UP to four Australian Army Black Hawk helicopters will conduct flights over Londonderry from October 19 to 24 as part of regular training exercises. The exercises ensure air crews are proficient at flying in all conditions. Flights will occur during the afternoon and evening, no later than 11pm. Officer commanding 171 Aviation Squadron, Major Matthew Williams, said the training had been designed to have as little impact on residents as possible but some noise would be noticeable. "People in surrounding areas will experience some noise as the helicopters travel to and from training locations," he said. "I would like to assure residents that all safety measures have been taken into consideration. Local authorities have been consulted, and the NSW Police Force has been briefed."