Detailed plans of Royal helicopter flights have been made public in advance for the first time, posing a massive security risk to the Queen and her family.
Incredibly, air traffic control updates that can be seen by millions now give the exact routes and times of the trips to be taken by senior Royals 48 hours before they take off.
The astonishing decision came amid growing fears that a drone could collide with a helicopter. It was hoped that publicising the routes would minimise this risk.
But there are also fears that terrorists could use the system to plot an attack – security experts have warned jihadis are planning to use drones loaded with explosives as deadly weapons.
Tracked: Prince Andrew (waving) is pictured at Gloucestershire on Friday as he boards the Royal Sikorsky
Using the information made public for the first time last week, The Mail on Sunday was able to see, two days in advance, that the Royal helicopter was flying from Windsor Castle to Cheltenham in Gloucestershire on Friday.
Prince Charles and Prince Andrew had separate official engagements in the area that day. Using co-ordinates given in the update, we were able to get close enough to photograph Prince Andrew boarding the Sikorsky S756 helicopter to fly home to Windsor – ironically after a visit to the Government spy HQ in Cheltenham. Buckingham Palace refused to say if Charles used the aircraft on that day.
The day before, the alert system showed the Royal helicopter was due to fly from Kensington Palace to Membury airfield in Berkshire, where Princess Anne had flown to visit a stud farm.
Last night former head of royal protection Dai Davies warned: ‘This gives me grave concern as to the overall risk potential.
‘Why bother spending millions of pounds on protecting the Royal Family on the ground, then make this information available in advance? I just despair.’
And security expert Professor Anthony Glees said: ‘It’s incomprehensible. Far from deterring people from flying drones nearby, they are in fact telling them how best to do so. To publicise where a Royal helicopter will be flying is to encourage terrorists, mad people and pranksters.
High-flyer: Princess Anne on a previous trip on the Royal helicopter
‘There are some things that should be secret and I think Royal flights are among them.’
Documents seen by this newspaper show that the extraordinary move to make the flight details public has been in part prompted by the menace posed by Unmanned Aerial Vehicles, with dozens of near-misses between drones and aircraft last year.
All pilots, including drone enthusiasts, are required before they fly to check a safety alert system known as NOTAM – Notice To Airmen – to see if there are any potential hazards. The alerts are distributed by the Civil Aviation Authority and NATS, the UK’s air traffic control body, via websites and apps.
Full details of Royal helicopter flights were not included on NOTAM lists, until a dramatic change last week prompted by a top-secret review.
Royal sources have told this newspaper that Scotland Yard and the Department for Transport did a risk assessment, which weighed up the possible consequences of providing advance notification of flights against the safety risks of not doing so.
The revelation that the details would be made public first came in a CAA newsletter sent out on Wednesday, which stated: ‘For flight safety reasons, the details of Royal helicopter flights are now being published by NOTAM and so will also be depicted on airspace mapping apps.’
A briefing sheet added that keeping well clear of Royal helicopters is ‘particularly relevant to operators of small unmanned aircraft (drones) as the crew of the Royal helicopter is unlikely to be able to see and manoeuvre clear of a conflicting drone during these critical stages of flight’. Pilots are ordered to ‘keep a good lookout and maintain adequate separation from the Royal helicopter’.
Military aircraft in particular must not enter what is known as a Royal Low-Level Corridor, covering an area five nautical miles around the flight route and from the ground to 1,000ft above the flying altitude. The protected zone lasts from 15 minutes before departure to 30 minutes after arrival at points along the route.
Take off: The Royal helicopter carrying Prince Andrew from Gloucester Airport on Friday
The first Royal helicopter flight to appear on the NOTAM system was a trip taken by Princess Anne on Thursday.
She took the Sikorsky – said to cost more than £2,000 an hour to fly – on a 67-mile journey to the Berkshire stud farm, then flew a further 36 miles home.
Before she took off, anyone checking the alerts would have seen the helicopter was due to take off from Kensington Palace at 10.45am, fly over Uxbridge Common, Iver, Cookham and Compton Vor – landing at Membury at 11.20am. A further flight was listed as taking off from the airfield at 1.10pm and landing at the Princess’s home Gatcombe Park in Gloucestershire 15 minutes later.
The NOTAM system also alerted pilots – and potential extremists – that another Royal helicopter would be taking to the air on Friday. It said that it would be taking off from Windsor at 9.45am, flying over Ascot Heath and Brize Norton then landing at Cheltenham racecourse at 10.20am – a distance of 90 miles.
Easily spotted: The aircraft flies over Ascot Heath while carrying Prince Andrew from Gloucester
The alert system also revealed that the helicopter would take off from Gloucestershire at 3.30pm and land back at Windsor 35 minutes later. The Court Circular showed that both Charles and Andrew had engagements in the area that day.
Charles visited a canal in Stroud and a timber merchant in Tetbury, before attending an opera performance in Cardiff. Andrew held an event at Cheltenham Racecourse before visiting GCHQ.
Our photographer saw Andrew board the Royal helicopter at Gloucestershire Airport, accompanied by a man and woman. Two pilots arrived shortly before 3.30pm to make checks before take-off.
The NOTAM system also gave advance details of a planned flight from Princess Anne’s home to Cardiff that was due to take place yesterday. It appeared to tie in with her planned appearance at the Wales v Scotland rugby match.
Last night, aviation consultant Paul Beaver, a former Army helicopter pilot, said he believed publicising Royal flight plans more widely would improve safety as it would encourage pilots and drone operators to stay clear. He said: ‘The greater risk is private planes, airliners, air taxis, air ambulances or drones flying into them.’
The CAA insisted that the publication of the flight information had been decided on by the Royal Household itself.
A statement said: ‘Following a review of helicopter flights by the Royal Household, route details will be provided to all airspace users including private pilots and drone users to allow them to remain clear.’
A spokesman for the Royal Household said: ‘We are not commenting on the change in arrangements and have nothing to add further to what the CAA has already said. ‘More broadly, in making travel arrangements, the Royal Household always seeks the best balance of security, efficiency and value for money.’