Individually Owned: 150,657
Corporate Owned: 137,281
Indianapolis Intl Airport
Aircraft Accident/Incident Report
Indianapolis, Indiana 46241
Wednesday, July 9, 1997 8:40 EST
NTSB Narrative Summary Released at Completion of Accident
While the aircraft was being loaded with passengers, the flight engineer found that the right main landing gear had partially collapsed. The fractured right main landing gear had recently been overhauled and had accumulated 51 cycles and 126 hours since installation 21 days prior to the fracture. An examination was made of the aft portion of the upper and lower lugs of the trunnion. Chromium plating was apparent on sections of the trunnion where the overhaul manual stated that 'No Chrome' was to be applied. The spherical bearing assembly, locking bolt and anti-rotation washer were also examined. For normal assembly, the aft trunnion of the gear is inserted into the inner diameter of the wing mounted spherical bearing. The spherical bearing that contacted the trunnion journal had an inner diameter which measured approximately 3.50 inches. The aft trunnion journal of the failed landing gear had an outer diameter that measured approximately 3.25 inches. During landing gear replacement, the maintenance procedures require that the proper sized spherical bearings, either 3.50 inch or the 3.25 inch inner diameter, be matched with the appropriate outer cylinder aft trunnion outside diameter.
NTSB Probable Cause Narrative
the improper installation of the incorrect spherical bearing by the company's maintenance personnel. A factor was the improper plating of the trunnion with chromium by the landing gear overhaul facility.
Event Information
| Type of Event | Incident |
| Event Date | 7/9/1997 |
| Event Day of the Week | Wednesday |
| Time of Event | 840 |
| Event Time Zone | Eastern Standard Time |
| Event City | INDIANAPOLIS |
| Event State | INDIANA |
| Event Country | -- |
| Zipcode of the event site | 46241 |
| Event Date Year | 1997 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | INDIANAPOLIS INTL |
| Event Location Nearest Airport ID | IND |
| 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 | -- |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Unknown |
| Time of the weather observation | 0 |
| 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 | Day |
| Lowest Ceiling Height | 300 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Unknown |
| Sky Condition for Lowest Ceiling | Overcast |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 1 |
| Air Temperature at event time (in degrees celsius) | 17 |
| Dew Point at event time (in degress fahrenheit) | 16 |
| Wind Direction (degrees magnetic) | 360 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 11 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| 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 | 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 | 11 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 5029 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jul 9 1997 12:00AM |
| NTSB Notification Time | 1200 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 8 2000 12:24PM |
| User who most recently changed record | dbo |
| Basic weather conditions | Instrument Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N770AT |
| NTSB Number | CHI97IA205 |
| 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 | Boeing |
| Aircraft Model | B-727-200 |
| Aircraft Series Identifier | B-727-200 |
| Aircraft Serial Number | 21953 |
| Certified Max Gross Weight | 197700 |
| 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 | 176 |
| Number of Engines | 3 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Jun 20 1997 12:00AM |
| Airframe hours since last inspection | 162 |
| Airframe Hours | 52509 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | AMERICAN TRANS AIR |
| Aircraft Owner Street Address | 7337 WEST WASHINGTON ST. |
| Aircraft Owner City | INDIANAPOLIS |
| Aircraft Owner State | IN |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 46251 |
| Operator is an individual? | -- |
| 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 | |
| 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 | Non-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 | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | IND |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 1825 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | LAS |
| Destination City | LAS VEGAS |
| Destination State | NV |
| Destination Country | |
| Specific Phase of Flight | Standing |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Dec 20 2002 12:42PM |
| User who most recently changed record | dbo |
| 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 | -- |