Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Covington, Kentucky 41011
Wednesday, May 8, 2002 11:00 EDT
NTSB Narrative Summary Released at Completion of Accident
The Bombardier CL600-2B19 regional jet experienced aileron control stiffness during cruise flight. The airplane was pushed back during a period of moderate to heavy rain. After pushback, the airplane was held on the taxiway for about 30 minutes while the rain continued. Takeoff also occurred during a period of heavy rain. After leveling off at flight level 280, while in cruise flight, the "AP TRIM IS LWD" caution annunciator illuminated. The first officer disconnected the autopilot, and found the aileron controls to be "stiff and binding." The captain then took control of the airplane, and also found the aileron controls to be stiff and binding. The captain applied "light to moderate" roll input and felt a snap. Aileron control then operated normally. The captain executed left and right turns with no additional problems or binding noted. The crew re-engaged the autopilot, and the flight continued to an uneventful landing. On the same date, two other CL600 regional jets from the same airline also experienced aileron stiffness after taking off at the same airport and in similar weather conditions. Both airplanes landed uneventfully. One of the airplanes diverted to an alternate airport. The investigation revealed that approximately 40 Bombardier CRJ CL-600-2B19 regional jets experienced in-flight aileron control stiffness after standing/taxiing in, or taking off during rainy conditions, then climbing to freezing temperatures. When the jets descended to above-freezing temperatures, the aileron control stiffness ceased. Testing revealed that aileron circuit binding occurred in the area of the Brake and Position Sensor Unit (BPSU) bay. Typically, within the bay, horizontally-oriented pulleys in the aileron control circuit would seize, and the aileron cable, after being subjected to water soaking, would freeze to the pulley. Water ingress to the bay most likely occurred via an aging self-contouring sealing pad on an access panel directly above the pulleys. The horizontal orientation of the pulleys, which had been used without difficulty in transport category aircraft for over 20 years, and the dished cross section of the pulley face allowed the retention of water when the airplane was parked. In addition, the drying of pulley grease over time, combined with water migration from rain, could temporarily allow the bearing to seize when the airplane reached altitude. A test on a dry-bearing pulley revealed that when water was applied to the pulley face, it remained pooled until the pulley was moved, when it flowed into the bearing. Prior to the incidents, the manufacturer had not issued specific instructions to inspect pulleys in the BPSU bay. Subsequent service letters and airworthiness directives to inspect the pulleys, grease the aileron cables and replace aging and seized pulleys, resulted in over 60 seized and deteriorating pulleys being found fleet wide. There have been no further aileron control stiffness events on aircraft which had undergone the new inspection/maintenance procedures.
NTSB Probable Cause Narrative
The manufacturer's failure to provide inspection criteria for the BPSU compartment aileron control pulleys, which resulted in eventual pulley corrosion, and subsequent control stiffness when seized pulleys and water-soaked aileron cables froze together at altitude. Factors included leaking BPSU bay access panel seals, precipitation, and freezing temperatures.
Event Information
| Type of Event | Incident |
| Event Date | 5/8/2002 |
| Event Day of the Week | Wednesday |
| Time of Event | 1100 |
| Event Time Zone | Eastern Daylight Time |
| Event City | Covington |
| Event State | KENTUCKY |
| Event Country | -- |
| Zipcode of the event site | 41011 |
| Event Date Year | 2002 |
| Event Date Month | 5 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 390246N |
| Event Location Longitude | 0843944W |
| 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 | Weather Observation Facility |
| Time of the weather observation | 1038 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | CVG |
| Elevation of weather observation facility | 882 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 1000 |
| Lowest Non-Ceiling Height | 500 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | Broken |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 0.75 |
| Air Temperature at event time (in degrees celsius) | 17 |
| Dew Point at event time (in degress fahrenheit) | 17 |
| Wind Direction (degrees magnetic) | 100 |
| 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) | 29.99 |
| 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 | 18 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 18028 |
| NTSB Notification Source | EROC |
| NTSB Notification Date | May 8 2002 12:00AM |
| NTSB Notification Time | 1340 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Jul 7 2005 10:33AM |
| User who most recently changed record | NTSB\JOHB |
| Basic weather conditions | Instrument Meteorological Cond |
| FAA District Office | Louisville |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N709CA |
| NTSB Number | NYC02IA097 |
| 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 | CL600-2B19 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 7044 |
| Certified Max Gross Weight | 51000 |
| 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 | Fixed |
| Aircraft, Type of Last Inspection | -- |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | No |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | COMAIR INC |
| Aircraft Owner Street Address | P.O. Box 75352 |
| Aircraft Owner City | Cincinnati |
| Aircraft Owner State | OH |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 45275 |
| 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 | COMA |
| 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 | Yes |
| Departure Airport Code | CVG |
| Departure City | Covington |
| Departure State | KY |
| Departure Country | USA |
| Departure Time | -- |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | OMA |
| Destination City | Omaha |
| Destination State | NE |
| Destination Country | USA |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | No |
| Evacuation occurred | No |
| Date of most recent change to record | Apr 14 2005 4:21PM |
| User who most recently changed record | PEAR |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | NA |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |