Shutting Down an Engine to Complete the Flight
 

I thought this was an interesting scenario showing how an event can be handled. I suppose imbalance considerations were part of the whole scenario as well.

"N ------ a Boeing 747-4--F operated by ----------, was conducting cargo flight XX--- from
Anchorage (PANC), AK to Miami Intl. (KMIA), FL. Approximately 1 hour into the flight, the flight
crew observed that the #1 engine was being fed fuel from the #1 main fuel tank instead of the
inboard tanks as was selected. It appeared as though the #1 fuel crossfeed valve was in the closed
position and the flight crew were unable to select it open, leaving the engines only source of fuel
being the fuel remaining in #1 main tank. As this was insufficient to supply the engine for the
duration of the flight, the flight crew contacted the company operations center for guidance, and the
decision was made to shut down the #1 engine and continue the flight to
destination. When the fuel remaining in the tank was sufficient to supply the engine for the
remaining duration of the flight to the destination, the #1 engine was restarted and normal aircraft
operations were resumed. An uneventful landing was completed in KMIA.

Company maintenance subsequently replaced the #1 engine crossfeed valve actuator, and the
aircraft was returned to service."

Interesting. Since they had no passengers aboard, they treated the situation as if they were making a three-engine ferry for part of the flight.

British Airways did it with pax aboard, just a little short of fuel at the end.
https://en.wikipedia.org/wiki/Britis...ays_Flight_268

To paraphrase the late Eric Morecambe - they had enough fuel but not necessarily in the correct tanks!

The incident reflected poorly on BA's procedures for fuel balancing having differed from that mandated by Boeing.

Here we go again…..:rolleyes:

Not sure where we are nowadays with flight continuation but certainly once upon a time under some jurisdictions continued flight on a four engined type reduced to 3 engines was acceptable as long as the rest of the route allowed further degradation to 2 engines, so you had to look hard at en-route MSAs vs 2 engined performance, and suitable and available en-route alternates

It was certainly allowable to continue on 3 engines with passengers on-board and I even ended doing it myself on one memorable sector.

As Meikleour says the main reason the BA flight made it into the headlines was fuel handling not an actual shortage of total fuel on board, and I think many of those at the company learnt something from that.

wiggy is absolutely right. I do wish people would stop making mountains out of molehills.

Engine certification
 

Both of you are ignoring the engine windmilling certification criteria which even with an undamaged engine they exceeded. This engine failure had unknown damage and even one of the passengers was asked what he observed.
BA had made a mess of the crossfeed drill as they had with the 777 evacuation drill as demonstrated at Heathrow.

Back in the late 70's VIASA did almost the same after took off from Caracas with a little difference/detail...it was a DC10, one less "stove" than the 747 :)

blind pew

Engine windmill criteria? Twelve years on the 744, never heard of that one.

Categorically, there was no such limitation on RR 744’s.

Perhaps the key factor that was brought up about that BA decision to continue was that the 744 is in fact certified for continued operation on 3 engines.

It wasn’t based on some general philosophy of 4 engine airplanes, rather that the -400 specifically had sufficient redundancy on the other engines, eg electric sources etc.

As I recall the -100 and -200 were not so certified but the -400 was (not sure on the -300).

(This is based on pprune members at the time, can’t personally confirm it).

For this flight it sounds like there can be no concerns as to not being certain of cause of the engine out. Some brought that up for BA although I seem to recall the report fully exonerating that aspect.

As was pointed out during my conversion course, a 744 on three engines has more redundancy than a 777 on two engines.

Still cat3b no DH, 4x hyd systems, one gen out (three remaining), three bleeds, three packs, the list continues…….

Amazing machine.

Locked door

Many years on the 744.
If the engine is not windmilling it burns more fuel.
Simples!

Locked door

yeah but on one engine….:E

I flew both (plus the Classic 747s) . I’m not going to dig out time expired FCOMs to check but whilst your equipment count is sort of correct as I recall it the T7 also had some interesting engineering workarounds to ensure redundancy/robustness.

I agree you can’t escape the basics of the engine count but in a funny way that made decision making in some circumstances easier….

.and FWIW I had more engine failures on the 744 than I had on the T7…

Easy to also overlook that if any other engine failed the one that was shut down to conserve fuel could just be restarted if need be for performance. This is not an engine failure, its a choice to shut down to allow that engine to be available for a normal approach and landing at the destination due to fuel constraints.

Definitely mountains of molehill stuff, although a good example of thinking outside the box to get the job done safely.

Also it was flying Anchorage to Miami, its basically within an hour of a suitable landing port the whole journey. Not sure what the issue is here?

Engine certification
 

There was no certification requirement for prolonged windmilling to be demonstrated for the RB211-524.

I did delete the engine type for de-identification purposes. But seeing as this came up…….it was a CF-6 engine. Don’t remember reading about any max limitation times for this engine in the limitations section.

FWIW I’ve contemplated something similar for an oil leak coming back from Sao Paolo. The plan was to shut the engine down once the oil reached a certain level allowing for a restart in the descent to have all engines operating for the approach. As it transpired the leak slowed as the quantity decreased meaning we never reached the quantity we nominated for shutdown.

For me ..... 747 = 1 and A330 = 2 (not at the same time but both on ETOPS sectors)

so lots of single engine jet time :-)

Creative solution to a interesting problem.
Sorted with help from MX control, dispatch, operations, so no doubt all legalities were considered.

I flew the -744 with the P&W4056 engine and had cause to shut one down half way back across the Pacific, SFO to HKG. It was because we were getting a fuel flow filter warning light. The only time I remember windmilling could become a possible problem was if the shut down was caused by loss of oil pressure and/or quantity leading to a windmilling engine without sufficient lubrication.

To get rid of unwanted maintenance messages on the -400 after it had been left unpowered for a while in a humid climate I followed a Boeing engineers advice and selected Alternate Flap switch to 'Alternate' for a few seconds then back to off, messages gone!