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cvgpilot
12th Feb 2009, 04:59
Hello,
I'm doing a little research and trying to find out what operators plan for regarding fuel at the equal time points. We are part 91 USA but I'd like advice on commercial, charter, and airlines do.
Part FAR 121.646 indicates 15 minutes of fuel on board. For crash fire and rescue, I've seen a requirement that they ICAO RFSS Category 4. Is it standard alternate minimums or just approach minimums? I don't see a runway length requirement. Does anyone have advice or experience on the technical and legal portion of EPT's? Thanks.

Spooky 2
12th Feb 2009, 05:16
Not sure what kind of an aircraft your operating but you might review the Part 135 ETOPS requirements as most, if not all corporate aircraft will not be able to comply with Part 121 guidelines.

Basically 121 looks at the "critical fuel" scenario which for fuel purposes, and snaps shots the aircraft to 10,000 for the diversion. The APU is running and there are icing considerations applied. This scenario assumes that you had a engine loss combined with a decompression. Most if not all corporate aircraft in oceanic ops have supplemental oxygen which eliminates the 10,000 EO cruise alt, thus they continue to have the range to make a suitable alternate which they may not be able to do at 10,000.

Each operator applies for and receives ETOPS approval based upon any number of variables, so what might work at say Delta, might look a little different at BA, or UAL, etc. although there are basic requirments applied to all.

Sorry for the vague answer but it's hard to put a definitive signature to every operation.

framer
12th Feb 2009, 10:02
Our flight planning depatment run three scenarios from the ETP and the one requiring the most fuel is applied. The 3 scenarios are;
1/Engine failure and descent to appropriate height.
2/ Engine failure and depressurization with descent to 10,000ft
3/ Depressurization, two engines, descent to 10,000ft

Most of the time the 2eng depressurized is the most critical. The flight plan fuel is 'built up' to ensure that at the ETP there is enough fuel to cover the worst of these three scenarios.

Spooky 2
12th Feb 2009, 11:34
Framer is correct. The Biz Jet flight plans typically offer several diffeerent scenarios. My comments were directed towards AC120-42A which while being somewhat dated, is still the basis for the Boeing ETOPS diversion flight planning management. Framer is also correct when he says that the two engine unpressurized at 10,000 will usually burn slightly more that a 1EO diverson.

Google AC120-42A and take a look as there is a lot of good material in there.

Henry VIII
15th Feb 2009, 22:13
I've seen a requirement that they ICAO RFSS Category 4I do confirm, it's the minimum legal RFFS requirement for ETOPS altn.I don't see a runway length requirement. ETOPS altns need to be suitable apt, which means to be adequate and with forecast wx within ETOPS planning minimas.

Here more infos. (http://www.pprune.org/tech-log/362177-etops.html)

As reported at all in that link would add only that planning requirements for ETP Minimum Fuel ceases during the flight, so it's legal to see fuel prediction at ETP below minimum planned.