[ChrisMarshallNY]

> STOL

I suspect the "V" is still "in theory," because it probably relies on those fans being rotated, and it looks like the ones in the demonstrator are fixed.

Once the rotation happens, a lot more factors come into play, and those problems are not new (see "Osprey").

I think that SCRAMJet engines also use fluid dynamics, in a similar manner.

[philip1209]

An issue with both the Osprey and the VTOL F-35 is that they each have two engines involved in VTOL. So, if one engine fails - then the plane becomes unbalanced and probably flips over. (That's why the F-35 has auto-ejection [1])

This technology is interesting because, if you can have one engine involved in VTOL (like the Harrier) but vector the thrust easily, then an engine failure during takeoff or landing can avoid spinning the plane.

[1] https://www.thedrive.com/the-war-zone/the-f-35b-can-eject-it...

[osigurdson]

>> An issue with both the Osprey and the VTOL F-35 is that they each have two engines involved in VTOL. So, if one engine fails - then the plane becomes unbalanced and probably flips over.

This is not correct for the V22 Osprey. Either engine can power both rotors through the wing driveshaft.

Disclaimer: I worked with the V22 engine control system at one point (AE1107)

[hef19898]

Than you had one hell of a problem to solve!

[dylan604]

Where do you get your information about the Osprey, because it is woefully incorrect. Part of the engineering challenge of the Osprey was specifically to overcome loss of engine. There is linkage connecting both props to either engine so if one engine were to fail, both props would still turn. It's one of the talking points about the damn plane. I'd be quite ashamed for posting such non-sense if I were you.

[indymike]

The F-35B is a different beast (lift fan plus tilting jet exhaust) than the Osprey (tilt rotor). The tilt-rotor Osprey has shafts that connect the engines so one can power the aircraft if the other fails. This design feature is also present in the V-280 Valor, the replacement for the Blackhawk helicopter.

[greedo]

The F-35B only has a single engine.

[dylan604]

Not one bit of info in the GP's post is correct. It's like it was intentionally posted. If it wasn't such an old account, I'd suspect some sort of chatbot was behind it.

[wkat4242]

No the F-35B has only one engine just like the A and C versions. The big fan at the back is powered by a driveshaft from the engine, it's not a separate engine.

And like the other commenter said the Osprey can power both props from one engine (I wonder how that performs though, I'd be surprised if it can sustain a fully loaded hover)