|
|
|
|
|
Performance data charts on the following pages are presented so that you may know what to expect from the airplane under various conditions, and also, to facilitate the planning of flights in detail and with reasonable accuracy. The data in the charts has been computed from actual flight tests with the airplane and engine in good condition and using average piloting techniques.
It should be noted that the
performance information presented in the range and endurance profile charts
allows for 45 minutes reserve fuel at the specified cruise power. Fuel flow data
for cruise is based on the recommended lean mixture setting. Some indeterminate
variables such as mixture leaning technique, fuel metering characteristics,
engine and propeller condition, and air turbulence may account for variations of
10% or more in range and endurance. Therefore, it is important to utilize all
available information to estimate the fuel required for the particular
flight.
Performance data is presented in
tabular or graphical form to illus trate the effect of different variables.
Sufficiently detailed information is provided in the tables so that conservative
values can be selected and used to determine the particular performance figure
with reasonable accuracy.
The following sample flight problem utilizes information from the various charts to determine the predicted performance data for a typical flight. The following information is known:
AIRPLANE
CONFIGURATION
Takeoff
weight
2600 Pounds
Usable
fuel
44 Gallons
TAKEOFF CONDITIONS
Field pressure
altitude
1500 Feet
Temperature
28 C (16 C above standard)
Wind component along runway 12 Knot
Headwind
Field
length
3500 Feet
CRUISE CONDITIONS
Total
distance
425 Nautical Miles
Pressure
altitude
7500 Feet
Temperature
16 C (16 C above standard)
Expected wind
enroute
10 Knot Headwind
LANDING CONDITIONS
Field pressure
altitude
2000 Feet
Temperature
25 C
Field
length
3000 Feet
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 2650 pounds. pressure altitude of 2000 feet and a
temperature of 30 C should be used and results in the following:
Ground
roll
1410 Feet
Total
distance to clear a 50-foot
obstacle 2380 Feet
These distances are well within the available takeoff field length. However, a correction for the effect of wind may be made based on NoteS of the takeoff chart. The correction for a 12 knot headwind is:
Ground roll, zero
wind
1410
Decrease in
ground roll
(1410
feet
13%)
- 183
Corrected ground
roll
1227 Feet
Total distance to clear a
50-foot obstacle, zero wind
2380
Decrease in total distance
(2380 feet x 13%)
- 309
Corrected total distance
to clear 50-foot obstacle
2071 Feet
|
|
|
|
|