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Decision to land with multple malfunctions

Started by acannata, Tue, 30 Aug 2016 12:27

acannata

Hi!
Yesterday I did made a flight taking off from LIRF at night during thuderstorms (clouds ceiling 1300'). TOW 359Tons. I programmed a fire on engine 4 @ 14500' during climb. Following engine fire I returned immediately to LIRF for an emergency (overweight) landing. I programmed antiskid failure @ 4500'. Aligned on 16L ILS (AP & AT on), @ 2000' RA suddenly 1 to 4 ELEC AC BUS failure occurred. AP and AT disengaged. No more radio altimeter, ILS and standard white tapes for engine parameters. Really a mess! Caught by "what happens next?" syndrome, I managed to recover aircraft control finally having a decent landing. Then I discovered on Malfunction page that the cause was a lightning strike.
My question for pilots in the Forum: in real airline operations, having not a better alternative to LIRF to land, how do you manage the multiple malfunctions occurred on approach with one EO? Do you land ASAP? Or do you abort the approach and try to fix the malfunctions secondary to ligthning strike landing later?
Thank you

Aldo

Kieber

Hi Aldo,
a quick approximate sequence:

Like in your scenario, if the engine fire is out, you have all the time in the world to think about the next action. A 3engine flight is not an emergency and needs no "land at the nearest suitable airport as soon as possible". Just inform ATC and your company.
Now think about a "suitable airport" taking in account a higher landing weight and of course the maintenance possibilities of your company. Sometimes your company recommend a maximum landing weight (for example 330 tons) to keep the costs for the "overweight landing check" in limits.
If you made the decision about your landing weight, ATC will assign you a fuel jettison area.
Now you perform your 3eng approach and there will be no problem to start a go around if it is necessary.
In your scenario I always suggest a go around and handle your problems before landing.(It also depends on the weather!)

But if you cannot stop the fire, you declare emergency and "land as soon as possible at the nearest suitable airport", I think, like you did it!
HTH
Walter

United744

#2
If I was a couple of miles out and visual with the field, I'd continue to land. No point flying longer than necessary with multiple failures, especially if you don't know the cause so close to touchdown. The longer you're airborne, the more opportunity to crash.

One RL airline has the attitude of flying away to diagnose problems, spending anywhere up to an hour holding just a mile from the field - senseless. Get it on the ground if you're able!

The only time I maybe wouldn't do this is if it affected landing (flap asymmetry, gear problem, brake problem,  or aircraft control problem).

Note carefully: this is only in the case of a couple of miles from touchdown with visual on the runway! IFR in the soup or somewhere in the circuit - go around/hold and see what's what. Multiple sudden failure is not the time to be waiting to run every checklist - you might crash before then.

At some point, you will HAVE to land as fuel is a finite resource and there is no telling if you will encounter more issues, so if you're already in position to do so, get it down.

Real life situation comes to mind: contradictory fault indications relating to hydraulics and flight controls. Combination theoretically impossible. Crew ignored the alerts and landed as emergency. Fault traced to wiring harness fault that shorted all the captions!!!

A famous one: Sioux City DC-10. Uncontained engine failure led to total hydraulic failure. No checklist for that one.

You never know what you will encounter.

Questions to ask: do you still have control? Do you still have thrust? Is there a fire? Keep an eye on hydraulics if required for flight controls. Position - where are you? Can you see/avoid terrain? What is MSA? After that, checklists if able while heading towards nearest suitable.

Hardy Heinlin

Hi Aldo,

did you perform the non-normal list for AC bus failure?

Or did you continue without AC power? Without AC power there is no jettison control, and battery power for the essential systems is only available for ca. 30 minutes, or 50 if your lucky.


Regards,

|-|ardy

Kieber

#4
Here a link to an interesting real example regarding multiple malfunctions......

http://www.atsb.gov.au/media/4173625/ao-2010-089_final.pdf

Cheers
Walter

acannata

Thank you all for the very interesting and prompt comments.
Walter, thank you for the report about QF32. It is a famous fact and it is very instructive about successful management of malfunctions.
Hardy, ac bus failure occurred @2000', on glideslope and maybe @6 nm from threshold. I did not experienced ac bus failure in the past. I did not perform the non normal checklist (no time!). Moreover, initially it was unclear for me if I had still thrust (no EPR white tapes). In the meanwhile the aircraft was descending and yawing (alone in the cockpit, another pilot unavailable for evaluation/suggestions/sharing of the workload). I suppose that I was @1200' (with runway in sight) when I regained full control of the plane. Therefore I decided to land. By the way, because of my lack of knowledge about ac bus system, I was unable to evaluate the reversibility of the failure and its effects on flaps and landing gear. Too much uncertainties, a lot of "stress" close to the ground and rwy in sight!I suppose that these are the reasons of my way to manage the problem.
Alternatives (open to discussion):
- flying in real-time: GA, non normal checklist, then new approach. Pro: landing after fixing the problem, systems in better conditions during approach and landing. Cons: without AP and AT the management of aircraft flight (#4 EO) AND checklists could be somehow difficult being alone in the cockpit.
- GA, non normal checklist, then new approach using pause and stop motion keys to gain time to evaluate and fix problems and fly the aircraft. Cons: maybe cumbersome and not so realistic.


Aldo

Britjet

All I would add is, if the aircraft is flying OK don't be tempted to land just because there is a runway there - unbeknown to you there could be things wrong with your handling ability, retardation and/or steering etc.

If you have time always try and work the most important checklists. In this case you were presumably hand-flying and trying to work a checklist as well, all solo! - not something that you would normally have to do in a 747.

Multiple technical failures are rare, of course - but they do happen, usually because something has gone 'bang" in a big way! I would suggest that if you run multiple failures from the IOS that you try to make them related - eg a tire failure with associated flap problems (due to tyre fragmentation) etc etc.

Peter

acannata

Thank you so much, Peter. Your video tutorials are really outstanding in terms of clarity of concepts, visual appearance and speech (easy to understand even for me!).

I did find an incident report about a 744 of Malaysia Airlines that experienced engine failure and later elec ac bus malfunction during approach to EGLL. Captain decided to continue the approach. A scenario not so different from mine (however, only one ac bus failed and the engine involved was #2). Nevertheless, the primary cause was hardware failure, not a lightning strike!

https://assets.publishing.service.gov.uk/media/5422f72e40f0b613420005d9/Boeing_747-4H6__9M-MPL_04-14.pdf

Cheers

Aldo