JRBarrett

Engine 2 Fail Light

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I have noted on all of my takeoffs, the the Engine 2 Fail light illuminates when advancing the power levers, then goes out. It should not do that.

The logic of the Engine 2 Fail light is that with weight on wheels, when the number 2 power lever is advanced beyond 82 degrees above the idle stop, a 15 second timer starts. If the engine does not reach at least 85 percent N1 in that time, then the light will illuminate.

Pilots test this during preflight before engine start by advancing the number two power lever to full, and insuring that the light illuminates within 15 seconds.

The reason for that system is that an engine 2 failure during the takeoff roll may not be immediately obvious to the pilots because there will be no thrust asymmetry with the loss of the center engine. If engine 1 or 3 fails the pilots will know immediately, because the aircraft will start to pull toward the side of the failed engine.

The Engine 2 Fail warning is disabled once the aircraft is in the air, so it won’t come on when doing normal power reductions during descent.

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9 minutes ago, JRBarrett said:

Pilots test this during preflight

Is this the config TO test

bob      …..thanks for the info Jim

 

edit .. just spotted it in the checklist  ..

Edited by onebob

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It can be done in conjunction with the takeoff config test. The config test works with any of the three power levers. You will get a takeoff config warning if all 4 slats are not extended, if any airbrake panel is up, if the parking brake is applied, if flaps are beyond 22 degrees, or if the horizontal stab trim is out of the green range.

The Engine 2 Fail test/warning is unique to the center power lever.

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4 hours ago, JRBarrett said:

I have noted on all of my takeoffs, the the Engine 2 Fail light illuminates when advancing the power levers, then goes out. It should not do that.

The logic of the Engine 2 Fail light is that with weight on wheels, when the number 2 power lever is advanced beyond 82 degrees above the idle stop, a 15 second timer starts. If the engine does not reach at least 85 percent N1 in that time, then the light will illuminate.

Pilots test this during preflight before engine start by advancing the number two power lever to full, and insuring that the light illuminates within 15 seconds.

The reason for that system is that an engine 2 failure during the takeoff roll may not be immediately obvious to the pilots because there will be no thrust asymmetry with the loss of the center engine. If engine 1 or 3 fails the pilots will know immediately, because the aircraft will start to pull toward the side of the failed engine.

The Engine 2 Fail warning is disabled once the aircraft is in the air, so it won’t come on when doing normal power reductions during descent.

Jim, that is good info. All I could find previously was the statement that :

Powerplant Conditions During Takeoff
Rapid displacement of the power levers (specifically the No. 2 engine
power lever) on the ground may cause the ENG-2 FAIL light to illuminate
momentarily.

You explanation clears up the 'why and how'.

Thx,

Al

 

Edited by ark

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Hi Jim,

Very happy to have you onboard here as well...

👍

We have a great community here at FSW...

Regards,
Scott

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1 hour ago, ark said:

Jim, that is good info. All I could find previously was the statement that :

Powerplant Conditions During Takeoff
Rapid displacement of the power levers (specifically the No. 2 engine
power lever) on the ground may cause the ENG-2 FAIL light to illuminate
momentarily.

You explanation clears up the 'why and how'.

Thx,

Al

 

The Fail light flickering momentarily on advancing power levers can occasionally happen, but what I see is it coming on steady for about three seconds, (then going off) on every takeoff. 

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11 hours ago, JRBarrett said:

The Fail light flickering momentarily on advancing power levers can occasionally happen, but what I see is it coming on steady for about three seconds, (then going off) on every takeoff. 

I noticed that also on my take off.

Also Jim (off the subject) do you think that it seems to take too much thrust to get this aircraft moving for taxi, or is it just me?  It makes me feel that the tires are low or something.

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6 hours ago, signmanbob said:

I noticed that also on my take off.

Also Jim (off the subject) do you think that it seems to take too much thrust to get this aircraft moving for taxi, or is it just me?  It makes me feel that the tires are low or something.

It does seem to take quite a bit of thrust to get moving. That may be due to the infamous FSX/P3D “excessive ground friction” problem that seems to affect a lot of different add-on aircraft on both platforms.

I know that various developers have come up with a variety of solutions to deal with the problem. I believe that there are adjustments that can be make to the section of the aircraft config file  dealing with the wheels and tires that can lessen the effect, but at a possible cost of losing braking efficiency at higher speeds.

Perhaps the user FDEdev offer some insights, as he appears to know a great deal about how sim flight models and airfiles work.

 

 

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3 hours ago, JRBarrett said:

It does seem to take quite a bit of thrust to get moving. That may be due to the infamous FSX/P3D “excessive ground friction” problem that seems to affect a lot of different add-on aircraft on both platforms.

I know that various developers have come up with a variety of solutions to deal with the problem. I believe that there are adjustments that can be make to the section of the aircraft config file  dealing with the wheels and tires that can lessen the effect, but at a possible cost of losing braking efficiency at higher speeds.

Perhaps the user FDEdev offer some insights, as he appears to know a great deal about how sim flight models and airfiles work.

 

 

 

Thank you for confirming my suspicions on this.   I will mention it to Flysimware.

To me, it's really annoying and I know that, like you said, other developers like PMDG, Leonardo, TFDi and Majestic have all dealt with this in their simulations without sacrificing.

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The 2 fail light says it illuminates for micro switch is open or the throttle is more than 84 degrees FCU and #2 engine is less than 84% N1.

So i believe i have coded it correct. What do you think?

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The information I have indicates that on the original (non-EX) Falcon 50, the Fail light is driven by N2, not N1. I’m going to verify this today or tomorrow, with an operator at my airport who has a Falcon 50, and current Dassault “Field” aircraft maintenance publications for that model.

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Just verified in the Falcon 50 AMM that the Fail light does indeed work off of N1. A Falcon 50 pilot at the operator who provided the information said he rarely sees the light come on when advancing power for takeoff, which probably indicates that N1 acceleration in the real aircraft on advancing throttles is faster than in the sim.

I know there are some definite limitations in the turbofan engine modeling done in accordance with the FSX/P3D SDK, that developers have to live with, unless they want to go to the time and expense of creating a custom engine model like PMDG, FSL etc.

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1 hour ago, JRBarrett said:

Just verified in the Falcon 50 AMM that the Fail light does indeed work off of N1. A Falcon 50 pilot at the operator who provided the information said he rarely sees the light come on when advancing power for takeoff, which probably indicates that N1 acceleration in the real aircraft on advancing throttles is faster than in the sim.

I know there are some definite limitations in the turbofan engine modeling done in accordance with the FSX/P3D SDK, that developers have to live with, unless they want to go to the time and expense of creating a custom engine model like PMDG, FSL etc.

Engine acceleration can be very realistically simulated just within the basic FDE. No need for custom programming at all. 

Furthermore FSX/P3D allows a much finer spool up speed control and realistic spool up curves than other sims.

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1 hour ago, FDEdev said:

Engine acceleration can be very realistically simulated just within the basic FDE. No need for custom programming at all. 

Furthermore FSX/P3D allows a much finer spool up speed control and realistic spool up curves than other sims.

If there are improvements that can be made, and you have the expertise, perhaps you should PM FlySimware and offer some guidance - help make a great product even better..

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17 hours ago, JRBarrett said:

Just verified in the Falcon 50 AMM that the Fail light does indeed work off of N1. A Falcon 50 pilot at the operator who provided the information said he rarely sees the light come on when advancing power for takeoff, which probably indicates that N1 acceleration in the real aircraft on advancing throttles is faster than in the sim.

I know there are some definite limitations in the turbofan engine modeling done in accordance with the FSX/P3D SDK, that developers have to live with, unless they want to go to the time and expense of creating a custom engine model like PMDG, FSL etc.

If you go to the aircraft cfg then [TurbineEngineData] and look for fuel_flow_gain = 0.0050

Increase this to 0.0060 for the N1 and N2 to spool up faster or try any value. Lower to spool slower. 

This rate right now is faster than the L35A project which our tech is a pilot of that plane. So i already increased this value. i would like to know if there is a way to find out what the spool up time is.

So feel free to add some input and play with that value.

Edited by Flysimware

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