The following information is derived from the FAAs Service Difficulty Reports and Aviation Maintenance Alerts. Click here to view “Airworthiness Directives.”
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Recently, a Cessna 172R made an off-airport landing after the pilot/CFI was unable to restart the engine following a power-off stall demonstration. The engine idle speed and fuel flow setting were found to be out of adjustment.
Other model 172R and 172S aircraft were examined and found to exhibit settings that were as much out of adjustment or worse than the one involved in the off-airport landing.
Reports concerning 182S and T206H models indicate this problem may involve all Cessna piston aircraft that have been manufactured since the company resumed production.
Cessna has published information in the applicable maintenance manuals that adequately describes the procedures to follow in order to check and set the engine idle, fuel flow, and speed settings on these aircraft.
The company may soon revise the ground idle test and the in-flight engine restart procedures applicable to these aircraft. Cessna may also issue additional service and operational information to help identify what appears to be a significant shift in the idle fuel flow.
The fuel servos used on these aircraft historically require seasonal or periodic minor adjustments to the idle fuel flow and speed settings, but the shifts being reported are considerably beyond the seasonal/periodic adjustments normally required.
Suspect Motors
Electric motors used in anti-collision and wing position lights are being sold as manufactured by Grimes Aerospace that in fact are counterfeit. The company has reported to the FAA that motors bearing Grimes part number A8113-1 and being sold as Grimes parts were not manufactured by the company. Grimes says the differences between the real motor and the counterfeit one include the following: Grimes uses an ink stamp for identification while the suspect parts have a metal plate. Grimes motors do not have serial numbers, while the suspect parts appear to have numbers from 235 to 384. Both shaft ends of the Grimes motors are sealed, while the suspect motors have open shafts. The wires protruding from the Grimes motor are sealed with a rubber grommet while the suspect motor is sealed with silicone.
Beech V35B Bonanza
Smoke Odor in the Cockpit
Shortly after takeoff, the pilot smelled smoke in the cockpit. He returned to the departure airport and landed safely.The technician discovered fuel leaking from the engine-driven fuel pump case halves. He found evidence of a flash fire and suspected it caused the smoke odor.Part time since overhaul – 1,500 hours.
Beech 58 Baron
Cabin Heater Defect
During a flight, the pilot smelled heater fumes in the cockpit. He terminated the flight.The technician conducted an operational test of the Janitrol B4500 cabin heater and found the combustion can was punctured at the aft end. Insufficient cool-down procedures prior to shutting down the heater could cause this type of damage.Part total time – 1,150 hours.
Beech 95-B55 Baron
Main Landing Gear Failure
During a landing approach, the left main landing gear failed to extend when the pilot selected the gear to the down position. All efforts to extend the gear failed.A technician found the left main gear uplock roller bearing was seized. AD 72-22-01 deals with this specific subject but does not apply to this aircraft serial number. The clearance between the uplock roller bearing and the uplock block was less than the manufacturer specified.
Cessna 172S Skyhawk
Wheel Brake Failure
The pilot reported the right wheel brake became inoperative during landing.While investigating, a technician discovered brake fluid leaking onto the cockpit floor. He also found the brake hose that runs from the right brake cylinder to the bulkhead under the rudder pedals, had a loose B-nut. Given the short amount of operating time, the B-nut may not have been properly torqued during assembly.Aircraft total time – 414 hours.
Cessna R182 Skylane
Improper Seat Rail Attachment
While complying with the requirement of Airworthiness Directive (AD) 87-02-03, the technician discovered the seat tracks were improperly attached.The seat tracks were installed with Cherry Max blind fasteners and oversized standard rivets. The blind fasteners are not approved for major structural installations. The oversized standard rivets reduced the required fastener hole edge distance to less than the required two-times the fastener diameter. The seat tracks were replaced.Part total time – 4,169 hours.
Cessna T210N Centurion
Nose Gear Door Damage
After takeoff, the pilot retracted the landing gear and heard a crunching sound that seemed to come from the nose gear. The pilot landed without further incident.A technician found the nose gear actuating rod end bearing was separated from the rod-end housing. This allowed the airload to close the right nose gear door prior to gear retraction. The resulting damage required replacement of the door and actuator rod-end. Part total time – 3,230 hours.
Cessna 340A
Landing Gear Defect
When the pilot extended the landing gear during an approach, he heard some abnormal sounds.The pilot told mechanics the airspeed may have been a bit high when he extended the gear. The technician found the right main gear bellcrank had broken, causing the inboard gear door to hang open at the end of the extension cycle.Strict adherence to published gear extension airspeed should prevent recurrence of this type defect.Part total time – 5,274 hours.
Piper PA-23-160 Apache
Engine Oil Leak
After takeoff, the pilot noticed a severe oil leak coming from the left engine cowling. The technician found the oil quantity was down by approximately 4 quarts. The oil leak was caused by separation of the oil system dipstick tube, which had been improperly safety-wired when it was last installed. The right engine showed the same defect.
Piper PA-28-161 Warrior
Engine Induction System Defect
During an annual inspection, the technician found the carburetor induction system air valve did not operate.The air valve assembly actuating lever was broken at a weld attachment. The technician found two other instances of the same defect.The original part was made from steel and the replacement levers are made of aluminum, which may not be strong enough to bear the operational loads.Part total times – 327, 623, and 186 hours.
Piper PA-31-350 Chieftain
Rough Engine Operation
The owner complained the engine was rough.A technician discovered one of the Bendix magnetos was operating intermittently. He opened the magneto and discovered the capacitor was coming apart. Bendix SB662A addressed this problem but only covers capacitors with date codes up to 9942. The capacitor in this case has a date code of 9948.Part total time – 219 hours.
Piper PA-32-301T Turbo Saratoga
Abnormally Low Engine Power
The pilot complained the engine would not develop normal power while flying at cruise altitude.A technician discovered the turbocharger wastegate butterfly valve was missing approximately 40 percent of the valve plate surface. Since the turbocharger turbine was not damaged, the plate may have eroded slowly from exposure to exhaust gas and heat.The engine had accumulated approximately 730 hours of operation since a factory overhaul. However, there was no indication or record the turbocharger was changed or repaired since it was installed.
Piper PA-46-350P Malibu
Defective Nose Gear Attachment
While towing the aircraft, a technician noticed the nose landing gear moving from side to side.The technician discovered the nose landing gear actuator attachment boss was improperly welded to the engine mount, with the weld going only about half way around the diameter. This aircraft was manufactured in 1998, and the maintenance records did not indicate any repair or other work in the area of this discrepancy.Part total time – 388 hours.
Twin Commander 690A
Landing Gear Operation
The pilot reported that during a landing approach, there was no response when he selected the landing gear to the down position. He lowered the gear using the emergency extension system and made a normal landing.A technician found a roll pin in the landing gear control handle linkage was broken. The roll pin was safety wired in position; however, the safety wire did not last very long after the pin failed. With the roll pin broken, the shaft turned inside the hole of the gear handle, which was severely worn. Aircraft total time – 6,000 hours.
