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chrisp390
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 3:57 am

I would not fly on SQ, despite their great product they seem to not have as much of a focus on safety as other airlines. Their decision not to divert plus the fact their aircraft was extremly close to the MH aircraft that got shot down while many other airlines had it marked as a no fly zone are 2 clear examples
 
col
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 4:11 am

Quoting chrisp390 (Reply 62):
I would not fly on SQ, despite their great product they seem to not have as much of a focus on safety as other airlines. Their decision not to divert plus the fact their aircraft was extremly close to the MH aircraft that got shot down while many other airlines had it marked as a no fly zone are 2 clear examples

2 clear examples of what. Incidents. Who do you fly with, because every carrier in the world has had incidents. Jeez some people should really read what they write several times before they post. This is ridiculous.
 
simpan97
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 5:29 am

Have any one noticed that the airplane actually flew through a giant storm when the power-loss occurred. Do you think this was a coincidence?

Twitter post, posted by Simon Proud.

 
flightless
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 5:33 am



Question: If the packs stop, does that trigger the masks to drop? Or is it only when a certain pressure altitude is reached?
 
wjcandee
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 5:40 am

BarneyCaptain, whose word I usually take as gospel, is certainly correct about the US policy. After Alaska 261, the basic policy is get it on the ground and don't try to fix it in the air or trust that you have fixed it in the air. Obviously you need to try to relight engines that have flamed out, but even if you are successful, the policy in the US today is to get it on the ground now. Any other factor, such as embarassment, passenger inconvenience, the sweetie waiting at the destination, etc., can have no weight in the decision. Alaska thought they had the thing basically under control, then they didn't.

It's a basic difference in the attitde towards safety, driven by the monumental consequences in the US if you are wrong. So something that is "completely-obvious" to a US pilot isn't as obvious to a pilot elsewhere, because of the safety culture, right or wrong, in the US.

Of course, stupid pussies that we are, we have long required a second person in the cockpit at all times on scheduled-carrier flights. Dang safety culture.

I'm not alarmed by the altitude loss, given that the relight procedure on most modern jet engines varies depending on whether you can get a certain percentage N2 in that engine -- 18% in the A320, for example. I don't know about these Rollers, but I'm guessing these pilots were willing to trade some altitude for an enhanced possibility of a quick and effective relight. But that's gonna be a decision based on a number of factors, including distance to nearest suitable.

As others have pointed out, there's no confirmed reporting that the incident chronology was that they were simply flying at cruise when they experienced a simultaneous loss of power in both engines. As has happend far too often before, they could have had a rollback in one, followed by manually inadvertently shutting down the other. Or somebody could have inadvertently done any number of things to shut them down followed by realizing their mistake and knowing that it wasn't a spontaneous failure of the equipment. Still, it would seem that one would want to ensure that no damage occurred to the engines (vis. the Pinnacle crash) when the shutdown occurred.

I simply don't understand why they had the confidence that the engines would STAY relit. But I'm sure we will hear more about the decisionmaking process as this unfolds.

Maybe this will be an example of what one airline considers to be "perfectly safe" (i.e. British Airways 747 3-engine flight across the continental US and then the Atlantic) being considered something else in the US, or maybe it will be completely obvious to all that not diverting was the right decision.
 
BoeingGuy
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 5:46 am

Quoting wjcandee (Reply 67):
Alaska thought they had the thing basically under control, then they didn't.

So did SW111 and AC797 think they had everything under control. AC overflew SDF; and SW111 first wanted to go back to BOS and then was dumping fuel rather than landing at YHZ.

Remember too that TACA at MSY got both engines re-lit (temporarily) and then flew past that Marine Base they could have made an emergency landing at. They didn't make MSY.
 
chrisp390
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 6:03 am

Quoting col (Reply 63):

Wjcandee explained it very well. I fly with US airlines, most British and Canadian ones plus CX to name a few. These are airlines based in jurisdictions that put a much greater emphasis on 'safety culture' than most other countries in the world
 
wjcandee
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 6:30 am

FWIW, a 13,000-foot altitude loss is going to be 5 minutes at 2500fpm, which another poster indicated was, in broad strokes, an appropriate descent rate for a windmill restart or a windmill-assisted restart (iie you're gonna supplement with some APU bleed). But neither I nor that poster purport to know the %N2 you're shooting for in an A330 with Rollers, nor what descent rate it's likely to take to accomplish that. (For example, on the CRJ with the GEs, because of the anti-FOD design of the engine nacelle, it takes somewhat more airspeed (and therefore more descent rate at no power) to accomplish a windmill relight.)

[Edited 2015-05-26 23:30:52]
 
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lammified
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 7:17 am

All things considered, I think we should all not jump to conclusions about what actually happened until a factual account of the incident is published by the Singapore AAIB. Speculation has never helped anyone...

In the modern day with AHM (or its Airbus equivalent) and Rolls Royce EHM, it is likely that the ground teams at SQ had a good appreciation of the situation on 9V-SSF at the time and I am certain that the crew would have consulted with their ground teams before making the decision to continue the flight to PVG.

Looking at the weather map posted earlier in the thread, HKG may not have been the best place to divert to anyway. The route from HKG to PVG has multiple large aerodromes capable of handling an A330 (FOC and XMN come to mind) and I am sure that if the situation was as bad as described, the crew would definitely have elected to land the aircraft.
 
CXfirst
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 7:52 am

Quoting Rara (Reply 39):
As to why the aircraft didn't divert to HKG: Keep in mind that a diversion only makes sense if it improves safety over the alternative. In this case, diverting to Xiamen would have been as safe as diverting to Hong Kong. Diverting to Taipei likewise, Wenzhou likewise, and so on all the way to PVG. In other words, as long as the aircraft is stable and flying, there's no real added safety benefit to landing as soon as possible

That is arguable. Sure, all those airports are as suitable, but landing at hkg with power to both engines is safer than diverting to any of the other airports after having engines fail again.

However, i will wait for a more detailed report before making my judgement, which will be based on whether they had complete engine failure or just power loss with a clear reason for why it happened.
 
nitepilot79
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 7:54 am

Quoting ChaosTheory (Reply 60):

Thanks.
 
kellmark
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 12:17 pm

I have to add a little something to this.

If it was a dual inflight power failure of some type, the following thoughts come up in my mind.

1. Even if the cause is known for the dual power failure, ie crew error, or mismanagement, or a weather event into heavy precipitation or icing, the flight should divert to the nearest suitable airport in point of time. No "ifs" "ands" or "buts". To continue on, is just unacceptable. A dual engine power failure is just too extreme. Remember, that a single engine failure on a twin, generally requires a diversion to the nearest suitable airport with the remaining engine. I would consider a dual failure of whatever type much more serious, even if power was restored. Until qualified maintenance personnel then have the chance to check out the aircraft, then it should not fly.

2. Once the aircraft landed at its destination, the authorities, meaning the Singapore authorities, should have grounded it until they had a chance to step in and investigate. Do they have a representative at the destination airport capable of determining if the aircraft was again safe to fly? I doubt it. After an incident like this it should not fly again, especially with passengers, until the the aircraft is inspected by the authorities, the CVR and FDR have been read out and the crew and maintenance people interviewed. Was that done? I doubt it. It apparently flew on another revenue flight within a few hours.

3. What kind of a dispatch system does the airline have? Was the flight being watched or tracked by ground operational control/dispatch personnel? In some systems, the flight dispatcher/flight operations officer would be tracking the flight, and the crew would be required to advise the dispatch center of any event like this. In that event, the dispatcher will, in some systems, have the authority to inform the crew to land at the nearest suitable airport and not continue to the destination. What does Singapore have in this regard?

4. Did the crew declare an emergency under these circumstances? If they didn't they should have. And if they did, why would they have continued?
 
airbazar
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 12:41 pm

Quoting hivue (Reply 48):
I think you missed my point. Would they continue to destination (as this airplane did) or divert to the nearest suitable airport 200 min away?

Either way, everyone would have their pants thoroughly soiled.

Quoting mandala499 (Reply 65):
If this was NOT a dual flame-out, OK, it's debateable, but if it was a dual flame out on the 330... Why the heck didn't they divert I don't know... again, LOTS of answering to do...

Maybe, just maybe, it wasn't a flame out at all? 
Quoting chrisp390 (Reply 69):
Wjcandee explained it very well. I fly with US airlines, most British and Canadian ones plus CX to name a few. These are airlines based in jurisdictions that put a much greater emphasis on 'safety culture' than most other countries in the world

And yet, the safest long haul U.S. carrier is DL in 26th place.
http://www.jacdec.de/airline-safety-ranking-2015/
 
wjcandee
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 2:39 pm

Quoting lammified (Reply 71):
it is likely that the ground teams at SQ had a good appreciation of the situation on 9V-SSF at the time and I am certain that the crew would have consulted with their ground teams before making the decision to continue the flight to PVG

I think this is wildly-optomistic.
 
catiii
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 2:49 pm

Quoting hivue (Reply 32):
what would be the proper action if they'd been on an, e.g., ETOPS 240 flight 200 minutes from nearest suitable? Also continue?

Who cares? It's utterly irrelevant to the issue at hand, as the situation is not remotely the same. So rather than try and throw some crap up on the wall about ETOPS to see what sticks and make yourself sound like you know what you're talking about, how about waiting for the official report?

Neither you nor I were in the cockpit when this happened, neither you nor I know the cause, and neither you nor I know the what, when, where, why, and how the decision to continue is made.
 
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lammified
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 3:14 pm

Quoting speedbored (Reply 86):
I think this is wildly-optomistic.

A SQ pilot shared that he was on an A330 to MLE and an ECAM message appeared. Before he even took any action, the company sent an ACARS message to the aircraft requesting to turn back to SIN.

With the telemetry being sent by aircraft nowadays, SQ in SIN would have had a good idea of what was happening on this flight.
 
cpqi
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 3:21 pm

Both the lack of diversion and the quick flight turnaroud must mean that the crew and airline had no doubt what the issue was and that it was fully resolved in flight. The options for that are very limited and include someone turning the engines off, someone fiddling with the fuel or something related to the wrong altitude. Perhaps you can add to this list

With regard to the number of engines it is not about the absolute number but about the percentage of engine power required for approved flight. Losing one in four could be just as much of a problem as losing one in two
I hate turbulence
 
mats01776
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 3:30 pm

This immediately came to mind: Software Cut Off Fuel Supply In Stricken A400M
http://aviationweek.com/defense/soft...are-cut-fuel-supply-stricken-a400m
 
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AirlineCritic
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 5:11 pm

Quoting Roseflyer (Reply 35):
I also think the regulators are going to look in to how this happened to an airplane that is only two months old. The airplane being so new raises some questions.

I too wondered about the same thing as mats01776. I don't seriously believe this is related, but funky new engine computer software ending up on both the A330 and A400M and causing a problem sounds really wild.
 
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CALTECH
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 6:30 pm

Divert divert divert.

Old article, and from Boeing, but,

http://www.boeing.com/news/frontiers/archive/2002/september/i_ca1.html

" If an engine goes out on any airplane, many times the safest option is to land at the nearest airport rather than continue."

" If you have two engines, there are two chances of engine failure. If you have four engines, there are four chances of engine failure. The chance of engine malfunction doesn't go down with four engines; it goes up."

" It also is important to note that more than 90 percent of airplane diversions have nothing to do with engines but rather involve weather, a sick passenger or other reasons."

" Records for the four-engine A340 show it has had twice as many diversions and turnbacks as the twin-engine 777, and the A340 has a lower average dispatch reliability rate than the 777"



4 engine airliners saw a much improved diversion rate when they started following ETOPS rules.

Personally, long flights over the oceans, I like 8 engines turning and burning, just sayin.

http://media-cache-ec0.pinimg.com/736x/d7/42/5d/d7425d003879a4ee39b0926fc5e8049b.jpg
You are here.
 
Kaiarahi
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 7:23 pm

Quoting mats01776 (Reply 67):
This immediately came to mind: Software Cut Off Fuel Supply In Stricken A400M

Could you explain the similarities and differences between the fuel management systems in an A400M (4 engine turboprop) and an A330 and how they might be relevant to this incident?
Empty vessels make the most noise.
 
RickNRoll
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 10:09 pm

Quoting CALTECH (Reply 69):
" It also is important to note that more than 90 percent of airplane diversions have nothing to do with engines but rather involve weather, a sick passenger or other reasons."

" Records for the four-engine A340 show it has had twice as many diversions and turnbacks as the twin-engine 777, and the A340 has a lower average dispatch reliability rate than the 777"

Those statistics imply different missions or some thing else is going on. They don't appear to be comparing apples and apples.
 
Ruscoe
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Wed May 27, 2015 10:37 pm

quote=simpan97,reply=52]Have any one noticed that the airplane actually flew through a giant storm when the power-loss occurred. Do you think this was a coincidence? [/quote]

That would explain why the aircraft continued and then returned after inspection. This is being reported in the Australia Press.

Read more at
http://www.9news.com.au/#i2WWWtePsgjtIUFF.99


In a statement, SIA said the Airbus A330-300, carrying 182 passengers and 12 crew members, "encountered bad weather at 39,000 feet about three and a half hours after departure" from Singapore.
Read more at http://www.9news.com.au/world/2015/0...-during-flight#MLFtwQeVfqSQzay8.99

Ruscoe
 
SIA747Megatop
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 12:14 am

Source from a pilot at the Group that he was flying through the airspace at the same time and believes it was icing, he metioned he had lightning strike go straight through his aircraft's engine.
I found the edit signature button
 
mats01776
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 12:32 am

Both A400M and A330 have FADECs from BAE (with Hispano Suiza contributions in A400M).
How much control logic they share is not apparent to me.

http://avherald.com/h?article=486d5637&opt=0
Quote:
Heard from a Reliable Source
By Stan on Wednesday, May 27th 2015 23:59Z

Hi Everyone,

Just contributing what I heard from those in the know about preliminary findings. SQ-836 had almost brand new engines. Hit turbulence which resulted in minor, momentarily fan blade contact with nacelle in both engines. This was detected by onboard computer. Logic commanded a wind down to prevent fan blade damage. Successful auto restart on one engine within a couple of minutes without crew action. Other engine did not fire up. Crew commenced drift down due single engine ops and perform engine fail checklist. Successful relight of second engine.

Crew weighed the risk of another engine fail and the notoriously draconic conditions (and weather conditions) for diversion in China airspace for non domestic flights and elected to press on. To turn back for HKG would have resulted in longer flight time.
 
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LAX772LR
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 2:28 am

Quoting BoeingGuy (Reply 55):
So did SW111 and AC797 think they had everything under control. AC overflew SDF; and SW111 first wanted to go back to BOS and then was dumping fuel rather than landing at YHZ.

Sorry, but that's not a very fair (nor accurate) depiction of SR111.

First, they were too high to land at BOS, and would've taken more time to attempt a landing there than they would've by going into YHZ........... which is *why* they opted to go to YHZ.

Second, the accident report makes it clear that they did not have sufficient time to reach YHZ either, even if they had not turned around to dump.
In the time frame between turning back toward the bay, the Mayday call, and the disappearance from radar; they would've still been several miles out from the airport.


[Edited 2015-05-27 19:34:14]
I myself, suspect a more prosaic motive... ~Thranduil
 
benjjk
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 2:32 am

Many people are still assuming both engines completely failed.

According to the FR24 track, the time it took to descent the 13,000ft was about 20-30 minutes.

Can an A330 glide on no engines at only -500fpm?

There is frustratingly little solid, reliable information here. But my opinion remains that there is far less to this incident than some people seem to think.
 
Kent350787
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 3:19 am

Quoting benjjk (Reply 76):
Can an A330 glide on no engines at only -500fpm?

Air Transat FL236 descended at around -2,000fpm.
S340/J31/146-300/F27/F50/Nord 262/Q100/200/E195/733/734/738/744/762/763/77W/788/789/320/321/332/333/345/359
 
wjcandee
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 4:19 am

Quoting benjjk (Reply 76):
But my opinion remains that there is far less to this incident than some people seem to think.

Well...the South China Morning Post is quoting SQ as saying that the pilots initiated a "controlled descent in order to" restart one of the engines, which sure sounds like a windmill relight to me. Which means the candle was out. Which would require any American carrier to land at the nearest suitable.

I also think that SQ is taking great pains to poo-poo this incident. Methinks they doth protest too much.

[Edited 2015-05-27 21:22:03]
 
BoeingGuy
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 5:43 am

Quoting wjcandee (Reply 78):
Well...the South China Morning Post is quoting SQ as saying that the pilots initiated a "controlled descent in order to" restart one of the engines, which sure sounds like a windmill relight to me. Which means the candle was out. Which would require any American carrier to land at the nearest suitable.

Why couldn't they have done a bleed air assisted start (e.g. a ground start) either from the APU or a cross-bleed start instead? Is the A330 not able to do that? But yes, high bypass engines actually have a smaller windmill start envelope than first generate turbofans.
 
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allegro
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 6:12 am

Quoting ThirtyEcho (Reply 90):
For my money, I prefer the B-36 and its ten engine power. Nice mix of piston and jet power, too. Would be safer if they had just added a couple of rocket packs for that secure over the fence feeling.

Lol ... where is the Like button?!?
Flown on: DC-3, DC-8, DC-9, DC-10, MD-11, MD-80, MD-90, 707, 717, 727, 737, 747, 757, 767, 777, 787, A300, A310, A320, A330,
 
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speedbored
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 6:44 am

This thread makes me laugh. So many people jumping to so many conclusions with almost no evidence whatsoever.

All we know for sure is that an aircraft "lost power" and descended for a while then continued to its destination.

"lost power" could mean anything from 1% to 100%. It could mean the engines stopped, it could mean they carried on working entirely normally but at a lower than expected thrust level.

One fact we can be certain of is that there is nowhere near enough information available publicly for any of us to know what happened so why don't we all wait for the official report before trying to dissect things too much and condemning the pilots for all-sorts of misdeeds?

Quoting benjjk (Reply 76):
But my opinion remains that there is far less to this incident than some people seem to think.

I tend to agree. Regardless of the competence, or otherwise, of the flight crew, simple self-preservation would suggest that they would have declared an emergency and diverted to the nearest airport if things were anywhere near as bad as many people seem to think they were. After all, even the coolest, calmest, pilots would probably need a change of underwear if both engines stopped on a twin  

The simple fact that they continued suggests to me that they identified the cause of the problem, and how to rectify it, and understood any likely consequences. But I will await further information before coming to any firm conclusions.
 
CaliAtenza
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 7:00 am

CNN as usual, is crying hoarse about this story. I hate how they delibarately scare the flying public....
 
wjcandee
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 7:12 am

Quoting BoeingGuy (Reply 79):
Why couldn't they have done a bleed air assisted start (e.g. a ground start) either from the APU or a cross-bleed start instead?

I'm not saying that they couldn't have. However, who says there was an engine available to do a cross-bleed start?

More intriguing to me, I thought you had a little more background on this stuff, which would help to answer your question.

Meaning that in a dual-out situation, and in broad-brush terms, the checklist goes as follows: the first move you consider is whether you can reasonably get the N2% up to a certain level (it's 18% for the A320 for example) by windmilling, simply because that's the fastest way you're going to be able to go to the next steps to get relit. And it's a reliable way as well. The second move is to use APU to help nudge what you've got over the magic number. Third is to spool up the APU (if it hasn't been MEL'd) and go through the whole APU engine start procedure. On certain Airbus aircraft, the display unit is going to remind you with a nice green dot at the airspeed that is expected to give you enough windmill rotation to go for a relight. (This is a nice feature, as the dead Pinnacle geniuses never put the nose of their CRJ over enough to get enough airspeed to windmill the engines up sufficiently for a relight, even if one or both hadn't core-locked from the flameout. At a stressful, high-workload time, that little reminder makes a nice target.)
 
wjcandee
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 7:20 am

Quoting speedbored (Reply 81):
The simple fact that they continued suggests to me that they identified the cause of the problem, and how to rectify it, and understood any likely consequences.

Well, IF, as suggested by the South China Morning Post today, quoting SIA officials, both engines did indeed fail, and they descended to windmill at least one engine for a relight, here's the answer to that:

Once you have even a single engine failure, it's not their decision to make anymore about whether it's safe to proceed to destination rather than diverting. Safety-conscious countries require airlines to have POLICIES about what to do when certain things happen. If you have to relight an engine on a US-flag certificated air carrier, your airline's policy is going to require you to land at the nearest suitable, regardless of whether you THINK you have identified the problem, think you have rectified it, and think you understand any likely consequences. Because once that happens, the decision is not yours to make. Your own personal opinion and judgement have been supplanted by a requirement, one that was developed to best protect the passengers and one that is written in blood.

It's also a policy that protects against the Draconian consequences, financial and possibly criminal, that arise under the US justice system when somebody thinks they know something but ends up killing a bunch of people because they were wrong.

[Edited 2015-05-28 00:23:43]
 
cheeken
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 8:58 am

Quoting speedbored (Reply 81):
So many people jumping to so many conclusions with almost no evidence whatsoever.

Isn't that the whole point of this forum?   

Quoting speedbored (Reply 81):
One fact we can be certain of is that there is nowhere near enough information available publicly for any of us to know what happened so why don't we all wait for the official report before trying to dissect things too much and condemning the pilots for all-sorts of misdeeds?

If only people knew how to do this!

I'm quite sure that they wouldn't have been able to do the return flight if ground crew didn't clear the plane for a flight.
 
longhaul67
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RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 9:47 am

Is it not a requirement to declare PAN emergency level in a situation like this? Do we know if they did this?
If this malfunction requires them to declare this, then surely they need to get on the ground ASAP?
 
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par13del
Posts: 10488
Joined: Sun Dec 18, 2005 9:14 pm

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 10:20 am

Quoting catiii (Reply 13):
Since no one knows WHY the engines shut down (maybe they were inadvertantly shut down by the flight crew)
Quoting speedbored (Reply 81):
Regardless of the competence, or otherwise, of the flight crew, simple self-preservation would suggest that they would have declared an emergency and diverted to the nearest airport if things were anywhere near as bad as many people seem to think they were.

All well and good except you missed one potential issue, what are the rules / regulations of the authorities of the airline and the governing body.
ETOPS requirements and operations are very stringent, and a large number of large twins do such operations on a daily basis.

Quoting wjcandee (Reply 84):
Once you have even a single engine failure, it's not their decision to make anymore about whether it's safe to proceed to destination rather than diverting. Safety-conscious countries require airlines to have POLICIES about what to do when certain things happen.

If the authorities in question do not have such requirements, then fine, if they do then a serious investigation is required.

Thankfully this is a discussion forum and we can discuss all possibilities, only the truth will set us free.
 
s5daw
Posts: 348
Joined: Mon May 30, 2011 8:15 am

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 10:36 am

Quoting CALTECH (Reply 69):
" If you have two engines, there are two chances of engine failure. If you have four engines, there are four chances of engine failure. The chance of engine malfunction doesn't go down with four engines; it goes up."

Good job mods, leaving marketing FUD here, but deleting laws of nature.

Again: the chance of one of the engines failing goes up with number of engines, but probability of losing all engines goes down drastically

What the above quote is really saying is simply: if planes had no engines, there would be no engine failures.
 
questions
Posts: 2337
Joined: Thu Sep 15, 2011 4:51 am

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 10:43 am

What is the passenger experience in situations like this? Do they hear the engines cut off? Power back up? Does the cockpit crew disable the "flight map" that passengers see on PTVs that includes things like altitude?
 
Ruscoe
Posts: 1748
Joined: Sun Aug 22, 1999 5:41 pm

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 11:11 am

Quoting s5daw (Reply 88):
Again: the chance of one of the engines failing goes up with number of engines, but probability of losing all engines goes down drastically

I believe that would only be true for independent events. If there is a common fault, in planning, design or manufacture, and there sometimes is. eg faulty common software, leaking fuel pipe, poorly manufactured oil pipe, then the chances are not so remote

Ruscoe
 
s5daw
Posts: 348
Joined: Mon May 30, 2011 8:15 am

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 11:28 am

Quoting Ruscoe (Reply 90):
I believe that would only be true for independent events. If there is a common fault, in planning, design or manufacture, and there sometimes is. eg faulty common software, leaking fuel pipe, poorly manufactured oil pipe, then the chances are not so remote

Yes of course. That's why even using engines produced in the same batch, or maybe the same day of week (friday sindrome) should be avoided.
A tragic example is the recent A400M crash. Maybe it's even a good idea to randomise firmware versions to avoid sth like this...

Thait said, in those examples the original quote also makes no sense. Yes, with more engines you are going to lose more engines in a dependent event, but that doesn't really mean anything.

[Edited 2015-05-28 04:29:56]
 
flyenthu
Posts: 590
Joined: Fri Dec 21, 2012 2:37 pm

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 12:28 pm

Hi,

The avherald's article has sat image of weather. It is a massive system with a slim break. Going around it seems like a substantial detour from planned track. I am not surprised at the decision to go through it. I think we need to get a more detailed analysis. We do not have sufficient info right now, we can only speculate.
 
Curiousflyer
Posts: 587
Joined: Sun Oct 22, 2006 3:19 am

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 5:26 pm

Will they eventually publish a detailed account of the issue? When?
 
User avatar
Finn350
Posts: 1601
Joined: Tue Jul 09, 2013 4:57 am

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 5:33 pm

Quoting questions (Reply 89):
What is the passenger experience in situations like this? Do they hear the engines cut off? Power back up? Does the cockpit crew disable the "flight map" that passengers see on PTVs that includes things like altitude?

I would suppose absence of engine noise would be the most noticeable effect, and potentially loss of electrical power to the cabin (I suppose APU would have started at the latest on the cut-off of the 2nd engine, though).
 
SonomaFlyer
Posts: 2237
Joined: Tue Apr 20, 2010 2:47 pm

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 5:52 pm

Quoting Curiousflyer (Reply 93):

Will they eventually publish a detailed account of the issue? When?

When the investigation is complete.

[Edited 2015-05-28 10:53:24]
 
bhill
Posts: 1883
Joined: Thu Sep 13, 2001 8:28 am

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 6:12 pm

If this was a "loss of power" and not a "engine shutdown" in BOTH engines...why the descent to "restart" engines that were "not" shut down? Makes sense if both engines actually shut down..i.e. 0% power being created and windmilling was needed to light them off again. But a "loss of power?" Odd.....
Carpe Pices
 
mffoda
Posts: 1099
Joined: Thu Apr 15, 2010 4:09 pm

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 6:54 pm

As some have suggested a possible relationship between the A330 and A400M incidents, It looks like there is no connection to A400M based on this new article.



"BERLIN: Analysis of the flight recorders of the A400M which crashed in Spain on May 9, killing four, indicated there were no structural faults but assembly quality problems, a senior Airbus executive said in a newspaper interview to appear on Friday.

"The black boxes confirm it. There was no structural fault, but we have a serious final assembly quality problem," Airbus group's chief of strategy Marwan Lahoud told the German daily Handelsblatt after receiving the first results of the analyses of the flight recorders.

In a statement released ahead of publication, Handelsblatt wrote that the units which control the engines of the turboprop A400M military cargo and troop transport were poorly installed during final assembly, which could have led to the engines malfunctioning and the plane crashing."


http://www.dailystar.com.lb/News/Wor...ity-problem-after-a400m-crash.ashx

https://in.news.yahoo.com/airbus-admits-assembly-quality-problem-174725125.html
harder than woodpecker lips...
 
User avatar
speedbored
Posts: 2230
Joined: Fri Jul 19, 2013 5:14 am

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 7:38 pm

Quoting bhill (Reply 96):
why the descent to "restart" engines that were "not" shut down?

Who says the descent was in order to do a restart? People, and many media outlets, are only assuming that the descent was to restart the engines. No official source has said so, so far.

The statement from SQ said:
" Both engines experienced a temporary loss of power and the pilots followed operational procedures to restore normal operation of the engines."

Absolutely no mention of engines stopping or needing to be restarted. "Loss of power" could be anything from 1% reduction in power to total shutdown. I'm sure there will be an official report at some point explaining exactly what happened.
 
slvrblt
Posts: 386
Joined: Tue Dec 28, 2004 11:19 pm

RE: SQ836 Lost Power To Both Engines, Drops 13000 Feet

Thu May 28, 2015 7:45 pm

OK. forgive me, I'm not a pilot - but this begs the question. So, educate me. To me this is shockingly similar to AF447. Fly into bad weather, [email protected] happens, plane freaks out and/or pilots do - and bad things happen.

In this SQ case, pilots are professional, they figure it out, get it together, and engines restart. AF447 had their engines lit, but the guys up front couldn't get it together. So it seems like the SQ pilots had to do some real work here and handled it.
Yes, I get it, there could be an issue with the engine manufacturer, not Airbus. This isn't trying to be a flame starter, honest, but DAMN, what is it with these A330's and less than perfect weather?? Or am I wrong? I don't hear of other wide bodies having carbon copy problems like this.

I was in a 777 not too long ago - captain came on and basically said we would have to go THRU some heavy weather, and get whacked, there was no way around it. The cabin crew was told to sit. It wasn't fun, that plane flew thru some really SH$%TTY weather - but it pretty much blasted its way thru and cruised on to its destination.
..everything works out in the end.

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