F-15 shutdown sounds

For consideration on future updates to the sound model of the F-15 here is a video of a JASDF F-15 shutting down in an unusual way that lets us hear sounds that we may not have before.

What was unusual about the shutdown?

What sounds are different?

Posted as feature request to the developers ;)

What was unusual about the shutdown?

What sounds are different?

The video demonstrates the sound of something else besides the engines being shut down. I'm not sure what they are. Any F-15 guys out there know what equipment it is?

The video demonstrates the sound of something else besides the engines being shut down. I'm not sure what they are. Any F-15 guys out there know what equipment it is?

I am not an F-15 guys and my F-15 experience is limited to a few launches and recoveries, but if you are referring to the sound @ around 1:31, then is something I don't remember ever hearing on any USAF F-15. Not saying is not there, simply saying I never heard it. So it might be F-15J specific, it could be the AMADs disconnecting. It would not make since for the JFS to be running, unless the F-15J uses an APU instead. It could be adjacent equipment or aircraft shutdown at that time. Not sure.

But you mention it was an unusual way to shut down, anything ells besides the sounds at around 1:31?

I am not an F-15 guys and my F-15 experience is limited to a few launches and recoveries, but if you are referring to the sound @ around 1:31, then is something I don't remember ever hearing on any USAF F-15. Not saying is not there, simply saying I never heard it. So it might be F-15J specific, it could be the AMADs disconnecting. It would not make since for the JFS to be running, unless the F-15J uses an APU instead. It could be adjacent equipment or aircraft shutdown at that time. Not sure.

 

But you mention it was an unusual way to shut down, anything ells besides the sounds at around 1:31?

The usual sound US F-15's make when shutting down is one engine at a time and sounds like the pilot increases thrust slightly just before shutting it down. I'm not sure what their actual procedure is, but it's not the one the JASDF pilot used in the above video.

Wikipedia states, "F-15J/DJs are identical to F-15C/Ds aside from the ECM, radar warning system, and nuclear equipment." So, the JASDF pilot just shut the whole thing down his way!

The usual sound US F-15's make when shutting down is one engine at a time and sounds like the pilot increases thrust slightly just before shutting it down. I'm not sure what their actual procedure is, but it's not the one the JASDF pilot used in the above video.

 

Wikipedia states, "F-15J/DJs are identical to F-15C/Ds aside from the ECM, radar warning system, and nuclear equipment." So, the JASDF pilot just shut the whole thing down his way!

The reason USAF F-15 rev up the engine prior to shut down is because the engine (PW). Before shut down you "scavenge" the engine, IIRC, it is to allow the oil to return to the tank, so you rev it to 75% RPM prior to shut down. I do not think PW-229 need this but F-16 with PW-220 do this as well. Same way that PW engines dump fuel after shutdown, most others like GE-100 does not.

Japanese F-15 have many differences from other versions. Most aircraft are like this, but the differences are in the details. I haven't look online to get the details but F-15J have many component, made under license, including the engines.

At any rate, I do not think we have enough info on the original video to tell if the noise even comes from the aircraft. If it does come from the aircraft, is it a F-15J specific thing.

PW220 When ready to shut down the engine,

oil scavenge should be performed, conditions permitting.

 

1. PW220 Throttle - Advance to 75-78 percent rpm

(stabilize for 5-10 seconds).

 

2. PW220 Throttle - Retard to IDLE for 1-2 seconds

 

PW220 Do not wait for engine to stabilize in

idle prior to shutdown. Timing begins when the

throttle reaches IDLE. Waiting longer than 1-2

seconds after the throttle reaches IDLE negates

the effects of the scavenge shutdown.