 On 23 April 1982 , a Sea King HC4 was ditched while performing a risky transfer of supplies to a ship at night , operating from the flagship HMS Hermes . On 12 May , a Sea King operating from Hermes crashed into the sea due to an altimeter problem ; all crew were rescued . On 19 May 1982 a Sea King , in the process of transporting SAS troops to HMS Intrepid from Hermes , crashed into the sea while attempting to land on Intrepid . Twenty @-@ two men were killed and nine survived . Bird feathers were found in the debris , suggesting a bird strike , although the accident 's cause is inconclusive . The SAS lost 18 men in the crash , their highest number of casualties on one day since the Second World War . The Royal Signals lost one man and the RAF one man . 
