Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Miami, Florida
Tuesady, May 11, 1999 14:45 EDT
NTSB Narrative Summary Released at Completion of Accident
During final approach to the airport and after the crew turned the autopilot off, American Airlines flight 916 began experiencing uncommanded rudder motion and high rudder pedal forces. The flight crew executed a go-around about 360 feet above ground level. Despite continued difficulties with the rudder, the flight crew was able to land the airplane successfully. Examination of the autopilot yaw actuator revealed two main findings: (1) the wiring to the two main valve solenoids had been cross connected, and (2) a foreign-particle contaminant in the green system engagement valve solenoid had prevented disengagement of the yaw actuator. Investigators found that when these two conditions exist, turn coordination system inputs can cause uncommanded rudder movements. Inspections of A300 and A310 airplanes after the incident resulted in the discovery of another American A300 with cross-connected solenoid wiring. American indicated that it had installed new autopilot actuator solenoids on this airplane and the rest of its A300 fleet. At the time the solenoids were installed, American's procedures did not include a check for proper installation of the solenoid wiring. The manufacturers of the airplane and the actuator have since incorporated new procedures to ensure that the solenoids are wired properly. As part of the investigation, numerous additional solenoids were examined for the presence of contaminants. Although contaminants were discovered on several other solenoids, they were smaller than that found on the incident airplane's engagement solenoid and did not affect solenoid functionality. Audits of the solenoid assembly process revealed the need to update production and inspection documentation and the need to include measures to prevent foreign particles from contaminating adjacent workstations. The manufacturer of the solenoids took corrective actions that included improving production facilities, implementing more stringent sampling and inspection procedures, and clarifying assembly instructions.
NTSB Probable Cause Narrative
Uncommanded rudder movement caused by a contaminant in the engagement valve solenoid that prevented disengagement of the autopilot yaw actuator and cross-connected wiring of the autopilot yaw actuator's main valve solenoids by the operator. Factors contributing to the incident were the lack of proper controls in the solenoid assembly process and the lack of procedures to detect miswired solenoids.
Event Information
| Type of Event | Incident |
| Event Date | 5/11/1999 |
| Event Day of the Week | Tuesday |
| Time of Event | 1445 |
| Event Time Zone | Eastern Daylight Time |
| Event City | MIAMI |
| Event State | FLORIDA |
| Event Country | -- |
| Zipcode of the event site | -- |
| Event Date Year | 1999 |
| 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 | Unknown |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Unknown |
| Time of the weather observation | |
| 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 | Not Reported |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| 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) | -- |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | 200 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 8 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | -- |
| 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 | 129 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 12642 |
| NTSB Notification Source | -- |
| NTSB Notification Date | May 11 1999 12:00AM |
| NTSB Notification Time | 1620 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Nov 26 2002 3:58PM |
| User who most recently changed record | NTSB\ZUZL |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N7082A |
| NTSB Number | DCA99IA058 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | No |
| Damage | None |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Airbus Industrie |
| Aircraft Model | 300-600 |
| Aircraft Series Identifier | 300-600 |
| Aircraft Serial Number | -- |
| Certified Max Gross Weight | -- |
| 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 | -- |
| 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? | -- |
| Operator Name | AMERICAN AIRLINES |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | DALLAS/FT WORTH INT'L AIRPORT |
| Operator City | DALLAS |
| Operator State | TX |
| Operator Country | -- |
| Operator Zip code | -- |
| Operator Code | AALA |
| 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 | International |
| Operator carrying Pax/Cargo/Mail | Passenger Only |
| Type of Flying (Per_Bus / Primary) | Unknown |
| Second Pilot on Board | Unknown |
| Departure Point Same as Event | No |
| Departure Airport Code | -- |
| Departure City | BOGOTA |
| Departure State | -- |
| Departure Country | CO |
| Departure Time | 0 |
| Departure Time Zone | -- |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | MIA |
| Destination City | MIAMI |
| Destination State | FL |
| Destination Country | USA |
| Specific Phase of Flight | Approach |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Oct 15 2002 10:25AM |
| User who most recently changed record | HILF |
| 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 | -- |