AC 49.13-1A 1972 aircraft specification is exceeded. To make this check, the following information is needed:
(1) The weight, arms, and moments of empty aircraft;
(2) The maximum weights, arms, and moments of the items of useful load which are located aft of the rearward c.g. limit; and
(3) The minimum weights, arms, and moments of the items of useful load which are located ahead of the rearward c.g. limit.
A typical example of the computation necessary to make this check, using the above data, is shown in figure 18.11.
661, LOADING CONDITIONS AND/OR PLACARDS.
If the following items have not been covered in the weight and balance extreme condition checks, or 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 which may be carried in the aircraft at any one time without exceeding either the maximum weight or c.g. 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.
(1) Examples of the computations for the above items are given in figures 18.12, 13.13, and 13.14 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.
662. EQUIPMENT LIST. A list of the equipment included in the certificated empty weight may be found in either the approved Airplane Flight Manual or the weight and balance report. Enter in the weight and balance report all required, optional and special equipment installed in the aircraft at time of weighing and/or subsequent equipment changes.
Chap 13 Page 257
a. Required equipment items are items so listed in the pertinent aircraft specification.
b. Optional equipment items are so liated in the pertinent aircraft specification and may be installed in the aircraft at the option of the owner.
c. Special equipment is any item not corresponding exactly to the descriptive information in the aircraft specification. This includes such items as flares, instruments, ashtrays, radios, navigation lights, carpets, etc.
d. Required and optional equipment may be shown on the equipment list making reference to the pertinent item number listed in the applicable specification only when they are identical to that number item with reference to description, weight, and arm given in the specification.
Show all special equipment items by making 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.
(1) Equipment Changes. 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, or baggage compartments. Figure 18.15 illustrates the effect on balance when equipment items are added within the acceptable c.g. limits and fore and aft of the established c.g. limits. Moment computations for typical equipment changes are given in figure 18.16 and are also included in the sample weight and balance sheet in figure 18.18.
663. SAMPLE WEIGHT AND BALANCE REPORT.
Suggested methods of tabulating the various data and computations for determining the
c.g., both in the empty weight condition and fully loaded condition, are given in figures
18.17 and 19.18, respectively, and represent a suggested means of recording this information.
The data presented in figure 18.17 have previously been computed in figures 13.10 and Par 660
Page 258 AC 48.13-1A 1972
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 Passengers, 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 TW 38466 2100 = + 18.3" 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 NUMBER OF POUNDS OF
OF FUEL PASSENGERS BAGGAGE * FULL * 2 rear * 100 39 1(F) 2(R) None * Conditions as entered from Figure 13.12 (F) Front seat (R) Rear seat FIGuRE 18.13.-Loading conditions: determination of the fuel and baggage permissible with maximum passengers.
18.11 for the extreme load conditions, and figure 13.16 for equipment change and represent suggested means of recording this information.
664. INSTALLATION OF BALLAST. Ballast is sometimes permanently installed for c.g. balance Par 663 purposes as & 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 c.g. position within acceptable limits with a minimum of weight increase. Permanent ballast is often Chap 13
AC 43.13-1A Page 259 1972
EXAMPLE OF THE DETERMINATION OF THE FUEL AND THE NUMBER AND
LOCATION OF PASSENGERS PERMISSIBLE WITH MAXIMUM BAGGAGE Weight (*) ×Arm (") = Moment ("#) Aircrait empty + 1169 + 10.6 + 12391 Ou 17 • 49 833 Pilot + 170 + 16 + 2720 Passenger 1) rear + 170 48 + 8160 Passenger (L) 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.
IM = 92036 2036 = + 18.7 The above computations show that with maximum 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 Ful 1(F) 1(R) Full * Conditions as entered from Figure 13.12 ** Conditions as entered from Figure 13.13 (F) Front seat (R) Rear seat FIGURE 18.14.-Loading conditions: determination of the fuel and the number and location of passengers permissible with maximum baggage.
Chap 13 Par 664
Page 260 AC 43.13-1A 1972
- WEIGHTS FORWARD C.G. LIMIT I REARWARD C.G. LIMIT Weights added anywhere between the C.G. limits will not upset the balance of the aircraft.
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.
FIGURE 18.15.-Effects of the addition of equipment items on balance.
Par 664 Chap 13
AC 43.13-1A Pago 361 1972 Forward Rearward
- Moments (counterclockwise) + Moments (clockwise) Wheel pants added (+B# at -1'') Battery added (+29# at +13") Battery removed (-24# at -29") Landing light removed (-1# at +4") DATUM Weight () x Arm () = Moment "")) ADDED Item 204 wheel pants Item 302b Battery + 6 + 29 +13 - 1 +877 - 8
REMOVED Item 302a Battery - 24 -29 +896 Item 303 Landing light - 1 + 4 - 4 This condition is shown properly entered on a sample weight and balance report on Figure 13.18 under Equipment Change.
FIGURE 18.16.-Example of moment and weight changes resulting from equipment changes.
Chap 13 Par 664
рад 262 AC 43,15-14 1972 MAKE MA-700 MODEL SCRIAL # 0000 REGISTRATION #_ N7234 DATUM IS leading odge of wing.
COMPUTE AS FOLLOWS IF AIRORAFT WEIONED
2. Main wheel weighing point la looated ( 1. Leveling means: level top longeron between friO NAR sear seats AFF) "PORWARD) (+ of datum.
3. Aotual neasured distance from the main weight point conterline to the tal. (or nose) point centerline 222"•
4. 011 over and above "ZERO" tank reading = (8. Gale.) (b.= Ibe.) (0. = In.)
ACTUAL EMPTY WEIGHT Weight Point Soale Reading - Tare Net Weight Right 564 564 Loft 565 Tail 67 27 Total Not Weight
CENTER OF GRAVITY AS WEIGHED 10" (a) Te1l wheel alro. (Item 2, 222) 0.0. relative to main wheel weighing points 100 11 40 1" + 122 =0.
¡tom 9, 1l6!
(b) Nose wheel airo. (Iten 3 - ) X (Item 8 - = CoG.
(Item 9 ° (a) Tail wheel airc. (Item 10a, + 720) C.Q. relative to datums added to (Item 2,+ 3) = + 10,6" • C.0.
(b) Nose wheel airc. (Item 10b, added to (Item 2 COMPUTE IF AIRCRAFT WEIGHED WITH OIL (Item 4) Weight ATT Moment Aircraft (9) (12 Less 011 (4b) (40) Empty Totala (a)
(b)- = (0) - • Empty weight C.O.
12. (a) REPAIR AGENCY_ DATE.
Name Number FIGuRE 18.17.—Sample weight and balance report to determine empty weight center-of-gravity.
Par 664 Chap 13
AC 43.13-1A age 263 1972
EQUIPMENT LIST "Required or Optional Iten Numbers as Shown in Aircraft Speoification 2 101 102 103 104 105 201 202 203 301 302 (в) 303 401(a) 402 Special Equipment Item Mako Model Weight Arm 3 Flares In Min. TIZ 03 25# 150" Enter above those items included in the empty weight.
WEIGHT AND BALANCE EXTREME CONDITIONS Approved fud Limit 8,5 " Approred max. weight 2100/ Approved aft limit 21,9"
TORNARD OREOK REARWARD C RECK Iton Weight I Moment Weight ArD Moment Aire, Empty + 12391 + 1169 + 10.6 + 12392 (9 0r 12a) |(11 or 120 (9 or 12a) K11 or 120) OL1 + 27 - 49 833 17 - 49 833 Pilot * 170 * 16 * 2720 + 170 + 16 2120 Fuol 83 + 22 1826 * 240 + 22 + 5280 Passenger (s) * 340 * 48 + 16320 Baggage * 100 + 75.5 * 7550 TOTAL + 143990 TH + 16104- TH + 2036=1W + 43428=1M ТУ - 16104 = +22,2" 11 = 43428 • 121231 = 1439 TH 2036 Most Forvard C.O. loontion Most rearvard C.O. location
LOADING SCHEDULE Gallons Number of Pounda oi of Fuel Passengers Baggage 40 2(R) 100 The above includes pilot and capacity o1l
EQUIPMENT CHANGE Computing New C.G.
Iten, Meke, and Model* weight Moment Airo. Empty + 1169 + 10.6 + 12391 (9 0r 12г) (11 or 120) 204 added 6 302(b) added 29 377 302(a) removed 24 → 696 303 removed NET TOTALS - 1179 = NW + 13454 = NM N1 = 13454 = + 12.4" = Now C.0. 1779 "ITEM NUMBERS WHEN LISTED IN PERTINENT AIRCRAFT SPECIFICATION MAY BE USED IN LIEU OF MITEM, MAKE, AND HODEL".
PREPARED BY DATE FIGURE 18.18.-Sample weight and balance report including an equipment change for aircraft fully loaded.
Chap 13 Par 664
Page 264 AC 43.13-1A 1972 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.
FIGURE 18.19.-Permanent ballast computation formula.
Par 664 Chap 13
AC 43.13-1A 1972 in the form of lead plate wrapped around and/or bolted to the fuselage primary structure (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 the particular aircraft. Placard permanent ballast "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 18.19 for ballast computation. When disposable ballast is carried, the local strength of the compartment in which the ballast is carried and the effect of the bal- Chap 13 Page 265 last on aircraft balance and weight should be investigated.
665. LOADING SCHEDULE. The loading schedule should be kept with the aircraft and usually forms a part of the airplane flight manual. It includes instructions on the proper load distribution, such as filling of fuel and oil tanks, passenger seating, restrictions of passenger movement; distribution of cargo, etc.
a. Other means of determining safe loading conditions, such as the use of a graphical index, load adjuster, etc., are acceptable and may be used in lieu of the information in paragraph 661.
b. Compute a separate loading condition when the aircraft is to be loaded in other than the specified conditions shown in the loading
666.-676. RESERVED.
Par 664
AC 49.13-14 Fage 267 1973 Chapter 14. ENGINES AND FUEL SYSTEMS Section 1. ENGINES
677. GENERAL, Persons should avail themselves of the manufacturer's manuals, service bulletins, and instruction books regarding the repair and overhaul, inspection, installation, and maintenance of aircraft engines. The repair and overhaul of engines are too many and varled for the different types and models of engines to mention here in specific detail.
678. INSPECTION. All moving and/or highlystressed parts and those subjected to high temperature should have a critical visual inspection at the time of overhaul. It is often necessary to supplement the visual inspection by employing one of the following procedures:
occur whenever an aircraft powerplant has been subjected to sudden deceleration or stoppage.
To fully evaluate any unsatisfactory findings resulting from this type of inspection, it will be necessary to refer to the applicable manu- to sad facturer's service and overhaul data. In addition, many of the prime aeronautical engine manufacturers now have specific recommendations on the subject of sudden stoppage involving their products. To assure continued airworthiness and reliability, it is essential that such data be used. In the event the manufacturer has not specified an instruction to follow, the following may be used as a guideline.
a. Wet or dry magnetic dust inspection of magnetic materials,
b. Wet or dry penetrant inspection of nonmagnetic materials,
c. X-ray or sonic inspection of any material, or
d. Hydrostatic inspection testing of fluid lines and internal passages and assemblies such as cylinder heads.
679. POWERPLANT SUDDEN STOPPAGE. For the purpose of this section, powerplant sudden stoppage refers to any momentary slowdown or complete stoppage of the main shaft of an aircraft powerplant; when the stoppage of a reciprocating or turboprop engine is the result of the rotating propeller striking a foreign object; or when the stoppage of a turbine engine is the result of ingestion of foreign objects or material. Any aircraft powerplant that has been subjected to sudden stoppage should be inspected to the extent necessary to assure continued safe operation. These procedures will serve as a guide for locating damage that may
a. Reciprocating Engine (Direct Drive).
(1) Powerpiant Exterior Inspection. Remove the engine cowling and examine the engine for visible external damage and audible internal damage.
(a) Rotate the propeller shaft to determine any evidence of abnormal grinding or sounds.
(b) With the propeller removed, inspect the crankshaft flange or splines for signs of twisting, cracks, or other deformation. Remove the thrust-bearing nut and seal and thoroughly inspect the threaded area of the shaft for evidence of cracks.
(c) Rotate the shaft slowly in 90° increments while using a dial indicator or an equivalent instrument to check the concentricity of the shaft.
(d) Remove the oil sump drain plug and check for metal chips and foreign material.
(e) Remove and inspect the oil screens for metal particles and contamination.
(f) Visually inspect engine case exterior for signs of oil leakage and cracks. Give particular attention to the propeller thrust-bearing area of the nose case section.
Chap 14 Par 677
(g) Inspect cylinders and cylinder holddown area for cracks and oil leaks. Thoroughly investigate any indication of cracks, oll leaks or other damage.
(2) Powerpiant Internal Inspection.
(a) On engines equipped with crankshaft vibration dampers, remove the cylinders necessary to inspect the dampers and inspect in accordance with the engine manufacturer's inspection and overhaul manual. When engine design permits, remove the damper pins, and examine the pins and damper liners for signs of nicks or brinelling.
(b) After removing the engine-driven accessories remove the accessory drive case and examine the accessory and supercharger drive gear train, couplings, and drive case for evidence of damage.
1. Check for cracks in the case in the area of accessory mount pads and gear shaft bosses.
2. Check the gear train for signs of cracked, broken, or brinelled teeth.
3. Check the accessory drive shaft couplings for twisted splines, misalignment and runout.
(3) Accessory and Drive Inspection. Check the drive shaft of each accessory, l.e., magnetos, generators, external supercharger, and pumps for evidence of damage.
(4) Engine Mount Inspection.
(a) Examine the engine flex mounts when applicable for looseness, distortion, or signs of tear.
(b) Inspect the engine mount structure for bent, cracked, or buckled tubes.
(c) Check the adjacent airframe structure for cracks, distortion, or wrinkles.
(d) Remove engine mount bolts and mount holddown bolts and inspect for shear, cracks, or distortion.
(5) Exhaust-driven Supercharger (Turbo) Inspection. Sudden stoppage of the powerplant can cause the heat in turbine parts to heat soak the turbine seals and bearings. This excessive heat causes carbon to develop in the seal area and varnish to form on the turbine bearings and journals.
Par 679 AC 43.13-1A 1972
(a) Inspect all air ducts and connections for air leaks, warpage, or cracks.
(b) Remove compressor housing and check the turbine wheel for rubbing or binding.
(6) Propeller Inspection Repair. Any propeller that has struck a foreign object during service should be promptly inspected in accordance with the propeller manufacturer's prescribed procedures for possible damage resulting from this contact with the foreign object and, if necessary, repaired according to the manufacturer's instructions. If the propeller is damaged beyond the repair limits established by the propeller manufacturer and a replacement is necessary, install the same make/model or alternate approved for this installation. Refer to the aircraft manufacturer's optional equipment list, applicable FAA Aircraft Specification, Data Sheet, or Supplemental Type Certificate Data.
b. Reciprocating Engine (Geared Drive). Inspect the engine, propeller and components as in preceding paragraphs.
(1) Remove the propeller reduction gear housing and inspect for:
(al Loose, sheared, or spalled cap screws or bolts.
(b) Cracks in the case.
(2) Disassemble the gear train and inspect the propeller shaft, reduction gears and accessory drive gears for nicks, cracks, or spalling.
c. Turbine, Engine, Ingestion Inspection. When the components of the compressor assembly or turbine section are subjected to ingestion damage, refer to the engine manufacturer's inspection and overhaul manual for specific inspection procedures and allowable tolerances. In general, an inspection after ingestion of foreign materials consista of the following areas:
(1) Inspect the external areas of the engine cases, attached parts and engine mounts for cracks, distortion, or other damage.
(2) Inspect the turbine disc for warpage or distortion.
(3) Inspect turbine disc seal for damage from rubbing or improper clearance.
(4) Inspect compressor rotor blades and stators for nicks, cracks, or distortion.
Chap 14
AC 43.13-1A 1972
(5) Check rotor and main shaft for misalignment.
(6) Inspect shaft bearing area for oil leaks.
(7) Inspect the hot section for cracks or hot spots.
(8) Inspect the accessory drives as prescribed under paragraph a (2) (b).
NOTE: Turbine disc seal rubbing ia not unusual and may be a normal condition. Consult the engine manufacturer's inspection procedures and table of limits.
d. Turboprop Engine Inspection.
(1) When sudden stoppage is the result of compressor ingestion of foreign material, inspect the engine as follows:
(a) Inspect the powerplant as described in paragraph c, "Turbine Engine, Ingestion Inspection."
(b) Inspect the reduction gear section as described in paragraph b(1) and b(2) where reduction gear damage is suspected.
12) When sudden stoppage is the result of the propeller striking foreign objects, inspect the engine as follow:
(a) Inspect the reduction gear section as described in paragraph b(1) and b(2).
(b) Inspect mainline shafts and coupling shafts for runout and spiral cracks.
(c) Inspect bearings for brinelling.
(d) Inspect engine compressor and turbine blades for tip clearance.
e. Approval for Returning Engine to Service.
(1) Correct all discrepancies found in the foregoing inspection in accordance with the engine manufacturer's service instructions.
(2) Test run the engine to determine that the engine, propeller, and accessories are functioning properly.
(3) After shutdown, check the engine for oil leak and check oil screens for signs of contaminants.
(4) If everything is normal the engine is ready for preflight runup and test flight.
680. CRANKSHAFTS. Carefully inspect for misalignment and replace if bent beyond the manufacturer's permissible service limit. Make no attempt to straighten crankshafts damaged in service without consulting the engine manu- Chap 14 Page 269 facturer for appropriate instructions. Worn journals may be repaired by regrinding in accordance with manufacturers' instructions. It is recommended that grinding operations be performed by appropriately rated repair stations or the original engine manufacturer to assure adherence to aeronautical standards.
Common errors that occur in crankshaft grinding are the removal of nitrided journal surface, improper journal radii, unsatisfactory surfaces, and grinding tool marks on the journals. If the fillets are altered, do not reduce their radii. Polish the reworked surfaces to assure removal of all tool marks. Most opposed engines have nitrided crankshafts and manufacturers specify that these crankshafts must be nitrided after grinding.
681. REPLACEMENT PARTS IN CERTIFICATED EN- GINES. Only those parts which are approved under FAR Part 21 should be used. Serviceable parts obtained from the engine manufacturer, his authorized service facility, and those which are FAA/PMA approved meet the requirements of FAR Part 21 and are acceptable for use as replacement parts. It is suggested that the latest type parts as reflected on the current parts list be obtained. Parts from military surplus stocks, which are applicable to the specific engine may be used provided they were originally accepted under the military procurement agency's standards, are found to be serviceable, and are not prohibited from use by the Administrator.
a. Parts for obsolete engines for which new parts are no longer obtainable from the original manufacturer or his successor are sometimes fabricated locally. When it becomes necessary to do this, physical tests and careful measurements of the old part may provide adequate technical information. This procedure is usually regarded as a major change which requires engine testing and is not recommended except as a last alternative.
b. Parts from certain military surplus tank or ground power unit engines are used on engines used in restricted aircraft and amateur-built aircraft. Users of such parts are cautioned to determine that they do not exceed the design Par 679