The following information is derived from the FAAs Service Difficulty Reports and Aviation Maintenance Alerts. Click here to view “Airworthiness Directives.”
The FAAs Aircraft Certification Office in Atlanta has received reports of problems with oil filters manufactured by Champion. The problems include collapsed elements, rubber gasket material inside the filter canister, and other one-time events. The reports were serious enough for the manufacturer and the FAA to launch an investigation, which revealed that the collapsed elements were caused by the engine oil bypass valve that is installed in some Textron Lycoming engines.
Champion addressed the problem in Aviation Technical Bulletin No. 91-3, dated March 1991. The rubber gasket material was from the antidrainback valve which, in some cases, had shifted. This problem was the subject of a manufacturers engineering change issued in April 1994. The number of reported problems has rapidly declined in the last 3 years. However, since some owners, operators, repair stations, and others tend to buy case lots of filters, it is likely that some of the older filters may still be on the shelf or in stock.
The FAA recommends that anyone who owns, operates or maintains a Textron Lycoming engine ensure it is in compliance with Champion ATB No. 91-3 and Textron Lycoming Service Instruction 1442. Regardless of engine manufacturer, oil filters that have a manufacturing date of July 1996 or earlier should be visually inspected. Look through the threaded hole in the base plate, with a flashlight if necessary, to determine if any material is blocking (even partially) the oil flow path. Do not use any filter that has even partial blockage.
The manufacturing date code is an eight-character string printed on the filter can. The second and third characters indicate the month of manufacture, and the fourth character is a letter that indicates the year of manufacture. Year codes F, E and D should be inspected and year code G through July should be inspected.
American Champion 7GCAA Citabria
Engine Exhaust System Interference
During an annual inspection, the technician discovered the engine exhaust system was chafing on engine mount bolts.Both the left and right exhaust pipes were rubbing on the lower engine mount bolts at the firewall. The submitter checked several like aircraft and found the same problem on all the aircraft.
Beech B300 King Air
Wing Structure Cracks
During a scheduled inspection, a crack was found on the upper surface of the right wing at wing station 93. Further investigation revealed the rib under the skin was also cracked.During a scheduled inspection of another like aircraft, working rivets were found on the left wing at wing stations 93, 85, and 75.5. These rivets are used to secure the ribs. Further investigation disclosed cracks in the stringers at these locations. Also, there was a crack in the rib on the right wing at wing station 93.Aircraft total times – 3,967 and 1,884 hours.
Cessna 172R Skyhawk
Engine Compartment Baffle Damage
During maintenance, technicians found a damaged baffle. The alternator positive battery wire had chafed a hole in the baffle in the right forward section of the engine compartment.Part total time – 337 hours.
Fuel Quantity System Damage
During an annual inspection, the technician found the top access panel on the right wing auxiliary fuel tank was leaking.When the access panel was removed to replace the gasket, the technician noticed the fuel quantity sending unit wires were exceptionally long. The insulation had been chafed off of the wires, and the bare wire was exposed at several locations. The same defect was found in the left auxiliary fuel tank.Since the wires were too long and not secured, they chafed against the fuel tank structure and the components. There are no provisions inside the fuel tank for securing the wires. The aircraft maintenance records indicated the fuel tank components were not changed or replaced since the aircraft was manufactured in 1978.The sending units and the wire harnesses were replaced with new parts, which also included the long wires.Part total time – 4,248 hours.
Cessna 560 Citation
Defective Pressurization System
Operators reported that the pressurization system was working erratically.An investigation of the system revealed that a pneumatic relay was not working properly, and the relay was replaced with a new unit. During an operational test, the pressurization system did not function. The new relay was replaced with another new unit and the system functioned normally.Part total time – 0 hours.
Navion Model A
Unserviceable Fuel Hose
During an annual inspection, the hose assembly used to supply fuel to the electric fuel pump was removed.The hose material was extremely frayed, weathered, stiff, and brittle. The support wire was broken at several locations and protruded through the outer cover. The attached identification tag indicated the hose assembly was manufactured in January 1947 and was probably installed as original equipment on this aircraft in 1948. The hose assembly is almost impossible to see, which probably contributed to its neglect.Part total age – 51 years. Part total time – 3,481 hours.
Piper PA-23-250 Aztec
During a high speed descent, the pilot felt a control flutter.An inspection of the flight surfaces revealed excessive play in the left stabilator tube. This problem was initially difficult to detect due to the spring loads on the bellcrank.A closer investigation revealed the bearing and hole in the attachment block for the stabilator tube were worn where they attach to the trim bellcrank. This allowed the trim tab to move, which caused movement in the stabilator and the the flutter in the control yoke.
Piper PA-24-250 Comanche
Cracked Vertical Fin Attach Point
During an annual inspection, the technician discovered a 0.3-inch crack in the vertical fin forward attach spar (fuselage) angle. This damage occurred aft of the channel assembly.AD 75-12-06 requires inspection of the bend-relief holes in this channel and the associated straps. No cracks were noted in these parts. The aircraft logs show no indication of prior damage to the fin or its attach points.Part total time – 3,930 hours.
Piper PA-32RT-300 Turbo Lance II
Poor Engine Performance
After the engine began running rough, the top cowling was removed to reveal the no. 3 cylinder fuel injection line had broken away from the weld which attached the line to the fitting. The technician discovered the fuel line had chafed a hole in the no. 4 cylinders oil return line. Also, the nos. 2, 4, and 6 cylinders fuel injection fittings were loose.Part total time – 1,767 hours.
Teledyne Continental O-470-R
During an annual inspection of a Cessna 182G, the technician completed an engine compression test and discovered that all six pistons were cracked.The cracks were all located in the same area of the upper piston pin boss. The cracks ran parallel to the piston pin, and one piston had lost a piece of the casting around the pin. Prior to disassembly, there were no operational problems, and it appeared this condition had existed for some time.Part total time – 1,277 hours.
Textron Lycoming O-320
Connecting Rod Excessive Clearance
After a factory overhauled engine was installed on a Cessna 172M, operations resulted in high oil temperature.The technician noticed an abnormal noise when he turned the propeller by hand. The cylinders were removed and the nos. 3 and 4 cylinder-connecting rods were found to have excessive side clearance. The lower end of the connecting rods had rubbed hard against their respective crankshaft journals.