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Aircraft Performance
The
KOCH Chart for Altitude and Temperature Effects(image)
Density Altitude Chart(image)
Center of Gravity Limits
for Cessna 182(image)
Takeoff Distance Performance
for Cessna 182 #1(image)
Takeoff Distance Performance
for Cessna 182 #2(image)
Pressure Altitude Correction Chart
Sample Weight and Balance for Cessna 182
Procedures for Working
Weight and Balance Sheet
Examples using charts to determine High Density Altitude
Performance
Using KOCH Chart to determine Performance
PRESSURE
ALTITUDE CORRECTION CHART [top]
| ALITITUDE SETTING IN HG. |
ALTITUDE ADDITION FOR
OBTAINING PRESSURE ALTITUDE |
| |
|
| 28.3 |
1,533 |
| 28.4 |
1,436 |
| 28.5 |
1,340 |
| 28.6 |
1,244 |
| 28.7 |
1,148 |
| 28.8 |
1,053 |
| 28.9 |
957 |
| 29.0 |
863 |
| 29.1 |
768 |
| 29.2 |
673 |
| 29.3 |
579 |
| 29.4 |
485 |
| 29.5 |
392 |
| 29.6 |
298 |
| 29.7 |
205 |
| 29.8 |
112 |
| 29.9 |
20 |
| 29.92 |
0 |
| 30.0 |
-73 |
| 30.1 |
-165 |
| 30.2 |
-257 |
| 30.3 |
-348 |
| 30.4 |
-440 |
| 30.5 |
-531 |
| 30.6 |
-622 |
| 30.7 |
-712 |
| 30.8 |
-803 |
Sample Weight
and Balance for Cessna 182 [top]
|
Weight |
Arm |
Moment |
| Empty Weight |
1772 |
35.72 |
63300 |
| Fuel (56 gal. max) |
__________ |
46.0 |
__________ |
| 6# per gallon |
|
|
|
| Pilot & Passenger |
__________ |
37.0 |
__________ |
| Rear Passengers |
__________ |
74.0 |
__________ |
| Baggage A |
__________ |
97.0 |
__________ |
| 120# max |
|
|
|
| Baggage B |
__________ |
115.0 |
__________ |
| 80# max |
|
|
|
| Total Weight
__________ |
Total Moments __________ |
MAXIMUM TAKEOFF WEIGHT-2950#
MAXIMUM
LANDING WEIGHT 2950#
2950 39.5 - 48.5
2400 34.4 - 48.5
2900 39.0 - 48.5
2300 33.4 - 48.5 Total Moment
= CG
2800 38.1 - 48.5
2200 33.0 - 48.5 Total Weight
2700 37.2 - 48.5
2100 33.0 - 48.5
2600 36.2 - 48.5
2000 33.0 - 48.5
2500 35.4 - 48.5
PROCEDURES
FOR WORKING WEIGHT AND BALANCE SHEET [top]
STEP 1- Using
your aircraft's weight and balance information, determine the empty weight
of the aircraft and the ARM for that weight. Multiply the weight times
the ARM and you will get the Moments. If you are only given the Empty
Weight and the Moment, just divide the Moment by the Weight and you will
get the ARM for the empty weight.
STEP 2- Determine
the number of gallons of fuel your aircraft will hold. Refer to the Sample
Loading Problems or your Weight and Balance information and obtain the
ARM for the fuel.
STEP 3- Determine
the ARM for the pilot and front passenger seats, the rear passenger seats
and baggage areas.
STEP 4- Using
your aircraft's Center Of Gravity Limits chart, start at gross weight
and list the CG Limits for that weight. Then proceed down on the CG Limits
chart and determine the forward and aft limits for each 100# of weight.
List those limits at the bottom of the weight and balance sheet you are
developing.
STEP 5- To work
a weight and balance problem, place the weight in each weight category.
Then multiply the Weight times the ARM and record the Moments.
STEP 6- Add up
the total Weight and then add up the total Moments. Your total Weight
should not exceed your gross weight. If so, make adjustments so that the
weight does not exceed gross weight.
STEP 7- Next,
divide the Total Moments by the Total Weight. This will give you a figure
that will tell you the CG location at the calculated weight of the aircraft.
STEP 8- Refer
to the information you recorded on the CG Limits for each weight. If the
CG falls within the limits of the forward and aft limits for that weight,
then your aircraft is loaded within the proper CG Limits. If it does not
fall within the CG Limits, them rearrange the weight so that it does fall
within the proper limits for that weight.
This Weight and
Balance Sheet is aircraft specific. Make one up for each aircraft that
you fly. Then, working a weight and balance problem stops being a problem
as the time required to work this form is less than 3 minutes. Therefore,
there is NO EXCUSE FOR FLYING AN AIRCRAFT OVER GROSS WEIGHT AND OUT
OF CG LIMITS.
BE SURE,
RATHER THAN SORRY
EXAMPLES USING CHARTS
TO DETERMINE HIGH DENSITY ALTITUDE PERFORMANCE IN SAMPLE AIRCRAFT*[top]
Using the charts provided in this section one can
work sample problems to determine aircraft performance.
Example #1
South Lake Tahoe, California-
field elevation 6264 feet MSL.
| Runway length- |
8544 feet |
8544 feet |
| Temperature- |
85º F |
30º C |
| Field elevation- |
6264 feet |
6264 feet |
| Altimeter setting- |
29.92 |
30.00 |
| Pressure Altitude- |
6264 MSL |
6190 MSL |
| Density Altitude- |
9310 feet |
9220 feet |
Example #2
Truckee Airport, Truckee, California-
field elevation 5900 feet MSL.
| Runway length- |
7000 feet |
7000 feet |
| Temperature- |
90º F |
33º C |
| Field Elevation- |
5900 feet |
590 feet |
| Altimeter setting- |
29.92 |
30.00 |
| Pressure Altitude- |
5900 feet |
5826 feet |
| Density Altitude- |
9186 feet |
9096 feet |
Example #3
Gansner Field, Quincy, California-
field elevation 3415 feet MSL
| Runway length- |
4100 feet |
4100 feet |
| Temperature- |
94º F |
33º C |
| Field elevation- |
3415 feet |
3415 feet |
| Altimeter setting- |
29.92 |
30.00 |
| Pressure Altitude- |
3341 feet |
3338 feet |
| Density Altitude- |
6397 feet |
6307 feet |
Example #4
Alpine County Airport, Markleeville, CA-
field elevation 5867 feet MSL
| Runway length- |
4440 feet |
| Temperature- |
90º F |
| Field elevation- |
5867 feet |
| Altimeter setting- |
29.92 |
| Pressure Altitude- |
5867 |
| Density Altitude- |
9146 feet |
| *Note: The temperatures
and altimeter settings shown here represent actual temperatures and
altimeter settings recorded at the above airports. |
USING
KOCH CHART TO DETERMINE PERFORMANCE[top]
|
Example #1
South Lake Tahoe Airport,
Cessna 182.
Takeoff Weight- 2950#
Pressure Altitude- 6264 feet MSL
Temperature- 85º F
Sea level takeoff distance- 1490 feet
% increase in takeoff distance- 200% or 2980 feet
Total takeoff distance- 1490 + 2980 = 4370 feet
% reduction in rate of climb- 70% ( if aircraft climbs at 500 fpm
at sea level then subtract 70% or 350 fpm for a climb rate of just
150 feet per minute.)
Takeoff Weight- 2400#
Pressure Altitude- 6264 feet MSL
Temperature- 85 degrees F
Sea level takeoff distance- 930 feet
% increase in takeoff distance- 200% or 1860 feet
Total takeoff distance- 930 + 1860 = 2790 feet
% reduction in rate of climb- 70% (if aircraft climbs at 700 fpm
at sea level then subtract 70 % or 490 fpm for a climb rate of just
210 feet per minute.)
Example #2
Truckee Airport, Cessna 182.
Takeoff Weight 2950#
Pressure Altitude- 5900 feet MSL
Temperature- 90º F
Sea level takeoff distance- 1650 feet
% increase in takeoff distance- 200% or 3300 feet
Total takeoff distance- 1650 + 3300 = 4960 feet
% reduction in rate of climb- 74% (if aircraft climbs at 500 fpm
at sea level then subtract 74% or 370 fpm for a climb rate of just
130 feet per minute.)
Takeoff Weight 2400#
Pressure Altitude- 5900 feet MSL
Temperature- 90 degrees F
Sea level takeoff distance- 950 feet
% increase in takeoff distance- 200% or 1900 feet
Total takeoff distance- 950 + 1900 = 2850 feet
% reduction in rate of climb- 74% (if aircraft climbs at 700 fpm
at sea level then subtract 74% or 518 fpm for a climb rate of just
182 feet per minute.
Example #3
Gansner Airport, Quincy,
CA
Takeoff Weight- 2950#
Pressure Altitude- 3341 feet MSL
Temperature- 94º F
Sea level takeoff distance- 1540 feet
% increase in takeoff distance- 100% or 1540 feet
Total takeoff distance- 1540 + 1540 = 3080 feet
% reduction in rate of climb- 56% ( if aircraft climbs at 500 fpm
at sea level then subtract 56% or 280 fpm for a climb rate of just
220 feet per minute.)
Takeoff Weight- 2400#
Pressure Altitude- 3341
Temperature- 94 degrees F
Sea level takeoff distance- 960 feet
% increase in takeoff distance- 100% or 960 feet
Total takeoff distance- 960 + 960 = 1920 feet
% reduction in rate of climb- 56% ( if aircraft climbs at 700 fpm
at sea level then subtract 56% or 392 fpm for a climb rate of just
308 feet per minute.)
Example #4
Alpine County Airport, Markleeville,
CA
Takeoff Weight- 2950#
Pressure Altitude- 5867 feet
Temperature- 90º F
Sea level takeoff distance- 1510 feet
% increase in takeoff distance- 180% or 2718 feet
Total takeoff distance- 1510 + 2718 = 4218 feet (Note: Runway length
of 4440’)
% reduction in rate of climb- 72% (if aircraft climbs at 500 fpm
at sea level then subtract 72% or 360 fpm for a climb rate of just
140 fpm.)
Takeoff Weight- 2400#
Pressure Altitude- 5867 feet
Temperature- 90º F
Sea level takeoff distance- 960 feet
% increase in takeoff distance- 180% or 1728 feet
Total takeoff distance- 960 + 1728 = 2688 feet
% reduction in rate of climb- 72% (if aircraft climbs at 700 fpm
at sea level then subtract 72% or 504 fpm for a climb rate of just
196 feet per minute.)
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