"Air Asia X" not "Air Asia" (technically different companies)
I'm quite surprised with a catastrophic engine failure that they didn't divert to the much much closer RAAF Learmonth's long runway (3000+m), vs turning around and flying for another 2 hours back to Perth. Most airlines have a policy for "nearest suitable airport" for this kind of failure.
http://flightaware.com/live/flight/XAX237/history/20170624/2250Z/YPPH/WMKKFrom the Wikipedia page for
https://en.wikipedia.org/wiki/RAAF_Learmonth, it's actually not unusual for a divert
On 7 October 2008, Qantas Flight 72 made an emergency landing at RAAF Learmonth.
On 1 June 2012, an AirAsia X flight to Perth made an emergency landing at RAAF Learmonth for fuel refilling.
Learmonth is designated an emergency alternative airport in the case of fog or bad weather affecting Perth Airport.
An AirAsia X Airbus A330-300, registration 9M-XXE performing flight D7-237 from Perth,WA (Australia) to Kuala Lumpur (Malaysia) with 359 people on board, was enroute at FL380 about 200nm southsouthwest of Learmonth,WA (Australia) when the left hand engine (Trent 772) suffered a blade fracture, ingested the blade resulting in severe damage in engine core and severe vibrations. The crew shut the engine down, drifted the aircraft down to FL200 and returned to Perth for a safe landing about 2 hours after the engine failure.
Passengers reported a large bang was heard followed by severe vibrations and sounds like a spinning washing machine. They were instructed to brace for landing.
Australia's emergency services reported they put their marine emergency services on stand by for a possible water landing of the aircraft north of Perth.
The airline reported the aircraft returned to Perth due to a technical problem without confirming an engine issue. Emergency services were called as precaution only as part of the standard operating procedures. The passengers were rebooked onto other flights.
http://avherald.com/h?article=4aac9f14&opt=0
Odd to leave that engine running ?
What is the failure mode on an "engine seizure"?
Can A330 fly with one ? I would think so for water certification.
Engine fan was wind milling, not seized. Aircraft may have flown at high speed too.
Can A330 fly with one ? I would think so for water certification.
A330 is certified for ETOPS-240 since Nov 2009, coincidentally the same month the aircraft concerned (9M-XXE) entered service.
https://en.wikipedia.org/wiki/ETOPSEngine fan was wind milling, not seized. Aircraft may have flown at high speed too.
Playback of the flight is available at
https://www.flightradar24.com/data/flights/d7237/#dda2d15You can see it descends to 24,000ft, later 20,000 and maintains airspeed.
Like Boffin said, it is surprising the flight didn't divert to Learmonth.
didn't divert to Learmonth
It certainly was shaking pretty good going from that video, but unfortunately that's not the only factor in deciding where to go.
A landing at Learmonth would make life much more difficult for everybody involved, it's not a simple fuel up and away you go job as it would be for a low fuel emergency, it's an engine replacement for a start and full airframe inspection I would expect having been subjected to that sort of vibration stress, the plane is not going anywhere for quite some time I expect. You also have to get the passengers sorted out, get a replacement aircraft to Learmonth to replane them, or some alternative means to Perth, accommodation, they are probably going to have to re-enter and exit Australia customs whatever the case which might be a problem at an RAAF base...
didn't divert to Learmonth
It certainly was shaking pretty good going from that video, but unfortunately that's not the only factor in deciding where to go.
A landing at Learmonth would make life much more difficult for everybody involved, it's not a simple fuel up and away you go job as it would be for a low fuel emergency, it's an engine replacement for a start and full airframe inspection I would expect having been subjected to that sort of vibration stress, the plane is not going anywhere for quite some time I expect. You also have to get the passengers sorted out, get a replacement aircraft to Learmonth to replane them, or some alternative means to Perth, accommodation, they are probably going to have to re-enter and exit Australia customs whatever the case which might be a problem at an RAAF base...
Actually the SOP for most airlines (and aircraft) for "one engine loss on a twin-engined aircraft" would say "land immediately at nearest suitable airport". Learmonth is certainly "suitable", with a 3000+m runway; existing commercial aviation facilities (although not large). Making it convenient for the owner of the aircraft shouldn't come into it.
For this reason, there's actually quite a few diversions to CYFB (Iqaluit, Canada), despite being near nothing.
Making it convenient for the owner of the aircraft shouldn't come into it.
Air Asia X is a very budget airline.
Not a single pilot will make decision in case of emergency based on money.
...
Going back to Sydney means bigger airport, better infrastructure (4km runway vs 3km, better emergency crew, home airline engineer, etc.), less or no fuel to dump, and likely, better pilot-airport familiarity.
Putting aside that you also are confusing Sydney with Perth (those two cities are about 4000 kilometers apart, further than Beijing to New Delhi), aviation is a tough cut throat business, pilots are quietly under pressure from company all the time, especially in the budget sector of the industry.
As you say yourself, factors like "home airline engineer" absolutely do factor into diversions where possible, and that's not a safety consideration, it's a financial/convenience/company one.
At the end of the day, there will be an investigation and report on the incident, which will certainly include analysis of the pilot's decision to return to Perth instead of other options.
Image from PPRUNE thread (unauthenticated as to if it's actually from this incident).
http://www.pprune.org/australia-new-zealand-pacific/596307-merged-air-asia-turnback-perth-25-jun-17-a-5.html
There will be an investigation, and I'm pretty sure 2 years from now when it comes out, you'll read that the Australian Transport Safety Bureau will report negatively on the pilot/company's decision to discount Learmonth, and instead head all the way back to Perth.
A landing at Learmonth would make life much more difficult for everybody involved, it's not a simple fuel up and away you go job as it would be for a low fuel emergency, it's an engine replacement for a start and full airframe inspection I would expect having been subjected to that sort of vibration stress, the plane is not going anywhere for quite some time I expect. You also have to get the passengers sorted out, get a replacement aircraft to Learmonth to replane them, or some alternative means to Perth, accommodation, they are probably going to have to re-enter and exit Australia customs whatever the case which might be a problem at an RAAF base...
I was working at Learmonth a couple of weeks ago, there is a small terminal building on the Gulf (East) side of the landing strip and the RAAF base is on the West side of the strip. The RAAF base is a "bare base" so whilst there is a massive airstrip and lots of dispersal areas for military aircraft there is not much else around and a handful of people on site, Wikipedia sums it up nicely:
https://en.wikipedia.org/wiki/RAAF_bare_basesA big factor in their decision making may have been that there are no ARFF facilities available at the airport, they are only brought in by the RAAF when the base is made operational.
And for the discussion of why they don't just land as near as possible, I guess that's for safety reason. Not a single pilot will make decision in case of emergency based on money.
Going back to Sydney means bigger airport, better infrastructure (4km runway vs 3km, better emergency crew, home airline engineer, etc.), less or no fuel to dump, and likely, better pilot-airport familiarity.
Sure, but
two hours extra flight time with that vibration?
Would seem like a no-brainer to me, get it on the ground ASAP.
Another possible solution to the vibration problem would be to break off a turbine blade at the other side of the fan, thereby restoring the balance***.
Finding a hacksaw and a volunteer to go out on the wing might be a problem though.
EDIT:
*** Yes, I am joking.
Another possible solution to the vibration problem would be to break off a turbine blade at the other side of the fan, thereby restoring the balance***.
Finding a hacksaw and a volunteer to go out on the wing might be a problem though.
EDIT:
*** Yes, I am joking.
It has happened....
https://en.wikipedia.org/wiki/Norman_Cyril_JacksonThis chap earned the Victoria Cross (highest award for gallantry) for going out onto the wing of a Lancaster bomber with a fire extinguisher to fight a fuel tank fire.
Tractors, oh tractors, there are so much fun
Tractors, oh tractors, they get the job done
Tractors work all day, tractors work all night
Got to bale the hay, got to bale it tight
The worst part could be the captain admitting that he was scared and asking the passengers to pray.
And for the discussion of why they don't just land as near as possible, I guess that's for safety reason. Not a single pilot will make decision in case of emergency based on money.
Going back to Sydney means bigger airport, better infrastructure (4km runway vs 3km, better emergency crew, home airline engineer, etc.), less or no fuel to dump, and likely, better pilot-airport familiarity.
Sure, but two hours extra flight time with that vibration?
Would seem like a no-brainer to me, get it on the ground ASAP.
It doesn't seem the vibration was much different than some air turbulence.
Airlines really do have to consider what will happen after the plane puts down. There were over 300 passengers on board; there need to be facilities on the ground to look after them (food, lodgings, people, etc.), a way to evacuate the passengers and get them on their way, and facilities to repair the airplane and get it back in the air.
All of these things affect a decision about where to divert to. Given that such aircraft are fully certified to fly with one engine and that this was not a life threatening emergency, the captain probably made an appropriate decision by the book.
Airlines really do have to consider what will happen after the plane puts down. There were over 300 passengers on board; there need to be facilities on the ground to look after them (food, lodgings, people, etc.), a way to evacuate the passengers and get them on their way, and facilities to repair the airplane and get it back in the air.
All of these things affect a decision about where to divert to. Given that such aircraft are fully certified to fly with one engine and that this was not a life threatening emergency, the captain probably made an appropriate decision by the book.
What do you mean by "such aircraft are fully certified to fly with one engine"? Following an engine failure, or engine shut down, the Airbus A330 has to land at the nearest suitable airport.
An engine failure on a twin engine aircraft is an emergency. The aircraft performance is highly degraded on one engine.
In today's world, the crew will contact the airline while still in the air. The airline will try to convince the captain to fly to an airport deserved by the airline, exactly for the reasons you gave. But if this turn out to be a bad decision; the captain will blamed.
At a small airline I flew for, there was a crew that had to face a cabin smoke/fire. The crew was able to put the smoke/fire out. They overflew a small town airport with no facilities and decided to continue to the main base, which was about 10 minutes away. The plane landed uneventfully. The captain was blamed (by the airline) of having placed the passengers in danger and was downgraded to first officer.
The choice of the nearest suitable airport should not be influenced by the passengers comfort once on the ground, or access to repair facilities. "suitable airport" is in reference to the aircraft capabilities and pilots workload; it is easier to make an approach to a runway when you have local knowledge of this particular airport. Of course, the type of emergency would play a big role in the decision.
Should a Boeing 747 continues to fly after an engine failure? The story of British Airways flight 268:
https://en.wikipedia.org/wiki/British_Airways_Flight_268 
What do you mean by "such aircraft are fully certified to fly with one engine"? Following an engine failure, or engine shut down, the Airbus A330 has to land at the nearest suitable airport.
An engine failure on a twin engine aircraft is an emergency. The aircraft performance is highly degraded on one engine.
Oh, then I stand corrected. Perhaps I should have said "fully able to fly with one engine".
If an engine failure on a twin engine aircraft is an emergency, what should we call an engine failure on a single engine aircraft?
What do you mean by "such aircraft are fully certified to fly with one engine"? Following an engine failure, or engine shut down, the Airbus A330 has to land at the nearest suitable airport.
An engine failure on a twin engine aircraft is an emergency. The aircraft performance is highly degraded on one engine.
Oh, then I stand corrected. Perhaps I should have said "fully able to fly with one engine".
If an engine failure on a twin engine aircraft is an emergency, what should we call an engine failure on a single engine aircraft?
Twin engine airliners do not have two engines for redundancy; they have two engines out of necessity.
In North America (in Canada at least), there are only two single engine aircraft that I know of that can legally carry passengers in commercial operation (Air Taxi type of operation); the Pilatus PC-12 and the Cessna Caravan. And this is because they both fly behind the very reliable Pratt & Whitney PT-6.
In a perfect world, all single engine aircraft pilots would take into consideration the possibility of engine failure when they plan their route.
Glider. People have glided planes as big as a 767, though nobody ever wanted to do so.
B767 and A330 were both glided, to successful landings; by Canadian crews
What do you mean by "such aircraft are fully certified to fly with one engine"? Following an engine failure, or engine shut down, the Airbus A330 has to land at the nearest suitable airport.
An engine failure on a twin engine aircraft is an emergency. The aircraft performance is highly degraded on one engine.
Oh, then I stand corrected. Perhaps I should have said "fully able to fly with one engine".
Many years ago, I was privileged to be part of a group that was given a ground tour of a 747. After walking past a 707, this thing looked HUGE ... and so did the engines.
Inside, we had a ground engineer escort us around and I had an opportunity to sit in the co-pilot's seat - and under the direction of the engineer, pushed some buttons! One of those brought up a display showing the air pressure in every one of the tyres. Very cool.
We then talked about the engines - and we were told that the 747 only needs the four engines to take off. So, yeah, it needs 4 engines. A fully laden Jumbo can fly and land on 2 - and an empty one on a single engine. So having these capabilities and knowing about them is essential in being able to assess a course of action in an emergency. They are not something you should plan on.
I asked what happens if, say, two engines failed on the same side of the aircraft - obviously curious on the resulting yaw moment. The reply came: "That's when the pilots earn their money".
It would seem very clear designing such capabilities into aircraft - especially passenger carrying commercial aircraft - has been around for a very long time. Further, inasmuch as much as we have had examples of aerial mechanics, that is not the norm. Problems need to be managed in the air since you can't just "pull over".
