WHO can I complain to? I was woken up at 1.48am on April 29 by a loud, thudding noise coming off the rotor blades of a low-flying helicopter moving from south west to north east directly overhead of a line taken from Evering Avenue across to the Wallisdown roundabout passing over Fraser Road, Poole.

I estimated the thudding from previous experience using a Db meter at around 100 Db or higher, which is unacceptable for night-time flights.

According to helicopter flight training, thudding stems from air interference as it is forced downwards to pass from the trailing rotor blade over the solid tail section of the helicopter but a louder than usual thudding, such as is occasionally caused by the police helicopter in daytime, is caused by a tighter manoeuvre than normal which is putting the rotor blades under enormous stress.

This, however, was a night flight by a heavier helicopter than the police might use.

Either the heli was descending out of partial cloud cover at speed and suddenly pulled up to avoid the Wallisdown hill or it was in the process of tight, high speed turn across Wallisdown heading south from the original straight flight path. Either way the louder stress noise would have been apparent in the cockpit.

The helicopter noise was so loud it woke me up, got me out of bed and I saw an engine flying low beneath part cloud cover. I was unable to guess height but the body was visible against the street lighting.

Next an ambulance siren which is acceptable, this noise was a loud intrusion and was severe noise pollution which was not warranted.

DOUGLAS MILLS, Fraser Road, Poole