On June 24, 2004, a Cessna 185F (registration N4585F) was involved in an aviation accident near Bozeman, MT. Investigators recorded the probable cause as: The failure of the brake disk attachment flange due to fatigue cracking originating from corrosion pitting, rendering the right wheel brake inoperative and leading to the ground loop. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During landing roll, the aircraft ground-looped left when the right main gear brake failed. Investigation revealed fatigue failure of the brake disk attachment flange, originating from corrosion pits.
Accident Overview
During the landing roll, the pilot applied heavy braking to turn off the runway at taxiway Echo. The aircraft suddenly and rapidly ground-looped to the left.
Post-Accident Inspection
An initial post-accident inspection revealed that the right main gear brake rotor assembly had torn loose from the wheel itself, rendering the right wheel brake totally inoperative.
Laboratory Analysis
The wheel hub and brake disk assembly were shipped to the NTSB Materials Laboratory. Examination determined that the brake disk attachment flange failed in fatigue in the bend around the attachment flange. The brake disk showed a substantial amount of general corrosion. Although the attachment flange met the minimum thickness requirements, most of its surface was covered by corrosion and corrosion pitting. The fatigue crack propagation that eventually led to the failure had originated in one of these corrosion pits.
Probable cause
The failure of the brake disk attachment flange due to fatigue cracking originating from corrosion pitting, rendering the right wheel brake inoperative and leading to the ground loop.
What happened in the 24 Jun 2004 Cessna 185F accident near Bozeman, MT?
During landing roll, the aircraft ground-looped left when the right main gear brake failed. Investigation revealed fatigue failure of the brake disk attachment flange, originating from corrosion pits.
What aircraft was involved and where did it happen?
The accident on 24 Jun 2004 involved a Cessna 185F, registration N4585F, at Bozeman, MT.
What was the probable cause of the accident?
The failure of the brake disk attachment flange due to fatigue cracking originating from corrosion pitting, rendering the right wheel brake inoperative and leading to the ground loop.
A SkyWalk Join't 3 paraglider crashed into the ground near Las Vizcachas, Chile, on September 1, 2024. The pilot and passenger sustained serious spinal…
PARAPENTE (ULTRALIVIANO NO MOTORIZADO)·2024-09-01DGAC Chile
A Cessna 172N struck electrical cables while on final approach to land at Aucó Aerodrome in Chile. The pilot was uninjured, but the aircraft sustained damage…
A Bombardier DHC-8-402 suffered a tail strike during landing at Puerto Williams on September 9, 2024. All 76 occupants were unharmed, but the aircraft…
A MYD JS-MD 3 glider veered off the runway and struck a wall at Vitacura Aerodrome on January 6, 2025. The pilot was uninjured, but the aircraft sustained…
A recreational paraglider flight in Puchuncaví, Chile, ended with the pilot sustaining serious injuries after a rapid descent and impact with a hillside on…
PARAPENTE (ULTRALIVIANO NO MOTORIZADO)·2025-03-29DGAC Chile
A Tecnam P2006T landed on its belly at an aerodrome in Poland after the crew failed to confirm landing gear deployment. The incident resulted in no injuries…