A remembrance service was being held on Sunday for the 11 men who died in a helicopter crash in the North Sea two years ago.
The crew and all nine passengers died when the Sikorsky S-76A went down between two gas platforms, 28 miles from Cromer, Norfolk, on 16 July 2002.
The aircraft was taking workers from Norwich Airport to a gas drilling rig.
A memorial plaque is to be unveiled at the St Nicholas Church, Great Yarmouth, by the Port Chaplain Peter Paine.
An Air Accidents Investigation Branch (AAIB) report said there had been an "anomaly" in the manufacturing of one of the blades which had been worsened by a lightning strike in 1999.
In the light of its findings, the AAIB ordered checks of Sikorsky S76s.