TM 55-1510-221-10
Figure 7-1. Takeoff Flight Path
ISA + 27°C . . . . . . . . . . . . . . . . . . . . . . . .
41% torque per engine
Enter
the
*MAXIMUM
ENDURANCE
POWER 1700 RPM Tables for ISA + 10°C ISA +
20°C and ISA + 30°C at 12,000 pounds and 11,000
pounds at 26,000 feet, and interpolate the fuel flows
for ISA + 17°C and ISA + 27°C at 11,200 pounds.
ISA + 17°C
Fuel Flow Per Engine . . . . . . . . . . . . . . . . . . . . . .
198.75 Lbs/hr
Total Fuel Flow
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
397.50 Lbs/hr
ISA + 27°C
Fuel Flow Per Engine . . . . . . . . . . . . . . . . . . . . . . . .
203.5 Lbs/hr
Total Fuel Flow
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
407 Lbs/hr
NOTE
For flight planning, enter these charts at
the forcasted ISA condition; for enroute
power settings and fuel flows, enter at the
actual indicated FAT.
Time and fuel used were calculated at MAXI-
MUM ENDURANCE POWER 1700 RPM as fol-
lows:
Time =
Fuel Used =
Distance Ground Speed
Distance x Total Fuel Flow
Ground Speed
Results are as follows:
7-13. RESERVE FUEL.
Reserve Fuel is calculated as 45 minutes at Max-
imum Range Power 1700 RPM. Use planned cruise
altitude (26,000 feet), forecasted ISA condition (ISA
+ 27°C) and estimated weight at end of planned
trip (10,309 pounds). (Since the lowest weight col-
umn in the tables is 11,000 pounds, assume weight
at the end of the planned trip to be 11,000 pounds,
and use that fuel flow value for this example.)
Enter the tables for MAXIMUM RANGE
POWER 1700 RPM for ISA + 20°C and ISA +
30°C at 11,000 Lbs and 26,000 feet, and read the
total fuel flows:
ISA + 20°C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
478 Lbs/hr
ISA + 30°C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
448 Lbs/hr
Then interpolate for the fuel flow at ISA + 27°C
as follows:
Change in Fuel Flow = 478 - 448 = 30 Lbs/hr
Change in Temperature = (ISA + 20°C) - (ISA
+ 30°C) = 10°C
Rate of Change in Fuel Flow = Change in Fuel
Flow ÷ Change in Temperature
7-5
