WPR17LA061

The pilot reported that he heard a loud crunch when he raised the landing gear shortly after takeoff. The pilot climbed the airplane to about 3,000 ft and attempted to lower the landing gear using both the normal and emergency gear extension procedures but was unable to do so and subsequently landed with the gear retracted, resulting in substantial damage to the lower fuselage. Examination revealed that the landing would not extend normally. The landing gear motor was found shorted out internally and the gearbox sector gear contacted the internal stop when retracted; therefore, the emergency gear handle was not in contact with the pinion and rotated freely. The crank assembly exhibited signs of excessive wear and excessive pinion shaft end play. The American Bonanza Society Air Safety Foundation’s Landing Gear Inspection Checklist and Repair Guide stated that, “if the sector gear [end] hits the stop in either the extended or retracted position, the gearbox and motor should be removed and overhauled. The most common cause of this condition is a gear motor that is due for overhaul.” The excessive wear within the gearbox caused the sector gear to lose contact with the pinion which caused the gear motor and emergency gear handle to rotate freely with no corresponding motion from the landing gear itself.

On February 1, 2017, about 1410 Pacific daylight time, a Beech 95-B55 airplane, N321BJ, sustained substantial damage when it was involved in an accident near Cameron Park, California. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that when he raised the landing gear shortly after takeoff, he heard a loud crunch as the gear entered the gear wells. The pilot climbed the airplane to about 3,000 ft and saw that the landing gear circuit breaker was popped, and the alternator was off. The pilot attempted to extend the landing gear normally several times after resetting the circuit breaker; however, the circuit breaker popped each time and the gear remained retracted. The pilot also attempted to use the emergency gear extension to no avail, and subsequently landed with the landing gear retracted which resulted in substantial damage to the lower fuselage. During a postaccident examination, the airplane was positioned on jacks and electrical power was supplied. The landing gear handle was put in the down position however, the gear would not extend normally as the landing gear motor did not respond and got hot. The emergency extension handle, and housing assembly was removed to extend the landing gear. During the removal, the bearing retaining ring was not secured and fell out. The gear motor was subsequently removed which allowed the landing gear extension to the down and locked position. The landing gear motor was function tested by applying 28 volts to both the clockwise and counterclockwise wires. It was determined that the motor was shorted out internally. The gearbox was disassembled; the gearbox sector gear contacted the internal stop when retracted and the emergency gear handle lost contact with the pinion, causing it to rotate freely. In turn, the emergency gear handle lost contact with the pinion and rotated freely. The crank assembly exhibited signs of excessive wear and excessive pinion shaft end play resulting in the gear handle to disconnect from the pinion gear when the sector gear was against the internal up stop. The American Bonanza Society Air Safety Foundation’s Landing Gear Inspection Checklist and Repair Guide stated: There should be 1/8 to 1/4 turn counterclockwise remaining to the stop when you crank the emergency handcrank down…If the sector gear hits the stop in either the extended or retracted position, the gearbox and motor should be removed and overhauled. The most common cause of this condition is a gear motor that is due for overhaul.