We have a PA18-180 towplane with 2 blade metal prop at East Sussex Gliding Club, UK and we have a noise problem with the local residents. We'd like to fit a 4 blade prop, but another club fitted one to a PA18-180 and the pilots reported severe vibration - they thought the tail would fall off! So word has got around that it's impossible to do. That is obviously nonsense as Bert TW's club operate one and there are two in Switzerland operated by the Groupe des Pilots de Montagne at Aeroclub Geneve for a long time. These ones seem to have a crankshaft extension- the prop stands much further forward than the standard 2 blade. Is that of significance? Any views on this? And will it make it quieter? We have a large muffler already.

MIke Millar