ddavid 149 Posted May 27, 2015 Report Share Posted May 27, 2015 It isn't raining airbuses...Sorry to quote you, John, but Airbus has another set of worries as a Singapore Airlines A330 loses power to both engines and descends 4000m before re-starting them:http://www.theguardian.com/world/2015/may/27/singapore-airlines-jet-plunges-4000m-after-losing-power-in-both-engines Maybe, this is similar to the engine loss experienced when flying through volcanic plumes? Not good for Airbus - or Rolls Royce for that matter. Cheers - Dai. Link to post Share on other sites
Bruce (a.k.a. brian747) 142 Posted May 27, 2015 Report Share Posted May 27, 2015 It does sound strange. One wonders why they couldn't have diverted around the "huge storm"; and also about the continuous ignition system. I don't know much about airbus FADECs, but I found this: "The ECU has the capability to detect an engine flame out. When a flame out condition is detected, continuous ignition is automatically selected. A flame out is detected when a rapid decrease in N2 occurs, or N2 is less than idle RPM (i.e. less than around 57%). If the rotary selector is in NORM position and a successful re-light is achieved, continuous ignition is discontinued after 30 seconds. If the engine does not re-light, continuous ignition stops when N2 is below 40%. This automatic ignition feature aids in the re-light of the engine in case of flame out or if the master lever is turned OFF inadvertently then back again." (See http://www.oaviao.com/pesquisa_codigo_empresas/manuais_voo/performance_airbus/continuous.html And if you need more depth, there's also http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=1&cad=rja&uact=8&ved=0CCQQFjAA&url=http%3A%2F%2Fwww.smartcockpit.com%2Fdownload.php%3Fpath%3Ddocs%2F%26file%3DEngine_Ignition_Selection.pdf&ei=BYhlVYziDovcUe33gcAM&usg=AFQjCNGZN4uBwbHuVsUlYzTy9BAXvTKaLw&sig2=OiqXvQ4xKCWMTWn2L_wC6A&bvm=bv.93990622,d.bGg which inter alia states that "RR does not require the crew to manually select igniters". Hmm...). It's the comments about "continuous ignition is discontinued after 30 seconds" and "continuous ignition stops when N2 is below 40%" which seem a little strange (but then, break me half and I've got Boeing written all the way through, so what do I know?). Is this really a feature that "aids in the re-light of the engine"? Seemingly, Airbus think so. Presumably, they train their crews for that scenario in the sweatbox simulator, too. In the event, the guys succeeded in getting both engines relit after losing 13,000 ft, but I bet they needed a change of underwear.... (Give me four engines, every time! But then, I *would* say that, wouldn't I)? Cheers, bruce a.k.a. brian747 P.S. Looking forward to seeing you in Kunming City, Dai. Did you get lost on the way? B. Link to post Share on other sites
ddavid 149 Posted May 27, 2015 Author Report Share Posted May 27, 2015 @ Mr Acker Brian: I'm waiting for the chemist in Kunming to finish developing my snaps! All will then be revealed... Cheers - Dai. Link to post Share on other sites
MartinW 0 Posted May 27, 2015 Report Share Posted May 27, 2015 Aliens. Link to post Share on other sites
Bruce (a.k.a. brian747) 142 Posted May 27, 2015 Report Share Posted May 27, 2015 @Dai Aha! It had to be something like that.... Cheers, B. Link to post Share on other sites
Captain Coffee 2,030 Posted May 28, 2015 Report Share Posted May 28, 2015 (Give me four engines, every time! But then, I *would* say that, wouldn't I)? But, but...then you would have to re-ignite 4 engines!!! Why do you want all the extra workload?! Link to post Share on other sites
dodgy-alan 1,587 Posted May 28, 2015 Report Share Posted May 28, 2015 These flying computers a getting rather worrying! Link to post Share on other sites
Bruce (a.k.a. brian747) 142 Posted May 28, 2015 Report Share Posted May 28, 2015 <groan> No, Alan, don't start me off.... Oops. Too late, you already have. Agreed, then. Flying computers is something that worries me, too. (Increasingly, in fact). OK, this is just me speaking out of turn as an amateur who is guilty of theorising, but in my humble opinion and on the basis of the few reports I've seen.... (And also FWIW) -- had I found myself in that situation in my virtual 747 I would already have switched on (by hand, using an old-fashioned physical switch on the overhead panel) a retro thing called "continuous ignition", designed to keep the fires lit when large quantities of water were being ingested. So regarding Airbus's comment that "RR does not require" me to manually select the igniters, well that's awfully kind of them but all I can say is that in that scenario someone in the cockpit would have had to physically restrain me from switching them on. (Much though I love and trust the automation, you understand. ) You'll note also that they carefully don't say that manually turning them on is forbidden, merely that "it isn't required". <sigh> As Moriarty put it in The Goon Show a million years ago, "Lay your head on this lovely anvil, Neddy, and close your eyes...". However, I suspect, too, that as soon as I had looked at the weather radar and seen a storm of that size in my path I'd have been on the radio to ATC requesting permission to divert around it to try and avoid such measures being needed, which is one of the things my fuel reserve is carried for. This is the sort of stuff that we used to call "airmanship", in the old days (before everything got all automated and the bean-counters started trying to tell pilots how and where to fly). OK, OK, I'm unreconstructed; I know it. The conventional wisdom states that you gotta play the percentages, and automation is usually more reliable than human beings, but.... But anyway, like I said, I'm not a pilot and I'm not type rated on an Airbus, so all my comments are worthless.... (YMMV, just my 2 cents, etc etc). Some more of my dried frog pills. please, and don't slam the lid of the box. Thank you. bruce a.k.a. brian747 Link to post Share on other sites
allardjd 1,853 Posted May 28, 2015 Report Share Posted May 28, 2015 I kind of agree and kind of disagree. I don't think the concept of highly automated airliners is fatally flawed and I believe Airbus is well down that path. Several industries do a very credible job of extracting lessons learned from bad events and working them into the body of knowledge of that industry. Aviation, particularly commercial aviation, is one of those. Its manufacturers, operators and regulators do a pretty fair job of that. As I noted in another thread, considering the large number of airliners operating world-wide every day, it's not exactly raining Airbuses, and you can't count the ones involving suicidal pilots. On the other hand, I personally prefer the Boeing philosophy of allowing the pilot a greater span of control with relatively less, and less intrusive, automation. It's my opinion that acceptable margins of safety are being achieved with both methods and both are being improved constantly. It's not raining Boeings either. In the final analysis, whether one of the methods becomes dominant may well come down to costs. The promises of lower crew training costs for more highly automated aircraft, for instance, have not materialized. Look up the training requirements for an A380 pilot. It may well be that in the end, there will be no significant cost differential between the two and if that's the case, the highly computerized airliners and the less automated ones may continue to share the airways in roughly equal numbers, as they do today. The operators will vote with their checkbooks and the cheaper alternative, if one emerges, inevitably will win. John Link to post Share on other sites
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now