Aviation safety investigations & reports

Boeing Co 747-200, DQ-FJI

Investigation number:
199901111
Status: Completed
Investigation completed

Factual Information

Following flap retraction shortly after the Boeing 747 departed Sydney, the crew reported a flap disagreement indication. The flaps could not be extended and were stuck in the up position. The aircraft returned to Sydney where the crew carried out a flapless landing.

An inspection revealed that the right inboard fore-flap carriage stop had failed. This resulted in extensive damage to the fore flap, mid flap, and overload failure of the right flap drive torque tubes.

Specialist examination found that the fore-flap carriage stop failed due to stress corrosion cracking. The cracking initiated at the bolt hole surface. The manufacturer's instructions require that the bolt should be installed with wet sealant, however inspection indicated that the sealant did not cover the centre portion of the bolt, potentially allowing moisture to enter.

General details
Date: 16 March 1999   Investigation status: Completed  
Time: 1400 hours ESuT    
Location   (show map): Sydney, Aero.    
State: New South Wales   Occurrence type: Flight control systems  
Release date: 02 January 2001   Occurrence category: Accident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer The Boeing Company  
Aircraft model 747  
Aircraft registration DQ-FJI  
Serial number 22145  
Type of operation Air Transport High Capacity  
Damage to aircraft Substantial  
Departure point Sydney, NSW  
Destination Nadi, FIJI  
Last update 13 May 2014