An air ambulance regularly flown by Prince William was nearly involved in a mid-air collision last August.
A report has revealed that the Eurocopter 145, used by the East Anglian Air Ambulance, was involved in a near-miss with a drone, with UK Airprox Board investigators admitting the accident was only avoided because of good fortune.
The report observed that there had been "high risk" of a crash, with the dramatic incident taking place 1,900ft above London.
Prince William was not onboard the aircraft at the time of the near-miss, although although the East Anglian Air Ambulance has confirmed the vehicle was flown repeatedly by the royal during his tenture with the service.
The drone, which was flying above its permitted altitude, passed within 98ft of the helicopter.
Earlier this year, meanwhile, a survey found that 52 percent of the British public would prefer to see Prince William succeed Queen Elizabeth rather than Prince Charles.
The poll, conducted by Opinium Research, found that just 27 percent of people would like to see Prince Charles become the King, while the report also revealed that 65 percent of UK adults still support a hereditary monarchy.
James Endersby, Managing Director of Opinium Research, said: "The monarchy clearly retains the support of the British public, and our tracker indicates that the institution is as popular now as it ever was.
"However, young people are not as invested as the older generation and this does raise questions about the future of the monarchy after the Queen - will the institution survive without one of history's most respected sovereigns?"
The research also found that 19 percent of UK adults hope Britain will become a republic in the future.
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