Individually Owned: 151,845
Corporate Owned: 143,699
Gallatin Field Airport
Aircraft Accident/Incident Report
Bozeman, Montana 59715
Thursday, June 24, 2004 15:10 MDT
NTSB Narrative Summary Released at Completion of Accident
During the landing roll, the pilot was applying heavy braking in order to turn off the runway at taxiway Echo, when the aircraft suddenly and rapidly ground-looped to the left. An initial post-accident inspection of the aircraft revealed that the right main gear brake rotor assembly had torn lose from the wheel itself, rendering the right wheel brake totally inoperative. The wheel hub and brake disk assembly were shipped to the NTSB Materials Laboratory, where it was 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, and 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 lead to the failure had originated in one of these corrosion pits.
NTSB Probable Cause Narrative
The failure of the right main gear brake disk attach flange during the landing roll, due to fatigue cracks emanating from numerous corrosion pits present on the surface of the disk, leading to the right brake becoming totally inoperative, and resulting in a rapid inadvertent ground-loop. Factors include hard braking applied by the pilot in order to turn off the active runway at an early taxiway, and considerable corrosion on the surface of the brake disk flange.
Event Information
| Type of Event | Accident |
| Event Date | 6/24/2004 |
| Event Day of the Week | Thursday |
| Time of Event | 1510 |
| Event Time Zone | Mountain Daylight Time |
| Event City | Bozeman |
| Event State | MONTANA |
| Event Country | -- |
| Zipcode of the event site | 59715 |
| Event Date Year | 2004 |
| Event Date Month | 6 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 454641N |
| Event Location Longitude | 1110927W |
| Event Location Airport | Gallatin Field |
| Event Location Nearest Airport ID | KBZN |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | 4471 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Witness |
| Time of the weather observation | |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | -- |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | -- |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 20 |
| Air Temperature at event time (in degrees celsius) | 24 |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | -- |
| Wind Speed (knots) | -- |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | -- |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 18350 |
| NTSB Notification Source | FAA Operations Center |
| NTSB Notification Date | Jun 24 2004 12:00AM |
| NTSB Notification Time | 1600 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Sep 13 2005 12:54PM |
| User who most recently changed record | NTSB\JOHB |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Helena FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N4585F |
| NTSB Number | SEA04LA117 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Cessna |
| Aircraft Model | 185F |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 1851092 |
| Certified Max Gross Weight | 3350 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 6 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | -- |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Kenneth D. Chapman |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Clayton |
| Aircraft Owner State | WA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 99110 |
| Operator is an individual? | No |
| Operator Name | -- |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | -- |
| Operator State | -- |
| Operator Country | -- |
| Operator Zip code | -- |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | -- |
| Certified for Part 133 or 137 Operation | -- |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | Personal |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | -- |
| Departure City | -- |
| Departure State | -- |
| Departure Country | -- |
| Departure Time | -- |
| Departure Time Zone | -- |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | BZN |
| Destination City | Bozeman |
| Destination State | MT |
| Destination Country | USA |
| Specific Phase of Flight | Landing - roll |
| Report sent to ICAO? | No |
| Evacuation occurred | No |
| Date of most recent change to record | Jun 22 2005 12:06PM |
| User who most recently changed record | STAM |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 30 |
| Runway Length | 9003 |
| Runway Width | 150 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |