Emery Worldwide Airlines Douglas DC-8-62F accident
Douglas DC-8-62F · Accident: airframe, component or system failure en route
From Seattle–Tacoma International Airport (SEA) to James M. Cox Dayton International Airport (DAY)
Event
- NTSB case
- DEN00FA078
- 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
Douglas DC-8-62F
- Aircraft type
- Douglas DC-8
- 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
- N990CF
- Operator
- Emery Worldwide Airlines
- Onboard fatalities
- Unknown
- Route
- From Seattle–Tacoma International Airport (SEA), Seattle, WATo James M. Cox Dayton International Airport (DAY), Dayton, OH
- 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
- Substantial
Cause areas
- Miscellaneous, bolt/nut/fastener/clamp/spring › Failure
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The airplane was in cruise flight at 37,000 feet msl. The captain said that they heard a loud bang and the airplane shook, and they immediately began to lose cabin pressurization. The engine instruments went dead on number two engine, and they pulled the number two emergency 'T' handle. He said that they donned their oxygen masks, began descending, and diverted to Denver. Postlanding examination of the number two-engine nacelle revealed that the inboard and outboard main engine cowlings had separated from the aircraft. An 18x6 inch hole was found half way up the fuselage (pressure bulkhead), just aft of the left wing; the left horizontal stabilator was also damaged. Further examination of the engine revealed that the 4 inch-diameter high-pressure bleed air duct had separated from the high-pressure relief valve, and the clamp that connected them was missing. The clamp was never located. According to the operator, failure of the clamp would dump high-pressure bleed air into the nacelle, resulting in over-pressurization and separation of the cowlings. The wire bundle, which transmitted the number two-engine monitoring data to the cockpit was found cut. There was no evidence of engine fire or fire in the nacelle cavity.
Probable cause
The failure of the clamp that secured the high-pressure bleed air duct to the high-pressure relief valve. Factors were the resulting excessive pressurization of the engine nacelle, and the subsequent separation of the engine cowling.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN00FA078
- Event ID
- 20001212X20794
- Case number
- DEN00FA078
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2000-04-28.
- API snapshot SHA-256: c55d87e4e2fdf27a3a4b968d8cd3706e50bd3e1468f0184d6e695ee2dfcc0bc6; retrieved 2026-09-18T16:39:11.471Z.