TM 1-1510-223-10
At Natrona County International (CPR):
Free Air Temperature ......................................68F
Field Elevation ........................................5348 feet4
Altimeter Setting ................................. 29.27 in. Hg
Wind .............................................330 at 10 knots
Runway 30 Length ..................................8686 feet4
Gradient .................................................. 0 3% up4
4Source: DOD TERM USLIAPV03, 9 JAN 92.
b.
Fahrenheit to Celsius Temperature Conversion .
Convert reported field temperatures at the departure and
destination airports from Fahrenheit to Celsius using the
FAHRENHEIT
TO
CELSIUS
TEMPERATURE
CONVERSION graph. Enter the chart at the appropriate
value on the F scale, read up to the reference line and
left to the corresponding value in C.
Billings-Logan International 59 F ..................... 15C
Natrona County International 68F .................. 20C
c.
Pressure
Altitude.
To
determine
the
approximate pressure altitude at origin and destination
airports, add 1000 feet to field elevation for each 1.00 in.
Hg that the reported altimeter setting value is below
29.92 in. Hg, and subtract 1000 feet for each 1.00 in.
Hg above 29.92 in. Hg. Always subtract 1000 feet for
each 1.00 in. Hg above 29.92 in. Hg. Then multiply the
answer by 1000 to find the difference in feet between
field elevation and pressure altitude.
Pressure Altitude at BIL:
29.92
-30.07
-0.15
-0.15 x 1000 feet = -150 feet
Field Elevation .....................................3649 feet
Pressure Altitude Correction .................-150 feet
Field Pressure Altitude .........................3499 feet
Pressure Altitude at CPR:
29.92
-29.27
+0.65
0.65 x 1000 feet = 650 feet
Field Elevation .........................................5348 feet
Pressure Altitude Correction .....................+650 feet
Field Pressure Altitude .............................5998 feet
d.
Wind Components. Determine the headwind
(tailwind) and crosswind component for the selected
runway. Compute the angle between the reported wind
at Billings-Logan International of 290 and the selected
runway heading of 340 to be 50 . Locate the line for
50 angle between wind direction and flight path on the
graph. Trace along the 50 line and locate the reported
wind speed of 15 knots (the point midway between the
10 and 20 knot wind speed lines). Read left to obtain
the headwind component and down to obtain the
crosswind component.
Headwind Component ...............................10 knots
Crosswind Component ..............................12 knots
e.
Takeoff Weight.
The
following
examples
illustrate the use of graphs which may restrict takeoff
weight.
NOTE
Do not exceed the maximum takeoff
weight limitation of 16,200 pounds.
(1)
Maximum takeoff weight as limited by tire
speed. Enter the graphs at 15 C, 3499 ft, 10 knots
headwind component, and read:
Flaps Up ………...Exceeds Structural Limit of 16,200 lbs
Flaps Approach ...Exceeds Structural Limit of 16,200 lbs
(2)
Maximum
takeoff
weight
to
achieve
positive one-engine-inoperative climb at lift-off. Enter
the graphs at 3499 feet pressure altitude, 15 C, and
read:
Flaps Up ................................................ 16,200 lbs
Flaps Approach ...................................... 16,200 lbs
(3)
Maximum enroute weight for 50-ft/minute
one-engine-inoperative
climb.
To
determine
the
maximum takeoff weight, the weight of the fuel used to
reach the MEA is added to the maximum enroute weight
obtained from the SERVICE CEILING - ONE ENGINE
INOPERATIVE graph. Use the TIME, FUEL, and
DISTANCE to CRUISE CLIMB graph to determine the
weight of the fuel used to climb. Use the CRUISE
POWER tables to determine the weight of the fuel used
to cruise to each MEA.
Enter the SERVICE CEILING - ONE ENGINE INOP-
ERATIVE graph at the conditions for each enroute MEA.
For example, enter the graph at the highest MEA altitude
Change 2 7-5
