The Stinson 108 Voyager Airworthiness Directives By Larry Westin - April 9, 1996 IMPORTANT - This NOT an official Federal Aviation Administrtion list of Airworthiness Directives. See your Licensed Airframe and Powerplant Mechanic who also holds an Inspection Authorization for a complete up to date list of Airworthiness Directives. DISCLAIMER: This list of FAA Airworthiness Directives is provided to help Stinson owners understand possible problems with Stinson aircraft. This list CANNOT be considered official, only Airworthiness Directives I know about are listed here. This list can help if you are planning to purchase a Stinson in knowing what areas to investigate before you buy. Obtain complete up to date airworthiness direcctives from a Licensed Airframe and Powerplant Mechanic who also holds an Inspection Authorization. This list is in three parts - Part 1 are AD's for the Stinson, Part 2 are AD's for the Franklin engine, Part 3 are AD's for Stinson Propellers. Part 1 - Stinson Airplane Each of these airworthiness directives should be shown as complied with in the aircraft log book. 47-50-11 Stinson: appplies to 108 series aircraft. Compliance required by March 1, 1948. The front ash trays shall be modified to the self-contained type or a "No Smoking" placard installed. Stinson service bulletin No. 246 covers a satisfactory method modifying these ash trays. 47-50-12 Stinson: applies to Model 108 Series Serial Numbers 1 through 3500. Compliance required every 100 hours of operation. Inspection of the stabilizer leading edge attachment to the fuselage should be made for fatigue cracks, after each 100 hours of operation. If fatigue cracks are present, reinforcements to the stabilizer fitting should be added. Inspection may be discontinued after reinforcement is installed. Stinson service bulletin No. 254 dated September 5, 1947, covers this same subject. 49-16-02 Stinson: Applies to All Models 108-2 and 108-3 Series Aircraft, serial numbers 2250 and up. Compliance required at next periodic inspection but not later than July 1, 1949. To prevent wing fabric loosening along the upper surface of the front and rear spars in the area of the fuel tank causing a spoiler action, remove the fuel tank and inspect the upper surface wing fabric for proper installation, looseness and deterioration. The fabric should be wrapped securely around spar flange ending att spar web. If fabric is not installed in this manner or it is loose, the following shall be accomplished. 1. Resecure fabric to wing structure using at least a 4-inch width of surface tape as reinforcement. Dope to upper wing fabric along spar and wrap securely around spar flange stopping at spar web. 2. Reinstall fuel tanks. 3. Seal 1/8 inch crevice on upper wing surface (between fuel tank and spar) flush with wing contour using perma-plastic sealing compound copatible with doped fabric surface. (3-M Weatherstrip cement manufactured by the Minnesota Mining and Manufaccturing Co., or equivalent, is acceptable). 4. All rework should be in accordance with Civil Aeronautics Manual 18. This supersedes AD 49-06-05. 50-17-02 Stinson: Applies to All Model 108 series Aircraft. Compliance required as indicated. A number of cases have been reported of broken core strands in the rudder cables where they pass over the pulley at fuselage Station 18.75 (first pulley aft of rudder pedals). To preclude failures, the following is therefore required: 1. Within the next 25 hours and at every 100 hours thereafter the following should be accomplished. Revmove the rudder cables from the pulleys, bend the cables in tight "U" where they pass over the pulley, being careful that permanent kinks are not formed, and inspect either visually or by touch. Replace all Cables showing signs of breakage. 2. The above inspection may be discontinued and the normal inspections resumed if the following is done: Remove the AN 210- 3A pulleys at fuselage Station 18.75; modify the pulley brackets and install larger pulleys, P/N 41001-2, and two cable guards, P/N SK253-2, in accordance with detailed instructions in Piper Service Bulletin No. 114 or an equivalent modification. 50-25-01 Stinson: Applies to All Model 108 Series Aircraft. Compliance required not later than September 1, 1950. Reports have been received of fuel seepage into the space between the inner cabin trim and the outer fabric covering of the fuselage. This results in soaking of insulating material in the cabin wall. The source of the fuel can be spillage during filling of tanks, thermal expansion of fuel in full tanks, or tank leakage. This fuel runs to the under surface of the wing, adhering to the lower ccurved surface of the trailing edge of the wing at the flap well, thence inboard to the fuselage and across ther rear window. Since the window seal is often not perfectly tight the fuel may then enter the cabin wall. To preclude the fire hazard of fuel soaked insulation within the caabin wall due to these causes, a drip strip similar to that shown in Figure 1 should be installed on the underside of each wing. This drip strip will prevent fuel from flowing from the wing to the fuselage. The AD has a figure here of the drip strip and its location. Piper Service Bulletin No. 115, dated march 31, 1950, covers this same subject. Part 2 - Franklin Engine 48-50-01 Franklin: Applies to All Bellanca 14-13, 14-13-12 and Stinson 108, 108-1 Aircraft Equipped with Franklin Model 6A4-150- B3 and B31 Engines with Serial Numbers 11000 to 14000 Inclusive. Compliance required after each 25 hours of operation. To prevent possible cylinder base flange failure, visual inspection for cracks just above the base flange should be made every 25 hours of operation on the early type cylinders until replaced by the later type cylinders. Early type cylinders have a flat section which extends 3/8 inch to 7/8 inch from the outer edge of the base flange. On later type cylinders the flate section has been practically elminated by extending the ribbed section close to the edge of the flange. It is urgently recommeded that early type cylinders be replaced at the earliest opportunity. Franklin Service Bulletin No. 69 covers this same subject and offers special discounts effective through January 1949, for cylinder replacements. This supersedes AD 48-47-02. 51-15-02 Franklin: Applies to All Franklin 6A4-165-B3 Engines Serially Numbered 33046 and Below Incorporating Original Crankcase (Left Half No. 18305; Right Half No. 18306). These Two Parts Form Crankcase Assembly, P/N 18553. The Number of Each Crankcase Half is Located on Each Casting Below the Number 1 and 6 Cylinder Location. To Be accomplished by July 15, 1951. Effective on and after this date, all applicable crankcases with 500 hours of operation since new or 250 hours since last overhaul should be inspected as follows: Remove crankcase cover and visually inspect the webbing near the main journal area for cracks. (1) Crankcases found to be free of cracks should be inspected at 250-hour intervals thereafter. In the event that the conditions described in (2) and (3) are detected, the provisions of (2) and (3) will apply. (2) Crankcases found with (a) surface indications, hairline cracks, or small wall cracks and (b) cracks starting at main bearing stud hole on the opposite side from main bearing support, may be operated further at the option of the owner. Such crankcases should be inspected at 50-hour intervals thereafter to dtermine progress of cracks. (3) Crankcases found fractured or with cracks that have progressed to the extent that they enter the main bearing supports (usually from back near (a) main bearing stud hole and (b) drilled oil hole) indicate that a complete break soon will occur. Such crankcases should be replaced with the reinforced crankcase assembly, P/N 18925 at which time no further inspection is required. Crankcase assembly P/N 18925 may be identified by casting No. 18905 appearing below No. 1 cylinder location and casting No. 18906 appearing below No. 6 cylinder location. Franklin Service News No. 10 also covers this subject. 51-28-02 Franklin: Applies to Model 6V4-178 Series Engines Prior to Serial Number 17690 and 6V4-200 Series Engines Prior to Serial Number 26235. Compliance required as indicated. To preclude the possiblity of oil pump failure, oil pump gears (P/N 10673 and 17736) must be inspected at each 300 hours of operation. Excessively galled gears must be replacced. If same part numbers are used for replacements, the 300-hour inspections will still apply. If carbonitrided oil pump drive gear, P/N 19377, and oil pump driven gear, P/N 19373, are installed, no further inspection is required. When these new carbonitrided gears are installed, suffix "P" must be stamped after the serial number of the engine on the nameplate - example: No. 1700P. Franklin Service Bulletin No. 86, revised November 1, 1951, covers this same subject. This supersedes AD's 51-22-02 and 51-11-03. 94-14-11 Franklin: Priority Letter issued on June 23, 1994. Docket No. 94-ANE-35. Applicability: Franklin Model 6A4-150-B3 and 6A4-150-63 reciprocating engines, installed on the following U.S. registered aircraf: N6209M, N74231, and N752C. Compilance: Required as indicated, unless accomplished previously. To prevent detonation due to low octane, which can result in severe engine damage and subsequent failure, accomplish the following: (a) For engines that are certified to operate on only 91 or higher octane aviation gasoline (avgas) within the next 2 hours time in service (TIS) after the effective date of this airworthiness directive (AD) perform an engine teardown and analytical inspection, and replace with servieable parts as necessary in accordance with the applicable overhaul manuals. (b) For engines that are certified to operate on 80 octane avgas, within the next 2 hours TIS after the effective date of the AD conduct a differential compression test on all cylinders in accordance with the applicable maintenacne manuals, and examine the oil filter by cutting the oil filter apart and spreading the filter paper out to look for metal particles. If metal particles are present, or if one or more cylinders shows unacceptable compression as specified in the applicable maintenance manuals, perform an engine teardown and analytical inspection, and replace with serviceable parts as necessary in accordance with the applicable overhaul manuals. NOTE: Additional guidance for conducting the differential compression tests is contained in paragraph 692 of Advisory Circular (AC) No. 43.13-1A, dated 1988. (c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved the Manager, Engine and Propeller Standards Staff. The request should be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Engine and Propeller Standards Staff. NOTE: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine and Propeller Standards Staff. (d) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of the AD can be accomplished. (e) Priority Letter AD 94-14-11, issued June 23, 1994, becomes effective upon receipt. FOR FURTHER INFORMATION CONTACT: Locke Easton, Aerospace Engineer, Engine and Propeller Standards Staff, FAA, Engine and Propeller Directorate, 12 New England Executive Park; telephone (617) 238-7113, fax (617) 238-7199. Part 3 - Propellers 47-50-13 Downer Bellanca and Stinson: Applies Only to Aircraft Equipped with Koppers Model Aeromatic F200 Propellers. Compliance required no later than the next 25-hour propeller lubrication and at 25 hours of operation thereafter. Inspect propeller hub as follows: Remove balancing band from both ends of hub barrel after index marking each to facilitate proper reassembly. Examine the other surfaces of the hub completely for indications of line cracks or fractures. The area of primary concern are (1) those beneath the balancing band, (2) the weld joint where hub barrel and mounting tube meet, and (3) the weld joint where mounting tube and mounting flange meet. Defective hubs should be removed from service. Koppers service bulletin No. 12, dated October 9, 1947, covers this same subject. 50-34-01 Koppers: Applies to All Aircraft Equipped with Model F200 "Aeromatic" Propellers (Does NOT apply to "Aeromatic Model 220 Propellers"). Compliance required in all cases no later than April 1, 1952. 1. Stinson Models 108-2 and 108-3 aircraft: Compliance required no later than first 200 hours of propeller operation. 2. Stinson Models 108 and 108-1 aircraft: Compliance required no later than first 400 hours of propeller operation. 3. If the total propeller operation time is unkown, or if a reasonably accurate estimate of totoal time cannot be made, compliance is required not later than the next 50 hours of operation. (Except for Stinson Series aircraft, compliance is required by not later than the next 50 hours of operation if the total operation time as of August 29, 1949,exceeds 500 hours.) Blade retaining flanges, P/N 3277 must be replaced with P/N 3277-1. When this change is accomplished a "-1" (dash one) is to be suffixed to the propeller assembly number on the nameplate to indicate compliance. Koppers Service Bulletin Nol. 24 covers this same subject. Stinson Models 108-2 and 108-3 only: (Compliance required by May 16, 1949). To avoid the possiblity of crankshaft or propeller failures resulting from excessive torsional vibration in the 2,700 to 2,800 r.p.m. range, all engine operation must be restricted to 2,650 r.p.m. maximum and propeller readjusted in accordance with Koppers Service Bulletin No. 22. As a further safety measure it is required that propellers which have accumulated any operating time in the 2,650 to 2,800 r.p.m. range be equipped with new blade retainer flanges P/N 3277-1. Koppers Service Bulletin Nol 23-E covers this same subject. This supersedes AD 49-42-1, for the purpose of clarifying the date of compliance. IMPORTANT - This NOT an official Federal Aviation Administrtion list of Airworthiness Directives. See your Licensed Airframe and Powerplant Mechanic who also holds an Inspection Authorization for a complete up to date list of Airworthiness Directives.