The Beaver is recovered from Jerusalem Bay. Source: ATSB. Australian air safety investigators are looking at whether smaller aircraft carrying fare-paying passengers should be fitted with lightweight digital recording systems in the wake of a fatal New Year’s Eve seaplane crash involving a British businessman and his family.The December 31, 2017, crash at Jerusalem Bay in the Hawkesbury River region north of Sydney made global news after it took the life of top UK executive Richard Cousins, his extended family and experienced seaplane pilot Gareth Morgan.With Cousins, the chief executive of Global food giant Compass Group, were his sons Edward and William as well as fiancé Emma Bowden and her 11-year-old daughter Heather.Cousins and Bowden, a magazine arts editor, were due to be married in July and the family had been eating at a waterfront restaurant.An interim report released Thursday by the Australian Transport Safety Bureau confirmed there were no problems with the DHC-2 Beaver seaplane and clarified the flight path taken by Morgan prior to the accident.The seaplane was not required to have a cockpit voice recorder or flight data recorder and was flying too low to be on radar.But some intriguing and skillful work by investigators unlocked passenger photographs from a damaged digital card and used them to determine most of the plane’s final journey.Witnesses provided additional information about its final moments.“With no onboard data available from the aircraft itself, transport safety investigators have been able to use witness statements and images retrieved from one of the passenger’s cameras, to determine what happened in the lead up to this accident,” ATSB transport safety executive director Nat Nagy said Thursday.The investigation found that after taking off from Cottage Point, the aircraft climbed and turned right into Cowan Creek heading towards the main Hawkesbury River into the prevailing wind on a standard departure path.However, while over a landmark known as Little Shark Rock Point, the aircraft made a right turn, reversing its direction.The aircraft leveled out before flying on a straight path directly towards Jerusalem Bay with a tailwind, entering the bay at an altitude below the surrounding terrain height.As the aircraft approached Pinta Bay the aircraft was seen to make a steep right turn during which the aircraft’s nose suddenly dropped before it hit the water in a near vertical position.A map of the flight path and the crash vicinity. Source ATB.A key to determining the flight path was damaged CF card from a Canon digital SLR camera recovered from the mud-filled aircraft cabin.The camera in the mud. Source: ATSBInvestigators clean and dried the damaged card but found they were unable to read it.They set about painstakingly removing four memory chips and a controller chip from the card by hand and transplanting into a similar CF card circuit board.The jubilant investigators discovered the card contained 362 images and a forensic reader managed to extract an additional 50 photographs.One of the images recovered from the camera. Source: ATSB.Five were of the passengers boarding the aircraft and another 22 were taken during the taxi and after the aircraft became airborne, nine of them over a 39-second interval.The last photograph was taken through the front windscreen with the seaplane in a right bank over Little Shark Rock Point heading south towards Cowan Bay.The ATSB teamed with the NSW Police Forensic imaging Section to conduct a re-enactment flight to establish the Beaver’s location and altitude at the time each of the passenger photographs was taken.This was done by matching the focal length and aperture setting using a DSLR camera on board a police helicopter flying over Cowan Creek to give a detailed latitude, longitude and estimated altitude.Although the last passenger photo was taken before the crash, several witnesses saw the plane enter Jerusalem Bay.A witness responding to a plea for information also provided the ATSB with a photograph taken from a boat and showing the aircraft turning near a point in the bay known as the Hole in the Wall.The last photo of the plane prior to the crash. Source; ATSB.After this investigators are relying on witness statements about what happened in the final moments of the crash.An analysis and any safety recommendations will have to wait for the final report, likely to be published in the second quarter of 2019.Among the issues being considered by the ATSB are the pilot’s health and autopsy report, similar occurrences involving Beavers in Australia and internationally as well as occupant egress and survivability.It is also looking at the fitment of lightweight flight recording systems “for passenger operations in aircraft with a maximum take-off weight less than 5700kg.”Sydney Seaplanes fitted its aircraft with GPs tracking devices capable of providing real-time position and flight data after the crash but there is no doubt such a device would have significantly helped the investigation had it already been installed.The Civil Aviation Safety Authority has just made new regulations removing the distinction between charter and regular public transport operators but a spokesman said they will not require digital recorders on smaller aircraft when they come into force.However, he said the regulator would look at any recommendations in the ATSB’s final report once it was published .