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-   -   QR920 11th August Doha-Auckland turns back shortly after takeoff (https://www.pprune.org/middle-east/624727-qr920-11th-august-doha-auckland-turns-back-shortly-after-takeoff.html)

Terego 19th Aug 2019 01:14

QR920 11th August Doha-Auckland turns back shortly after takeoff
 
The above flight (Boeing 777-200LR) suffered some sort of engine failure or anomaly during takeoff and after dumping fuel returned to Doha. I was a passenger on this flight and was looking for further information mainly out of curiosity but also because my PhD was on turbine blade materials! The incident was reported in the NZ press and also on avherald:

As I can't post url's please search for QR920 on nzherald.co.nz and avherald sites

The reports give a very bald account of the incident but also has a photograph which seems to show a hole in the lefthand engine casing at the hot end- looks like a turbine blade decided to go on holiday? What I recall (it was 3.30 in the morning and was not initially paying much attention) was a normal takeoff roll until around the time the aircraft was rotated, when there was a sharp bang. The aircraft climbed to around 2/3000 feet at which point the throttles were rolled back quite sharply and the aircraft levelled also quite sharply. A rather anxious message was put out from the cockpit for a particular person to join them urgently in the cockpit- the captain of the relief crew perhaps? We were told that due to a transient abnormal engine indication, 'out of caution' we would be returning to Doha after dumping fuel. We were told to expect fire engines on the runway and not to be alarmed. After about an hour or so dumping fuel we returned to Doha and an uneventful though rather heavy and long landing, and returned to the gate under the aircraft's own power. A replacement aircraft took us to Auckland some 5 hours late. Recognising the pilot's nationality from his accent, from a south east Asian country where culturally giving bad news is avoided, I was initially concerned about what we might not have been told but in the end the return was uneventful. Is there a source of further information on this flight? Departing turbine blades (if that is indeed what happened) are a source of concern! Aircraft Registration A7-BBC.

FlightDetent 19th Aug 2019 11:29

There's your link. Incident: Qatar B772 at Doha on Aug 11th 2019, engine problem on departure

Airmann 19th Aug 2019 12:28

Sounds like all went absolutely according to plan.

As for an explanation

Yes obviously something inside the jet core ripped a hole through the turbine end of the engine .Thank God that was all, we've seen a number of engines exploding and even sending shaprenel through the fuselage and killing pax.

As for the sharp level off they would have been using an instant level off mode instead of the usual altitude capture. That would have been at their safe altitude to accelerate and retract the flaps, at that point they would reduce thrust to maximum continuous from takeoff power and then continue to a safe altitude to finalize things for a return. In Doha the minimum safe altitude is around 2500 feet so they would probably not have gone higher than that.

As for the person they called to the flight deck, it probably would have been the chief purser in order to brief him/her of the situation and the action they were planning on taking. The relief pilots would usually be in the cockpit for takeoff and landing.

Good on the captain for coming on the PA and reassuring the pax and mentioning the fire engines.

Glad things worked out. That's what the training is there for.

Jack D 19th Aug 2019 20:28


Originally Posted by Airmann (Post 10549113)
Sounds like all went absolutely according to plan.

As for an explanation

Yes obviously something inside the jet core ripped a hole through the turbine end of the engine .Thank God that was all, we've seen a number of engines exploding and even sending shaprenel through the fuselage and killing pax.

As for the sharp level off they would have been using an instant level off mode instead of the usual altitude capture. That would have been at their safe altitude to accelerate and retract the flaps, at that point they would reduce thrust to maximum continuous from takeoff power and then continue to a safe altitude to finalize things for a return. In Doha the minimum safe altitude is around 2500 feet so they would probably not have gone higher than that.

As for the person they called to the flight deck, it probably would have been the chief purser in order to brief him/her of the situation and the action they were planning on taking. The relief pilots would usually be in the cockpit for takeoff and landing.

Good on the captain for coming on the PA and reassuring the pax and mentioning the fire engines.

Glad things worked out. That's what the training is there for.

Quite a few holes in this one, instant level off an all .. nonsense . What might be worthy of discussion is, if an engine was shut down on a twin engine aircraft, is it a good idea to fly around for 1 hr on the sole remaining live engine when a perfectly good airfield is available within a very short flight time ...

On the other hand I wasn’t there ..

Phantom Driver 19th Aug 2019 21:40

also a few questions about this one....


and returned to the gate under the aircraft's own power.
taxiing a heavy T7 to the gate on one donk not the wisest ( or easiest ) of moves .

APU_inop 21st Aug 2019 11:31


Originally Posted by Phantom Driver (Post 10549485)
also a few questions about this one....



taxiing a heavy T7 to the gate on one donk not the wisest ( or easiest ) of moves .

It's standard ops, done even by FOs who haven't taxiied anything bigger than a ME-piston plane before. The -200 is even easier.

APU_inop 21st Aug 2019 11:46


Originally Posted by Jack D (Post 10549438)


Quite a few holes in this one, instant level off an all .. nonsense . What might be worthy of discussion is, if an engine was shut down on a twin engine aircraft, is it a good idea to fly around for 1 hr on the sole remaining live engine when a perfectly good airfield is available within a very short flight time ...

On the other hand I wasn’t there ..

Landing and stopping a 777 at MTOW is indeed possible as it is certified to do so but opens a whole can of worms.



from a south east Asian country where culturally giving bad news is avoided, I was initially concerned about what we might not have been told but in the end the return was uneventful. Is there a source of further information on this flight? Departing turbine blades (if that is indeed what happened) are a source of concern! Aircraft Registration A7-BBC.
If further flight was considered unsafe/impossible, they wouldn't have dumped fuel. Congratulations on only having a 5hr delay as most airlines would have dealt much worse with a situation like this!

Jack D 21st Aug 2019 14:50


Originally Posted by APU_inop (Post 10550635)
Landing and stopping a 777 at MTOW is indeed possible as it is certified to do so but opens a whole can of worms.

https://www.youtube.com/watch?v=L-by8dZrSJs



If further flight was considered unsafe/impossible, they wouldn't have dumped fuel. Congratulations on only having a 5hr delay as most airlines would have dealt much worse with a situation like this!

Always the same age old discussion but land at the nearest suitable airport equates to time ( Boeing) there is no can of worms with a long enough Rwy. except perhaps hot brakes and possible tire deflation
Anyway it all ended well and this is the main thing after all.
As I mentioned I wasn’t there so can’t really judge events but it’s interesting to discuss in a non judgmental manner

Phantom Driver 21st Aug 2019 22:05


It's standard ops, done even by FOs who haven't taxiied anything bigger than a ME-piston plane before. The -200 is even easier.
Really ? I would be interested to know where this is "standard ops" , and I'm not talking about shutting one down as you turn into the gate to save a few kgs of gas for the experts in the fuel monitoring department . Jet blast from a GE90-115 is always a consideration when taxiing at heavy weights on 2 engines at the best of times , let alone on one donk , especially if you make the mistake of allowing the jet to "settle" in any turns . It's a long way from the runway to most gates at DOH. Shut down and tow in would have been the preferred option if there had been serious damage to the engine , even if already secured .

On the other hand , there may be more ( or less ) to this story than is being reported in the media . The report ( by the pax ) stated that the aircraft returned to the gate "under it's own power" .. It cannot be concluded that the engine was shut down during the incident . I am pretty sure the crew would have followed QR procedures to the letter . They run a tight ship there .


Yes obviously something inside the jet core ripped a hole through the turbine end of the engine .
No further comment .

fatbus 22nd Aug 2019 07:10

All the experts now come out !

casablanca 22nd Aug 2019 07:21

I believe the general principal is if it took off it will also land. Although when 100 tons over the landing weight nobody guarantees you won’t have hot brakes and deflate some tires or worse
In Delta or some legacy carrier with union protection you are a hero either way.
while working at various foreign carriers I would tend to dump fuel as any damage to the plane will likely have negative consequences on your employment... I wish it were more black and white!

Landflap 22nd Aug 2019 10:22

JackD; your assertion that "nearest" equates to time (Boeing), really ? Where does Boeing go in direct conflict with even the most basic language dictionary. Look up "near". It is a distance factor, not time. I have no wish to thread creep or open up the tired old discussion but "nearest" and "suitable" are well defined and enforced in most training discussions. Losing a donk out of two means you have lost 50% of your power and by regulatory definition, that is a "Mayday". In terms of pure airmanship, you really do want to get down in case the remaining donk blows too. Now you are poling a big fat glider ! Departure airfield may be nearest but may not be suitable . I certainly would not have circled about dumping fuel. I too, was not there but at least, a safe outcome was achieved. One for the "What would you have done" discussion groups eh ?

Jack D 22nd Aug 2019 18:14


Originally Posted by Landflap (Post 10551534)
JackD; your assertion that "nearest" equates to time (Boeing), really ? Where does Boeing go in direct conflict with even the most basic language dictionary. Look up "near". It is a distance factor, not time. I have no wish to thread creep or open up the tired old discussion but "nearest" and "suitable" are well defined and enforced in most training discussions. Losing a donk out of two means you have lost 50% of your power and by regulatory definition, that is a "Mayday". In terms of pure airmanship, you really do want to get down in case the remaining donk blows too. Now you are poling a big fat glider ! Departure airfield may be nearest but may not be suitable . I certainly would not have circled about dumping fuel. I too, was not there but at least, a safe outcome was achieved. One for the "What would you have done" discussion groups eh ?

But you are saying exactly the same as me .. nearest suitable airport means closest suitable in terms of time
nothing else’. Suitable in this case was the departure airfield .. you agree ? The definition of suitable is open to discussion of course but as DOH is the closest and presumably the Wx was not limiting then where could be more suitable ?

Jack D 22nd Aug 2019 18:19

Sorry I forgot the wording is land at the nearest suitable airport .. so time is the governing factor or put it this way . 2 Airports are suitable the nearest is chosen because you get there faster that’s all. Possibly further in ground distance but “ nearer “ in terms of flight time

Landflap 23rd Aug 2019 09:15

Jack ; See ? I was, rather, hoping to avoid this - done to death -discussion. "Nearest suitable" does NOT mean suitable in terms of time -"nothing else". As you say . Oh dear. Land at the nearest suitable means (1) NEAREST in terms of distance . Note any dictionary , (2) SUITABLE refers to things like performance criterior ( Not suitable if the runway is grass-eh ? Maybe concrete but is it long enough ? Is the field, actually, open ? ) etc, etc, etc .

Here's the thing and something for you to ponder. In my last Company's Command Selection Board of which I was a member, we posed the question ; Twin engine, en route to dest, bang, lost a donk OVERHEAD a company regular field. Down the road is another company regular field (Suitable) and with a strong tailwind forecast, you will reach it quicker than descending in the hold for the overhead (nearest, ole mate ,) field. When you inform Company that you are descending in the hold, engine out, mayday procedure for that lovely long, SUITABLE and very familiar airfiled right under your backside, they ask you to go to the en-route because they have a spare engine there & you will be back aloft for destination within six hours. Worse, where you are intending to go is suffering a employment dispute and there is no engine spare holding . What do you do ?

Those bowing to commercial pressure, failing to understand simple terminology like (nearest), failing to have fully grasped the meaning of "suitable" were shown the door. Nearest suitable door, actually.

Jack D 23rd Aug 2019 09:45


Originally Posted by Landflap (Post 10552295)
Jack ; See ? I was, rather, hoping to avoid this - done to death -discussion. "Nearest suitable" does NOT mean suitable in terms of time -"nothing else". As you say . Oh dear. Land at the nearest suitable means (1) NEAREST in terms of distance . Note any dictionary , (2) SUITABLE refers to things like performance criterior ( Not suitable if the runway is grass-eh ? Maybe concrete but is it long enough ? Is the field, actually, open ? ) etc, etc, etc .

Here's the thing and something for you to ponder. In my last Company's Command Selection Board of which I was a member, we posed the question ; Twin engine, en route to dest, bang, lost a donk OVERHEAD a company regular field. Down the road is another company regular field (Suitable) and with a strong tailwind forecast, you will reach it quicker than descending in the hold for the overhead (nearest, ole mate ,) field. When you inform Company that you are descending in the hold, engine out, mayday procedure for that lovely long, SUITABLE and very familiar airfiled right under your backside, they ask you to go to the en-route because they have a spare engine there & you will be back aloft for destination within six hours. Worse, where you are intending to go is suffering a employment dispute and there is no engine spare holding . What do you do ?

Those bowing to commercial pressure, failing to understand simple terminology like (nearest), failing to have fully grasped the meaning of "suitable" were shown the door. Nearest suitable door, actually.

Me too, but sorry I don’t agree with you neither do Boeing
You were exploring the meaning of suitable and tying it to commercial pressure. As I understand it the enroute airport would be reached quicker in terms of time you don’t mention how much quicker ? A few minutes or longer ? , never mind.
That makes this airport( the enroute) the nearest suitable, spare engine or no spare engine that is not relevant neither is the possible industrial dispute unless it involves RFF or some such thing
You may just have canned a lot of “ suitable” guys with your flawed interpretation of “nearest suitable”“btw I’m not Just offering my opinion you can confirm with Boeing . Anyway it’s worthy of discussion as there are so many variables, the definition of closest and nearest for example being one of them.

I am sure that your upgrade interview technique involved more than this particular question and scenario and you tried to get an overall picture of a candidates suitability


Jack D 23rd Aug 2019 10:04

Don’t mean to be a pedant but this might clarify in terms of definition of nearest . There are always many variables and considerations and I offer this only as an official FAA ( hence Boeing) definition nothing more.

FAA regulations part 121 sec 121.565 engine inoperative landing reporting

It states nearest suitable airport “ in terms of time “

APU_inop 23rd Aug 2019 11:42


Originally Posted by Landflap (Post 10552295)
Jack ; See ? I was, rather, hoping to avoid this - done to death -discussion. "Nearest suitable" does NOT mean suitable in terms of time -"nothing else". As you say . Oh dear. Land at the nearest suitable means (1) NEAREST in terms of distance . Note any dictionary , (2) SUITABLE refers to things like performance criterior ( Not suitable if the runway is grass-eh ? Maybe concrete but is it long enough ? Is the field, actually, open ? ) etc, etc, etc .

Here's the thing and something for you to ponder. In my last Company's Command Selection Board of which I was a member, we posed the question ; Twin engine, en route to dest, bang, lost a donk OVERHEAD a company regular field. Down the road is another company regular field (Suitable) and with a strong tailwind forecast, you will reach it quicker than descending in the hold for the overhead (nearest, ole mate ,) field. When you inform Company that you are descending in the hold, engine out, mayday procedure for that lovely long, SUITABLE and very familiar airfiled right under your backside, they ask you to go to the en-route because they have a spare engine there & you will be back aloft for destination within six hours. Worse, where you are intending to go is suffering a employment dispute and there is no engine spare holding . What do you do ?

Those bowing to commercial pressure, failing to understand simple terminology like (nearest), failing to have fully grasped the meaning of "suitable" were shown the door. Nearest suitable door, actually.

Boeing elaborates on the "Nearest suitable airport" in detail in both the Boeing 777 FCTM (Non-normal ops 8.3) and in the QRH checklist instructions, none of your assertions have any support there.
These documents provided by the manufacturer are much better than a dictionary from the stationery in the case of an emergency.

Adequate and Suitable aerodromes are not the same.

The crew seem to have solved the emergency in a way that was perfectly safe, legal and at the same time saving millions of dollars when avoiding aircraft and runway damage, blocking a busy runway in a very busy peak hour. Everyone happy except for the mighty PPRUNE investigation board.

Jack D 23rd Aug 2019 11:55


Originally Posted by APU_inop (Post 10552397)
Boeing elaborates on the "Nearest suitable airport" in detail in both the Boeing 777 FCTM (Non-normal ops 8.3) and in the QRH checklist instructions, none of your assertions have any support there.
These documents provided by the manufacturer are much better than a dictionary from the stationery in the case of an emergency.

Adequate and Suitable aerodromes are not the same.

The crew seem to have solved the emergency in a way that was perfectly safe, legal and at the same time saving millions of dollars when avoiding aircraft and runway damage, blocking a busy runway in a very busy peak hour. Everyone happy except for the mighty PPRUNE investigation board.

All correct imho I liked the QRH and FCTM references I added the FAA reference to indicate what is supported by the regulating authority in terms of a definition.. nothing to do with any dictionary definition

Anyway this was interesting and this member of the pprune investigation board is signing off .. and well done to the crew who landed at the nearest suitable and probably closest airport with the minimum of fuss !

casablanca 23rd Aug 2019 15:11

Boeing QRH has term nearest suitable airport which doesn't seem to imply a time.
In case of time critical items like smoke/fire they also use terminology "earliest"/ and 'Immediate" which implies immediate diversion to a runway or in a severe situation flight crew should consider over-weight landing, tailwind landing, or even ditching. This is in the checklist instructions -non normal checklist


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