Report 09-004, Britten Norman BN2A-Mk III Trislander, ZK-LOU loss of engine propeller assembly, near Claris, Great Barrier Island, 5 July 2009
Shortly after take-off at approximately 1305 on 5 July 2009, the right engine propeller assembly of ZK-LOU, a 3-engine Trislander, separated from the engine crankshaft and struck the side of the aeroplane. Nobody was seriously injured, but the aeroplane fuselage was extensively damaged and a passenger door was removed, leaving a large opening adjacent to some passengers.
Undetected corrosion of the propeller flange had led to extensive cracking and its eventual failure. Safety issues identified included the need for detailed checking of overseas component records to ensure their reported in-service hours were accurate and for periodic crack checking of propeller flanges for corrosion damage. A safety recommendation regarding component record-checking was made to the Director of Civil Aviation, and the Civil Aviation Authority issued a Continuing Airworthiness Notice regarding inspections of crankshaft flanges for corrosion.
The report includes this section on damage to the aircraft...
The right engine crankshaft flange that attached to the propeller hub had fractured through lightening holes in the flange. The complete propeller assembly had released from the fractured crankshaft flange and struck the side of the fuselage adjacent to the engine, substantially damaging the fuselage. The fuselage skin had been penetrated in places and a passenger window Perspex had shattered, but nobody was seated in that passenger row. Immediately behind the window the propeller assembly struck a passenger door next to which a passenger had been seated. The door hinges were damaged and the door fell from the aeroplane, leaving a large hole in the side of the fuselage by the passenger (see Figure 2).
No part of the propeller assembly entered the cabin, but the cabin interior lining and insulation were damaged and pushed inwards onto some of the passengers (see Figure 3).
The abstract talks about extensive damage while this doesn't seem to talk of much major damage at all. This raises the question, what has happened to ZK-LOU? And an even bigger question... when is ZK-LGF going to fly?