Trans World Airlines Boeing 747-131 incident
Boeing 747-131 · Incident: gear collapsed during landing
From Luis Munoz Marin International Airport (SJU) to an unrecorded destination
Event
- NTSB case
- NYC95IA043
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Incident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Boeing 747-131
- Aircraft type
- Boeing 747
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N53116
- Operator
- Trans World Airlines
- Onboard fatalities
- Unknown
- Route
- From Luis Munoz Marin International Airport (SJU), San Juan, PRTo not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Landing · landing roll
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Gear collapsed
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Minor
Cause areas
- Landing gear, main gear › Fractured
- Other maintenance personnel › Maintenance, overhaul, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
DURING LANDING ROLL, THE LEFT MAIN GEAR OUTER CYLINDER SEPARATED. METALLURGICAL EXAMINATION REVEALED A PRE-EXISTING FATIGUE CRACK IN THE SCHRADER VALVE HOLE. THE HOLE, INCLUDING THE FATIGUE REGION, CONTAINED A LAYER OF NICKEL APPLIED DURING OVERHAUL AS A MEANS OF RESTORING THE ORIGINAL TOLERANCES OF THE PART. THE CRACKING INITIATED FROM A 0.009-INCH-DEEP GOUGE OR FILING MARK IN THE NICKEL LAYER. BECAUSE OF THE PRESENCE OF THIS AND SIMILAR NEARBY MARKS, THE CORNER FAILED TO COMPLY WITH THE OVERHAUL REQUIREMENT OF A RADIUS PF 0.6 TO 0.9 INCH AT THE FATIGUE INITIATION LOCATION. ALSO, A BEVEL FOUND IN THE NICKEL LAYER AT THIS CORNER, DID NOT COMPLY WITH THE CORNER REQUIREMENT. THE CYLINDER HAD 82,131 HOURS OF TOTAL TIME AND 14,951 CYCLES, AND WAS LAST OVERHAULED AND RETURNED TO SERVICE SEPTEMBER 30, 1988. ALSO, GOUGES, AND FILING MARKS WERE DETERMINED TO BE THE SOURCE OF THE CRACK.
Probable cause
Improper maintenance overhaul which resulted in a fatigue crack.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC95IA043
- Event ID
- 20001206X02785
- Case number
- NYC95IA043
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (5)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 100bdc17513d0965832a841578e14f7b55fcc003046876a7acbecfdcc37cd65c; retrieved 2026-09-18T18:05:10.811Z.
- The NTSB's operator name is blank for N53116; the operator shown is the name the NTSB records it doing business as.