LAX94LA030

After moving the landing gear handle to the up position, the cockpit began filling with smoke. The pilot noticed that the gear appeared to be hung in an intransit position. The smoke, which smelled of burning electrical insulation, became heavier, and heat could be felt on the cockpit floor. The pilot returned to the airport, and the gear collapsed during landing. Examination revealed that the landing gear motor and associated wiring were burned, and the cockpit flooring appeared to be partially melted. The right landing gear actuator was found to have been improperly overhauled, which resulted in three gear teeth breaking and jamming the actuator. Beech mandatory service bulletin no. 2035, rev. Ii, requiring replacement of the 200-AMP gear motor circuit breaker with a 60-AMP breaker to prevent gear motor damage, was not accomplished on this airplane.

On October 27, 1993, at 2315 Pacific daylight time, a Beech 200, N191FL, incurred an electrical fire in the landing gear motor and associated wiring during the takeoff initial climb at Reno, Nevada. The aircraft returned to the Reno Cannon International Airport with the landing gear jammed in a partially retracted configuration and the gear collapsed on touchdown. The aircraft was operated by the pilot and was on a cross country personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed for the operation. The aircraft incurred substantial damage. The certificated private pilot and his four passengers were not injured. The flight was originating at the time of the mishap as a cross country flight to San Carlos, California.

In a verbal statement, the pilot reported that just after moving the landing gear handle to the up position in the initial climb, the cockpit began to fill with smoke. The pilot said he dumped the cabin in an attempt to clear the smoke. He noticed the landing gear appeared to be hung in an intransit position and he pulled the cockpit circuit breaker. The pilot stated that the smoke, which smelled of burning electrical insulation, appeared to get heavier and heat could be felt on the cockpit floor. The pilot said he requested and received a return to airport landing clearance from the control tower, and, just after touchdown, the right main landing gear collapsed.

An FAA airworthiness inspector from the Reno, Nevada, Flight Standards District Office, examined the aircraft. According to his report, the electrical landing gear motor and the associated wiring were burned and the cockpit flooring appeared to be partially melted from radiant heat exposure. The structural landing gear attach points and other bulkhead components in the fuselage sustained major damage.

The landing gear system electrical components, motor, main gear box, and the right main landing gear actuator were removed from the aircraft for detailed examination. The system electrical components examined consisted of: 1) landing gear motor relay K100, 2) landing gear remote circuit breaker CB100, and 3) landing gear remote circuit breaker relay K101.

The system electrical components were found to function within specifications for the 200 ampere gear motor circuit protection requirement. The test reports are attached to this report.

According to the examination report, disassembly of the landing gear motor revealed evidence of excessive current flow at the motor. Burned windings were found on the rotor. Loose balls of solder were noted on the commutator, which was distorted from heat. The motor brushes were within wear limits, but brittle from heat exposure.

The right main landing gear actuator was sent to the FAA Aircraft Certification Office in Wichita, Kansas, for disassembly and examination by Beech Aircraft. The actuator was found in an intermediate position and the shaft would only rotate one turn before encountering a hard stop. Disassembly revealed that two gear teeth had separated from the screw housing ring gear, with one lodged between the ring gear and the pinion gear. According to the Beech Aircraft report of the examination, the actuator was assembled with insufficient shims in place. The lack of shims resulted in insufficient end play and excessive side loads on the gear teeth, which ultimately caused the gear teeth separation and jamming of the actuator.

Review of the aircraft maintenance records revealed that the landing gear actuators were overhauled in September of 1993 at the last aircraft inspection event. The aircraft had accrued 12 operating hours since the landing gear actuators were reinstalled.

Beech Aircraft Service Bulletin 2035 (Rev II) was issued in 1985 and revised in August of 1990. The Bulletin concerns the replacement of the 200 ampere landing gear motor circuit breaker with a 60 ampere rated breaker to prevent motor damage due to excessive electrical current. Beech Aircraft considers the bulletin mandatory in nature. Examination of the aircraft maintenance records revealed that SB 2035 was not accomplished.