Event Details

Title:Uncontained engine failure, Northwest Airlines, Inc., Boeing 747-151, N607US, Honolulu, Hawaii, May 13, 1971
Micro summary:This Boeing 747-151 experienced an uncontained failure of the #3 engine, resulting in a diversion.
Event Time:1971-05-13 at 1330 HST
File Name:1971-05-13-US.pdf
Publishing Agency:National Transportation Safety Board (NTSB)
Publishing Country:USA
Report number:NTSB-AAR-71-16
Site of event:Climb, 1301', Honolulu
Departure:Honolulu International Airport, Honolulu, Hawaii, USA
Destination:Tokyo International Airport (Haneda), Tokyo, Japan
Airplane Type(s):Boeing 747-151
Flight Phase:Climb
Operator(s):Northwest Airlines
Type of flight:Revenue
Serious Injuries:0
Other Injuries:0
Executive Summary:Northwest Airlines Flight 9, a Boeing 747-151, N607US, as a regularly scheduled passenger flight between San Francisco, California, and Tokyo, Japan, with an intermediate stop at Honolulu, Hawaii. At departure from Honolulu, 31 revenue passengers and 11 crewmembers were on board. During takeoff from Honolulu at 1330 HST, it was necessary to reduce power on the No. 3 and No. 4 engines from the predicted 1.395 to 1.33 engine pressure ratio in order to maintain exhaust gas temperature within operating limits. Rudder adjustment was also made during climb after takeoff for the same reason.

Shortly after takeoff, while the aircraft was in a right turn at 1,300 feet m.s.l., a separation of the second-stage turbine disk occurred and pieces penetrated and ruptured the high-pressure turbine case and engine cowling.

A fire warning and severe vibration ensued which terminated following fire extinguisher discharge and engine shutdown procedures. Fuel jettison was accomplished to reduce weight to the maximum allowable for landing. The flight returned to the Honolulu International Airport and landed safely at 1351 H.s.t. There were no injuries to passengers or crew.

The National Transportation Safety Board determines that the probable cause of this incident was the in-flight separation of the second-stage turbine disk of the No. 3 engine. The separation of the disk was the result of a fatigue crack which originated in a nickel-plated area of the reworked turbine air seal land and progressed into the base material under operating loads.
Learning Keywords:Operations - Maintenance
Systems - Engine - Uncontained Engine Failure
Other - Manufacturing Issues
Consequence - Damage - Airframe or fuselage
Close match:Uncontained engine failure, Douglas DC-9-32, May 5, 1994


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