u00bgw

I sat first row on the right side of the plane. 20 minutes after take off I happen to look back and I could see the engine fan idil and not spinning. It stayed that way for another 25 minutes. Then I looked back and it was spinning. Weirdest thing....

u00bgw

I should have taken a picture because that engine was not spinning.

BTW...flight was from Indianapolis to Baltimore.

I seriously just figured it was shutoff at cruising altitude to save fuel. Then restarted before descending for landing. Obviously after reading thru this thread that is not a normal procedure.

xliioper

I'd guess your eyes were playing tricks on you and the fan was not actually stationary. I would expect the fan to continue to spin after a shutdown due to windmill effect.

nsx

That's the rotor of the first compressor stage. As far as I know that rotor is linked to the other rotors, so they would all have been stopped and the engine would not have been producing thrust. It's odd that the airflow into the engine wasn't strong enough to force the rotor to turn backwards, but maybe the engine has a feature that prevents reversal.

If it was only 25 minutes then perhaps your intended destination was the closest available airport to set down. If you PM the flight information to FT member OPNLguy he may be able to look it up and comment.

OPNLguy

I retired July 1st..

kerflumexed

Congrats on that very wise decision.

rsteinmetz70112

I don't know about jet engines but propellers can generally be locked in place and feathered because the drag caused by a rotating, unpowered prop is greater than for a fixed prop. I imagine a jet rotor would have the same effect and produce more drag by rotating in the wind than by being locked in place.

Dunbar

There was that BA 747 crew flying from LAX to London that created quite a stir when they shut down an engine fairly early in the flight. They proceeded to fly most of the flight to London on 3 engines and missing countless opportunities to make a precautionary landing in the US.

tusphotog

Nope. There's no way to "lock" the fans in place on jets. They spin around. You can see this on a breezy day.

There are quite a few more blades that are in a fixed position compared to the prop planes. The Q400 has a six bladed fan, and the blades can be moved to improve thrust.

The 737 has 24 blades on the exterior fan disc (the one you can see), IIRC.

Congrats!

Good to see you post again!

etna

Try a double Wild Turkey. The engines don't spin, but the cabin does.

rsteinmetz70112

I ran across an FAA document which allowed for a rotor locking device and set standards for it's use. I don't know if any engines are so equipped, and they may not be in use when a plane is parked.

https://www.faa.gov/regulations_poli...mentID/1029688

OPNLguy

What the FAA missed on that one was that the BA flight wasn't operating under US FARs, but the regs of the UK aviation authority.

Under US FARs, an engine failure on a twin necessitates a diversion to the nearest suitable airport in point-of-time. If a 3- or 4-engined aircraft has one fail, it can continue to the original destination if doing so is deemed just as safe as diverting to the nearest suitable airport.

The UK's regs are nearly identical, but whereas a dispatcher of a US-registered airline 747 flying LAX-LHR on only 3 engines might have thought it was ill-advised (and could insist on landing ASAP), the UK regulatory system give the flight's pilot-in-command (PIC) total discretion--there is no joint responsibility between PIC and dispatcher as is the case with operating under the US FARs.