Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Billings, Montana 59101
Wednesday, May 29, 1996 16:45 MDT
NTSB Narrative Summary Released at Completion of Accident
The crew lost elevator trim after leveling at flight level (FL) 310, and they had to hold continuous control pressure to maintain level flight. Total air temperature was -50 degrees C at altitude. The captain elected to continue flight to the destination. Normal elevator trim operation was regained as the aircraft descended through 16,000 feet on its approach (total air temperature -7 degrees C); the flight subsequently landed without further incident. Postflight inspections of the elevator trim actuators by FAA inspectors revealed paint overspray on the elevator trim actuator push rods, scoring and corrosion on the push rods, and white desiccant windows on the actuators. The airline's FAA principal maintenance inspector (PMI) reported that there had been 10 unscheduled removals of DO-328 elevator trim actuators in the last 2-1/2 years for moisture and/or freezing in flight; that maintenance check cards did not address checking desiccant windows for moisture contamination or color criteria for checking the desiccant windows; that teardown reports from the vendor, AVIAC Technologies of France, indicated the paint overspray on the push rods was damaging the actuator quad rings during operation; and that he believed that damage to the quad rings was allowing moisture to enter the actuator housings.
NTSB Probable Cause Narrative
paint overspray on the elevator trim actuator push rods, which damaged the actuator quad rings during normal operation and allowed water to enter the actuators; and the resultant freezing of the actuators. Factors relating to the incident included the aircraft manufacturer's failure to adequately protect the actuators from overspray during aircraft painting, insufficiently defined maintenance procedures by the aircraft manufacturer, and low temperatures at cruising altitude.
Event Information
| Type of Event | Incident |
| Event Date | 5/29/1996 |
| Event Day of the Week | Wednesday |
| Time of Event | 1645 |
| Event Time Zone | Mountain Daylight Time |
| Event City | BILLINGS |
| Event State | MONTANA |
| Event Country | -- |
| Zipcode of the event site | 59101 |
| Event Date Year | 1996 |
| Event Date Month | 5 |
| 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 | Full |
| Investigator's weather source | Pilot |
| Time of the weather observation | 0 |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Unknown |
| Sky Condition for Lowest Ceiling | Unknown |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 0 |
| Air Temperature at event time (in degrees celsius) | -50 |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | 0 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 0 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | -- |
| 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 | 23 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 5019 |
| NTSB Notification Source | -- |
| NTSB Notification Date | May 29 1996 12:00AM |
| NTSB Notification Time | 1623 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 8 2000 10:01AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N336PH |
| NTSB Number | SEA96IA104 |
| 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 | Dornier |
| Aircraft Model | 328 |
| Aircraft Series Identifier | 328 |
| Aircraft Serial Number | 3014 |
| Certified Max Gross Weight | 30071 |
| 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 | 34 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Apr 25 1996 12:00AM |
| Airframe hours since last inspection | 219 |
| Airframe Hours | 3846 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | FIRST SECURITY BANK OF UTAH |
| Aircraft Owner Street Address | 79 S. MAIN ST. |
| Aircraft Owner City | SALT LAKE CITY |
| Aircraft Owner State | UT |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 84111 |
| 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 | 19521 PACIFIC HIGHWAY S. |
| Operator City | SEATTLE |
| Operator State | WA |
| Operator Country | |
| Operator Zip code | 98188 |
| Operator Code | QXEA |
| 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/Cargo |
| Type of Flying (Per_Bus / Primary) | Unknown |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | Yes |
| Departure Airport Code | BIL |
| Departure City | |
| Departure State | MT |
| Departure Country | |
| Departure Time | 1525 |
| Departure Time Zone | MDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | GEG |
| Destination City | SPOKANE |
| Destination State | WA |
| Destination Country | |
| Specific Phase of Flight | Climb |
| 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 | -- |