Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Chicago, Illinois 60666
Wednesday, December 27, 2000 21:10 CST
NTSB Narrative Summary Released at Completion of Accident
The captain said that during takeoff from O'Hare International Airport (ORD) the airplane accelerated normally, rotated, and "jumped into the air". At 800 feet agl, the captain called for the climb checklist. It was about this time that the captain noticed that he could not trim nose down. The captain had the first officer check his trim switch and the backup system. They did not respond. The captain elected to bring the airplane back to ORD. The captain said that both he and the first officer had their control yokes pushed forward to the stop and were still climbing. The captain said he was finally able to stop the climb and level the airplane at approximately 8,000 feet. The captain said they declared an emergency and referred to the Pitch Trim 1 and 2 Failure checklists. The checklist directed they lower flaps to 9 degrees. "When we brought in the flaps, the aircraft pitched way nose high. We were out of control." The captain regained control of the airplane and had the first officer retract the flaps. The captain said they lowered the landing gear. It improved the airplane's stability slightly. They pulled and reset the trim circuit breakers twice. These actions did nothing. The captain said he lined up for an approach to runway 9R. The captain determined he was too high to land, so he executed a 360-degree descending turn. On completion of the turn, the captain said they needed to slow down so they deployed the spoilers. The captain said the airplane abruptly pitched way up. The captain said he and the first officer pushed both yokes forward. The captain advanced the throttles, and retracted the spoilers. "That second, I banked hard left, 50 to 60 degrees as I recall, and chopped the power. It took all our abilities to get the nose down." After they got the airplane back under control, the captain said approach control informed them that runway 4R was straight ahead. The captain elected to land on runway 4R. The captain said he left the airplane configured as it was (landing gear down, flaps and spoilers retracted) and flew a long shallow approach. "I said to myself, God please let me land this airplane. Over the runway, I chopped the power and let it settle on the runway." A post-incident examination of the airplane's spoiler control unit revealed that when the spoilers were given the command to retract, the unit was not sending an input to the horizontal stab control unit (HSCU) to put in 1 unit of nose down stabilizer trim. Examinations of the trim system components and the other airplane systems revealed no anomalies. Following the incident, the airplane's manufacturer revealed that the horizontal stab actuator was determined to be inadequate to move the horizontal stabilizer in all flight conditions. "The incidents are most likely caused when the flight crew fails to trim the airplane after takeoff before reaching a certain airspeed where the air loads on the stabilizer may overpower the trim actuator, resulting in the horizontal stabilizer not responding to the pitch trim command from the flight crew." The manufacturer issued an alert service bulletin mandating the installation of a cockpit placard and revisions to the airplane flight manual establishing a maximum speed of 160 knots to pitch-trim after takeoff. The FAA issued an emergency AD mandating the installation of the cockpit placard and revisions to the airplane flight manual. The FAA has also tasked the manufacturer to make design changes that will enable the trim actuator to handle increased load limits. The FAA has also mandated changes that will provide improved pitch trim failure indications and ergonomic improvements of the yoke trim switches.
NTSB Probable Cause Narrative
The jammed horizontal stabilizer trim that occurred during the airplane's initial climb after takeoff. Factors relating to the incident were the inadequate capability of the horizontal stabilizer trim actuator to move the stabilizer during all flight phases, and the inadequate design of the system by the manufacturer.
Event Information
| Type of Event | Incident |
| Event Date | 12/27/2000 |
| Event Day of the Week | Wednesday |
| Time of Event | 2110 |
| Event Time Zone | Central Standard Time |
| Event City | CHICAGO |
| Event State | ILLINOIS |
| Event Country | -- |
| Zipcode of the event site | 60666 |
| Event Date Year | 2000 |
| Event Date Month | 12 |
| 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 | Unknown |
| 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 | |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | ORD |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | -- |
| Lighting Conditions | Not Reported |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | 7000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| 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) | -14 |
| Dew Point at event time (in degress fahrenheit) | -18 |
| Wind Direction (degrees magnetic) | 350 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 11 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| 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 | 12 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 12128 |
| NTSB Notification Source | FAA Message Traffic |
| NTSB Notification Date | Dec 28 2000 12:00AM |
| NTSB Notification Time | 900 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Aug 26 2002 11:11AM |
| User who most recently changed record | NTSB\MONR |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N721HS |
| NTSB Number | CHI01IA055 |
| 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 | Embraer |
| Aircraft Model | EMB-135LR |
| Aircraft Series Identifier | EMB-135LR |
| Aircraft Serial Number | -- |
| Certified Max Gross Weight | -- |
| Aircraft Category | Airplane |
| Aircraft Registration Class | Unknown |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | -- |
| Number of Engines | -- |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Unknown |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | Unknown |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | -- |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | -- |
| Aircraft Owner State | -- |
| Aircraft Owner Country | -- |
| Aircraft Owner Zipcode | -- |
| Operator is an individual? | No |
| Operator Name | AMERICAN EAGLE AIRLINES, INC. |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 4333 AMON CARTER BLVD MD 5494 |
| Operator City | FORT WORTH |
| Operator State | TX |
| Operator Country | -- |
| Operator Zip code | 76155 |
| Operator Code | SIMA |
| 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) | Unknown |
| Second Pilot on Board | -- |
| Departure Point Same as Event | Yes |
| Departure Airport Code | ORD |
| Departure City | -- |
| Departure State | IL |
| Departure Country | -- |
| Departure Time | 0 |
| Departure Time Zone | -- |
| Destination Same as Local Flt | -- |
| Destination Airport Code | LSE |
| Destination City | LACROSSE |
| Destination State | WI |
| Destination Country | -- |
| Specific Phase of Flight | Climb |
| Report sent to ICAO? | -- |
| Evacuation occurred | No |
| Date of most recent change to record | Jul 26 2002 10:40AM |
| User who most recently changed record | SULP |
| 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 | -- |