Individually Owned: 150,657
Corporate Owned: 137,281
Phoenix Sky Harbor Intl Airport
Aircraft Accident/Incident Report
Phoenix, Arizona 85034
Friday, June 13, 2003 17:30 PDT
NTSB Narrative Summary Released at Completion of Accident
The airplane was climbing through 23,000 feet for flight level 290 (29,000 feet) when the stab trim/mach trim caution illuminated on the instrument panel indicating both channels 1 and 2 were inoperative, and subsequently the pitch trim system could not be moved. The captain maintained the airplane's airspeed below 215 knots, and initiated a return to the departure airport. The flight crew took turns at the controls. To maintain the airplane in the proper attitude, the first officer had to maintain about 30 pounds of backpressure on the yolk to counteract the trim forces. The captain landed the airplane uneventfully. Maintenance crews believed the failure was in the captain's stab trim disconnect switch, which they suspected was stuck in the cutout position. The switch was replaced with another unit. A second stab trim failure event occurred 32 days later in the same airplane. The captain reported that during a descent from flight level 290, both channels of stab trim and mach trim failed with a corresponding "AP Pitch Trim" message. After about 2 minutes, the captain was able to reset both stab trim channels and then the mach trim. The airplane landed uneventfully. The maintenance crew removed and replaced the Horizontal Stabilizer Trim Control Unit (HSTCU) to correct the discrepancy. The airplane's flight data recorders (FDR's) were removed, and the data downloaded. The data revealed that 17 minutes into the flight on the first occurrence the stabilizer trim discrete changed from 'on' to 'off.' The data for the second occurrence revealed that 96 minutes into the flight the stabilizer trim discrete changed from 'on' to 'off' for about 2 minutes, and then back to 'on.' The stab trim disconnect switch and the HSTCU were tested, and both functioned within the manufacturer's specifications. Under physical examination it was noted that the HSTCU's access panel door cam-type fastener's shoulder guide was missing from one of the two door latching fittings. The shoulder half was located loose inside the HSTCU circuitry area of the unit. Engineers described the electrical circuit boards as having a heavy coat of protective/sealing varnish that would protect the circuits from shorts caused by debris. Additionally, each trim channel is on a separate circuit board in the HSTCU. The simultaneous failure of both trim channels due to a single piece of debris is unlikely. A search of the Federal Aviation Administration Service Difficulty Report (SDR) database for Stab Control System anomalies in the CL-600 from 1995 to July 10, 2003, identified 67 dual channel stab trim failures. Twenty-seven percent of the dual trim failures were identified as cockpit trim disconnect switch issues; 52 percent were identified as HSTCU/HSTA/MCU issues; and 21percent were not resolved or could not be duplicated on the ground. The airplane in question, serial number 7325, was not listed in the results as having any reported flight control discrepancies in the database.
NTSB Probable Cause Narrative
the simultaneous failure of both horizontal stabilizer trim channels on two separate occasions for undetermined reasons.
Event Information
| Type of Event | Incident |
| Event Date | 6/13/2003 |
| Event Day of the Week | Friday |
| Time of Event | 1730 |
| Event Time Zone | Pacific Daylight Time |
| Event City | Phoenix |
| Event State | ARIZONA |
| Event Country | -- |
| Zipcode of the event site | 85034 |
| Event Date Year | 2003 |
| Event Date Month | 6 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 332603N |
| Event Location Longitude | 1120029W |
| Event Location Airport | Phoenix Sky Harbor Intl |
| Event Location Nearest Airport ID | KPHX |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 80 |
| Degrees magnetic from airport | 360 |
| Airport Elevation | 1135 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1756 Mountain Standard Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | KPHX |
| Elevation of weather observation facility | 1135 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | MST |
| 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) | 10 |
| Air Temperature at event time (in degrees celsius) | 37 |
| Dew Point at event time (in degress fahrenheit) | 1 |
| Wind Direction (degrees magnetic) | 260 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 11 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.75 |
| 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 | 52 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 18488 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Jun 13 2003 12:00AM |
| NTSB Notification Time | 1730 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Oct 27 2005 6:51AM |
| User who most recently changed record | NTSB\JOHB |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | WP-FSDO-Scottsdale, Arizona |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N97325 |
| NTSB Number | LAX03IA199 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | Yes |
| Damage | None |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Bombardier |
| Aircraft Model | CL-600-2B19 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 97325 |
| Certified Max Gross Weight | 53000 |
| 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 | 53 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | AAIP |
| Date of Last Inspection | Jun 11 2003 12:00AM |
| Airframe hours since last inspection | 22 |
| Airframe Hours | 11087.2 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Mesa Air Group |
| Aircraft Owner Street Address | 410 N 44th St, Ste 700 |
| Aircraft Owner City | Phoenix |
| Aircraft Owner State | AZ |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 85008 |
| 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 | MASA |
| Owner has at least one certificate | -- |
| 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 | Scheduled |
| Indicates Domestic or International Flight | Domestic |
| Operator carrying Pax/Cargo/Mail | Passenger Only |
| Type of Flying (Per_Bus / Primary) | -- |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | PHX |
| Departure City | Phoenix |
| Departure State | AZ |
| Departure Country | USA |
| Departure Time | 1613 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | BOI |
| Destination City | Boise |
| Destination State | ID |
| Destination Country | USA |
| Specific Phase of Flight | Climb - to cruise |
| Report sent to ICAO? | Yes |
| Evacuation occurred | No |
| Date of most recent change to record | Jul 18 2005 4:48PM |
| User who most recently changed record | COOS |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 26 |
| Runway Length | 11489 |
| Runway Width | 150 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |