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From my experience, I have seen a grounded out wire coming from the throttle position switch going to the esdc cause a similar problem. It kept frying the ESDC and DEC. We went through 3 EDSC's and 2 DEC before we found the wire. Hell, before you got up to 20%, once the AC gen was online, it started to shut. Then go over the horn to hope that it would reset and it would just stay shut. I know I mentioned (16 News - USAF F-16s make emergency landing at Fukuoka, Japan) about GE's having the servo cartridge in the hydro pump that can clog causing that but on that note, even our CEDS we got a servo loop fault and it was verified that the nozzle was at the closed diameter. But Pratts use air so I can't see a similar problem happening like that. But, don't quote me on that.

From the sound of it, I think it is an electrical if not electrical component problem. But that is my two cents. Let us know what is was when u find out thought.

Mush

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As Joe said earlier, its what got you into SEC mode that you have to worry about.

All the electronic engine control systems I have worked with recommend, when a failure occurs in flight, switching into the lane or loop which is in control.

The System Safety logic behind this action is that you know that something has happened to a primary system, you have no indication of which, if any, system will be next affected; for example, if your next failure is a transient bus failure then the system may reboot and try to re-energize into the failed control loop, this may result in sparks out of both ends and general corruption.

If you look at any modern aircraft wiring logic you will see that the electronic control loops will generally be powered off the primary bus however the primary ignition and one control loop should be powered off the battery bus. Failure to wire the systems this way has been a lessons learned in a few programs.

CENC R2 fixed it

Nice fix. That was simple. I am suprised a fault wasn't kicked out to the DEEC for a CENC failure. Awsome!!!

Mush

Mushmouth wrote:

Nice fix. That was simple. I am suprised a fault wasn't kicked out to the DEEC for a CENC failure. Awsome!!!

Mush

Actually we did get a fault on the ground run. After she was started (nozzle still closed) went from Pri to SEC. In SEC the lite did come on and RPM increased about 3-5% with a slight rise in FTIT, back to PRI and lite goes out and RPM and FTIT decreased. Performed this at least 3 times with Engine guys looking at CEDS. Nozzle never moved or crep, just stayed hard closed.

It wasn’t until I rapidly moved the throttle back and forth to see how the engine would respond, that’s when I got Eng fault lite and both bit balls flipped on the ground.

It's good ya'll went up there and played with it for yourselves and were able to generate a good starting point for troubleshooting. I know some guys that would just stare at the book lost and wouldn't have a clue. Good job!!
Here's a shot for ya Beer

Mush

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Forum: F-16 Procedures

Is SEC mode really safe?