The board of inquiry found that standard operating procedure dictated that the commanders of 5th Infantry Brigade were not required to declare the helicopter's mission to any other authority, as the flight was to occur in brigade airspace on a brigade task.[2][7] Gazelle XX377 was equipped with an IFF transmitter, but this was turned off. In the opinion of the board, "had IFF been in use there is little doubt that Cardiff would not have engaged the aircraft that night."[2] At the time, less than half of the land force's helicopters were fitted with IFF transmitters, and those that were had been ordered not to use them because they inhibited the tracking systems of the British ground-based Rapier anti-aircraft missile batteries.[2][9] A misconception about the Royal Navy's ability to engage air targets over land led to the navy not being informed that the army's helicopters were not using IFF.