Comair Flight 5266
Canadair CL-600-2B19 · Incident: airframe, component or system failure en route
From Appleton International Airport (ATW) to Cincinnati Northern Kentucky International Airport (CVG)
Event
- NTSB case
- CHI02IA083
- 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
- Visual Meteorological Cond
Canadair CL-600-2B19
- Aircraft type
- Canadair CL-600
- 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
- N991CA
- Operator
- Comair
- Onboard fatalities
- Unknown
- Route
- From Appleton International Airport (ATW), Appleton, WITo Cincinnati Northern Kentucky International Airport (CVG), Covington, KY
- 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 · climb to 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
- Compressor assembly › Separation
- Lubricating system › Blocked(partial)
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The scheduled commercial passenger flight returned to the departure airport after the number two engine's low pressure turbine module separated from the engine and departed the airplane while climbing through 3,000 mean sea level and 4 nautical miles from the airport. Examination of the B-sump forward scavenge screen revealed that the entire screen area was blocked with coke including several metallic flakes, the largest of which was 1/3 inch by 1/3 inch. The screen was also partially collapsed. An oil sample from the B-sump forward scavenge line was black and contained black particles. The B-sump aft scavenge screen was estimated to have been approximately 90 percent blocked and contained some metallic flakes. An oil sample from the B-sump aft scavenge line was black and contained black particles. The C-sump forward scavenge screen contained a block of about 75 percent with coke. The center portion of the screen was clear. The C-sump aft screen was 5 percent blocked. The oil filter contained black particles and black oil. The impending bypass button on the oil filter was popped.
Probable cause
The separation of the low pressure turbine module due to coke resulting in the blockage of the oil system.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI02IA083
- Event ID
- 20020301X00292
- Case number
- CHI02IA083
- 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: db6c902849562129b5d960957a4f9266dfd3258def85faf6a946d6d3f5dd99bf; retrieved 2026-09-18T16:05:27.011Z.