Cessna SkyHawk SP 172S NAV III 2005 Pilot Operating Handbook page 167

CESSNA
MODEL 172S NAV '"
FUEL REQUIRED (Continued)
SECTIONS
PERFORMANCE
With an expected 10 knot headwind, the ground speed for cruise is
predicted to be:
117
-10
107 Knots
r
Therefore, the time required for the cruise portion of the trip is:
342 Nautical Miles
=
3.2 Hours
107 Knots
r'.
\
The fuel required for cruise is:
3.2 hours X 8.9 gallonslhour
=
28.5 Gallons
A 45-minute reserve requires:
45
60
X
8.9 gallons
I
hour
=
6.7 Gallons
The total estimated fuel required is as follows:
Engine start, taxi, and takeoff
Climb
Cruise
Reserve
Total fuel required
1.4
2.6
28.5
6.7
39.2 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.
172SPHAUS-00
U.S. 5-7