Return versus Diversion

[Cann0nF0dd3r 21]

I thought this was an interesting case: https://en.wikipedia.org/wiki/British_Airways_Flight_268

O.O Thats insane!

[skelsey 765]

 

 

Thats insane!

 

Not really.

 

A 747 on three engines still has more engines than a 777 with all engines operating, and it can fly perfectly adequately on two as well.

 

The route from LAX to LHR is, for the first several hours, over land with many, many potential diversionary airfields within easy reach. Terrain (once over the Rockies) is not really a consideration (apart from a small portion of the route over Greenland), affording the crew plenty of opportunities to assess the situation prior to the Atlantic crossing. I'm sure if there had been anything to suggest a bigger problem than a simple surge and shutdown, the crew would have diverted.

 

The fuel management issue was unfortunate, but that really is a separate matter.

[phil747fan 14]

Simon,

 

could you point me out in any FCOM, FCTM, QRH where you can conduct an international flight with water crossing intentionally on 3 engines with over 9 hours flying time?

 

i never heard about doing it in the three operations i was dispatching 747-744.

 

Phil

 

ps: because except for ferry purpose there is no way load or pax should be on a ferry flight ....

[skelsey 765]

Phil,

 

 

 

could you point me out in any FCOM, FCTM, QRH where you can conduct an international flight with water crossing intentionally on 3 engines with over 9 hours flying time?

 

FCTM 8.3

 

 

The regulations regarding an engine failure on a four engine airplane are slightly

more flexible than for two engine airplanes. If not more than one engine has failed

or is shutdown, most regulatory agencies specify that the pilot-in-command may

proceed to another airport if, after considering weather, airplane condition, fuel

remaining, air traffic and other pertinent factors, the chosen course of action is as

safe as landing at the nearest suitable airport.

 

A single engine failure is not a "land at nearest suitable airport" in the QRH.

 

If it is not safe to continue on three engines in that particular scenario -- a simple surge and precautionary shutdown, remember, not a fire or a rotor burst or anything like that (indeed, I suspect it's very likely that if necessary the engine could have been restarted), in co-ordination with a well-resourced airline maintenance operation, Rolls-Royce no doubt monitoring telemetry etc to know exactly what was up with the engine -- then we should presumably ground all B777s immediately as they regularly fly several hours from any suitable airport on just two engines, no?

[Copper. 78]

I think the FAA disagreed, but eventually caved...

 

My personal opinion is that the OEI ferry clause was cleverly extrapolated.

 

I don't think Boeing/FAA ever though someone would be <descriptor> enough to actually make a "go" decision during commercial ops with OEI when they permitted OEI ferry into the manuals.

 

A loss of engine 2 power (electrical, hydraulic, thrust, pneumatic), inherently means a loss of some redundancy. Undoubtedly, in my opinion (I say again, my opinion) this made the mission less safe. Add to that, that the crew couldn't have known whether there might have been any latent problems.

 

The easier option, and in my opinion, the safer option, was to turn back. But the crew chose not, and very nearly set a precedent for all other pilots to uncomfortably follow. I think most operators would've elected to turn back, and the historical data will reflect that.

[phil747fan 14]

the AFM says a different story ...appendix 4.

 

seems one operator strechted the ferry operation that should be operated only with no cargo load and pax ....

[skelsey 765]

I suspect we'll have to agree to disagree, but...

 

Three-engine ferry has absolutely nothing to do with it.

 

The (FAA-certified) Boeing QRH does not consider a single engine failure/shutdown on the B747 as a 'plan to land at the nearest suitable airport' issue. Do you not think that if it were a critical safety issue that Boeing (or the FAA) would have put that in the QRH?

 

Likewise, the Boeing (FAA-certified) FCTM, quite rightly, recognises that a single engine failure on a quad is not the same situation as an engine failure on a twin and permits the Commander to exercise his/her judgement.

 

Are there circumstances in which a single engine failure would demand an immediate landing? Sure there are. But I disagree that a surge and precautionary shutdown is one of them.

 

You really lose barely anything with a single engine failure in the 747 - I couldn't list them off the top of my head but virtually everything is normal. Approach, landing, stopping - all normal. IIRC I think you can even do a 3 engine autoland but don't quote me on that.

 

It's not like they shut the engine down and just decided immediately to carry on all the way to London. It would have been carefully thought out and the situation constantly evaluated all the way across the USA. Again - there were plenty of potential diversion airports all along the route, presumably with suitable weather conditions, and little terrain of concern. How is it less safe (which is what the FCTM says) to say, for instance, 'let's carry on to LAS and re-evaluate the situation there.' 'OK, we're at LAS, all looks good, no sign of any other effects, let's carry on towards SLC (for instance) and see how we get on on the way - if anything comes up that we don't like the look of we'll divert' and so on, compared to flying round in circles over LA for 40-60 minutes dumping/burning off fuel followed by a landing at close to MLW?

[phil747fan 14]

Simon,

 

that is true we agree to disagree ...

 

it is already said what if?  imagine what if the diversion didnt went well when a second engine issue will happen what if in the middle of the atlantic? ... they had the engine issue at 400 feet just starting the climb they took a chance and it works but doesnt mean it has to be done ... and if you look of the operation of a engine out ferry operation which in the AFM appendix 4 there is some lines about max weight to operate and where to operate a ferry flight and being cautious to have enough alternate airports and using route to avoid icing conditions, again with no pax nor load so this is has everything to with it. i was still working in ops when it happens and we had EROPS ETOPS 180 for 747-400 and it is not a twin ...we had a few diversions after that and we never had a flight over 3 hours on 3 engines ... they strechted: they were lucky.   

 

it was a premiere for an airline to push the boundary of the 747-400 and it went well.

 

but again im no more in the industry and things may have changed but i was lucky that i never to be in that situation i do not imagine our chief pilot nor director of operations ....

[Copper. 78]

I've taken in what you've said, and agree that we'll have to agree to disagree.

 

I'm typing from a phone so my response and accuracy is limited.

 

Again, the requirements of the manuals and UK/EU law were met. The PIC played within the bounds of the rules, but arguably, outside of <manufacturer/US> expectations.

 

At the back of the QRH, there is a section there I believe that speaks to the "land at nearest..." clause. It says something in the order of, it applies to, but NOT LIMITED TO, xyz cases. Further, I think the FCTM section is being construed. When I read it, to me it said that the pilot need not dive to the very nearest/closest serviceable strip in the immediate vicinity of the aircraft ppos (unless that strip happens to be perfect), but, rather, she/he may, after considering the relevant factors, continue to the next nearest suitable. For example, to the next airport where that particular airline may have the facilities and commercial agreements to handle a unexpected diversion.

 

I think it is Boeing and the FAA's possible failing in that they did not make it more definite that you HAVE to land at the next best strip... and in their attempt to leave a bit of breathing space and flexibility for operators, were taken advantage of, in this particular case. Again- my opinion.

 

I consider the act "less safe" (but not "un-safe") on the basis that an entire power plant was lost, and, the decision making process was such that it was deemed ok to continue. The 747 can definitely handle it, no doubt about it, but, the "go/continue" aspect in the procedures, I believe, are predicated on the fact that your are "going/continuing" to the nearest best airport to address your problem, not "going/continuing" to destination.

 

Note- I don't doubt the performance of the 747 with OEI. In fact, I think a saw in a doco that the level of redundancy is overkill. I guess, in the end it comes down to the risk factor. Fortunately, operators are not expected to continue their mission with OEI as a result of this act. (The bean counters must've been on holiday).

 

Thanks for the well thought out posts, Simon.

[phil747fan 14]

oh yes Simon the way the 747 is built , is really overkill ... and designed on table in the 60s with safety in mind.

 

in every part of electrical, pneumatic and hydraulic there is always a back up.

 

 

 

i enjoy the tone of the discussion.

[Meekg 86]

Having flown long haul on twins and quads (A330-A340) I'm with Simon on this.

During my first A340 training one of the sim scenario was an engine failure right overhead BIKF enroute to KJFK... After 10 years on twins the first thing I did was looking for an adequate airport on my ND.

Only later I realised our altitude penalty was barely 2000ft, we were still significantly overweight and we could have comfortably made the east coast or get back to Europe, if commercially required.

I learnt I had to change my mindset and that was the whole training objective.

As per my operator's OM-A an engine failure on a quad does not qualify as land ASAP, unless of course other risks are present (other systems damage as a result, leaks etc).

Three engine ferry regulations are for dispatch purpose, different ballgame.

As per 2 engine failure (on A340) it is a normal failure practiced at all sim proficiency checks, the aircraft flies as well as a A330 on single engine... I'm not as expert on Boeing but I would presume it would be the same , if not better.

Regards

[Copper. 78]

Sorry, Mike... you've come to the wrong forum... we speak Boeing in these parts (haha just kidding)

 

Back to topic-

I don't think aircraft performance is being called into question, rather, what is being challenged (at least from my end) is the risk analysis and decision making on whether to continue to destination (on long missions over the Atlantic) with an eng out scenario. Especially for an airline like BA, who would have the resources to address the failure.

 

The way I'm seeing things, however right or wrong it might be (I'm not a pilot), is that you're sub-consciously changing the airplane from a 4 engined airplane, to a 3 engined airplane - convincing yourself that such a change is normal - and then subsequently re-dispatching yourself, predicating the mission as being a 3 engined airplane with contingencies based on 2 engine operating performance... aaall the way (over water, in this case) to the destination.

 

Again, it is not a question of if the plane can do it, we know, or can guess that it can... but it's a question of, is it worth doing? Is it worth degrading flying operations to that point? With the continual push to find the boundary of what is acceptable, and what is not, where does the push end? At a serious incident or accident? What are the chances of an EFATO? Equally, you've just had an EFATO, what are the chances of another occurring? Is that risk acceptable?

 

I don't know what the numbers say, I'm not privy to them, but dare I say that the decision to divert or return is almost always made...

 

I should probably read the report and ruling to get the technical perspective of the incident.

 

I'm enjoying the tone of the discussion, too.

[Meekg 86]

Not my fault, I've been wishing for a PMDG Airbus for two decades... never say never.

Brian, generally speaking all decisions, which are not prescriptive and/or predicated by a checklist or regulation, are taken on a basis of risks and benefits assessment.

There are decision making models used for that... google FORDEC (among others) if you never came across, it's interesting.

Ultimately when everybody agrees the Captain impose his wrong decision on everybody else... basics of CRM. ;-)

Boeing pilots of course don't need all this... they can feel the aircraft feelings through the yoke and can use good old airmanship. :-P

[Copper. 78]

You know... just quietly, A PMDG Airbus would be amazing. But I never said that, did I?!        ;-)

 

I've never heard/seen FORDEC. I just googled it - I found it interesting. Not useable, for me... but interesting all the same.

 

"I am one with the plane, the plane is one with me"... haha

[Flamin_Squirrel 71]

Interesting discussion.

 

I don't think returning to destination necessarily makes any more sense than proceeding (apart from crossing the Atlantic, I'll make no judgement on that). 

 

If you're not going to make an immediate landing, why not burn the fuel doing something useful like getting closer to your destination rather than dumping it? Assuming alternates are available en-route of course.

 

Holding/dumping/returning would involve landing at MLW too, is that something that 747-400 drivers would want to avoid if they could? Max Vref, stopping distances etc.