Business Express Airlines Flight 426
Saab-Scania AB (Saab) SF-340-A · Accident: airframe, component or system failure while standing
From Philadelphia International Airport (PHL) to John F. Kennedy International Airport (JFK)
Event
- NTSB case
- NYC95LA197
- 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
- Accident
- 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
Saab-Scania AB (Saab) SF-340-A
- Aircraft type
- Saab Scania Ab (saab) SF-340
- 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
- N742BA
- Operator
- Business Express Airlines
- Onboard fatalities
- Unknown
- Route
- From Philadelphia International Airport (PHL)To John F. Kennedy International Airport (JFK), Jamaica, NY
- 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
- Standing · engine(s) operating
- 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
- Substantial
Cause areas
- Hydraulic system, line › Failure, total
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The turboprop airplane was standing on the taxiway awaiting takeoff. The flightcrew had feathered the left propeller, and was using the left engine high-pressure bleed air for running the airplane's air conditioners. While standing, several warning lights illuminated, and the crew determined that they had a fire in the vicinity of the left engine. The engines were shut down, and the airplane was evacuated. Examination of the wing revealed that a titanium flap line, between the wing and flap panel, had failed for an undetermined reason. After the line separated, it broke two electrical wires, struck a bolt end, and the MIL-5606 hydraulic oil caught on fire. Flightcrews had experienced previous false bleed air leak lights. The airplane manufacturer stated that the compartment temperature where the fire erupted should have been no higher then 70 degrees C. The bleed air leak warning lights were activated by 204 degree C sensors. The MIL-5606 flash point was 110 degrees C. The use of a feathered engine to power air conditioners was the engine manufacturer's procedure. The procedure was not in the airplane manual, but was approved by the FAA Principal Operation Inspector.
Probable cause
the failure of a titanium hydraulic line, which resulted in an uncontained hydraulic fluid wing fire. A factor was the use of a procedure by the operator, approved by the FAA, but not approved by the airplane manufacturer, which resulted in compartment temperatures reaching 204 degrees C, where the failed line sprayed the hydraulic fluid.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC95LA197
- Event ID
- 20001207X04356
- Case number
- NYC95LA197
- 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: dbf0f305c0c38cd85fcead9746473f6b561625f32892e95799d3854594dacd28; retrieved 2026-09-18T17:58:08.147Z.