3 ms·

At at guess, because the maximum landing weight of a A330 is 187,000 kg but the maximum takeoff weight is 242,000 kg. They'd have to burn off fuel before landin

At at guess, because the maximum landing weight of a A330 is 187,000 kg but the maximum takeoff weight is 242,000 kg. They'd have to burn off fuel before landing or risk crushing the landing gear. The A330 doesn't have fuel dumping nozzles as standard equipment so that may not have been an option. Edit: From a slightly dodgy source http://www.pprune.org/tech-log/117765-a330-fuel-consumption.html http://www.pprune.org/tech-log/117765-a330-fuel-consumption.... they'd burn 6 tonnes on takeoff and another ~7 in the 1.5 hours before the engine failed, and approx another 7 before landing but I don't know what the consumption would be like for a single engine return. That gives 20 tonnes total fuel burn. At those figures the 5:40 flight would take 41.5 tonnes of fuel, plus a bit extra.

skykooler 9y ago
So why not circle above the airport it's already near, instead of heading off for another one and just hoping it makes it?
- ubernostrum 9y ago
  If the other engine goes, odds are they're not going to make any airport, even the nearby one, even if they're circling it. If Perth has better facilities for handling the problem, and it's "we'll make it there or we won't make it anywhere", might as well go back to Perth.
- sitharus 9y ago
  That I can't say. Perhaps Perth was a much better equipped airfield. If you're going to hang around in the air for two hours you may as well get somewhere better able to handle your emergency. The chances of a dual engine failure on an ETOPS-240 (240 minutes single engine operation) certified plane are very small.
  - SyneRyder 9y ago
    Perth isn't an airfield, it'a a major city :) For comparison, Learmonth/Exmouth has a population of ~2000 people, Perth has a population of 2 million.
ubernostrum 9y ago
You are almost certainly correct. Getting rid of fuel to get down to max landing weight is a concern any time there's a problem this early in a long flight. And needing to sometimes fly a bit before you can land safely is, well, the whole idea behind ETOPS. For those unfamiliar with the acronym (officially: "ExTended OPerationS", sarcastically: "Engines Turn Or Passengers Swim"), it refers to a certification process for twin-engine aircraft, to demonstrate that they can safely operate far from any airport, since their engine reliability is sufficient to allow extended periods of single-engine flight if and when necessary. An ETOPS rating is given in minutes. For example, ETOPS-60 would mean the plane is approved to fly routes that might require up to 60 minutes of single-engine flying in order to reach a landing site after one engine fails. The Airbus A330 is approved (depending on the exact variant and configuration the airline buys) for either ETOPS-180 or ETOPS-240.
- nayuki 9y ago
  ETOPS is covered in this easy-to-digest video by Wendover Productions: https://www.youtube.com/watch?v=HSxSgbNQi-g https://www.youtube.com/watch?v=HSxSgbNQi-g
  - ubernostrum 9y ago
    I haven't watched that one, but the ones I have watched have been... a bit spotty/incomplete about aviation stuff.
- uhnuhnuhn 9y ago
  You can land safely above maximum landing weight, although it might cause damage to the tires or in extreme cases to the landing gears. Overweight landings are performed frequently[1] in emergencies, especially when an emergency occurs on or right after take-off. There may still have been other overriding reasons not to land at the closest airfield in this case. We just don't know enough yet. [1] http://avherald.com/h?search_term=overweight+landing&opt=0&dosearch=1&search.x=0&search.y=0 http://avherald.com/h?search_term=overweight+landing&opt=0&d...
- sshanky 9y ago
CPAhem 9y ago
The odd issue is why the vibration continue after he shut down the engine? Was it an avionics issue instead? Two previous issues[1] have occurred in the same airspace (near Learmonth) with similar Airbus aircraft from Qantas. "The incident again fueled media speculation regarding the significance of the Harold E. Holt facility, with the Australian and International Pilots Association calling for commercial aircraft to be barred from the area as a precaution until the events are better understood, while the manager of the facility has claimed that it is "highly, highly unlikely" that any interference has been caused." [1] https://en.wikipedia.org/wiki/Qantas_Flight_72#Subsequent_Qantas_Flight_71_incident https://en.wikipedia.org/wiki/Qantas_Flight_72#Subsequent_Qa...
- jwildeboer 9y ago
  The vibration continued because the shut off turbine was windmilling, AFAICS. Nothing you can do. Except reducing airspeed to zero AKA landing the bird.
  - toomuchtodo 9y ago
    Windmilling with an ingested turbine blade :(
cryptonector 9y ago
One would think that fuel dumping nozzles should be required equipment. My other thought as to why they went back is that they could get the aircraft repaired more easily there. Anyways, glad it turned out alright!
- sitharus 9y ago
  It depends on the aircraft. The FAA requires (and therefore every airline that wants to fly to the US has) fuel dumping if the aircraft cannot perform a go-around (aborted landing) after an engine failure. A modern twin-engine aircraft can do this so they omit the complexity and weight of the fuel dumping system. If the worst happens an overweight landing is an option, it's just not desirable. The landing gear should be able to handle it without collapsing but may take significant damage.

skykooler 9y ago

So why not circle above the airport it's already near, instead of heading off for another one and just hoping it makes it?

ubernostrum 9y ago
If the other engine goes, odds are they're not going to make any airport, even the nearby one, even if they're circling it. If Perth has better facilities for handling the problem, and it's "we'll make it there or we won't make it anywhere", might as well go back to Perth.
sitharus 9y ago
That I can't say. Perhaps Perth was a much better equipped airfield. If you're going to hang around in the air for two hours you may as well get somewhere better able to handle your emergency. The chances of a dual engine failure on an ETOPS-240 (240 minutes single engine operation) certified plane are very small.
- SyneRyder 9y ago
  Perth isn't an airfield, it'a a major city :) For comparison, Learmonth/Exmouth has a population of ~2000 people, Perth has a population of 2 million.

ubernostrum 9y ago

You are almost certainly correct. Getting rid of fuel to get down to max landing weight is a concern any time there's a problem this early in a long flight. And needing to sometimes fly a bit before you can land safely is, well, the whole idea behind ETOPS. For those unfamiliar with the acronym (officially: "ExTended OPerationS", sarcastically: "Engines Turn Or Passengers Swim"), it refers to a certification process for twin-engine aircraft, to demonstrate that they can safely operate far from any airport, since their engine reliability is sufficient to allow extended periods of single-engine flight if and when necessary. An ETOPS rating is given in minutes. For example, ETOPS-60 would mean the plane is approved to fly routes that might require up to 60 minutes of single-engine flying in order to reach a landing site after one engine fails. The Airbus A330 is approved (depending on the exact variant and configuration the airline buys) for either ETOPS-180 or ETOPS-240.

nayuki 9y ago
ETOPS is covered in this easy-to-digest video by Wendover Productions: https://www.youtube.com/watch?v=HSxSgbNQi-g https://www.youtube.com/watch?v=HSxSgbNQi-g
- ubernostrum 9y ago
  I haven't watched that one, but the ones I have watched have been... a bit spotty/incomplete about aviation stuff.
uhnuhnuhn 9y ago
You can land safely above maximum landing weight, although it might cause damage to the tires or in extreme cases to the landing gears. Overweight landings are performed frequently[1] in emergencies, especially when an emergency occurs on or right after take-off. There may still have been other overriding reasons not to land at the closest airfield in this case. We just don't know enough yet. [1] http://avherald.com/h?search_term=overweight+landing&opt=0&dosearch=1&search.x=0&search.y=0 http://avherald.com/h?search_term=overweight+landing&opt=0&d...
sshanky 9y ago

CPAhem 9y ago

The odd issue is why the vibration continue after he shut down the engine? Was it an avionics issue instead? Two previous issues[1] have occurred in the same airspace (near Learmonth) with similar Airbus aircraft from Qantas. "The incident again fueled media speculation regarding the significance of the Harold E. Holt facility, with the Australian and International Pilots Association calling for commercial aircraft to be barred from the area as a precaution until the events are better understood, while the manager of the facility has claimed that it is "highly, highly unlikely" that any interference has been caused." [1] https://en.wikipedia.org/wiki/Qantas_Flight_72#Subsequent_Qantas_Flight_71_incident https://en.wikipedia.org/wiki/Qantas_Flight_72#Subsequent_Qa...

jwildeboer 9y ago
The vibration continued because the shut off turbine was windmilling, AFAICS. Nothing you can do. Except reducing airspeed to zero AKA landing the bird.
- toomuchtodo 9y ago
  Windmilling with an ingested turbine blade :(

cryptonector 9y ago

One would think that fuel dumping nozzles should be required equipment. My other thought as to why they went back is that they could get the aircraft repaired more easily there. Anyways, glad it turned out alright!

sitharus 9y ago
It depends on the aircraft. The FAA requires (and therefore every airline that wants to fly to the US has) fuel dumping if the aircraft cannot perform a go-around (aborted landing) after an engine failure. A modern twin-engine aircraft can do this so they omit the complexity and weight of the fuel dumping system. If the worst happens an overweight landing is an option, it's just not desirable. The landing gear should be able to handle it without collapsing but may take significant damage.