QF-EK broken promises

[Infrequent]

(Answered my own question ... no bearing on this thread ... back to normal service ...)

 

[samh004]

perhaps not my best worded post: ETOPS definitions are not local; the ability to fly an aircraft using ETOPS requires both airframe certification and airline certifcation. CASA has certainly allowed ETOPS for Australian air operators (e.g. virgin MEL-JNB). The problem with that route was that the flight time was much longer than for 4 engine aircraft and the route was axed. That does not apply to most (not all) routes that QF flies.

This is off topic, but I do believe ETOPS played a critical roll in VA's JNB service failing. The reason the flight time was longer was because ETOPS restrictions made them fly a different route to the 4-engines 747. They were required to fly closer to a diversion point if they lost an engine, but the 747 would still have 3 so it was not. So I believe ETOPS really did play a role, as I understand it.

 

[jb747]

With regard to ETOPs.... The standard varies for different aircraft. The QF 767-300s were 180 minutes, but the -200s were 120. The 787 is very long time...pretty much to the point that it's not really limiting. The ETOPs time limit defines the distance that the aircraft can be from a usable adequate airport. It doesn't have to be a main or destination, but it has to be something that you could actually get into. The weather has to be accounted for as well. The speed is at single engine speed and altitude.

But, ETOPs isn't the only limit. You must also allow for depressurisation. In that case, it's a descent to 14,000' until the oxygen runs out, then the rest of the way at 10,000'. This can be extremely limiting, especially in an aircraft that has oxygen generators instead of gaseous oxygen.

And...you also have to account for the loss of an engine at any point along the route. This is much less limiting in a quad, because, although you're actually more likely to have a failure, the cost is only in the region of 10-15% more fuel flow, whereas the twins are more like 30%.

These are all separate limits, and all have to be accounted for.

 

[dairyfloss]

With regard to ETOPs.... The standard varies for different aircraft. The QF 767-300s were 180 minutes, but the -200s were 120. The 787 is very long time...pretty much to the point that it's not really limiting. The ETOPs time limit defines the distance that the aircraft can be from a usable adequate airport. It doesn't have to be a main or destination, but it has to be something that you could actually get into. The weather has to be accounted for as well. The speed is at single engine speed and altitude.

But, ETOPs isn't the only limit. You must also allow for depressurisation. In that case, it's a descent to 14,000' until the oxygen runs out, then the rest of the way at 10,000'. This can be extremely limiting, especially in an aircraft that has oxygen generators instead of gaseous oxygen.

And...you also have to account for the loss of an engine at any point along the route. This is much less limiting in a quad, because, although you're actually more likely to have a failure, the cost is only in the region of 10-15% more fuel flow, whereas the twins are more like 30%.

These are all separate limits, and all have to be accounted for.

Now, I'm pretty nifty with a spreadsheet, jb747... but this one must be a doozy!

Cheers,
Matt.

 

[katiebell]

This is off topic, but I do believe ETOPS played a critical roll in VA's JNB service failing. The reason the flight time was longer was because ETOPS restrictions made them fly a different route to the 4-engines 747. They were required to fly closer to a diversion point if they lost an engine, but the 747 would still have 3 so it was not. So I believe ETOPS really did play a role, as I understand it.

OT but also what I read in the aviation lit.

 

[medhead]

Sorry how is Etops discussion off topic. The OP has raised fleet selection choices in this wide ranging discussion, ETOPS requirements are surely an integral part of those decisions.

 

[Anna]

What are ETOPS anyway?

 

[jb747]

What are ETOPS anyway?

https://en.wikipedia.org/wiki/ETOPS

 

[BAM1748]

What are ETOPS anyway?

For the crew to see on their walk around.....
https://www.flickr.com/photos/15264656@N02/23053500985/in/album-72157624589171835/

 

[Himeno]

What are ETOPS anyway?

Something not all aircraft have, but is generally needed for 2 engine aircraft (and sometimes 4) in order to legally fly more then an hour away from a suitable airfield.

Only some of AA's A321 fleet has ETOPS. Those ETOPS rated A321s are used for their flights to Hawaii. A few months ago, they got in trouble for using a non rated aircraft for a HNL flight by mistake. (They had a last minute aircraft swap and forgot to make sure the new aircraft had the needed rating)