Par 10-18 Page 10-13 Items added forward of the datum:
( + ) weight x (-) arm = (-) moment.
Items added to the rear of the datum:
( + ) weight x ( + ) arm = ( + ) moment.
Items removed forward of the datum:
(-) weight x (-) arm = ( + ) moment.
Items removed rear of the datum:
(-) weight x ( + ) arm = (-) moment.
(3) The total weight of the airplane is equal to the weight of the empty aircraft plus the weight of the items added minus the weight of the items removed.
(4) The total moment of the aircraft is the algebraic sum of the empty weight moment of the aircraft and all of the individual moments of the items added and/or removed.
10-19. W&B EXTREME CONDITIONS. The W&B extreme conditions represent the maximum forward and rearward CG position for the aircraft. Include the W&B data information showing that the CG of the aircraft (usually in the fully loaded condition) falls between the extreme conditions.
a. Forward W&B Check. When a forward W&B check is made, establish that neither the maximum weight nor the forward CG limit listed in the TCDS and Aircraft Specifications are exceeded. To make this check, the following information is needed:
(1) The weights, arms, and moment of the empty aircraft.
(2) The maximum weights, arms, and moments of the items of useful load that are located ahead of the forward CG limit.
(3) The minimum weights, arms, and moments of the items of useful load that are located aft of the forward CG limit. A typical example of the computation necessary to make this check, using this data, is shown in Figure 10-10.
b. Rearward W&B Check. When a rearward W&B check is made, establish that neither the maximum weight nor the rearward CG limit listed in the TCDS and Aircraft Specifications are exceeded. To make this check, the following information is needed:
(1) The weight, arms, and moments of the empty aircraft.
(2) The maximum weights, arms, and moments of the items of useful load that are located aft of the rearward CG limit.
(3) The minimum weights, arms, and moments of the items of useful load that are located ahead of the rearward CG limit. A typical example of the computation necessary to make this check, using this data, is shown in Figure 10-11.
FIGURE 10-10. EXAMPLE OF CHECK OF MOST FORWARD WEIGHT AND
BALANCE EXTREME
- DATUM
- NO BAGGAGE
NO PASSENGERS
FULL OIL -MINIMUM FUEL -PILOT ONLY FORWARD C.G. LIMIT TO CHECK: MOST FORWARD WEIGHT AND BALANCE EXTREME.
GIVEN:
Actual empty weight of the aircraft - 1169# Empty weight center of gravity- -+ 10.6" *Maximum weight- --2100# *Forward C.G.. limit - + 8.5" *Oil capacity. 9 qts. - - 17# at -49" *Pilot in farthest forward seat equipped with controls (unless otherwise placarded) -- - 170# at +16" *Since the fuel tank is located to the rear of the forward C.G. limit, munimum fuel should be included.
METO HP = 165 = 13.75 gal. x 64. -- 83# at +22" 12 12 * Information should be obtained from the aircraft specification.
Note: Any items or passengers must be used if they are located ahead of the forward C.G. limit.
Full fuel must be used if the tank is located ahead of the forward C.G. limit.
CHECK OF FORWARD WEIGHT AND BALANCE EXTREME Weight (#) x Arm (*) = Moment (*#) Aircraft empty + 1169 + 10.6 + 12391 + 17 - 49 833 Pilot + 170 + 16 + 2720 Fuel + 83 + 22 + 1826 Total + 1439 (TW) + 16104 (TM) Divide the TM (total moment) by the TW (total weight) to obtain the forward weight and balance extreme.
IM = 16104 = + 11.2" TW 1439 Since the forward C.G. limit and the maximum weight are not exceeded, the forward weight and balance extreme condition is satisfactory.
Par 10-19 Page 10-14
FIGURE 10-11. EXAMPLE OF CHECK OF MOST REARWARD WEIGHT AND
BALANCE EXTREME -DATUM
- MAXIMUM BAGGAGE
- MAXIMUM PASSENGERS FULL OIL→ MAXIMUM FUEL PILOT ONLY REARWARD C.G. LIMIT TO CHECK: MOST REARWARD WEIGHT AND BALANCE EXTREME.
GIVEN:
Actual empty weight of the aircraft • 1169# Empty weight center of gravity- • 10.6" *Maximum weight -- 2100# *Rearward C.G.. limit- • 21.97 *Oil capacity. 9 qts. - - 17# at -49" *Baggage, placarded do not exceed 100 1bs - • 100# at +75.5" *Two passengers in rear seat, 170# x 2 - 340# at +48" *Pilot in most rearward seat equipped with controls (unless otherwise placarded) - 170# at +16" *Since the fuel tank is located aft of the rearward C.G. limit full fuel must be used 240# at +22" * Information should be obtained from the aircraft specification.
Note: If fuel tanks are located ahead of the rearward C.G. limit minimum fuel should be used.
CHECK OF REARWARD WEIGHT AND BALANCE EXTREME Weight (#) x Arm (*) = Moment (*#) Aircraft empty + 1169 + 10.6 + 12391 Oil 17 - 49 833 Pilot (1) + 170 + 16 + 2720 Passenger (2) + 340 + 48 16320 Fuel (40 gals.) + 240 + 22 + 5280 Baggage + 100 + 75.5 + 7550 Total + 2036 (IW) + 43428 (TM) Divide the TM (total moment) by the TW (total weight) to obtain the rearward weight and balance extreme.
IM = 43428 = + 21.3" TW 2036 Since the rearward C.G. limit and the maximum weight are not exceeded, the rearward weight and balance extreme condition is satisfactory.
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Par 10-20 Page 10-16
10-20. LOADING CONDITIONS AND/OR PLACARDS. If the following items have not been covered in the W&B extreme condition checks and are not covered by suitable placards in the aircraft, additional computations are necessary. These computations should indicate the permissible distribution of fuel, passengers, and baggage that may be carried in the aircraft at any one time without exceeding either the maximum weight or CG range. The conditions to check are:
a. With full fuel, determine the number of passengers and baggage permissible.
b. With maximum passengers, determine the fuel and baggage permissible.
c. With maximum baggage, determine the fuel and the number and location of passengers.
d. Examples of the computations for the above items are given in Figures 10-12, 10-13, and 10-14 respectively. The above cases are mainly applicable to the lighter type personal aircraft. In the case of the larger type transport aircraft, a variety of loading conditions is possible and it is necessary to have a loading schedule.
FIGURE 10-12. LOADING CONDITIONS: DETERMINATION OF THE NUMBER OF
PASSENGERS AND BAGGAGE PERMISSIBLE WITH FULL FUEL
EXAMPLE OF THE DETERMINATION OF THE NUMBER OF PASSENGERS AND BAGGAGE
PERMISSIBLE WITH FULL FUEL Actual empty weight of the aircraft 1169# Empty weight center of gravity - 10.6" Maxımum weight- - 2100# Datum is leading edge of the wing Forward center of gravity limit -- 8.5" Rearward center of gravity limit- 21.9" Oil capacity, 9 qts.; show full capacity 17# at -49" Baggage, maximum 100# at +75.5" Two passengers in rear seat, 170# x 2 - 340# at +48" Pilot in most rearward seat equipped with controls (unless otherwise placarded) - 170# at +16" Full fuel, 40 gals. x 6# -- 240# at +22" Weight (#) x Arm (*) = Moment (*#) Aircraft empty + 1169 + 10.6 + 12391 Oil + 17 - 49 833 Full Fuel + 240 + 22 + 5280 Passengers 2 rear + 340* + 48 +16320 Pilot + 170 + 16 + 2720 Baggage + 100 + 75.5 + 7550 Total + 2036 (IW) + 43428 (IM) Divide the TM (total moment) by the TW (total weight) to obtain the loaded center of gravity.
TM = 43428 = + 21.3" TW 2036 The above computations show that with full fuel, 100 pounds of baggage and two passengers in the rear seat may be carried in this aircraft without exceeding either the maximum weight or the approved C. G. range.
This condition may be entered in the loading schedule as follows:
GALLONS OF FUEL NUMBER OF PASSENGERS POUNDS OF BAGGAGE Full 2 Rear 100 * Only two passengers are listed to prevent the maximum weight of 2100 Ibs. from being exceeded.
Par 10-20 Page 10-17
FIGURE 10-13. LOADING CONDITIONS: DETERMINATION OF THE FUEL AND
BAGGAGE PERMISSIBLE WITH MAXIMUM PASSENGERS
EXAMPLE OF THE DETERMINATION OF THE POUNDS OF FUEL AND BAGGAGE PERMISSIBLE
WITH MAXIMUM PASSENGERS Weight (#) X Arm (*) = Moment (*#) Aircraft empty + 1169 + 10.6 + 12391 Oil 17 - 49 833 Pilot + 170 + 16 + 2720 Passenger (1) front + 170 + 16 + 2720 Passenger (2) rear + 340 + 48 +16320 Fuel (39 gals.) + 234 + 22 + 5148 Baggage Total + 2100 + 38466 Divide the TM (total moment) by the TW (total weight) to obtain the loaded center of gravity.
TM = 38466 = + 18.6" TW 2100 The above computations show that with the maximum number of passengers, 39 gallons of fuel and zero pounds of baggage may be carried in this aircraft without exceeding either the maximum weight or the approved C. G. range.
This condition may be entered in the loading schedule as follows:
GALLONS OF FUEL NUMBER OF PASSENGERS POUNDS OF BAGGAGE *Full *2 Rear * 100 39 1(F) 2(R) None * Conditions as entered from Figure 10-12 (F) Front seat (R) Rear seat Par 10-20 Page 10-18
FIGURE 10-14. LOADING CONDITIONS: DETERMINATION OF THE FUEL AND
THE NUMBER AND LOCATION OF PASSENGERS PERMISSIBLE WITH
MAXIMUM BAGGAGE
EXAMPLE OF THE DETERMINATION OF THE FUEL AND THE NUMBER AND LOCATION OF
PASSENGERS PERMISSIBLE WITH MAXIMUM BAGGAGE Weight (#) x Arm (*) = Moment (*#) Aircraft empty + 1169 + 10.6 + 12391 Oil 17 - 49 833 Pilot + 170 + 16 + 2720 Passenger (1) rear + 170 + 48 + 8160 Passenger (1) front + 170 + 16 + 2720 Fuel (40 gals.) + 240 + 22 + 5280 Baggage + 100 + 75.5 + 7550 Total + 2036 + 37988 Divide the TM (total moment) by the TW (total weight) to obtain the loaded center of gravity.
TM = 37988 - = + 18.7 TW 20366 The above computations show that with maximun baggage, full fuel and 2 passengers (1 in the front seat and 1 in the rear seat) may be carried in this aircraft without exceeding either the maximum weight or the approved C. G. range.
This condition may be entered in the loading schedule as follows:
GALLONS OF FUEL NUMBER OF PASSENGERS POUNDS OF BAGGAGE *Full *2 Rear * 100 ** 39 *1(F) 2(R) **None Full 1(F) 1(R) Full * Conditions as entered from Figure 10-12 ** Conditions as entered from Figure 10-13 (F) Front seat (R) Rear seat
10-21. EQUIPMENT LIST. A list of the equipment included in the certificated empty weight may be found in either the approved AFM or the W&B report. Enter into the W&B report all required, optional, and special equipment installed in the aircraft at time of weighing and/or subsequent equipment changes.
a. Required equipment items are listed in the pertinent Aircraft Specifications.
b. Optional equipment items are listed in the pertinent Aircraft Specifications and may be installed in the aircraft at the option of the owner.
Par 10-20 Page 10-19
c. Special equipment is any item not corresponding exactly to the descriptive information in the Aircraft Specifications. This includes items such as emergency locator transmitter (ELT), tail or logo lights, instruments, ashtrays, radios, navigation lights, and carpets.
d. Required and optional equipment may be shown on the equipment list with reference to the pertinent item number listed in the applicable specifications only when they are identical to that number item with reference to description, weight, and arm given in the specifications.
Show all special equipment items with reference to the item by name, make, model, weight, and arm. When the arm for such an item is not available, determine by actual measurement.
10-22. EQUIPMENT CHANGE. The person making an equipment change is obligated to make an entry on the equipment list indicating items added, removed, or relocated with the date accomplished, and identify himself by name and certificate number in the aircraft records.
Examples of items so affected are the installation of extra fuel tanks, seats, and baggage compartments.
a. Figure 10-15 illustrates the effect on balance when equipment items are added within the acceptable CG limits and fore and aft of the established CG limits.
FIGURE 10-15. EFFECTS OF THE ADDITION OF EQUIPMENT ITEMS ON
BALANCE
WEIGHTS FORWARD C.G. LIMIT - REARWARD C.G. LIMIT Weights added anywhere between the C.G. limits will not upset the balance of the aircrait.
-WEIGHT FORWARD C.G. LIMIT- -REARWARD C.G. LIMIT Any weights added ahead of the forward C.G. limit would tend to upset the balance around the forward balance limit.
WEIGHT FORWARD C.G. LIMIT -REARWARD C.G. LIMIT Any weights added aft of the rearward C.G. limit would tend to upset the balance around the rearward balance limit.
Par 10-21 Page 10-20
b. Moment computations for typical equipment changes are given in Figure 10-16 and are also included in the sample W&B sheet in Figure 10-18.
10-23. SAMPLE W&B REPORT. Suggested methods of tabulating the various data and computations for determining the CG, both in the empty weight condition and the fully loaded condition, are given in Figures 10-17 and 10-18, respectively, and represent a suggested means of recording this information. The data presented in Figure 10-17 have previously been computed in Figures 10-10 and 10-11 for the extreme load conditions and Figure 10-16 for equipment change, and represents suggested means of recording this information.
FIGURE 10-16. EXAMPLE OF MOMENT AND WEIGHT CHANGES RESULTING
FROM EQUIPMENT CHANGES Forward Rearward Moments (counterclockwise) + Moments (clockwise) Wheel pants added (+6# at -1") Battery added (+29# at +13") Battery removed -24# at -29") Landing light removed (-1# at +4") DATUM- Weight (#) × Arm (") = Moment ("#) ADDED Item 204 wheel pants + 6 - 1 - 6 Item 302b Battery + 29 + 13 +377
REMOVED Item 302a Battery - 24 -29 +696 Item 303 Landing light - 1 + 4 4 This condition is shown properly entered on a sample weight and balance report on Figure 10-18 under Equipment Change.
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FIGURE 10-17. SAMPLE WEIGHT AND BALANCE REPORT TO DETERMINE
EMPTY WEIGHT CENTER OF GRAVITY MAKE MA-700 MODEL A SERIAL # 0000 REGISTRATION # N1234 DATOM IS_ leading edge of wing
COMPUTE AS FOLLOWS IF AIRCRAFT WEIGHED
1. Leveling means: level top longeron between front and rear seats.
2. Main wheel weighing point is located - "FORWARD) (+ 3" AFT) of datum.
3. Actual measured distance from the main weight point centerline to the tail (or nose) point centerline 222 "
4. Oil over and above "ZERO" tank reading = (a. - Gals.) (b.- Lbs.) (c. - In.)
ACTUAL EMPTY WEIGHT Weight Point Scale Reading Tare = Net Weight
5. Right 564 564
6. Left 565 565
7. Tail 67 27 40
8. Nose
9. Total Net Weight 1169
CENTER OF GRAVITY AS WEIGHED
10. C.G. relative to main wheel weighing point:
(a) Tail wheel airc. (Item 3, 222), x (Item 7, 40 ) = C.G.
(Item 9, 1169)
(b) Nose wheel airc. (Item 3 ---) x (Item 8 ---- ) = C.G.
(Item 9 --- )
11. C.G. relative to datum:
(a) Tail wheel airc. (Item 10a, + 7.6) added to (Item 2, + 3) +10.6" = C.G.
(b) Nose wheel airc. (Item 10b. added to (Item 2, ) = = C.G.
COMPUTE IF AIRCRAFT WEIGHED WITH OIL (Item 4) Weight Arm Moment Aircraft (9) (11) Less Oil (4b) (4c) Empty Totals (a) (b)
(b) -- -= (c) = Empty weight C.G.
12. (a)
REPAIR AGENCY DATE Name Number Par 10-23 Page 10-22
FIGURE 10-18. SAMPLE WEIGHT AND BALANCE REPORT INCLUDING AN
EQUIPMENT CHANGE FOR AIRCRAFT FULLY LOADED
EQUIPMENT LIST *Required or Optional Item Numbers as Shown in Aircraft Specification 105 106 201 202 302(a) 303 401(a) 402 Special Equipment Item Make Model Weight Arm 3 Flares 1-1/2 Min XYZ 03 25# 105" Enter above those items included in the empty weight.
WEIGHT AND BALANCE EXTREME CONDITIONS Approved fid limit 8.5" Approved max. weight 2100# Approved aft limit 21.9" Item FORWARD CHECK REARWARD CHECK Weight Arm = Airo. Empty + 12391 + 1169 (9 or 12a) (11 or 12c) (9 or 12a) (11 or 12c) Oil + 17 - 49 - 833 Pilot + 170 + 16 + 2720 Fuel + 83 + 240 + 22 + 5280 Passenger (s + 340 + 48 + 16320 Baggage + 100 + 75.5 + 7550 TOTAL + 1439 = TW + 16104 = TM + 2036 = TW +43428=IM IM = 16104 = +11.2" = IM = 43428 = +21.3" = TW 1439 TW 2036 Most Forward C.G. location Most Rearward C.G. location
LOADING SCHEDULE Gallons Number of Pounds of of Fuel Passengers Baggage 40 2(R) 100 The above includes pilot and capacity oil
EQUIPMENT CHANGE Computing New C.G.
Item, Make, and Model* Weight Arm Moment Airc. Empty + 1169 + 10.6 + 12391 (9 or 12a) (11 or 12c) 204 added + 6 - 1 - 6 302(b) added + 29 + 13 + 377 302(a) removed - 24 + 29 + 696 303 removed - 1 + 4 - 4 NET TOTALS - 1179 = NW + 13454 = NM NM = 13454= +11.4" = New C.G.
NW 1179 *ITEM NUMBERS WHEN LISTED IN PERTINENT AIRCRAFT SPECIFICATION MAY BE USED IN LIEU OF "ITEM, MAKE, AND MODEL".
PREPARED BY DATE_ Par 10-23 Page 10-23
10-24. INSTALLATION OF BALLAST. Ballast is sometimes permanently installed for CG balance purposes as a result of installation or removal of equipment items and is not used to correct a nose-up or nose-down tendency of an aircraft. It is usually located as far aft or as far forward as possible in order to bring the CG position within acceptable limits with a minimum of weight increase. Permanent ballast is often lead plate wrapped around and bolted to the fuselage primary structure (e.g., tail-post, longerons, or bulkhead members). Permanent ballast invariably constitutes a concentrated load; therefore, the strength of the local structure and the attachment of the ballast thereto should be investigated for the design loading conditions pertinent to that particular aircraft. Placard permanent ballast with "Permanent ballast - do not remove." It is not desirable to install permanent ballast by pouring melted lead into the tail-post or longerons due to difficulties that may be encountered in subsequent welding repair operations. It should be noted that the installation of permanent ballast results in an increase of aircraft empty weight. See Figure 10-19 for ballast computation. The local strength of the compartment in which the ballast is carried and the effect of the ballast on aircraft W&B should be investigated when disposable ballast is carried.
FIGURE 10-19. PERMANENT BALLAST COMPUTATION FORMULA Desired C.G. location Actual C.G. location Location of ballast to D - Distance in inches desired to move C.G. of airplane. be added W - Weight of airplane as loaded.
X - Distance in inches from point where ballast is to be installed, to the desired location of the new C.G.
B - Weight of ballast required in pounds.
B = D × W Compute the new C.G. of the aircraft with ballast installed.
NOTE: If greater accuracy is desired, repeat the entire formula using the NEW aircraft weight and the NEW C.G. in the second operation.
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