Allegiant Air Douglas DC 9 83 incident
Douglas DC 9 83 · Incident: powerplant system/component malfunction/failure on approach
From Orlando Sanford International Airport (SFB) to James M. Cox Dayton International Airport (DAY)
Event
- NTSB case
- ENG17IA017
- 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
- Unknown
- 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
- Unknown
Douglas DC 9 83
- 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
- N881GA
- Operator
- Allegiant Air
- Onboard fatalities
- Unknown
- Route
- From Orlando Sanford International Airport (SFB), Orlando, FLTo James M. Cox Dayton International Airport (DAY), Dayton, OH
- Aircraft age
- About 29 years (built 1988)
- 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
- Approach
- Defining eventThe 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
- Powerplant system/component malfunction/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
- Aircraft › Aircraft power plant
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The No. 2 engine fire was caused by the uncontained failure of the generator main rotor. Deformed generator rotating components and/or metal fragments radially released by the generator severed the constant speed drive (CSD)-to-oil cooler return line located adjacent to the generator. The severed line sprayed oil onto hot generator and engine case surfaces that subsequently ignited.
The sections of the generator main rotor that remained intact and the metal fragments recovered from the generator case exhibited extensive thermal and impact damage that precluded material analysis.
The operating history of the failed generator was not available and federal regulations do not require operators to maintain hour and cycle counts for non-life limited components. An estimate of generator operating hours was provided by Allegiant Air and the date of manufacture was provided by UTC Aerospace Systems. Based on the available records the generator main rotor was never overhauled or re-wound and the total operating hours likely exceeded the 40,000 hour recommended overhaul interval specified in UTC Aerospace Systems service information letter (SIL) 449.
Probable cause
The probable cause of the No. 2 (right) engine fire was an uncontained generator failure. Deformed rotating generator components and/or metal fragments radially released by the generator severed the constant speed drive-to-oil cooler return line located adjacent to the generator and caused oil to spray onto hot generator and engine case surfaces that subsequently ignited.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ENG17IA017
- Event ID
- 20170320X74630
- Case number
- ENG17IA017
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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: 1d1beb4c318ced86944d88da1aacfbeddfe85cdeee554f622ba84f52233f1d7e; retrieved 2026-09-16T05:06:27.931Z.