Originally Posted by
SpazSinbad
Reason for the swift descent?
Smoke gets in your eyes.
Not familiar with the specifics of the F135 engine, but it's standard design practice on jet engines that the high-pressure fuel doesn't only go into the burner - it's used as muscle for various actuators such as variable vanes and bleeds, etc. - so lots of fuel lines snaking their way around the engine. Typical pressure downstream of the fuel metering unit is around 300 psi - so any crack in a fuel line is going to result in a large fuel leak - not only do you have a big risk of fire if a line fails, you lose muscle pressure to the various actuators. In other words, bad things are likely to happen.
Smoke (or flames) is a pretty common indicator...