ETOPS/ER Question
 

I would like to ask a ETOPS/ER questions in the expanded context of the 'total package' i.e. Engine, Airframe, Communication, Navigation, Human Factors, and so on.

Let me try and cut to the chase by offering up the 'angle' I am working towards: I am trying to determine the importance of having aeronautical charts onboard an ETOPS aircraft operating an ER route.

I think one would agree that an engine shutdown, and only an engine shutdown, would be the 'best of the worst' things that could go wrong in an ETOPS/ER scenario. However, their are 'probabilities' for other system failures to occur, as a direct or indirect result of the failure event. These 'other' failures can significantly add to the challenge already being experienced by the crew.

Back to the question with an direct example: an ETOP twin on a North Atlantic route experiences a single engine failure and loss of the essential bus power or at least the loss of the primary navigation system. Radio communication is sparse, maybe the HF propagation is poor, and so on. The aircraft isn't in immediate flight danger but they have to make their diversion as soon as possible. How important are the paper charts at this point?

Maybe not the best example, but a probable one? Maybe someone has a better example. Again my interest is in determining the importance of the paper charts. I know that nowadays most people just fly the FMS, but what if you don't have it as part of a cascade failure?

Any insight into this would be most appreciated.

I suppose the charts are there for the big picture; overall SA. The designated ETP airport(s) are not necessarily the first choice. One look at the plotting chart and I know if I'm closer to Santiago or Shannon, Lajes or Kef, etc. Then I want the charts for the overland portion for terrain awareness(even with EGPWS).

What gave you the impression that there arent any paper charts on-board? Our twins cross the Atlantic with a comprehensive Jeppesen set of manuals?

Mutt :)

I would think the paper charts would be vital. Suppose you lost the FMS, but had some of the radios including a VOR/DME, or some other combination of failures. How could you navigate without the charts and the nav information contained in them? Stand-by instruments alone wouldn't be enough if you didn't have some means of navigation.

Having some voice communication would allow you to be radar vectored I suppose, but other combinations of failures might not allow this. I suppose a chase plane could also be sent after you and then it could guide you to a landing field. I think only certain improbable failure scenarios would create a need for the charts, but it would be very nice to have them in the event of such a scenario.

Thanks to all who have responded so far. To narrow the question a little more, what if all charts were in digital format running on some sort of display device (laptop or Avionics).

How important would it be for this system to be 'full-up' available? Of course there are many different primary and secondary failure scenarios that could affect viewing charts on a 'powered device', along with the probabilities of each occurring and alternative means to acquire information(cascade failures, communications, 'benign-ness' of the region, and so on)...

The question now is how significant, or important, would the charts be in an ETOPs configuration if they were digital and the unit subscribed to ship's power - a system that has probabilities of failure?

Please forgive me of any message posting irregularities; I am a new user of this site.

Thanks again.

Forgive me for some selective editing with regard to the quotes. :)

At times there is no getting away from the fact that a paper document is prefferable. How many of us download a pdf file and print it for ease of use and to gain a better view of "the big picture" ?

Absolutely vital that the desired information is readily accessable.


"Probabilities" is the magic word. The 767-300 aircraft that I fly has only 30 minutes battery power (assuming a 100% healthy battery). So, assuming your implied worse case scenario i.e. a total loss of A.C. power .... Well, I'm sure you've figured that one out already :)

If you think about it, it could be just as problematical in a non-ETOPs environment when your take-off or enroute alternate is more than 30 minutes away !!!!

Hope this helps.

Eli - Could you not (depending on conditions) turn off the battery and turn the IRUs off to conserve battery power for later in the divert (in order to have power avail for getting the gear down)?