Individually Owned: 150,657
Corporate Owned: 137,281
Monterey Peninsula Airport
Aircraft Accident/Incident Report
Monterey, California 93940
Wednesday, June 16, 1999 22:00 PDT
NTSB Narrative Summary Released at Completion of Accident
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.
NTSB Probable Cause Narrative
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 attach boss.
Event Information
| Type of Event | Accident |
| Event Date | 6/16/1999 |
| Event Day of the Week | Wednesday |
| Time of Event | 2200 |
| Event Time Zone | Pacific Daylight Time |
| Event City | MONTEREY |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 93940 |
| Event Date Year | 1999 |
| Event Date Month | 6 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | MONTEREY PENINSULA |
| Event Location Nearest Airport ID | KMRY |
| 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 | 254 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 2154 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | 90 |
| Weather Observation Facility ID | MRY |
| Elevation of weather observation facility | 254 |
| Distance of event from weather observation facility (units?) | 1 |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Night/Dark |
| Lowest Ceiling Height | 400 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Unknown |
| Sky Condition for Lowest Ceiling | Overcast |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 9 |
| Air Temperature at event time (in degrees celsius) | 12 |
| Dew Point at event time (in degress fahrenheit) | 11 |
| Wind Direction (degrees magnetic) | 230 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 9 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 29 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 5 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1697 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jul 2 1999 12:00AM |
| NTSB Notification Time | 941 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Aug 14 2001 2:57PM |
| User who most recently changed record | MONR |
| Basic weather conditions | Instrument Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N480K |
| NTSB Number | LAX99LA241 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Rockwell |
| Aircraft Model | 690B |
| Aircraft Series Identifier | 690B |
| Aircraft Serial Number | 11543 |
| Certified Max Gross Weight | 10325 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 8 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Nov 3 1998 12:00AM |
| Airframe hours since last inspection | 34 |
| Airframe Hours | 4687 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | NATHAN THOMPSON |
| Aircraft Owner Street Address | 9195 GUNBARREL RIDGE ROAD |
| Aircraft Owner City | BOULDER |
| Aircraft Owner State | CO |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 80301 |
| Operator is an individual? | -- |
| 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? | No |
| Certified for Part 133 or 137 Operation | Unknown |
| 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) | Business |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | 48V |
| Departure City | TRI-COUNTY |
| Departure State | CO |
| Departure Country | |
| Departure Time | 1900 |
| Departure Time Zone | MDT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | MRY |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | Landing |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 14 2001 10:24AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 10R |
| Runway Length | 7600 |
| Runway Width | 150 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |