# Accident 19990616042129A: Gulstm 690B, Monterey, CA, June 16, 1999

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: June 16, 1999, 22:00 local time
- Place: Monterey, CA
- Airport: Monterey Peninsula
- Damage: Substantial damage
- Phase of flight: Roll-Out (Fixed Wing)
- Operating rules: General operating rules (Part 91)
- Location: 36.6009° N, 121.8800° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=36.6009&lon=-121.8800&mi=10
- Aircraft: N480K, registered now (https://openairdocs.org/aircraft/N480K) (OpenAirDocs)
- Registry model: Rockwell International 690B (registry code 7630516, https://openairdocs.org/model/rockwell-international-690b) (OpenAirDocs)
- Registry engine: AiResearch TPE331-5&6SER (registry code 01515, https://openairdocs.org/engine/airesearch-tpe331-5-6ser) (OpenAirDocs)
- Reported make and model: GULSTM 690B
- People aboard: 5
- Fatal injuries: 0
- Pilot flight hours: 5,650 total, 950 in this make and model, 8 in the last 90 days
- NTSB investigation: [NTSB LAX99LA241](https://openairdocs.org/ntsb/LAX99LA241) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19990616042129A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

(.4)THE PILOT AND COPILOT REPORTED THAT THEY WERE ON APPROACH AND AS THEY PASSED THE OUTER MARKER, THEY OBSERVED THREE GREEN LIGHTS INDICATING THE LANDING GEAR WAS EXTENDED. THEY OBSERVED HYDRAULIC PRESSURE OF ABOUT 1,000 PSI DURING THE LANDING CHECKS.  THE PILOT SAID HE LANDED THE AIRPLANE WITH A SLIGHT TAILWIND, OBSERVED TWO BETA LIGHTS, AND HE PULLED THE POWER LEVERS INTO GROUND IDLE/REVERSE.  SHORTLY THEREAFTER, HE FELT THE LEFT LANDING GEAR COLLAPSE AND HE OBSERVED ONE RED UNSAFE LIGHT AND TWO GREEN LANDING GEAR LIGHTS, WITH A CORRESPONDING GEAR WARNING HORN.  POSTACCIDENT EXAMINATION OF THE LEFT MAIN GEAR REVEALED THAT A PIECE WAS FRACTURED FROM THE INBOARD GEAR-FORGING BOSS, WHICH HOUSES A CLEVIS FOR THE ATTACHMENT OF THE HYDRAULIC CYLINDER.  THE CLEVIS REMAINED ATTACHED TO THE HYDRAULIC CYLINDER, WHICH IN THE FULLY EXTENDED POSITION IS CONSISTENT WITH GEAR DOWN.  METALLURGICAL EXAMINATION OF THE FRACTURE FACES REVEALED FEATURES TYPICAL OF OVERSTRESS SEPARATION.  NO PRE-EXISTING CRACKS OR OTHER DEFECTS WERE FOUND ON THE FRACTURE.  A REVIEW OF THE COMMANDER MAINTENANCE MANUAL INDICATES THAT AN ADJUSTMENT MUST BE MADE TO THE CYLINDER OVER TRAVEL FOLLOWING GEAR MAINTENANCE TO  OBTAIN THE PROPER DRAG BRACE PRELOAD. THE LEFT HAND HYDRAULIC CYLINDER, MAIN LANDING GEAR AFT WHEEL WELL DOOR, AND HYDRAULIC COMPONENTS WERE REPLACED ABOUT 34 HOURS BEFORE THE ACCIDENT.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       (-23)DURING THE LANDING ROLL ON RUNWAY 1 OR THE MRY AIRPORT, AND WHILE APPLYING REVERSE THRUST, THE LEFT MAIN LANDING GEAR COLLAPSED, CAUSING SUBSTANTIAL DAMAGE TO LOWER FUSELAGE, LEFT ENGINE AND PROPELLER.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB LAX99LA241](https://openairdocs.org/ntsb/LAX99LA241), Jun 17, 1999: Rockwell 690B (N480K), Monterey, CA, substantial damage. Probable cause: The failure of maintenance personnel to properly adjust the drag brace preload during recent landing gear maintenance, which resulted in the overload failure and separation of the hydraulic cylinder…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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