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The MiG-25 can supposedly damage its engines by commanding too much thrust and gaining too much speed. Somewhere around mach 3 damage to the engines is likely, I believe.

What about the F-16?

What happens if the pilot, at altitude, attempts to simply go as fast as it will go?

I believe the F-16 has FADEC (Full Authority Digital Electronic Control). The MiG-25 does not. I imagine this would limit the amount of fuel flow by some limit.

However, even if this is true, is it still possible for the pilot to exceed the ordinary limits imposed by the computer?

As a bonus question, it would be interesting to also mention if this does or does not apply to other fighters, in particular the F-14, F-15 and F/A-18.

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  • $\begingroup$ I'm interested to hear the answer to this. Intuitively, it seems foolish that a military plane would be limited to a non-damaging regime as mission success may well include outcomes with damaged engines or even destroyed aircraft which it seems it would be foolish to prohibit in a non-civilian context. $\endgroup$ – Dannie May 25 at 20:40
  • $\begingroup$ The Panavia Tornado's RB199 engines have a system called 'datum' operated with a 2 position switch, low and High. This basically allows the engine more temperature in the combustion chamber and, consequently more power. Downside is it drastically reduces the life of the engine and incurs a big maintenance penalty every time it was used. It was soon inhibited in the Low setting and safety wired. $\endgroup$ – Swampy Aug 21 at 14:52
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Yes, you can overheat and damage an F100 or F110 engine just like any other jet engine. It has mechanical and thermal limits that may not be exceeded. And it often happens as part of high performance military flying, though it can make you very unpopular with your crew chiefs and inevitably with you commanding officers if you keep willfully exceeding the limits and damaging engines.

FADEC systems ie “power by wire” systems just use a computer to administer engine control commands based on pilot inputs. They do not necessarily limit a flight crew from giving inputs that can exceed engine parameters.

Earlier engines were more finicky about this, in particular to exceeding hot section temperature limits or compressor stalls. The F-14A with the TF-30 engines was particularly prone to compressor stalls and could be treacherous during critical phases of flight. Improved intake diffuser, gas core aerodynamics, advancements in materials science and manufacturing plus improvements to fuel control units reduced the risks but did not eliminate them.

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  • $\begingroup$ Very interesting. Any stories that could be references of F-16 engines being damaged from too aggressive use? $\endgroup$ – AlphaCentauri May 27 at 5:58
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Of course you can.

It's exactly the same situation as on the 787 or A320. If you insist on always using full 100% thrust for every takeoff and all the way through climb-out, you will cause excessive wear to the engines, resulting in inevitable early failure. The system doesn't stop you from doing this, because for all it knows, you are flying a marginal situation and need all that power to stay alive.

This is a "safety system vs. safety system" type problem, like whether you should have a "low water level shutoff" on a diesel fire pump. The shutoff might save a \$50,000 engine by sacrificing a \$50,000,000 warehouse.

End of the day, even on an A320, you make it pilot discretion. You bet your bippy the F-16 does exactly the same thing. Yes, you can and should abuse the F-16 engine when it's necessary for safety, however that also gives you the freedom to abuse the engine when it is not.

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  • $\begingroup$ "If you insist on using 100% power", of course we know the other extreme, leading to a stall on climb out. Although a safe climb out at less than 100% power can be pre-programmed with a lower rate of climb, are jet pilots really discouraged to push safety limits to "save" the engines? $\endgroup$ – Robert DiGiovanni May 26 at 3:10

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