Forum: F-16 Procedures

Question, we have a problem with one of our F16's. The overheat caution light comes on every flight. We checked the ECS and the overheat leads. Nothing found. We changed the engine, allmost all ECS valves. Does anyone have a clou were to start?????? Crying or Very sad

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You need to get the pilot to run the overheat light checklist in the Dash One which will allow you to isolate the problem. There is some stuff that happens in flight that you cannot duplicate on the ground.

Best Regards,

If the jet is equipped with a CSFDR, the recorded data should be examined. Overheat caution light illumination is a recorded event. LM Aero Flight Safety has years of experience in analyzing such data. Field support personnel at Ogden and/or Product Support Engineering at LM Aero should also be able to assist.

Joe - If the light has come on in flight, each pilot experiencing it should have completed the overheat light checklist already.

You probably have a hot air leak somewhere Doh

… when the light illuminates in flight the check list should call for throttle to idle and see what happens, if light does not go out air source to off and see what happens.
Tie her down, run her in mil for a while with heat turned to max in manual and see if you can dupe it.
Look for a leak in the ECS package area, I bet that’s where it’s at! Lots of hard to hook up sh*t in there!
Reason it happens in flight is because that is a long duration … let it cook in on the ground for a while should produce a dupe! Because things expand

Before I get beat up again ... do what the FI says first Rolling Eyes

It could be something like a missing -250 seal in a bleed air duct conection, but wont illuminate the lite until the loop gets to that required temperature?

Hi Larry,

Operative words - "should have"...

Best Regards,

It could be that there is a hot air (bleed air) leak in one of both main wheel wells. It will most probably not trigger on the ground because the well is open.

The loops can also be damaged (bend to sharp).

Well since you're already following the FI, I'll offer up another point to chase.

Check the welds/flanges of the ECS system especially near the joints, clamps and supports.

I know if the engine has a cracked flange, or a flange that isn't tight, it can leak air at higher settings and set off overheat or fire lights. Since you've changed the motor, you've eliminated that possibility.

TEG

I ran into a very similar problem when I was in Osan a few years back. Every flight we'd get a code 3 for overheat on this particular bird (88-0531?). Anyways, we'd get APG to run that thing for hours. We'd run it through burner and back down to idle. We did every ECS check in the book and couldn't find anything wrong. We busted the safety wire on all the loops (pain the *SS saftey wiring them back up) and all resistance checks were good for each segment as per the 26FI(?). Fire overheat boxes tested fine and all wires for the system shot fine. We'd CND it and send it back up only to have it code 3 on take off and come back down heavy! Well we tore all the ducts out and changed EVERY seal on EVERY bleed air duct. In the process of doing so, we found a crack inside the grooves of the metal accordian hose that connects to the ECS turbine! Our guess as to why we couldn't duplicate it on the ground was due to the fact that the ejector ground shut off valve was open creating enough of a vaccuum in the bay to stop the light from coming on. Anyways, long story but I'd try tricking out the ejector shot off valve in the ECS bay and see if that dupes the problem. It may just give you a direction to go in.

Thank you very much soo far. Still nothing found. We tried all your tips. Now we want to use thermo stickers inside the AC to tell us were to find the hotspot.
More tips are welcome!!! Bang Head

Maybe you could use and IR heat gun to check the the temps around the ducts? Open all the panels and check around seals to see if one is leaking that you can't feel. I don't know of if your support section would have one, but I would bet that there is an orginzation on base that does. Maybe CE?

One other thing! I remember one time when our bleed air check valve had come apart, we had to scope the ducts to find all the parts and in doing so, found a duct that had corroded and broken apart. It wasn't visible from the outside due to the insulation, but the hole was obvious when looking through the scope. Maybe you could try to scope the ducts as well.

What block of F-16 are you dealing with? Is there CSFDR data available? Have you requested assistance from depot or from LM Aero Product Support Engineering? If not, why not?

Some Fire departments have the IR heat sensing guns to check A/C for hot brakes when a Ground Emergency is called.

Forum: F-16 Procedures

F16 with overheat caution