SECTION 5
PERFORMANCE
CESSNA
MODEL 172N
CRUISE CONDITIONS
Total distance
Pressure altitude
Temperature
Expected wind enroute
LANDING CONDITIONS
Field pressure altitude
Temperature
Field length
320 Nautical Miles
5500 Feet
20
°
C (16
°
C above standard)
10 Knot Headwind
2000 Feet
25
°
c
3000 Feet
TAKEOFF
The takeoff distance chart, figure 5-4, should be consulted, keeping in
mind that the distances shown are based on the short field technique.
Conservative distances can be established by reading the chart at the next
higher value of weight, altitude and temperature. For example, in this
particular sample problem, the takeoff distance information presented for
a weight of 2300 pounds, pressure altitude of 2000 feet and a temperature of
30
°
C should be used and results in the following:
Ground roll
Total distance to clear a 50-foot obstacle
1045 Feet
1885 Feet
These distances are well within the available takeoff field length. Howev
er, a correction for the effect of wind may be made based on Note 3 of the
takeoff chart. The correction for a 12 knot headwind is:
12 Knots x 10% = 13% Decrease
9 Knots
This results in the following distances, corrected for wind:
5-4
Ground roll, zero wind
Decrease in ground roll
(1045 feet x 13%)
Corrected ground roll
Total distance to clear a
50-foot obstacle, zero wind
Decrease in total distance
(1885 feet
x
13%)
Corrected total distance
to clear 50-foot obstacle
1045
.!a§.
909 Feet
1885
245
1640 Feet
1 July 1979