Cessna 172R Pilot Operating Handbook page 121

CESSNA
SECTION 5
MODEL 172R
PERFORMANCE
The resultant cruise distance is:
Total distance
320
Climb distance
-12
Cruise distance
308 nm
With an expected 10 knot headwind, the ground speed for cruise is
predicted to be:
109
-10
99 Knots
Therefore, the time required for the cruise portion of the trip is:
308 Nautical Miles
3.1 Hours
99 Knots
The fuel required for cruise is:
3.1 hours X 7.3 gallons/hour = 22.7 Gallons
A 45-minute reserve requires:
45
60
X 7.3 gallons / hour = 5.5 Gallons
The total estimated fuel required is as follows:
Engine start, taxi, and takeoff
1.1
Climb
1.6
Cruise
22.7
Reserve
5.5
Total fuel required
30.9 Gallons
Once the flight is underway, ground speed checks will provide
a
more accurate basis for estimating the time enroute and the
corresponding fuel required to complete the trip with ample reserve.
Dec 2/96
5-7