The official report into the Clutha tragedy in Glasgow in which 10 people died has renewed calls for police helicopters to be fitted with flight recording equipment.
The long-awaited conclusions of the Air Accidents Investigation Branch (AAIB) confirmed that the helicopter which crashed in to the packed pub did not have a flight recorder.
Following a fatal air ambulance crash in July 1998 the AAIB recommended that the Civil Aviation Authority (CAA) should "encourage the development" of lightweight and low-cost flight recorders and "consider" whether they should be used in emergency service helicopters.
Similar statements were made by the AAIB to international aviation regulators following private helicopter crashes in July 2003 and January 2005.
Following the Clutha crash, the AAIB has gone further and recommended that the CAA "requires" all police helicopters to be "equipped with a recording capability that captures data, audio and images in crash survivable memory".
But new helicopters should only be required to have full black box flight recorders from January 2018, the AAIB added.