Figure 4-6 Computing Remaining EFRs

CHAPTER FOUR

T-6A NAVIGATION

Fuel flow for training purposes is based on a NATOPS fuel flow at sea level and 180 KIAS

which is 480 pounds/hour or 8 pounds/minute.

Example: In Figure 4-5, the ETE between points A and B is 8+20 min. At 8 pounds/minute, this

equates to 70 pounds. Subtracting this Figure from an initial fuel quantity at point "A" will give

you the fuel remaining at point "B" (860 - 70 = 790)

Given the data in Figure 4-5, what is the EFR at C? The answer is computed in Figure 4-6.

Using the CR-2 computer, we find 92 pounds of fuel are required to get from B to C. This is

rounded up to 95 pounds, and then subtracted from 790 to get 695 pounds.

A to B:

B to C:

C to D:

108

087

002

DIST

21.5

DIST

34.5

ETE

7+10

ETE

8+20

ETE

11+30

ALT

1500

ALT

1500

ALT

1500

EFR

635

EFR

790

EFR

695

AFR

MCF

BINGO:

Figure 4-6 Computing Remaining EFRs

Compute remaining EFRs for each point of your low-level routing in the same manner. Each

point has EFR and BINGO data, therefore; you will have one information block for each point on

your chart, including the target. The last information block, however, will indicate your first

heading and altitude after completing the low-level route.

Return Enroute EFRs

In order to compute mission completion fuels, we need to compute the EFR at the IAF. Using

the normal thrust climb chart, find the time, fuel, and distance required to climb to planned flight

altitude. For mission planning, assume your climb begins at sea level. Subtract the climb

distance from the total return leg distance to compute cruise distance. Given the following data,

compute the time and fuel required to reach the IAF:

Measured distance from low-level exit to IAF [via flight planned (stereo) route]: 79 NM From

Stereo Route listing: Level off altitude 9000 feet after low-level. EFR at low-level exit point:

480 pounds.

4-6

FUEL PLANNING, JET LOGS, DD 175