Probable cause
The mechanic’s failure to torque check the axle-to-spring gear attachment bolts per the manufacturer's Annual/100-Hour Airframe Inspection Checklist, resulting in fatigue failure of the bolts.
NTSB analysis
While applying the left brake during taxi after landing, the pilot first heard a "loud pop from the left gear" and during further brake application, the left axle and wheel assembly separated. Two MS20008H22 bolts and one AN509-616-35 screw that secure the axle to the spring leg were fractured. The failure mode of the bolts was due to fatigue, and was typical of bolts that are insufficiently torqued. The mechanic who last inspected the airplane used his own checklist and did not torque check the bolts and screw, which is required by the manufacturer's Annual/100-Hour Airframe Inspection Checklist.
Text from the NTSB. Open the NTSB docket for MIA08LA174 for the full record.
Event
- Date
- Aug 26, 2008
- Type
- Accident
- Place
- Clarksdale, Mississippi
- Nearest airport
- Fletcher Field Airport (CKM)
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Schweizer Aircraft Corp G-164B
- N-number
- N3633S
- Category
- Airplane
- Damage
- Substantial
- Operating rule
- Part 137 (agricultural)
- Purpose of flight
- Aerial application
Other records under this N-number
From the NTSB aviation accident database: N-registered aircraft, events since 2008, data through Oct 28, 2026. The file is published monthly, so the latest weeks are incomplete and recent records can change. The official source is the NTSB aviation investigation search. CheckAero is independent and not affiliated with the NTSB.