Trans World Airlines Flight 732
Douglas DC-9-34 · Incident: airframe, component or system failure during initial climb
From St. Louis Lambert International Airport (STL) to Toronto Pearson International Airport (YYZ)
Event
- NTSB case
- CHI98IA169
- 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
Douglas DC-9-34
- Aircraft type
- Douglas DC-9
- 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
- N928L
- Operator
- Trans World Airlines
- Onboard fatalities
- Unknown
- Route
- From St. Louis Lambert International Airport (STL)To Toronto Pearson International Airport (YYZ), Toronto
- 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
- Initial climb
- 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
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Cause areas
- Flight/nav instruments, rate gyro › Failure
- Other maintenance personnel › Maintenance, installation, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The flight experienced a flight control malfunction after takeoff. The flight declared an emergency and returned to the airport safely with no damage to the aircraft or injuries to the crew or passengers. The Captain stated: 'After takeoff the aircraft began to yaw and roll in a cyclic fashion left and right. I switched the yaw damper off and on to ensure that the yaw damper was on. Yaw and roll continued and appeared to increase in its yaw amplitude as the airspeed increased... I declared an 'Emergency' and requested an immediate return for a landing with the emergency equipment standing by... The landing was made in a normal fashion without damage to the aircraft or injury to anyone on board. Total air time was 6 minutes.' The Stability Augmentation Computer, Part 2587826-3, S/N 0270890 was inspected at the TWA Maintenance Facility. The inspection determined that the yaw rate gyro of the Stab Aug Computer had been installed in a reverse position that was 180 degrees opposite from the correct position.
Probable cause
the yaw rate gyro of the Stab Aug Computer had been installed in a reverse position that was 180 degrees opposite from the correct position.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI98IA169
- Event ID
- 20001211X09811
- Case number
- CHI98IA169
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- 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, damage. 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: 52ada375366616d696d56806e17612811611d7c3833089c2ba88c9aaecbc7e99; retrieved 2026-09-18T17:10:10.702Z.