Aviation safety investigations & reports

Embraer-Empresa Brasileira De Aeronautica EMB-120 ER, VH-FNQ

Investigation number:
199805073
Status: Completed
Investigation completed

Summary

As the pilot of the Brasilia was applying takeoff power, a nickel leading edge erosion strip separated from one of the left propeller blades. The strip then bounced off the tarmac under the aircraft and struck the right propeller blades. The engines were shutdown and all passengers disembarked safely.

The propeller blades had completed a total of 17,161 hours in service. The last repair work including the fitment of the nickel sheath protective strips took place approximately 2,100 hours prior to the incident.

The erosion strip was recovered and was forwarded for specialist metallurgical examination. This examination confirmed that the erosion strip had separated due to loss of adhesion at the adhesive to sheath interface.

The propeller blade and the failed portions of the nickel sheath were returned to the manufactuer for detailed examination including investigation of the procedures used to perform the nickel sheath replacement. It was found that the sheath had been bonded using an approved adhesive AF111. Inspection of the nickel sheath showed that the surface had been prepared correctly prior to the adhesive being applied. Examination of the blade and nickel sheath showed the cause of the separation to be cracking of the sheath-to-blade bond joint. Spectrum analysis of the adhesive showed the presence of silicone.

The investigation determined that this contamination was introduced during the bonding process. Review of the process showed that an adhesive tape containing silicone had been used, and this is considered to be the most likely cause of the introduction of silicone.

The propeller manufacturer has reviewed its procedures associated with this process. Improvements have been identified, and are being incorporated into the manufacturer's Component Maintenance Manuals.

General details
Date: 13 November 1998   Investigation status: Completed  
Time: 0935 hours EST    
Location   (show map): Bundaberg, Aero.    
State: Queensland   Occurrence type: Propeller/rotor malfunction  
Release date: 06 September 1999   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Embraer-Empresa Brasileira De Aeronautica  
Aircraft model EMB-120  
Aircraft registration VH-FNQ  
Serial number 120-054  
Type of operation Air Transport Low Capacity  
Damage to aircraft Minor  
Departure point Bundaberg, QLD  
Departure time 0935 hours EST  
Destination Brisbane, QLD  
Last update 13 May 2014