   • It was able to carry substantial bomb-loads, around 3200 lbs if I recall versus the Merlin powered P-51's 2000 lb loads
3. Other
   • The nose-gear made for easier landings, better initial acceleration on takeoff, and better visibility when taxiing
   • Visibility in the 6 o'clock position would likely be superior to the P-51 through P-51C.
   • It might have had more docile stall-characteristics, and might have been easier to land on short-fields
   • The extra engine might have made for greater survivability when flying over oceans and possibly even in air-to-ground configurations (that said, the P-47 is king in air-to-ground).

Disadvantages

1. Performance
   • The P-51 had a faster rate of roll than the P-38's until the P-38J/N came around
   • The P-51 had a much faster critical mach number and placard limits in dives than any aircraft in the USAAF inventory, as far as I know.
   • The P-51A had a superior rate of climb from about 5000-15000 feet, which is a very useful altitude block
   • The P-51B had a superior rate of climb from below 10,000 - 15,000 feet or so, and above 25,000 feet.
2. Armament: I'm not sure if the P-51 had any advantage except that it had more guns
3. Other
   • The cockpit was said to be better designed from a human-factors standpoint than the P-38
   • Visibility to the front and sides was superior to the P-38 on all variants, with visibility to the rear superior on the P-51D
   • The cockpit seemed to have less issues with extreme cold and frosting in the cockpit over the P-38

I could be wrong on this, but that's basically what I seem to have grasped so far. I am curious how fast the P-38 could go with the dive recovery flaps in terms of mach number.

On early models (B/Cs), ammunition doors & landing gear doors sometimes opened under high-gee conditions (frequently during high-speed dives) - this often then overstressed the wings, with several aircraft losing a wing and crashing (witnessed by other pilots). This was eventually resolved. You mentioned this in passing without mentioning its deadly effect. There was at least one P-51B lost to this in April 1944*, so not completely solved as per your date.

That's an interesting piece of data that I didn't know prior to this point

I found such tables for Northern Hemisphere.
Atmospheric Temperature Profiles of the Northern Hemisphere

Very valuable data

That looks more like a bowling ball than a baby...

Any more mass quoting and Fubar57's going to be apoplectic

 

[michael rauls]

Regarding the P-38

Advantages

1. Performance
   • The earlier P-38's (E/F) had a superior rate of climb to the unlettered P-51's; against the P-51A it was superior from 0-5000 and from around 20,000 feet up
   • The earlier P-38's (F/G) seemed to be able to out accelerate earlier P-51 models (P-51/P-51A) in level flight from 0-250 mph and probably a bit above that
   • I would not be surprised if it would out-accelerate the P-51 in a dive initially due to it's greater mass -- I wouldn't do it long though (mach tuck is a bitch).
   • The P-38's seemed to have better zoom climb performance all the way up to the P-51B at least, while close -- it'd hang on a bit longer.
   • The P-38J's long-range wing-tanks didn't upset the CG as much as the Mustang's did, so it didn't require as much burning of internal fuel before switching to drop-tanks.
2. Armament
   • The armament centered in the nose provides a greater range of, well, ranges where it can accurately hit other aircraft
   • The 20mm cannon also provides substantial hitting power over the P-51's all 0.50 armament
   • It was able to carry substantial bomb-loads, around 3200 lbs if I recall versus the Merlin powered P-51's 2000 lb loads
3. Other
   • The nose-gear made for easier landings, better initial acceleration on takeoff, and better visibility when taxiing
   • Rear visibility was probably better on the P-38 up to the P-51D owing to the shape of it's canopy
   • It might have had more docile stall-characteristics, and might have been easier to land on short-fields
   • The extra engine might have made for greater survivability when flying over oceans and possibly even in air-to-ground configurations (that said, the P-47 is king in air-to-ground).

Disadvantages

1. Performance
   • The P-51 had a faster rate of roll than the P-38's until the P-38J/N came around
   • The P-51 had a much faster critical mach number and placard limits in dives than any aircraft in the USAAF inventory, as far as I know.
   • The P-51A had a superior rate of climb from about 5000-15000 feet, which is a very useful altitude block
   • The P-51B had a superior rate of climb from below 10,000 - 15,000 feet or so, and above 25,000 feet.
2. Armament: I'm not sure if the P-51 had any advantage except that it had more guns
3. Other
   • The cockpit was said to be better designed from a human-factors standpoint than the P-38
   • The cockpit seemed to have less issues with extreme cold and frosting in the cockpit over the P-38
   • The P-51D's cockpit probably had better visibility, overall, to the rear hemisphere

I could be wrong on this, but that's basically what I seem to have grasped so far. I am curious how fast the P-38 could go with the dive recovery flaps in terms of mach number.


That's an interesting piece of data that I didn't know prior to this point

While off topic: What kind of rate of climb are we talking about?

Very valuable data

That looks more like a bowling ball than a baby...

Any more mass quoting and Fubar57's going to be apoplectic

In dont think the dive recovery flaps changed the maximum speed of the p38 in a dive. It would still be mach .68 which I think is around 470 at 25,000 feet.( the speed of sound can vary somewhat with temperature and humidity). What they would do is take away the threat of uncontrolled flight into terrain if this speed were exceeded.
Also I believe the p38 out climbs the Mustang at any altitude. As I understand it the p51 was better at most things but acceleration and climb is where the p38 shines. Have read quite a few times the p38 was the fastest climbing US fighter by quite some margin.

 

[XBe02Drvr]

Wes, if you read this chime in on other GA or Corp twins with the same characteristics.

As far as I know, the P38 (and perhaps the Mosquito) was unique in this regard due to its extremely high power to weight ratio and the rotation direction of its counter-rotating propellers giving both engines "critical" behavior regardless of which one fails. Most twins are a little underpowered for single engine flight, which means that the maximum thrust asymmetry they can develop is relatively low compared to a powerhouse like the Lightning. This means that they can maintain directional control with rudder down to a relatively low speed (VMCa), which is usually somewhere close to the speed where the airframe wants to lift off.
Because of the huge loss of performance with an engine failure, most twins require very precise handling and all the thrust the running engine can muster to eke out a meager rate of climb. The resulting flat climb gradient can present real problems in climbing out of a "hole in the hills" airport on one engine. (Which is why you don't try it! Go back and land.)
High powered machines like the Lightning and Mosquito are capable of generating humungoid thrust asymmetries, and because of their high speeds, are generally not endowed with huge rudders, thus sentencing them to an absurdly high VMCa. So the "golden rule" of keeping it pinned to the ground 'til past VMC just isn't practical in this case. But here the saving grace is that there's so much power in the remaining engine, that it will climb at less than full throttle, reducing asymmetry (and VMC) and saving your bacon.
Cheers,
Wes

 

[P-39 Expert]

Regarding the P-38

Advantages

1. Performance
   • The earlier P-38's (E/F) had a superior rate of climb to the unlettered P-51's; against the P-51A it was superior from 0-5000 and from around 20,000 feet up
   • The earlier P-38's (F/G) seemed to be able to out accelerate earlier P-51 models (P-51/P-51A) in level flight from 0-250 mph and probably a bit above that
   • I would not be surprised if it would out-accelerate the P-51 in a dive initially due to it's greater mass -- I wouldn't do it long though (mach tuck is a bitch).
   • The P-38's seemed to have better zoom climb performance all the way up to the P-51B at least, while close -- it'd hang on a bit longer.
   • The P-38J's long-range wing-tanks didn't upset the CG as much as the Mustang's did, so it didn't require as much burning of internal fuel before switching to drop-tanks.
2. Armament
   • The armament centered in the nose provides a greater range of, well, ranges where it can accurately hit other aircraft
   • The 20mm cannon also provides substantial hitting power over the P-51's all 0.50 armament
   • It was able to carry substantial bomb-loads, around 3200 lbs if I recall versus the Merlin powered P-51's 2000 lb loads
3. Other
   • The nose-gear made for easier landings, better initial acceleration on takeoff, and better visibility when taxiing
   • Rear visibility was probably better on the P-38 up to the P-51D owing to the shape of it's canopy
   • It might have had more docile stall-characteristics, and might have been easier to land on short-fields
   • The extra engine might have made for greater survivability when flying over oceans and possibly even in air-to-ground configurations (that said, the P-47 is king in air-to-ground).

Disadvantages

1. Performance
   • The P-51 had a faster rate of roll than the P-38's until the P-38J/N came around
   • The P-51 had a much faster critical mach number and placard limits in dives than any aircraft in the USAAF inventory, as far as I know.
   • The P-51A had a superior rate of climb from about 5000-15000 feet, which is a very useful altitude block
   • The P-51B had a superior rate of climb from below 10,000 - 15,000 feet or so, and above 25,000 feet.
2. Armament: I'm not sure if the P-51 had any advantage except that it had more guns
3. Other
   • The cockpit was said to be better designed from a human-factors standpoint than the P-38
   • The cockpit seemed to have less issues with extreme cold and frosting in the cockpit over the P-38
   • The P-51D's cockpit probably had better visibility, overall, to the rear hemisphere

I could be wrong on this, but that's basically what I seem to have grasped so far. I am curious how fast the P-38 could go with the dive recovery flaps in terms of mach number.


That's an interesting piece of data that I didn't know prior to this point

While off topic: What kind of rate of climb are we talking about? The figures in post #134 are accurate for the P-39N, although using meters instead of feet was a little different. Climb was about 2650fpm at 20000', 1950fpm at 25000' with a service ceiling of 38500'. Substantially better than most all other planes (FW190, F6F, F4U, P-38F/G, P-47B/C/D, Zero, Typhoon). Better than a Me109G up to 20000' and about the same above. Nowhere near a SpitfireIX in 1943 but nothing else was either.

Very valuable data

That looks more like a bowling ball than a baby...

Any more mass quoting and Fubar57's going to be apoplectic

See text above.

 

[P-39 Expert]

you want to play games with guns and ammo? I wonder How a P-47 does with only six guns and 200 round per gun?

My Bad guys. The figures I used for the P-47-10 came from a report dated 11 Oct. '43.
In the A. Purpose section it states:
"1. To report results of flight tests on P-47D-10 airplane, AAF No. 43-75035 run at the
manufacturer's plant. Airplane equipped with Pratt & Whitney R-2800-63 engine with
water injection; standard Curtiss 714-1C2-12 propeller; type A-17 turbo regulator. Airplane
ballasted to simulate the following conditions: Six .50 caliber guns; 300 rounds per gun;
305 gallons gasoline; 15 gallons water; 14 pounds pyrotechnics. In this condition the gross
weight was 13,234 pounds with a C.G. wheels up, of 29.63 percent M.A.C. Mixture auto-
rich; throttle wide open on all tests. Horsepower data obtained with torquemeter."

I was actually shooting for an earlier version without the water injection and 8 guns.[/QUOTE]
Don't bother, not enough difference to worry about. The earlier version was slower by 6mph at 27000' and 300fpm at 20000'. Enjoy the time with your family.

 

[XBe02Drvr]

It wasn't even him who got the thread temporarily closed

But he clearly felt chastised all the same.