A memorial is to be unveiled to honour four young men who died when their Halifax Bomber crashed in a Lincolnshire field.
The four, from the Royal Canadian Air force and the RAF, took off from Yorkshire on 1 September 1942 on a routine mission to Germany.
But the engine caught fire and the crew were ordered to bail out.
Around 200 people are expected to attend the service near the crash site, at Mumby near Alford, on Saturday.
David Hill, one of the organisers, said: "We thought that
when we're gone there'd be no-one to remember (the crash) and we ought to do something to mark the site of the crash and the brave lads who gave their lives on behalf of our country 62 years ago."