2.2.3. Isolated Airport Procedure 

For such an airport, there is no destination alternate. The regulatory takeoff fuel quantity must include: 

 Taxi fuel 

 Trip fuel 

Additional fuel: This quantity must be higher than the quantity necessary for a two hour flight at normal cruise consumption. 

2.2.4. Unrequired Destination Alternate Airport 

A destination alternate airport is not required, if the following conditions are met: 

2.2.4.1. Domestic Operations 

“FAR 121.619 

(a) […] However, no alternate airport is required if for at least 1 hour before and 1 hour after the estimated time of arrival at the destination airport the appropriate weather reports or forecasts, or any combination of them, indicate--

(1) The ceiling will be at least 2,000 feet above the airport elevation; and 

(2) Visibility will be at least 3 miles1.” 

2.2.4.2. Flag Operations 

“FAR 121.621 

(1) The flight is scheduled for not more than 6 hours and, for at least 1 hour before and 1 hour after the estimated time of arrival at the destination airport, the appropriate weather reports or forecasts, or any combination of them, indicate the ceiling will be: 

(i) At least 1,500 feet above the lowest circling MDA, if a circling approach is required and authorized for that airport; or 

(ii) At least 1,500 feet above the lowest published instrument approach minimumor 2,000 feet above the airport elevation, whichever is greater; and 

1 Miles stands for Statute Miles (1 mile = 1,609 m). 

(iii) The visibility at that airport will be at least 3 miles, or 2 miles more than thelowest applicable visibility minimums, whichever is greater, for the instrument approach procedures to be used at the destination airport.” 

2.2.5. Redispatch Procedure 

This procedure permits aircraft to carry less contingency fuel than in the standard case. This is interesting in case of fuel capacity, or takeoff limitations. Operators select a point called the decision point along the planned route (Figure I9). At this point, the pilot has two possibilities: 

Reach a suitable proximate diversion airport, taking into account the maximum landing weight limitation. 

Continue the flight to the destination airport, when the remaining fuel is sufficient. 

This procedure is interesting for flag and supplemental operations, for which contingency fuel depends on flight time. The FAR regulation states: 

“FAR 121.631 

(a) A certificate holder may specify any regular, provisional, or refueling airport, authorized for the type of aircraft, as a destination for the purpose oforiginal dispatch or release

(b) No person may allow a flight to continue to an airport to which it has been dispatched or released unless the weather conditions at an alternate airport that was specified in the dispatch or flight release are forecast to be at or above the alternate minimums specified in the operations specifications for that airport at the time the aircraft would arrive at the alternate airport. However, the dispatch or flight release may be amended en route to include any alternate airport that is within the fuelrange of the aircraft […] 

(c) No person may change an original destination or alternate airport that is specified in the original dispatch or flight release to another airport while the aircraft is en route unless the other airport is authorized for that type of aircraft and theappropriate requirements […] are met at the time of redispatch or amendmentof the flight release.” 

Using this procedure, the fuel required is the greatest of: 

F1 = taxiA + tripAC + 10% Trip timeBC + alternateCD + holdingD + Additional 

F2 = taxiA + tripAE + 10% Trip timeAE + alternateEF + holdingF + Additional 

When comparing standard fuel planning to the redispatch procedure fuel planning, the maximum contingency fuel reduction is 10% of the trip time between A and B. 

F1 = taxiA + tripAC +  10% Trip timeBC  + alternateCD + holdingD + Additional 

STD= taxiA + tripAC +  10% Trip timeAC + alternateCD + holdingD + Additional 

2.2.6. ETOPS Procedure 

Similar to JAR ETOPS Procedure (chapter 1.1.6) 

2.2. Fuel Management 

FAR 121 does not provide fuel management rules, but the operating manual has to address appropriate procedures. Operators usually adopt the following rules:

2.2.1 Minimum Fuel at Landing Airport 

The remaining fuel in flight must be sufficient to proceed to an airport where a safe landing can be made. The minimum quantity of remaining fuel at landing is defined in the operating manual, and is usually equivalent to the final reserve (fuel quantity necessary to fly for a period of 30 to 45 minutes at 1,500 feet above the airport in ISA conditions at holding speed).