Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Spokane, Washington 99212
Wednesday, March 31, 1999 19:43 PST
NTSB Narrative Summary Released at Completion of Accident
The flight crew reported that, while in cruise flight, the number 1 hydraulic (utility) fluid quantity dropped below the low red mark on the gauge. The flight crew switched to the secondary hydraulic system and diverted to a nearby airport, where a landing was made without incident. Maintenance personnel inspected the aircraft and found a hydraulic line to the flap drive motor was chafed through and leaking. The flight crew reported that this was the second time that day that the number 1 hydraulic system fluid level had dropped. Prior to the last departure, maintenance personnel had serviced the system with hydraulic fluid. On that occasion, the flight crew ran the engines and cycled the flight controls while maintenance personnel looked for leaks. No leaks were found and the aircraft departed on the next leg of the scheduled flight.
NTSB Probable Cause Narrative
A chafed hydraulic line.
Event Information
| Type of Event | Incident |
| Event Date | 3/31/1999 |
| Event Day of the Week | Wednesday |
| Time of Event | 1943 |
| Event Time Zone | Pacific Standard Time |
| Event City | SPOKANE |
| Event State | WASHINGTON |
| Event Country | -- |
| Zipcode of the event site | 99212 |
| Event Date Year | 1999 |
| Event Date Month | 3 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | |
| Event Location Nearest Airport ID | |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1956 Pacific Standard Time |
| Direction of event from weather observation facility (degrees) | 270 |
| Weather Observation Facility ID | GEG |
| Elevation of weather observation facility | 2372 |
| Distance of event from weather observation facility (units?) | 40 |
| Time Zone of the weather observation | PST |
| Lighting Conditions | Night/Dark |
| Lowest Ceiling Height | 18000 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Unknown |
| Sky Condition for Lowest Ceiling | Broken |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 3 |
| Dew Point at event time (in degress fahrenheit) | -6 |
| Wind Direction (degrees magnetic) | 340 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 7 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Unknown |
| 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 | 44 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 5002 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Mar 31 1999 12:00AM |
| NTSB Notification Time | 2000 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 12 2000 11:27AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N477AU |
| NTSB Number | SEA99IA045 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | None |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Fokker |
| Aircraft Model | F.28 MK 4000 |
| Aircraft Series Identifier | F.28 MK 40 |
| Aircraft Serial Number | 11226 |
| Certified Max Gross Weight | 71000 |
| 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 | 69 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | ATLANTIC CREDIT CORP. |
| Aircraft Owner Street Address | P.O. BOX NC1-002-38-20 |
| Aircraft Owner City | CHARLOTTE |
| Aircraft Owner State | NC |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 28255 |
| Operator is an individual? | -- |
| Operator Name | HORIZON AIR |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 8070 NE AIRTRANS WAY |
| Operator City | PORTLAND |
| Operator State | OR |
| Operator Country | |
| Operator Zip code | 97218 |
| Operator Code | |
| Owner has at least one certificate | Yes - certificate holder |
| 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 | Scheduled |
| Indicates Domestic or International Flight | Domestic |
| Operator carrying Pax/Cargo/Mail | Passenger Only |
| Type of Flying (Per_Bus / Primary) | Unknown |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | BIL |
| Departure City | BILLINGS |
| Departure State | MT |
| Departure Country | |
| Departure Time | 1928 |
| Departure Time Zone | MST |
| Destination Same as Local Flt | -- |
| Destination Airport Code | SEA |
| Destination City | SEATTLE |
| Destination State | WA |
| Destination Country | |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:30AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 0 |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |