Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation A-81-064
Details
Synopsis: ON JANUARY 31, 1981, NORTHWEST ORIENT AIRLINES FLIGHT 79, WITH 43 PASSENGERS, DEPARTED DULLES INTERNATIONAL AIRPORT FOR SEATTLE, WASHINGTON. WHILE CLIMBING THROUGH 7,000 FEET, THE FLIGHTCREW NOTICED SEVERE VIBRATIONS IN THE NO. 3 ENGINE, FOLLOWED BY A LOUD EXPLOSION. THEY SHUT DOWN THE NO. 3 ENGINE IMMEDIATELY. THERE WAS NO FIRE OR PRIOR REPORT OF ENGINE MALFUNCTION. THE FLIGHT RETURNED TO DULLES AND MADE A SAFE LANDING WITHOUT FURTHER INCIDENT. EXAMINATION OF THE PRATT AND WHITNEY AIRCRAFT JT9D TURBOFAN ENGINE DISCLOSED THAT THE NO. 3 NOSE COWL ASSEMBLY AND FAN CASE HAD SEPARATED FROM THE AIRCRAFT. THE NO. 2 ENGINE HAD INGESTED DEBRIS WHICH RESULTED IN FOREIGN-OBJECT DAMAGE. THE SOURCE OF THE DEBRIS IS STILL UNDER INVESTIGATION.
Recommendation: THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: ISSUE AN AIR CARRIER MAINTENANCE BULLETIN URGING OPERATORS AND MAINTENANCE PERSONNEL TO USE EXTREME CAUTION WITH ANY ELECTRICAL EQUIPMENT IN THE VICINITY OF TITANIUM ALLOY FAN BLADES TO MINIMIZE THE POSSIBILITY OF ARC BURN. THIS BULLETIN SHOULD ALSO DESCRIBE THE APPEARANCE OF ARC BURN IN TITANIUM AND POINT OUT THE NATURE OF DAMAGE CAUSED BY SUCH BURNS AND THE POSSIBLE CONSEQUENCES OF THIS DAMAGE.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: Chantilly, VA, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA81IA008
Accident Reports: Northwest Airlines 79 McDonnell Douglas DC-10-40, N143US
Report #: AAR-81-10
Accident Date: 1/31/1981
Issue Date: 6/3/1981
Date Closed: 10/20/1981
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 10/20/1981
Response: The issuance of Maintenance Bulletin 72-15 should effectively alert personnel to the dangers associated with the use of electrical equipment in the vicinity of titanium alloy fan blades. Safety Recommendation A-81-64 is classified "Closed--Acceptable Action."

From: FAA
To: NTSB
Date: 8/19/1981
Response: FAA LTR: WE HAVE ISSUED A MAINTENANCE BULLETIN INSTRUCTING PRINCIPAL AIRWORTHINESS INSPECTORS TO EMPHASIZE TO THEIR ASSIGNED OPERATORS THAT EXTREME CAUTION SHOULD BE USED WITH ANY ELECTRICAL EQUIPMENT IN THE VICINITY OF TITANIUM ALLOY FAN BLADES TO MINIMIZE THE POSSIBILITY OF ARC BURN.