ALASKA AIR EMERGENCY LANDING HAWAII
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I flew a lot from LAX to HNL. Not only were we committed to press on passing the ETP, when westbound, once 300 miles out SFO was closer than LAX and until within 300 miles of HNL, Hilo was closer than HNL. And, the flip side going HNL to LAX.
My understanding with this event is the checklist instructed the crew to shut the engine down as apposed to reduce to idle.
It raises some interesting questions.
Do you ignore a checklist considering the fact that you are midway between the mainland and HI?
I assume that leaving it at idle keeps some ancillary services running such as a gen (not a Boeing guy) which is probably what the crew were thinking????
If the engine has some health issues wouldn’t it make more sense to shut it down then possibly restart it for the approach and landing or have the relight checklist at hand for a quick restart in case the other donk developed issues along the way?????
Would running the engine with an oil filter bypass indication AND a chip detector indication for the remainder of the flight make it worse?
I am not advocating either way but there are so many different ways to proceed with such an event.
It raises some interesting questions.
Do you ignore a checklist considering the fact that you are midway between the mainland and HI?
I assume that leaving it at idle keeps some ancillary services running such as a gen (not a Boeing guy) which is probably what the crew were thinking????
If the engine has some health issues wouldn’t it make more sense to shut it down then possibly restart it for the approach and landing or have the relight checklist at hand for a quick restart in case the other donk developed issues along the way?????
Would running the engine with an oil filter bypass indication AND a chip detector indication for the remainder of the flight make it worse?
I am not advocating either way but there are so many different ways to proceed with such an event.
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a 737-800?
that’s hard work! I can barely take a UK to Canaries in that flight deck! 4 hrs each way, and I stand up for some time each sector. How long is it to Hawaii? At least I have airports all along the way
It's five to six hours from the west coast to Hawaii, depending on the winds and such. But any more 737/757 and A320's are the 'norm' between the US mainland (especially near the west coast) and Hawaii (Hawaiian uses 767/A330s, planning to switch to 787s in the future, but they are the exception). And yes, it's a long flight on a 737...
"Mildly" Eccentric Stardriver
A company I used to fly for had at one time the longest regular 737 route in the world Gatwick to Malabo in Equatorial Guinea. Something in the region of 7 hours.
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Here is the checklist procedure :
ENGINE OIL FILTER BYPASS
Condition: An engine OIL FILTER BYPASS alert illuminated indicates an impending bypass of the scavenge oil filter.
AUTOTHROTTLE (If engaged) . . . . . . . . . . . . . . . . Disengage [Allows thrust lever to remain where manually positioned.]
THRUST lever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Retard Retard until the OIL FILTER BYPASS alert extinguishes or thrust lever is closed.
If the OIL FILTER BYPASS alert extinguishes: Operate the engine at reduced thrust to keep the alert extinguished.
If the OIL FILTER BYPASS alert remains illuminated: Accomplish the ENGINE FAILURE/SHUTDOWN checklist.
ENGINE OIL FILTER BYPASS
Condition: An engine OIL FILTER BYPASS alert illuminated indicates an impending bypass of the scavenge oil filter.
AUTOTHROTTLE (If engaged) . . . . . . . . . . . . . . . . Disengage [Allows thrust lever to remain where manually positioned.]
THRUST lever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Retard Retard until the OIL FILTER BYPASS alert extinguishes or thrust lever is closed.
If the OIL FILTER BYPASS alert extinguishes: Operate the engine at reduced thrust to keep the alert extinguished.
If the OIL FILTER BYPASS alert remains illuminated: Accomplish the ENGINE FAILURE/SHUTDOWN checklist.
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Here there is a hybrid situation. The engine is not providing thrust, but it is not shut down. It does require the 'One engine inoperative landing checklist'. How much of the Engine Failure/Shutdown checklist does it need? Depending on the sharp end experience that can be a simple or confusing discussion. It does require leadership.
1) A jet engine at idle IS producing thrust - just less thrust than you might like. It is NOT causing drag, as a windmilling, shut-down engine does.
2) Whether it "requires" the OEI checklist is a matter of SOP. Our SOP (4-engine airplane) did not. Whether it is smart to refer to that checklist is another matter. Yes, it is a good idea to refresh your memory on what is impacted. You still have the associated generator, hydraulic pumps, and bleed air; you have reverse idle available on landing. You will need significantly less rudder input than if the engine was shut down. Your performance will be somewhat better than if it was shut down. Depending on the runway, flap limitations in the OEI checklist may or may not be prudent.
A jet engine at idle IS producing thrust - just less thrust than you might like. It is causing LESS drag than a windmilling, shut-down engine does.
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Are you advocating flying an approach with one engine at idle, and using only the other engine for thrust & speed control, but using standard 2 engine approach technique & flaps? A single engine approach, or 2 engine approach, is IMHO about thrust available and not electrics & hydraulics etc. I assume they'd have the APU running, just in case. I can understand there is a different philosophy on a 4 pot to a 2 pot. I wonder why, with one engine operating at idle on any type, you would not apply OEI techniques.
Remember did they not discover United once sent a non ETOPS 738 to Hawaii from the mainland ? Was it stranded and flown back empty with flight crew only
however unless the engine has catastrophic failure better to keep it idling just in case the other gives issues
remember Kegworth where they shut down the good un
however unless the engine has catastrophic failure better to keep it idling just in case the other gives issues
remember Kegworth where they shut down the good un
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About the only correlation between PNR and ETP is that ideally your PNR should be beyond the ETP between your departure and destination.
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A Squared
Shuttle sector with round trip fuel outbound , there's essentially no geographic PNR to the origin, but there will be an ETP between origin and destination.
No, not even close ETP and PNR are two completely different things. ......... on shorter legs with large fuel loads, you can return to your point of departure at any point including overhead your destination.
Shuttle sector with round trip fuel outbound , there's essentially no geographic PNR to the origin, but there will be an ETP between origin and destination.
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Yeah. "beyond destination" is sort of an awkward way to phrase it, but that's what our flight planing software prints on our flight plans: "PNR is beyond destination" . It could be that "no PNR" might be a clearer way to say it.
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https://onemileatatime.boardingarea....ane-to-hawaii/
It was American, not United -- and an A321, not a B738 -- if we are remembering the same incident. And yes, it was ferried back empty.
https://onemileatatime.boardingarea....ane-to-hawaii/
https://onemileatatime.boardingarea....ane-to-hawaii/
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Are you advocating flying an approach with one engine at idle, and using only the other engine for thrust & speed control, but using standard 2 engine approach technique & flaps? A single engine approach, or 2 engine approach, is IMHO about thrust available and not electrics & hydraulics etc. I assume they'd have the APU running, just in case. I can understand there is a different philosophy on a 4 pot to a 2 pot. I wonder why, with one engine operating at idle on any type, you would not apply OEI techniques.
Yes, there is a difference between 2-engine and 4-engine airplanes. However, with OEI, they both have about the same relative performance - the ability to continue from V1 at max certified T/O weight and safely get airborne. One big difference is that with an inboard engine at idle or inoperative, the 4-engine airplane handles almost the same as with all running; just add a few % N1 and a bit of rudder trim (been there, done that). Assuming this event happened just after the ETP, the crew still had a couple hours to evaluate the situation, call Dispatch for guidance, and make a decision on how to land. Also, after a relatively long flight for the type, the landing weight was relatively low, so performance was less of an issue.
Indeed, SOME of the items in the OEI checklist may be applicable, so it is certainly worth reviewing. However, running and following it blindly may not be a good idea. For example, one item may well be "FUEL CONTROL switch (affected engine) . . . . . . Confirm . . . . . CUTOFF".
FWIW, there is no OEI checklist for the 744, though there is a "Two Engines Inop" checklist. That means we use the same "techniques" landing with OEI as we do with all 4 running...
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The oil filter bypass opens when the pressure in the oil filter increases past a certain psi. I have had it due to metal particles in the filter and the checklist has you retard the thrust lever until the message disappears, if it does not disappear the engine has to be shutdown. The emergency would have been declared as the aircraft could not maintain its assigned flight level on one engine and would need to descend. However I would not call the subsequent landing an emergency landing. To me an emergency landing is when there is difficulty with the aircraft handling or some doubt the aircraft can be landed safely and stopped on the runway without risk to passengers. One engine running at idle is hardly an emergency landing.
A jet engine at idle IS producing thrust - just less thrust than you might like. It is causing LESS drag than a windmilling, shut-down engine does.
There ya go, fixed it for you.
There ya go, fixed it for you.
I think a pressure balance needs to be done in order to assess the Net forces. Keep in mind the nacelle produces most of the drag, son what goes on in the engine pressure (forward and aft) makes up the difference.
The oil filter bypass opens when the pressure in the oil filter increases past a certain psi. I have had it due to metal particles in the filter and the checklist has you retard the thrust lever until the message disappears, if it does not disappear the engine has to be shutdown. The emergency would have been declared as the aircraft could not maintain its assigned flight level on one engine and would need to descend. However I would not call the subsequent landing an emergency landing. To me an emergency landing is when there is difficulty with the aircraft handling or some doubt the aircraft can be landed safely and stopped on the runway without risk to passengers. One engine running at idle is hardly an emergency landing.
I'm not saying that you are wrong in this case, but most filter blocking indicators that I have run into do not just detect absolute pressure but use a differential pressure switch ( or two pressure switches) to detect when filter blocking is about to become a problem. It will, of course, continue to alarm if the situation deteriorates.
But the intention is to alarm before unfiltered oil start streaming through the bypass relief valve.
If by reducing engine speed you can reduce the differential pressure across the filter then you should be safe provided that the by-pass did not open while the alarm was active.
And you don't really know whether that happened or not.