Data source?
At least Darren's data had a little more detailed information.
P-38 vs P-51
- Thread starter jtg
- Start date
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At least Darren's data had a little more detailed information.
Ministry of Supply data sheets.
You saw the Tony LeVier video that was posted upthread didn't you? I think that about covers it as far as the fighter community was concerned. Different story with the bomber boys, I'm sure.
Cheers,
Wes
Wes,
I think the LeVier video was good but what I don't know was when it came out and what was actually being taught at the school house.
Cheers,
Biff
I don't know either, but given that the P38 with all of its quirks was thrust into what had been a solidly single engine culture, it seems probable that the training system might take a bit of time to catch up. The bomber / transport community "owned" the multi engine training structure, so AT6 nuggets from the fighter pipeline were probably going straight into P38s with no dual control trainers available. Interesting question. Anybody out there know?
Cheers,
Wes
Hello XBe02Drvr,
There are a few differences with the airshow birds and the ones flown in combat.
First of all, I don't believe the typical airshow P-38 will have operational Turbochargers which means there is going to be less power available.
Next and most importantly, a lot more items can be stripped from a P-51 without screwing up the CoG location.
With the P-38, all that armament and armour and such is up front and I know at least one of the manuals states that if there is no ammunition being carried, the aircraft must be ballasted to maintain proper CoG.
Another advantage in low speed flight for the P-38 is that its Fowler Flaps add quite a bit of additional wing area so a normal comparison of wing loading doesn't tell the full story either.
- Ivan.
And if you're taking off heavily loaded with partial flaps, your VMC is going to be higher still and your safe takeoff speed reached even farther down the runway.
Cheers,
Wes
Wes,
Good point. To piggyback on that certain air carriers do takeoffs in their B767 757s at flaps 5 rather than 15 when performance allows. The flaps 5 allows you to stay on the runway longer to accelerate to a higher speed prior to takeoff. Once airborne, you get to accelerate altitude faster (than flaps 15), and to reach clean maneuvering speed quicker as well. Same goes for a V1 cut profile (engine out takeoff continued). The excess performance gained from the higher speed takeoff is actually a larger safety margin. And it burns 300-500 lbs less fuel.
Cheers,
Biff
FLYBOYJ
"THE GREAT GAZOO"
Hi Ivan -
From my time at Reno I heard from the piston pounders that the CG for the Mustangs raced there was actually really squirly, even with the stock birds. Crew chiefs really watched their "Ps and Qs" after the Ghost incident. As there were no P-38s racing I have no knowledge how this would compare. I believe that only one or 2 of the airworthy P-38s have fully operational turbochargers. I vaguely remember reading the ballast required on a non-armed P-38 was easily installed and not that much. I know I have some data on this buried in a box.
I crewed in the jet class and was totally anal on my bird's weight and balance as we stripped a whole bunch of sh*t out of the aircraft prior to getting serious
Hello FLYBOYJ,
I thought the accident with Galloping Ghost / Jimmy Leeward resulted from the loss of a trim tab on the elevator which caused a severe pitch up (enough to collapse the pilot's seat). I had not heard that it was a CoG issue that was the cause.
The mention about ballasting can be found in a British manual on the Lightning. Perhaps it is also found elsewhere.
Do you happen to know if any of the P-51s with CoG issues were converted to carry a passenger?
In looking at where components are in the P-51, we know the Fuselage fuel tank is well behind the CoG and the wing armament is very near the CoG or slightly behind. The armour plate behind the cockpit is also reasonably far aft, so all of these would tend to move the CoG slightly forward to improve stability a bit.
With the P-38, it does make one wonder what would happen if the ammunition were expended in flight rather than just not loaded on the aeroplane. In any case, if there is concern for just some ammunition, what happens when a 20 mm cannon and 4 .50 cal MGs are also removed from the same area?
- Ivan.
FLYBOYJ
"THE GREAT GAZOO"
You are correct but after that mishap the feds came down hard on everyone with a very watchful eye. I do know that there were W&B issues brought up with many participants.
I've seen some discussion about P-38 ballast. Were the British notes about the model 322?
I've never heard about any CG issues with 2 seater P-51s but my guess the weight of the original radios and armor plate behind the pilot would make up for human ballast.
Don't readily know but remember, Lockheed did put another human in that nose. They also threw another body in piggy back and even threw a big radar below the nose. I think there was a wide envelope to play with.
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MiTasol
1st Lieutenant
Back in the real round engine days Grumman on the Trackers fitted two rudders, one behind the other. The rear rudder was for all normal flight ops. They built in a system using the torque sensors so that an engine failure automatically punched the front rudder hard over to compensate for the yaw. Given the aircraft was designed to operate at extra low altitude and used spoilers for roll control this was probably the only reasons that the aircraft did not produce a big splash if an engine failed.
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NAS Ops Dept had 3 SH3s, 2 US2Bs, a C1, a U11 (Piper Aztec), and a base CO who felt all his pilots should be 100% interchangeable. So his fixed wing fliers were out practicing autorotation in SH3s and his rotorheads were out doing V1 cuts in Stoofs....with predictable results. Nobody died, fortunately, but a lot of metal got bent, and the CO's retirement ceremony was moved earlier by almost a year.
Two SH3s suffered collapsed gear / tail rotor amputation hard landings, the overrun arresting cables got a workout, and a US2B and the C1 got parked in the mangroves at various times.
Cheers
Wes
FLYBOYJ
"THE GREAT GAZOO"
Reluctant Poster
Tech Sergeant
- 1,682
- Dec 6, 2006
Attached is the history of the 496th Fighter Training Group which was tasked with training P-38 and P-51 pilots for the 8th and 9th Air Forces. Table 2 "Accident Analysis" shows that accidents were actually rare during take off. It also shows a much higher accident rate for the P-38.
FLYBOYJ
"THE GREAT GAZOO"
michael rauls
Tech Sergeant
- 1,679
- Jul 15, 2016
I find the data in the table surprising. With the p38 being very difficult to stall and the Mustangs lack of stall warning and difficulty in recovery( so i have read anyway) I would have expected these rates to be much different.
Notice that the greatest discrepancy in accident RATES is in the in-flight category. There the P38 has three critical flight regimes to the P51's two, namely, accelerated stalls and compressibility dives (both), and engine-out flight (P38 only).
Having lived and worked in the world of ACM training, I would lay odds on compressibility and single engine handling as being the Lightning's two Achilles heels in the combat training environment.
Cheers,
Wes
drgondog
Major
The 496th was usually the first stop for inbound ETO replacements. I have two 'suspicions'. The first is that the 'in type' hours for the P-38 pilots were far lower than the P-51, compounding multi-engine complexity in comparison to AT-6 to P-40 or AT-6 to P-51. Some multi engine training in 1943 did proceed from AT-6 to C-45 'variants' but a C-45/B-25 is a long way from realistic P-38 prep.
The second point would be based on extrapolating the % category for P-51 hours = 23,417 hours to 7, 432 hors for P-38 would reduce (on pro-rata basis)
P-51 Hours = 7432, Acc = 22, A/c lost = 7, pilots KIFA = 3, [1000 hour % don't change], Type Acc = Flight/9.2, Landing/8, Taxi/4.4 total; -----> which really shows the high accident rates of P-38 vs P-51 as a % of hours logged.
The second point relates to first (namely in type low training hours for P-38 hours), namely the P-38 was particularly more complicated based on in-flight pro-rata comparisons - P-51 = 9.2 to P-38 = 24 for same number of hours (pro-rata).
Speculating that KIFA lost to compressibility may not have been the leading causes as both the problem and the warnings were well known by Jan 1944. More likely (IMO) were the lingering process issues of moving low Boost/low RPM cruise conditions to High Boost/RPM until AAF/ETO complied with Lockheed and Allison recommendations. Additionally, the Intercooler/turbo and oil cooler issues on the J early designs weren't fully ironed out until the March timeframe when the -15's arrived.
