Individually Owned: 150,657
Corporate Owned: 137,281
Greater Pittsburgh Airport
Aircraft Accident/Incident Report
Pittsburgh, Pennsylvania 15231
Friday, May 7, 1993 12:51 EDT
NTSB Narrative Summary Released at Completion of Accident
SHORTLY AFTER TOUCHDOWN AT MEMPHIS, TN, A SEVERE VIBRATION WAS FELT BY THE FLIGHTCREW IN THE COCKPIT. THE FLIGHTCREW THOUGHT THE VIBRATION WAS GENERATED BY THE RIGHT MAIN GEAR SO THEY HAD MAINTENANCE PERSONNEL CHECK THE RIGHT MAIN GEAR. NO ANOMALIES WERE NOTED. THE FLIGHT CONTINUED TO PITTSBURGH, PA, AND SHORTLY AFTER TOUCHDOWN, THE LEFT MAIN GEAR COLLAPSED. POST INCIDENT EXAMINATION OF THE LEFT MAIN GEAR REVEALED THAT TWO SPACERS IN THE TORQUE LINK ASSEMBLY WERE FOUND TO HAVE BEEN IMPROPERLY INSTALLED. THE INVESTIGATION ALSO REVEALED THAT DURING RE INSTALLATION OF THE TORQUE LINKS AND SHIMMY DAMPER AT THE LAST MAINTENANCE CHECK, THE TWO SPACERS WERE INSTALLED IN REVERSE OF THEIR NORMAL POSITIONS. ACCORDING TO FOKKER, REVERSAL OF THE TWO SPACERS WOULD RESULT IN AN UNDAMPED FREE PLAY BETWEEN THE UPPER AND LOWER TORQUE LINK RESULTING IN OSCILLATIONS IN THE LATERAL MODE OF THE LANDING GEAR. REVIEW OF USAIR'S AIRCRAFT MAINTENANCE MANUAL, SUPPLIED BY FOKKER, REVEALED THAT THE TWO SPACERS THAT WERE INCORRECTLY INSTALLED ON THE INCIDENT AIRPLANE WERE NOT DESCRIBED BY DIMENSIONS OR VERBIAGE.
NTSB Probable Cause Narrative
THE IMPROPER INSTALLATION OF THE SPACERS BY THE MECHANIC AND THE UNCLEAR INFORMATION SUPPLIED FROM THE MANUFACTURER AND OPERATOR REGARDING THE INSTALLATION OF THE SPACERS.
Event Information
| Type of Event | Incident |
| Event Date | 5/7/1993 |
| Event Day of the Week | Friday |
| Time of Event | 1251 |
| Event Time Zone | Eastern Daylight Time |
| Event City | PITTSBURGH |
| Event State | PENNSYLVANIA |
| Event Country | -- |
| Zipcode of the event site | 15231 |
| Event Date Year | 1993 |
| Event Date Month | 5 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | GREATER PITTSBURGH |
| Event Location Nearest Airport ID | PIT |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | 1103 |
| Weather Briefing Completeness | Full |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1302 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 1 |
| Weather Observation Facility ID | PIT |
| Elevation of weather observation facility | 1103 |
| Distance of event from weather observation facility (units?) | 1 |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 25000 |
| Sky/Lowest/Cloud Conditions | Thin Broken |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 20 |
| Air Temperature at event time (in degrees celsius) | 22 |
| Dew Point at event time (in degress fahrenheit) | 5 |
| Wind Direction (degrees magnetic) | 350 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 8 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 30 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | Minor |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | 1 |
| Injury Total None | 50 |
| Injury Total Serious | -- |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 5020 |
| NTSB Notification Source | -- |
| NTSB Notification Date | May 7 1993 12:00AM |
| NTSB Notification Time | 1255 |
| Fiche Number and/or location -used to find docket information | 50237 |
| Date of most recent change to record | Dec 11 2000 1:18PM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N867US |
| NTSB Number | BFO93IA070 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | Minor |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | FOKKER |
| Aircraft Model | F28-MK-0100 |
| Aircraft Series Identifier | F28-MK-010 |
| Aircraft Serial Number | 11312 |
| Certified Max Gross Weight | 98000 |
| 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 | 103 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Feb 4 1993 12:00AM |
| Airframe hours since last inspection | 416 |
| Airframe Hours | 6578 |
| ELT Installed | Yes |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | USAIR |
| Aircraft Owner Street Address | 2345 CRYSTAL DRIVE |
| Aircraft Owner City | ARLINGTON |
| Aircraft Owner State | VA |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 22227 |
| Operator is an individual? | -- |
| Operator Name | USAIR |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | 2345 CRYSTAL DRIVE |
| Operator City | ARLINGTON |
| Operator State | VA |
| Operator Country | |
| Operator Zip code | 22227 |
| Operator Code | USAA |
| 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 | No |
| Departure Airport Code | MEM |
| Departure City | MEMPHIS |
| Departure State | TN |
| Departure Country | |
| Departure Time | 1019 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | Landing |
| 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 | 32 |
| Runway Length | 8100 |
| Runway Width | 150 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |