Final Reserve Fuel

[lutz]

Hi,
I'm looking for additional information/background on different final reserve fuel requirements for domestic vs. international flights in the FAA world (or elsewhere if anyone should be aware...)
Fact check first - my understanding is for FAA, turbo powered aircraft, part 121:
fuel for 30 minutes @ 1.500 feet, holding fuel flow (International)
fuel for 45 minutes @ normal cruise consumption (domestic)

My questions are:
1. Is this correct at all, or did I miss / misunderstand something here?
2. What is the ratio behind it? Coming from the European world, I have a hard time to understand why the final reserve fuel requirements for the same airport and aircraft should differ when you took off on this or the other side of the border...?
3. Are there similar rules imposed by other CAAs?

Thanks!
PS: I had posted a similar question in an other forum, but I think this one is more appropriate... Blame it on my lacking exerience...

[eckhard]

I think the 45 minutes reserve is required under 14 CFR part 91 (private ops), whereas the airline boys get away with just 30 minutes under 14 CFR part 121.

The difference is probably historical in origin. The airlines have dispatch departments and are also required to carry contingency fuel. They also have the concept of 're-clearance' available to them. These disciplines and techniques, coupled with the requirement to keep records, means that the regulations allow them to reduce the final reserve fuel to 30 minutes.

So I don't think the difference is necessarily due to 'international' v. 'domestic', but rather 'private' v. 'airline'.

For a more detailed and up-to-date explanation, refer to e-CFR

edited after re-reading the OP: I guess the longer sectors involved in 'International Ops' meant that the airlines needed the flexibility of a smaller final reserve fuel requirement at the planning stage. I suppose the rationale was partly that the longer sectors would have had more planning input and in-flight monitoring than the shorter domestic ones.

[BOAC]

I guess the longer sectors involved in 'International Ops' ??? West Coast to East Coast = 'domestic' in FAR-land, yes? Cuba to Miami is ???????????????????

[Brian Abraham]

Cuba to Miami is ?????????????International of course BOAC. :E LAX - HNL domestic. (insert scratch head icon)

[MarkerInbound]

Lutz,

1. Yes, those are the correct numbers. I'm guessing you are talking about jet airplanes as the regs break down "turbine engine powered other than turbo-propeller" and "non-turbine and turbo-propeller." I would reference Eckhard to

§ 121.639 Fuel supply: All domestic operations.
No person may dispatch or take off an airplane unless it has enough fuel—
(a) To fly to the airport to which it is dispatched;
(b) Thereafter, to fly to and land at the most distant alternate airport (where required) for the airport to which dispatched; and
(c) Thereafter, to fly for 45 minutes at normal cruising fuel consumption or, for certificate holders who are authorized to conduct day VFR operations in their operations specifications and who are operating nontransport category airplanes type certificated after December 31, 1964, to fly for 30 minutes at normal cruising fuel consumption for day VFR operations.

If he can find a non-tranport category, post 1964 airplane in 121 ops, I'd like to know what it is.

2. Ah, so we can have more questions on tests? These rules were first issued in 1964. You have to keep in mind these are the requirements to start the flight and not a requirement for fuel remaining at block in. Under the Flag Rules, in addition to the 30 minutes is a requirement for enough fuel for 10 percent of the time enroute. So a 3 hour flight would require three hours fuel, plus 18 minutes fuel, plus fuel to the alternate (if required) plus the 30 minutes at 1500 feet. My understanding is because the early 1960s weather reporting and forecasting was not as good as it is now the 10 percent was to account for errors in forecasting. The farther the the plane flew, the more extra fuel required.

We'll skip the "island rule" and redispatching.

3. I have no idea what other CAAs require.

[BOAC]

(insert scratch head icon) - that's two of us scratching, Brian, looking for any logic in the FAR.:)

[MarkerInbound]

LAX - HNL domestic. (insert scratch head icon)
LAX-HNL is Flag per 110.2


Flag operation means any scheduled operation conducted ...
(2) Locations: ...

(ii) Between any point within the 48 contiguous States of the United States or the District of Columbia and any point outside the 48 contiguous States of the United States and the District of Columbia.

There is a provision for the Administrator to grant a waiver to operate under domestic rules on a point to point case.

[BOAC]

Are you saying the 'Flag' reserve requirement is different to the OP, then? You do not mention 'Flag' in your post #5