Forum: F-16 Design & Construction

In the recent <a href="http://www.f-16.net/interviews_article23.html">interview with MSgt. Erik Singletary</a>, he mentioned that during an incentive flight, the jet experienced a mechanical failure that included a "doughnut panel ".

Can someone please explain what this is???

Thank you.

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It is a completely round panel/fairing that slides over the exhaust and mates to rest of the aircraft. It's called a "donut" because it is round.

In the picture he references, look at the exhaust, and where the engine turns into airframe, that is where the donut is located. How this panel mates with the aircraft is what he is mentioning. Notice that the panel doesn't seem to be aligned with the rest of the airframe.

damageinc75 wrote:

In the recent <a href="http://www.f-16.net/interviews_article23.html">interview with MSgt. Erik Singletary</a>, he mentioned that during an incentive flight, the jet experienced a mechanical failure that included a "doughnut panel ".

Can someone please explain what this is???

Thank you.

The Doughnut panel (4409) came off/apart when the turbine (or T-flange) failed, which was a common Pratt issue back in the day. We had a similar incident when I was TDY to the PI from Misawa, 1990. One of our jets 85-557 had a burn through (I think it was the 1 O'clock fuel nozzle) and the tail end blew out. Not only the doughnut, but the bathtub and rudder ISA panels were destroyed.
When we were arrived at Cubic bay (the base it IFE'd to), the ISA was dangling by its hydraulic lines. What a job the pilot did in getting that wreck on the ground!

VAL