The Sikorsky S7 was forced to veer away to avoid mid-air collisions as it ferried Camilla from Sandringham to her home in Wiltshire.
First it was within nine seconds of a head-on crash while travelling at 150mph with an aircraft carrying parachutists.
An air traffic controller at RAF Marham, Norfolk, who was monitoring the flight, told investigators the collision risk had been “high”.
Then as the chopper was attempting land 45 minutes later, it had to complete a desperate emergency manoeuvre at 161mph to avoid a glider, MailOnline reported.
The pilot said he was fortunate to have spotted the glider half a mile away as he ‘had been flying into the sun’.
Both incidents happened on July 25 last year after Camilla and Prince Charles had visited the Sandringham Flower Show, according to UK Airport Board reports.
It’s thought at the time Charles remained in Norfolk while the helicopter transporting his wife took off at 1.11pm from Anmer Hall, Prince William’s home.
Six minutes after it took took off, RAF Marham air traffic control – saw a de Havilland Canada DHC-6 had taken off from Skydive Chatteris, Cambridgeshire.
The pilot of the DHC, which was heading north-east towards the Sikorsky, should have alerted RAF Lakenheath, Suffolk.
According to the reports he forgot to as it was “his eighth flight that day’.
RAF Lakenheath made “numerous” attempts to contact the DHC-6 pilot, who failed to respond as he was “distracted by passengers in the back”.
Then a minute later – RAF Marham warned the Sikorsky the DHC-6 was approaching at 110mph.
The Sikorsky pilot was forced to raise his altitude to 5,400ft – and the DHC-6 which was ascending failed to turn away.
Next, the Sikorsky pilot veered right at the same time when an alert sounded in the cockpit and the RAF Marham controller told him to steer away.
The DHC-6 pilot was said to have seen the helicopter “come into his field of view from behind the instrument panel” – prompting him to veered to the right.
Less than an hour later when the Sikorsky was due it land it avoided a glider at 1,800ft.
Buckingham Palace declined to comment.
Skydive Chatteris has been approached for comment.