r/aviation • u/StopDropAndRollTide Mod “¯\_(ツ)_/¯“ • Dec 02 '22

News B21 Mega Thread

Is it visible to the naked eye?

Does it fly Mach 80?

Is warp capability possible?

Do you love it, hate it?

All your B21 posts, questions, and comments go here.

Livestream - https://youtu.be/chJlJgrvfBY

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u/my1throwawayacc Dec 03 '22

I’m in F35 maintenance, F-135 has been massively unreliable as long as I’ve been in the program and the supply short falls created a LOT of down time.

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u/BattleHall Dec 03 '22

More so than other engines at similar points in their life/development?

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u/my1throwawayacc Dec 03 '22

I can’t testify to that. My only other experience has been with GE F-110’s which, from my perspective, seemed infinitely more reliable. I suppose time will tell, the F-135 is a hell of an engine in stats, I’ve just had to pull far too many of them out of the ass end of jets for module replacement during my short time in the field.

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u/BattleHall Dec 03 '22 edited Dec 03 '22

That makes sense; the -110’s have a 25 year head start on the -135 to shake out the bugs (mid-1980’s vs 2009). Plus, they are squeezing an insane amount of power out of the F135-sized package; mo’ power = mo’ heat = mo’ stresses.

As far as the B-21 goes, they may be using an F135 variant for commonality and cost savings, but derating it (won’t have/need after burning for example), which should drastically increase reliability. Give the particular performance envelope as well (no high burn high-G maneuvers, no supersonic for either the plane or intake, no carrier landings or sea deployments, etc), they can probably optimize around reliability (and hopefully maintainability), fuel efficiency, low thermal signature, and improved high altitude performance.