Simmons Airlines Flight 3588
Aerospatiale ATR-72-212 · Incident: airframe, component or system failure en route
From OKC Will Rogers World Airport (OKC) to Dallas Fort Worth International Airport (DFW)
Event
- NTSB case
- FTW96IA024
- 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
Aerospatiale ATR-72-212
- Aircraft type
- Aerospatiale ATR-72
- 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
- N263AT
- Operator
- Simmons Airlines
- Onboard fatalities
- Unknown
- Route
- From OKC Will Rogers World Airport (OKC), Oklahoma City, OKTo Dallas Fort Worth International Airport (DFW), DALLAS/FT WORTH, TX
- 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
- En route · cruise
- 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
- Minor
Cause areas
- Engine compartment › Fire
- Fuel system, line fitting › Failure
- Fuel system, line › Leak
Not plotted · Location withheld: coordinates are missing, conflicting, invalid, or have no accepted acquisition method. No substitute location has been invented.
NTSB narrative
During normal cruise, the left engine experienced a 20% loss of torque. The crew was informed by company maintenance personnel that they might be experiencing a possible fuel nozzle leak on that engine. The #1 engine fire warning light illuminated, and the fire horn activated. The captain secured the engine and discharged the #1 fire suppression agent. Immediately following the discharge, the associated warning lights on the fire handle and condition lever extinguished. An uneventful single engine landing was completed and the passengers deplaned without further incident. Evidence of thermal damage was found in the aft section of the engine in the area of the lower turbine support case. Examination of the system revealed that 3 of the 144 'O' rings associated with the 14-nozzle fuel system were deteriorated or damaged. Also, during the investigation, testing at the engine manufacturer's facility revealed that the inside diameter of the copper gasket used at the fuel drain nipple was 30 to 40% larger than required. This resulted in misalignment and a leak at the fitting.
Probable cause
'O' ring failure in the fuel line to the left engine nozzle assemblies, which resulted in a fuel line leak and a left engine compartment fire.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW96IA024
- Event ID
- 20001207X04685
- Case number
- FTW96IA024
- 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. 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: 2ac0527c464f8416d6fa787c373932937c2565815d9aa6c8f0522ea708d3eb15; retrieved 2026-09-18T17:56:55.244Z.