P-38 & The Yoke

[Captain Virgil Hilts]

First off, the P-38 apparently didn't suffer nearly so much with asymmetric thrust as you might think. Considering how well Stan told me it flew on one engine, I seriously doubt he was standing on one rudder pedal and cranking the yoke around just to maintain normal level flight.

Second, this is not a regular GA engine we're talking about, this is a 1710 cubic inch 1750HP engine, it uses a lot of fuel, so running one leaves you enough power to not only still climb, but also to cruise at well over 200MPH, while reducing fuel consumption dramatically.

By the way, the yoke was actually on a control column, so the elevators were controlled just like if a stick were used, except you have two hands holding the yoke and exerting that force. The yoke itself allowed you two hands to control the "broad chord" ailerons which were way out toward the ends of a rather large wingspan. Again, this is not a GA type light aircraft, it is a large, relatively heavy, high performance aircraft. You needed a lot of muscle to control it. Every pilot who flew it that I talked to liked the yoke, feeling that it reduced the effort required to fly the plane hard, and allowed them to perform at their best with strength in reserve for a longer period of time.

[MachFly]

I'm not talking about holding...we're discussing getting a low fuel P-38 back to base during a combat mission.

Right. Turning the engine off would increase endurance, if you want to increase your range (which is what you want in combat) you want to keep both engines on. So if your going to/from combat you want to increase your range and shorten the time it would take you to get there, for that scenario it's best to keep both engines on. The only time when you would want to increase your endurance is if your holding.

[colmbo]

Right. Turning the engine off would increase endurance, if you want to increase your range (which is what you want in combat) you want to keep both engines off. So if your going to/from combat you want to increase your range and shorten the time it would take you to get there, for that scenario it's best to keep both engines on. The only time when you would want to increase your endurance is if your holding.

FYI keeping both engines off will greatly reduce your range.  Dramatically so.

[MachFly]

FYI keeping both engines off will greatly reduce your range.  Dramatically so.

Typo, fixed now. But you knew what I meant.

[MachFly]

First off, the P-38 apparently didn't suffer nearly so much with asymmetric thrust as you might think. Considering how well Stan told me it flew on one engine, I seriously doubt he was standing on one rudder pedal and cranking the yoke around just to maintain normal level flight.

Second, this is not a regular GA engine we're talking about, this is a 1710 cubic inch 1750HP engine, it uses a lot of fuel, so running one leaves you enough power to not only still climb, but also to cruise at well over 200MPH, while reducing fuel consumption dramatically.

By the way, the yoke was actually on a control column, so the elevators were controlled just like if a stick were used, except you have two hands holding the yoke and exerting that force. The yoke itself allowed you two hands to control the "broad chord" ailerons which were way out toward the ends of a rather large wingspan. Again, this is not a GA type light aircraft, it is a large, relatively heavy, high performance aircraft. You needed a lot of muscle to control it. Every pilot who flew it that I talked to liked the yoke, feeling that it reduced the effort required to fly the plane hard, and allowed them to perform at their best with strength in reserve for a longer period of time.

A pilot who really likes their airplane will not tell you anything bad about it. That 1750HP engine produces a lot of thrust and torque that you have to count, the blades are also pretty big so the P-factor would be noticeable.
Now your saying that it's not a regular GA aircraft, well just for the record my GA aircraft can fly higher and faster on a single engine than 90% GA aircraft with everything working. So don't think that I'm used to the airplane not being able to do anything on a single engine.

The elevator motion of a normal yoke don't really bother me, the problem with the yoke are the aileron motions and the fact that it's big and gets in the way.  

[Guppy35]

A pilot who really likes their airplane will not tell you anything bad about it. That 1750HP engine produces a lot of thrust and torque that you have to count, the blades are also pretty big so the P-factor would be noticeable.
Now your saying that it's not a regular GA aircraft, well just for the record my GA aircraft can fly higher and faster on a single engine than 90% GA aircraft with everything working. So don't think that I'm used to the airplane not being able to do anything on a single engine.

The elevator motion of a normal yoke don't really bother me, the problem with the yoke are the aileron motions and the fact that it's big and gets in the way.  

Nothing personal Machfly, but if I have  to choose between Kelly Johnson's designs and yours, I'm going with Kelly Johnson.

For whatever reason he felt the wheel worked better.  Maybe he didn't like the idea of a stick banging the knees of his pilots, or maybe he felt like they could get more muscle into it with grips for two hands.

As for the guys shutting down an engine due to fuel, all I can do is pass on what they did.  Corky Smith feathered his engine due to low fuel.  Apparently he had his reasons.

When you start challenging the guys who really flew the thing in combat and making excuses for why they wouldn't tell the truth about their plane , the conversation starts to be pointless pointless.  We're not arguing about whether the 38 is better then the 51 etc.  We're talking about using the controls and a yoke.  Hardly a reason to make things up as all these guys would have flown birds with a conventional stick as well.

[Delirium]

When you start challenging the guys who really flew the thing in combat and making excuses for why they wouldn't tell the truth about their plane , the conversation starts to be pointless pointless.

+1

I did this some time ago.

You are ignoring this user. Show me the post.

[colmbo]

Right. Turning the engine off would increase endurance, if you want to increase your range (which is what you want in combat) you want to keep both engines on. So if your going to/from combat you want to increase your range and shorten the time it would take you to get there, for that scenario it's best to keep both engines on. The only time when you would want to increase your endurance is if your holding.

Here's what I did in the TA with the P-38.  Set up at 7000 MSL, cruise power setting of 35"/2800RPM.  With both engines running fuel flow ends up at 155GPH with a TAS of 285.  With one engine shut down and the same power setting fuel flow drops to 78GPH with a TAS of 220.

With 78 gallons of fuel and both engines running you'll ditch after 143 miles while I'll be able to fly 220 miles back to base by using one engine.

Using those power settings/fuel flows/TAS it's a 50% reduction in fuel consumption but only a 23% reduction in TAS.

[MachFly]

Nothing personal Machfly, but if I have  to choose between Kelly Johnson's designs and yours, I'm going with Kelly Johnson.

So what are you going to do when you want to take a friend up? 

For whatever reason he felt the wheel worked better.  Maybe he didn't like the idea of a stick banging the knees of his pilots, or maybe he felt like they could get more muscle into it with grips for two hands.

So did the guys who did not give the F-4 a gun.

When you start challenging the guys who really flew the thing in combat and making excuses for why they wouldn't tell the truth about their plane , the conversation starts to be pointless pointless.  We're not arguing about whether the 38 is better then the 51 etc.  We're talking about using the controls and a yoke.  Hardly a reason to make things up as all these guys would have flown birds with a conventional stick as well.

I did not mean they were not telling the truth about it. I meant that when you like a certain plane a minor disadvantage will be invisible to you, it's quite possible that thought they liked the yoke because the liked the whole plane.

[MachFly]

Here's what I did in the TA with the P-38.  Set up at 7000 MSL, cruise power setting of 35"/2800RPM.  With both engines running fuel flow ends up at 155GPH with a TAS of 285.  With one engine shut down and the same power setting fuel flow drops to 78GPH with a TAS of 220.

With 78 gallons of fuel and both engines running you'll ditch after 143 miles while I'll be able to fly 220 miles back to base by using one engine.

Using those power settings/fuel flows/TAS it's a 50% reduction in fuel consumption but only a 23% reduction in TAS.

According to AH's E6B the max cruise for the P-38L is 35MP & 2300RPM. I think at that setting the results might be different.

I'll go check. 

[MachFly]

Here's what I did in the TA with the P-38.  Set up at 7000 MSL, cruise power setting of 35"/2800RPM.  With both engines running fuel flow ends up at 155GPH with a TAS of 285.  With one engine shut down and the same power setting fuel flow drops to 78GPH with a TAS of 220.

With 78 gallons of fuel and both engines running you'll ditch after 143 miles while I'll be able to fly 220 miles back to base by using one engine.

Using those power settings/fuel flows/TAS it's a 50% reduction in fuel consumption but only a 23% reduction in TAS.

According to AH's E6B the max cruise for the P-38L is 35MP & 2300RPM. I think at that setting the results might be different.

I'll go check.  

Okay I made the test and basically I got the same results as you. If you want I can post the numbers but they show exactly the same thing.

However, I did the test on autopilot and it was not compensating for asymmetric thrust. The airplane was in a constant turn and the ball was not centered. When you did your test did you keep the autopilot on?
I'll do the same test again manually to get more accurate results. With greater control deflection and the same power setting (and fuel burn) I expect the TAS to drop. Will post the numbers in a few hours. (don't have time for another test right now)

[colmbo]

According to AH's E6B the max cruise for the P-38L is 35MP & 2300RPM. I think at that setting the results might be different.

I'll go check. 

Typo..I used 2300 RPM

[MachFly]

Typo..I used 2300 RPM

Roger

BTW was it a P-38L that you tested?

[colmbo]

L or J, don't remember.

Used auto level and bumped in a bit of rudder trim...about 1/2 ball out.

[Captain Virgil Hilts]

So what are you going to do when you want to take a friend up? 

I watched Steve Hinton take a 78 year old man up in "Glacier Girl". Looked to me like the passenger really enjoyed the ride, it lasted 1/2 an hour.



And I'll take what Captain Art Heiden and Captain Stan Richardson told me about the P-38 on one engine as well as fuel consumption and how well the yoke worked as gospel.