Incident Overview
On March 6, 2022, at approximately 2130 central standard time, a Beech 200 airplane, registration N8170J, was substantially damaged during a gear-up landing at Gulfport-Biloxi International Airport (GPT), Gulfport, Mississippi. The pilot and four passengers were not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a business flight.
Sequence of Events
According to the pilot, while on an instrument approach to Stennis International Airport (HAS) in Bay St Louis, Mississippi, he attempted to extend the landing gear but it would not extend. He requested to hold while trying to manually extend the gear, but the manual extension handle was jammed. He diverted to GPT and again attempted gear extension without success, leading to a gear-up landing.
Federal Aviation Administration (FAA) inspectors reported that during the gear extension process on approach to HAS, passengers heard a loud bang under the floor panels. The pilot diverted to GPT and the manual extension attempt was unsuccessful as the landing gear system was jammed. The aircraft landed with the gear retracted, sustaining substantial damage to the fuselage and empennage. After landing, a small fire occurred under the right engine nacelle.
Postaccident Examination
Postaccident examination of the landing gear by the FAA revealed that the gear remained jammed and could not be actuated with the gear handle or manual extension. Investigators cut the landing gear drive shafts to the left and right gear actuators. The left drive shaft was successfully rotated using channel lock pliers. The right drive shaft barely moved and exhibited a binding sound and feel during rotation attempts. The aircraft was relocated to a recovery facility where the right main landing gear actuator was removed and sent to the FAA aircraft certification office (ACO) in Wichita, Kansas.
Actuator Examination
Textron Aviation, under FAA ACO supervision, examined and disassembled the right main landing gear actuator. The examination findings included:
1. The initial component failure originated between the straight bevel gear set. 2. Breakage of the teeth from the pinion gear varied in fracture surface and location. Individual broken teeth showed cracking features that would have developed progressively before failure. A group of six adjacent broken teeth had evidence of shear overload and tensile overload, indicating abrupt failure possibly related to shock overloading. Smearing during final failure stages obscured additional evidence. 3. The broken pinion gear teeth exhibited internal secondary cracks. 4. The driven gear teeth were plastically deformed and cracked along the tip of the addendum as it smeared against the broken section of pinion teeth. Additional cracks near the root of the driven gear could not be confirmed as fatigue or overload cracking. 5. Appropriate grease was present and abundant within the housing. 6. Both gears were confirmed to be the correct alloy per drawing requirements. 7. The pinion gear had effective case hardening to the appropriate depth but did not meet drawing requirements for minimum case hardness. 8. The driven gear did not have evidence of case hardening and did not meet drawing requirements for both effective case depth and minimum case hardness.
Maintenance History
A review of maintenance records showed that on January 6, 2015, the right main landing gear actuator was overhauled and later reinstalled. As of the accident date, the actuator was due for overhaul or replacement every 8,000 cycles, with 7,429 cycles remaining. On October 20, 2021, during a maintenance phase inspection at 12,449 total cycles, the main landing gear mechanical actuators were inspected per the aircraft maintenance manual with no defects noted. As of the accident date, the actuator was to be inspected every 1,000 cycles, with 945 cycles remaining.