 Public opinion towards aviation generally is worsening , based on increasing environmental concerns relating to emissions and noise , and private flying has been criticised by <unk> to a government consultation on aircraft noise as a frivolous or selfish activity . In terms of environmental complaints and <unk> made to the CAA that relate specifically to GA , noise is " by far " the most common subject . Half of the 2 @,@ 000 noise complaints made annually to the CAA concern GA operations , most of which relate to aerobatics , helicopters using private sites , air balloon incidents , parachute dropping , and alleged low flying . 
