getting to grips with aircraft performance 如何掌握飞机性能 2(29)

1.1.3. Unrequired Destination Alternate Airport

An alternate airport is not required, when all of the following conditions are met:
.  
Flight time does not exceed 6 hours from takeoff to landing

.  
At the destination airport, two separate runways1 are available

.  
From one hour before to one hour after the Estimated Time of Arrival (ETA) a VMC (Visual Meteorological Condition) approach and landing can be made from the minimum altitude sector.

1.1.4. Decision Point Procedure

This procedure permits aircraft to carry less contingency fuel than in the standard case.
Operators select a point called the decision point along the planned route (Figure I2). At this point, the pilot has two possibilities:
1 Separate runways: Separate landing surfaces which do not overlay or cross such that if one of the runways is blocked, it will not prevent the plane type from operating on the other one, and each has a separate approach procedure based on a separate aid

.  
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.

Using this procedure, the fuel required is the greatest of:
“AMC OPS 1.255 [F1:] sum of
.  
Taxi fuel;

.  
Trip fuel to the destination aerodrome, via the decision point;

.  
Contingency fuel equal to not less than 5% of the estimated fuel consumption from the decision point to the destination aerodrome;

.  
Alternate fuel, if a destination alternate is required;

.  
Final reserve fuel;

.  
Additional fuel; and

.  
Extra fuel if required by the commander; or,

[F2:] sum of

.  
Taxi fuel;

.  
The estimated fuel consumption from the departure aerodrome to a suitable en-route alternate, via the decision point;

.  
Contingency fuel equal to not less than 3% of the estimated fuel consumption from the departure aerodrome to the en-route alternate;

.  
Final reserve fuel;

.  
Additional fuel; and

.  
Extra fuel if required by the commander.”

Which gives:
F1 = taxiA + tripAC + 5% tripBC + alternateCD + holdingD + additional + extra
F2 = taxiA + tripAE + 3% tripAE +  holdingE + additional + extra

Comparing the standard fuel planning and the decision point procedure fuel planning, the maximum contingency fuel reduction is 5% of the trip fuel between A and B.

F1 = taxiA + tripAC +  5% tripBC + alternateCD + holdingD + additional + extra STD= taxiA + tripAC +  5% tripAC  + alternateCD + holdingD + additional + extra
1.1.5. Pre-Determined Point Procedure
　
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