Douglas DC-8-62F N990CF

Summary

On 28 April 2000 at about 03:30 local time, a Douglas DC-8-62F registered N990CF, operated by Emery Worldwide Airlines, was involved in an accident near Denver, Colorado, United States. 5 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

28 April 2000 at 03:30

Classification

Accident

Location

Denver, Colorado, United States

Coordinates

39.8493, -104.6998

Aircraft

Douglas DC-8-62F

Registration

N990CF

Category

Airplane

Engines

4

Operator

Emery Worldwide Airlines

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Seattle → Dayton

Aircraft damage

Substantial

Weather

VMC

Light

Night/Dark

NTSB number

DEN00FA078

Nobody was injured.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full 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.

Quoted verbatim from the NTSB record.