Aircraft Quirks

[R988]

Early P-40s apparently had a tendancy to somersault or backflip in certain maneuvers, later models had the longer fuselage and some other modifications to fix this.

 

[FLYBOYJ]

Flyboy- not only the P-38 heater was poor but the defroster was lousy too. Imagine not being able to see well out of the canopy. "Are those P-51s or 109s? Hmmm?" The Allisons were never set up properly for high altitude cold performance either producing many failures and aborts.

Yep - heard that too from many of the old timers when I worked there - The windows really fogged up duing a dive....

Early P-40s apparently had a tendancy to somersault or backflip in certain maneuvers, later models had the longer fuselage and some other modifications to fix this.

When you stalled the aircraft, yu had to watch "pitch attitude." This is common with a lot of high performance aircraft and some jets as well.

 

[Sgt. Pappy]

Lol I know this is old post, but is it not true that by the time the p-38L-5-LO came around, the cockpit heater and defroster problem was corrected? According to http://www.p-38online.com and according to the person who wrote it, the L-5 had fixed all those problems mentioned above plus new, uprated engines which also solved the aborts caused by engine failures.

Apparently, the P-38J's engines and all earlier models were injesting the low-grade fuel in England that was also saoked with rainwater. This resulted in common engine failure. The following site has A LOT of information on the P-38 (if you scroll down to the very bottom, there is information in that last post about the P-38L's heating systems), but I'm not so sure how reliable it is... I've checked its 'about' page and its maker says it only has posts from reliable people: http://yarchive.net/about.html

So if anyone knows of more P-38 information regarding heaters and engine failures being fixed (or not fixed) in the Lockheed's long life, please notify me.

Thanks all!
cheers

 

[Soundbreaker Welch?]

I had heard that about the fuel tank in the back fuselage of the P-51 hurting performance.

Seems like bad fault if you are forced to fight right away in a battle, and you can't fuel up the back tank because you can't perform manuvers when it's full, and you still need all the fuel you can get to up in the air.

I guess thats why long distance helped the P-51 more than hindered it.

 

[FLYBOYJ]

I had heard that about the fuel tank in the back fuselage of the P-51 hurting performance.

Seems like bad fault if you are forced to fight right away in a battle, and you can't fuel up the back tank because you can't perform manuvers when it's full, and you still need all the fuel you can get to up in the air.

I guess thats why long distance helped the P-51 more than hindered it.

You were supposed to use fuel from the center fuselage tank first, I think that's mentioned in the POH.

 

[Hop]

Lol I know this is old post, but is it not true that by the time the p-38L-5-LO came around, the cockpit heater and defroster problem was corrected? According to http://www.p-38online.com and according to the person who wrote it, the L-5 had fixed all those problems mentioned above plus new, uprated engines which also solved the aborts caused by engine failures.

These "fixes" seemed to coincide with the P-38 being withdrawn from the 8th AF, where most of the problems had occured, probably due to the long times spent at high altitudes. I suspect the problems would have continued if the P-38 had continued in the same role.

Apparently, the P-38J's engines and all earlier models were injesting the low-grade fuel in England that was also saoked with rainwater. This resulted in common engine failure.

Apparently, though, the Merlin engines in Spitfires, Mosquitos and Mustangs (and Lancs etc) didn't have a problem with the fuel. Neither did the radials in the P-47 and B-17s (and Halifaxes etc). Not even the Allisons in the P-51As had a problem.

That suggests the problem was with the P-38, not the fuel (especially as nearly all the aviation fuel in the UK came from the US, with middle East production mostly going to the far east air forces)

There may have been a problem with fuel in mid 1943, when the US abrupbtly changed the formulation of the fuel they were shipping, from 4.8cc of tetraethyl lead to 5.5cc. The British tests at that time showed the new fuel had particular problems in Allison engines, which were not approved for combat power using US sparkplugs, and caused severe fouling of british plugs after 20 hours.

 

[Twitch]

Re: P-38 Plugs- a crew chief told me they pulled all newly arrived P-38s' plugs in the ETO which were Atlas brand and replaced them with the Brit plugs gapped at .035.

 

[wmaxt]

These "fixes" seemed to coincide with the P-38 being withdrawn from the 8th AF, where most of the problems had occured, probably due to the long times spent at high altitudes. I suspect the problems would have continued if the P-38 had continued in the same role.



Apparently, though, the Merlin engines in Spitfires, Mosquitos and Mustangs (and Lancs etc) didn't have a problem with the fuel. Neither did the radials in the P-47 and B-17s (and Halifaxes etc). Not even the Allisons in the P-51As had a problem.

That suggests the problem was with the P-38, not the fuel (especially as nearly all the aviation fuel in the UK came from the US, with middle East production mostly going to the far east air forces)

There may have been a problem with fuel in mid 1943, when the US abrupbtly changed the formulation of the fuel they were shipping, from 4.8cc of tetraethyl lead to 5.5cc. The British tests at that time showed the new fuel had particular problems in Allison engines, which were not approved for combat power using US sparkplugs, and caused severe fouling of british plugs after 20 hours.

The problems were corrected except for the plug fouling, which came at least partialy from the use of 104/150 fuel (J/L models). With early P-38s (pre J) The lead at high altitudes/high temps, would precipitate out in the intercoolers and it was a race to see if the lead globs ruined the valves or the lowered octain detonated first. Art Heiden and others remarked the Heat etc problems were fixed. Go to the following site for more on the 150 fuel issues,
http://www.spitfireperformance.com
has info on this including the clearence for P-38J's to use 65" in the ETO and up to 75" in the AAF in general. Use the 104/150 grade fuel link.

The early P-51s had a 30% abort rate in the begining to. The abort rate was so bad for P-51s that their comanders called them "Experimental Planes" for a while. These aborts ranged from head gaskets to plug fouling. When the fuel issues were corrected both aircraft ceased having problems of this kind.

It's true the early P-38s had issues but here are a couple of ditties from the Pacific

Don't give me a P-51
It was all right for fighting the Hun
But if fighting the Jap you try
You'll run out of sky
Don't give me a P-51

Or

The P-38 is some machine
She'll dive, loop and climb
and turn on a dime
To every pilot, she's the queen

All fighters have their quirks!

wmaxt

 

[Sgt. Pappy]

Great info guys.. o and sorry that i didnt clarify about those engines hops... the P-38's engines couldn't take the low grade fuel... it was the combination of the engine malfunctions and the fuel that caused the accidents.

Still looking up information on that heating system though... RAWR lol still can't find any.

However, I did find something else. Early P-38's only had one electrical generator powering both curtiss-electric props. If that generator went out, the props would go into feather.

 

[FLYBOYJ]

Great info guys.. o and sorry that i didnt clarify about those engines hops... the P-38's engines couldn't take the low grade fuel... it was the combination of the engine malfunctions and the fuel that caused the accidents.

Still looking up information on that heating system though... RAWR lol still can't find any.

However, I did find something else. Early P-38's only had one electrical generator powering both curtiss-electric props. If that generator went out, the props would go into feather.

Very early P-38s. Normally each engine had it's own electrical producing capability.

Many of the accidents were attributed to the pilots lacking engine out training, especially on take off....

 

[Sgt. Pappy]

OO I see.. but wait... wmaxt, when you said that 'the problems were fixed' does that mean engine failures at high altitude were not as common anymore - about as common as the P-51's engines aborts?

But these spark plug foulings... about how common were they? My sources seem to show that the spark plugs SOLVED the actual problem of hihg-alt. engine failure.

 

[Jank]

Related subject from my post on another thread:
----------------------------------------------

Remember when Yamamoto was killed? That particular mission, flown by the 339th, was labeled "SQUADRON 339 P-38 MUST AT ALL COSTS REACH AND DESTROY. PRESIDENT ATTACHES EXTREME IMPORTANCE TO MISSION." The planes were in tip top condition to be able to carry out this critically important mission. Even so, they had more than 10% of their flight turn back due to "engine problems."

Until the J model the problems were pretty bad.

http://home.att.net/~ww2aviation/P-38.html
Many of the P-38's assigned to escort missions were forced to abort and return to base. Most of the aborts were related to engines coming apart in flight. The intercoolers that chilled the fuel/air mixture too much. Radiators that could lower engine temps below normal operating minimums. Oil coolers that could congeal the oil to sludge. These problems could have been fixed at the squadron level. Yet, they were not. It took the P-38J-25-LO and L model to eliminate these headaches.

http://bob.hentges.lu/articles/en/p38.html
The Allison engines of the Lightnings proved to be somewhat temperamental, with engine failures actually causing more problems than enemy action. It is estimated that every Lightning in England changed its engines at least once.

The powerplant problems were not entirely the Allison engine's fault. Many of the reliability problems were actually due to the inadequate cooling system, in particular the cumbersome plumbing of the turbosupercharger intercooler ducting which directed air all way from the supercharger out to the wingtips and back. In addition, the lack of cowl flaps were a problem. In the European theatre of operation, temperatures at altitude were often less than 40 degrees below zero and the Lightning's engines would never get warmed up enough for the oil to be able to flow adequately. Octane and lead would separate out of the fuel at these low temperatures, causing the Allisons to eat valves with regularity, to backfire through the intercooler ducts, and to throw rods, sometimes causing the engine to catch fire.

These problems bedeviled the Lightnings until the advent of the J version with its simplified intercooler ducting and the relocation of the oil cooler to a chin position underneath the propeller spinner. When the P-38J reached the field, the Allison engine was finally able to attain its full rated power at altitude, and the engine failure rate began to go down.

 

[Sgt. Pappy]

Wow you people are awesome... any tips for searching for information like you guys do? I don't want to keep aggrivating you lol. But, once again, thanks.

 

[FLYBOYJ]

Great info Jank, but a note, most of the problems noted were mainly encountered in the ETO. Early G's and H's had their problems but for the most part their FMC rates were good in the PTO...

 

[Twitch]

Aborts were an accepted occurance simply due to the fact that airplanes of the time were very complicated entities. They still are. DOn't read too much into it. Guys turned back for a huge variety of reasons real or perceived. At times a "rough running" engine at the cruise speed of the squadron could cause and "I'm turning back." Pilots were attuned to their machines and literally could feel subtle vibrations and sense other problems by the way the crate reacted.

Today fighters would mostly not abort once in flight but would not be deemed flightworthy by the crew chief and allowed to take off at all. The diagnostics has improved to the point where that happens instead of in-mission turn backs. Lot safer all around if problems are found and the aircraft is scratched from flight status ie., you don't risk losing the plane or pilot.

 

[FLYBOYJ]

I think a major source of these problems were improper leaning by the pilots. If you run an aircraft engine too rich, you will foul the plugs, to lean and you'll burn valves. In many -1s it was SOP to put the mixture control at full rich when you went into combat, this was done for cooling. I believe that many times the mixture controls weren't adjusted after combat which created other problems.

I know that many fighters had an auto mixture feature but I believe that many pilots still went with their own mixture settings for various reasons...

 

[Jank]

Twitch said, "Aborts were an accepted occurance simply due to the fact that airplanes of the time were very complicated entities."

Indeed. The occurrence rate however, appears to have been far higher in the P-38 than with any of the Stang or Thunderbolt models. Hence the problem. If the occurrence rate was on average with other aircraft used in the P-38's role, it would not have been an issue.

Flyboy said, "I think a major source of these problems were improper leaning by the pilots.

Doesn't sound like "pilot error" to me. Sounds like there were genuine mechanical issues.

 

[FLYBOYJ]

Doesn't sound like "pilot error" to me. Sounds like there were genuine mechanical issues.

NOPE!! The pilot leans out the engine and changes the airfuel mixture based on density altitude and operation. This is purely an operator function and controlled by the pilot and the pilot only!! unless the aircraft is equipped with autolean which will take about 50% of the process away from the pilot.

 

[Marshall_Stack]

I don't know if this is considered a "quirk", but the wildcat didn't have hydraulic retraction of the landing gear. It was done manually with the pilot having to crank a handle 29 times until it came up. As the plane was going into its climb after takeoff, the plane could be seen going on an erratic path as the pilot was trying to crank up the gear and fly at the same time.

 

[FLYBOYJ]

I don't know if this is considered a "quirk", but the wildcat didn't have hydraulic retraction of the landing gear. It was done manually with the pilot having to crank a handle 29 times until it came up. As the plane was going into its climb after takeoff, the plane could be seen going on an erratic path as the pilot was trying to crank up the gear and fly at the same time.

True - Wildcat pilots I met said that they learned to master turning the crank and flying at the same time.