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Yankee_One

RED lights when using rudder on P-38

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Hi,

 

don t know if this should  or should not  be.

 

When using the rudder on the P-38, red lights are turning on. I DO NOT have any other keybindings on my rudder except toe brakes.

 

Any ideas?

 

Thank you for any kind of help.

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You might expect the lights to be triggered by the engine failure itself. In fact they are triggered by the extreme rudder movement made by the pilot when his engine fails.    The light is not saying 'Your right engine has lost power',  it is saying 'I notice you have just jammed on an excessive amount of left rudder so maybe your right engine has failed and needs to be feathered.'   🙂

Edited by 56RAF_Roblex
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3 hours ago, 56RAF_Roblex said:

 

You might expect the lights to be triggered by the engine failure itself. In fact they are triggered by the extreme rudder movement made by the pilot when his engine fails.    The light is not saying 'Your right engine has lost power',  it is saying 'I notice you have just jammed on an excessive amount of left rudder so maybe your right engine has failed and needs to be feathered.'   🙂

 

So it is the rudder sayin' "hey maybe, just maybe check your engine" and not the engine sayin' "rudder, please"? Interesting system.

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Thanks Bert_Foster

 

and all the other guys for responding.

 

So, can i gnore it in this game? It has no impact, or?

 

Edited by Yankee_One

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Nope, it is just a "crude" warning light to show which engine to feather when you do  have an engine failure. 

 

One of the more common mistakes is feathering the wrong engine in a twin when you have engine problems. 

 

This helps with standard procedure for engine failure 

 

Identify 

Verify 

Rectify

 

Cheers, Dakpilot 

 

 

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Still, the question is not what the light is, but why it's on even when there's no engine failure, at least that's how I understand OP's question.

 

I need to take a look at these lights myself.

Edited by Art-J

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9 hours ago, von_Michelstamm said:

What a silly system. Basically crying wolf

 

Better than accidentally feathering the wrong prop over the oecean, 500 miles from your airfield and 100 miles from the shore.

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I get it, but it’s a less than optimal solution from a pure design perspective. Seems it should only come on during an actual engine failure.
Considering the especially (even overly) complex engineering that went into the p38, I’m really curious why they did it this crude way. They must have had a good reason. 
 

Edited by von_Michelstamm

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12 hours ago, 56RAF_Roblex said:

 

You might expect the lights to be triggered by the engine failure itself. In fact they are triggered by the extreme rudder movement made by the pilot when his engine fails.    The light is not saying 'Your right engine has lost power',  it is saying 'I notice you have just jammed on an excessive amount of left rudder so maybe your right engine has failed and needs to be feathered.'   🙂

It’s like the 1940s equivalent of Clippy asking if you want to write a letter!

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22 minutes ago, Bremspropeller said:

 

Better than accidentally feathering the wrong prop over the oecean, 500 miles from your airfield and 100 miles from the shore.

 

Actually, that scenario is likely recoverable as you would have altitude.  The worst case scenario would be right after takeoff.

 

As to why the light at all if it's not actually tied to engine performance, it was added because of the surprising number of accidents experienced in training due to the wrong engine being feathered.  No one seemed to miss the obvious loss of power but a surprising number had trouble quickly identifying the correct motor in the very stressful moments immediately following an engine problem shortly after takeoff.

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The standard for identifying which engine has failed is 

 

"dead leg = dead engine" 

 

When you lose an engine you naturally will give large rudder input to correct the yaw the "dead" (one not being used) leg is the side of engine failure

 

Having identified the engine you (try to) verify with engine instrumentation.. Revs MP, pressures

 

Then rectify the situation.. feather and close throttle. 

 

All of this may need to be done very quickly for example just after t/o, engine parameters may not give you the instant info you need, hence dead leg dead engine. 

 

Having a warning light on rudder input is a foolproof and simple visual aid system to help identification. 

 

After critical feathering and closing throttle, 

and hopefully reducing drag enough to fly on one engine, correct emergency shut down procedures can be done in a more collected manner by the book. Fuel/oil shutoff valves fuel pumps, generators etc. etc. 

 

As has been said, incorrectly identifying the failed engine was and is a very common cause of accidents in multi engined A/C even with experience and  training 

 

Cheers, Dakpilot 

 

Edited by Dakpilot
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10 hours ago, Art-J said:

Still, the question is not what the light is, but why it's on even when there's no engine failure, at least that's how I understand OP's question.

 

I need to take a look at these lights myself.

 

No the question is 'Why is the OP kicking in enough violent left rudder to trigger the lights when there is no engine failure'  😉  (Sorry Yankee 😜 )

Edited by 56RAF_Roblex
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6 hours ago, von_Michelstamm said:

I get it, but it’s a less than optimal solution from a pure design perspective. Seems it should only come on during an actual engine failure.
Considering the especially (even overly) complex engineering that went into the p38, I’m really curious why they did it this crude way. They must have had a good reason. 
 

 

It may very well be the optimal solution thanks to its simplicity. A circuit like that is trivial to implement using a pair of switches detecting large rudder inputs.

 

With the primitive electronics of the era, it's not so easy to make a system that can detect the engine failure itself (you'd have to measure torque, velocity, etc). If the simpler system works 99% of the time, there's no reason to choose something far more complicated.

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15 hours ago, 56RAF_Roblex said:

 

No the question is 'Why is the OP kicking in enough violent left rudder to trigger the lights when there is no engine failure'  😉  (Sorry Yankee 😜 )

 

 

No problem, because the fault is on my MFG Crosswind rudders😁

 

I only operate them.........😛

 

AND its not only left rudder, i a have TWO LEGS, so you forgot to mention the right rudder too😉

 

Edited by Yankee_One

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On 10/26/2019 at 12:12 PM, chuter said:

Actually, that scenario is likely recoverable as you would have altitude.  The worst case scenario would be right after takeoff.

 

Depends. There's always a way of dying if you try hard enough.

If for some reason you can't unfeather the prop again, you probably won't make it 500 miles with all the additional drag anyway - no matter if the bad engine actually survives or not.

 

On 10/26/2019 at 7:50 AM, Art-J said:

Still, the question is not what the light is, but why it's on even when there's no engine failure, at least that's how I understand OP's question.

 

I need to take a look at these lights myself.

 

The question would be how the lights actually work.

They could be tied to an input device that doesn't feed off any engine-parameter at all, but might be tied to a yaw-rate gyro, or tied to your rudder pedals.

 

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The B-25 had a similar system, except that it was just to tell the pilot how far he had pushed the rudder pedals. Simple electrical engineering is all it is. 

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15 hours ago, LukeFF said:

The B-25 had a similar system, except that it was just to tell the pilot how far he had pushed the rudder pedals. Simple electrical engineering is all it is. 

 

So,

 

nothing to worry about.

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