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Fly A to B, make an approach to the minima, missout and then divert to an alternate C and then hold at the alternate for 30 mins at 1500ft and then land with 30 mins fuel remaining?
What is the fuel flow that the 30 mins fuel remaining, is based on?
Since the NBAA is an US association I'm pretty sure it is in accordance with FAR 91.167 or 135.223.
Sec. 91.167 - Fuel requirements for flight in IFR conditions.
(a) No person may operate a civil aircraft in IFR conditions unless it carries enough fuel (considering weather reports and forecasts and weather conditions) to --
(1) Complete the flight to the first airport of intended landing;
(2) Except as provided in paragraph (b) of this section, fly from that airport to the alternate airport; and
(3) Fly after that for 45 minutes at normal cruising speed or, for helicopters, fly after that for 30 minutes at normal cruising speed.
(b) Paragraph (a)(2) of this section does not apply if:
(1) Part 97 of this chapter prescribes a standard instrument approach procedure to, or a special instrument approach procedure has been issued by the Administrator to the operator for, the first airport of intended landing; and
(2) Appropriate weather reports or weather forecasts, or a combination of them, indicate the following:
(i) For aircraft other than helicopters. For at least 1 hour before and for 1 hour after the estimated time of arrival, the ceiling will be at least 2,000 feet above the airport elevation and the visibility will be at least 3 statute miles.
(ii) For helicopters. At the estimated time of arrival and for 1 hour after the estimated time of arrival, the ceiling will be at least 1,000 feet above the airport elevation, or at least 400 feet above the lowest applicable approach minima, whichever is higher, and the visibility will be at least 2 statute miles
Sec. 135.223 IFR: Alternate airport requirements.
(a) Except as provided in paragraph (b) of this section, no person may operate an aircraft in IFR conditions unless it carries enough fuel (considering weather reports or forecasts or any combination of them) to--
(1) Complete the flight to the first airport of intended landing;
(2) Fly from that airport to the alternate airport; and
(3) Fly after that for 45 minutes at normal cruising speed or, for helicopters, fly after that for 30 minutes at normal cruising speed.
(b) Paragraph (a)(2) of this section does not apply if Part 97 of this chapter prescribes a standard instrument approach procedure for the first airport of intended landing and, for at least one hour before and after the estimated time of arrival, the appropriate weather reports or forecasts, or any combination of them, indicate that--
(1) The ceiling will be at least 1,500 feet above the lowest circling approach MDA; or
(2) If a circling instrument approach is not authorized for the airport, the ceiling will be at least 1,500 feet above the lowest published minimum or 2,000 feet above the airport elevation, whichever is higher; and
(3) Visibility for that airport is forecast to be at least three miles, or two miles more than the lowest applicable visibility minimums, whichever is the greater, for the instrument approach procedure to be used at the destination airport.
You were closer than mha--it is to the destination, fly an approach, miss, hold for 5 mins at 5,000 AFL for clearance to alternate, fly to, approach and land at the alternate with 30 minutes of fuel at 1,500 AFL at holding speed, all under no-wind, ISA temps. The data is right out of the AFM, perfect climb on the recommended climb schedule, cruise at LRC or "normal" cruise as spec'd by the manufacturer, descent at optimum descent point, etc. There are no allowances for ATC delays, less than optimum flight levels, vectors, etc.
NBAA IFR reserves are quoted as the amount of fuel required for the following profile:
- a 5 minute approach at sea level
- climb to 5000 feet
- a 5 minute hold at 5000ft
- climb to cruise altitude for the diversion to alternate
- cruise at long range power
- descend to sea level
- land with 30 mins of holding fuel at 5000ft.
The CJ2 Flight planning guide gives NBAA IFR reserves for alternates at 100,200 and 300nm using the above profile.
Most bizjet OEMs are using the range based on the NBAA profile with a 100 nm alternate, gives a nicer range number. In years past, the standard for jets was a 200nm alternate, but marketing won.
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