Piper CHEROKEE ARCHER II Pilot Operating Handbook page 66

PIPER AIRCRAFT CORPORATION
PA-28-181, CHEROKEE ARCHER II
(d) Descent
SECTIONS
PERFORMANCE
The descent data will be determined prior to the cruise data to provide the descent distance
for establishing the total cruise distance.
Utilizing the cruise altitude and temperature we determine the basic time, distance and fuel
for descent (Figure 5-25). These figures must be adjusted for the field elevation and temperature
at the destination airport. To find the necessary adjustment values, use the existing altitude and
temperature conditions at the destination airport as variabJes to find the time, distance and fuel
values from the graph (Figure 5-25). Now, subtract the values obtained from the field conditions
from the values obtained from the cruise conditions to find the true time, distance and fuel
values needed for the flight plan.
The values obtained by proper utilization of the graphs for the descent segment of our
example are shown below.
(1)
Time to Descend (17 min. minus 10.5 min.)
(2)
Distance to Descend (40.5 miles minus 25.5 miles)
(3)
Fuel to Descend (1.7 gal. minus 1 gal.)
(e) Cruise
6.5 min.*
15 miles*
.7 gal.*
Using the total distance to be traveled during the flight, subtract the previously calculated
distance to climb and distance to descend to establish the total cruise distance. Refer to the
appropriate Avco Lycoming Operator's Manual when selecting thi cruise power setting. The
established altitude and temperature values and the selected cruise power should now be utilized
to determine the true airspeed from the appropriate Speed Power graph (Figure 5-15 or 5-17).
Calculate the cruise fuel flow for the cruise power setting from the' information provided by
the Avco Lycoming Operator's Manual.
The cruise time is found by dividing the cruise distance by the cruise speed and the cruise
fuel is found by multiplying the cruise fuel flow by the cruise time.
The cruise calculations established for the cruise segment of our flight planning example are
as follows:
(I)
Total Distance
(2)
Cruise Distance
(e)(l) minus (c)(4) minus (d)(2), (360 miles minus
13 miles minus 15 miles)
(3) Cruise Power
(4) Cruise Speed
(5)
Cruise Fuel Consumption
(6) Cruise Time
(e)(2) divided by (e)(4), (332 miles divided by 127 MPH)
(7)
Cruise Fuel
(e)(5) multiplied by (c)(6), (7.6 GPH multiplied by 2.62 hrs.)
*
reference Figure 5-25
**
reference Figure 5-17
ISSUED:
AUGUST
15, 1975
REVISED: MARCH 16,1979
360 miles
332 miles
65'k rated power
127 MPH TAS**
7.6 GPH
2.62 hrs.
19.8 gal.
REPORT:
VB-760
5-5