The camera had been between his arm rest and the side-stick unit which controls the aircraft's altitude, and became wedged in when his seat moved forward.
"The aircraft was cruising at FL 330 when the captain's personal D-SLR camera was placed between his seat-arm rest and his side stick controller,' the report states.
"Shortly afterwards, when he adjusted the position of his seat, the side-stick was deflected fully forward which resulted in the aircraft rapidly entering a steep descent.
"The captain who was alone on the flight deck while the co-pilot took a break, was unaware that his camera had caused the pitch down."
The report states that the captain's seat was moved forward around two minutes before the plane lost altitude, "creating a slight physical jam of the camera between the front of the armrest and the rear base of the side-stick".
His seat then moved forward again, forcing the side-stick fully forward "and initiating the pitch-down command."
The report author describes the incident as a "near-miss" and said there was a "realistic potential for the loss of the aircraft and 198 of our people".
There were nine crew members and 189 servicemen and women on board the flight, who had been served their meal and were enjoying the in-flight entertainment when when the plane suddenly lost altitude while cruising at 33,000ft on its way to the main British base in Afghanistan.
At its fastest, it dropped at a rate of 15,800 feet per minute with the resulting g force enough to lift passengers out of their seats, as their belongings and other items were hurled across the cabin.
"A large number of passengers and crew had been thrown towards the ceiling," the report states.
"A significant volume of loose articles, including bags, personal effects, teapots, paper cups and bins were flying around the cabin while some passengers were shouting."
According to the report, at the time of the plunge, the co-pilot had been out of the cockpit and was among those thrown towards the roof.
"Immediately prior to the pitch-down, the co-pilot felt a sensation similar to turbulence. The Purser also reported a similar sensation, describing it as a "jolt", it states.
"As the aircraft pitched down, the co-pilot was lifted to the cabin roof and, while experiencing weightlessness, re-entered the flight deck through the open door.
"He described a confusing scene with audio alarms sounding and a violent shaking of the aircraft.
"The captain shouted repeatedly that he could not disengage the autopilot. With his feet on the flight deck roof, the co-pilot reached down and attempted to disengage the autopilot by pulling back on his side-stick; an action which appeared to have no effect."
As the pilots were able to level the plane, the captain decided to land the air craft as soon as possible, and the flight was diverted to the US Air Force's Incirlik Air Base in southern Turkey.
Of those on board, 25 passengers and seven crew members were injured, and were cared for by medical personnel travelling as passengers, as well as by medics at Incirlik.
The report states that one passenger had an 'acute stress rection' and was administered oxygen by a doctor. They were taken to hospital upon landing. A cabin crew member was also hyperventilating but was cared for by a colleague.
Passengers without NATO travel orders then had to stump up £10 in cash for a visa allowing them to pass through immigration, with the servicemen and women having to club together to buy the visas as the British Embassy was unable to transfer the money.
The passengers were later taken back to the UK, with their flights to Afghanistan re-scheduled for a later date. Ten were told they were no longer required to deploy, while a further 12 did not have to for medical or pastoral reasons.
Damage to the aircraft included 50 broken in-flight entertainment sockets, seven dented ceiling panels, five broken florescent light tubes and five damaged hand rails, but there was no reported damage to the flight deck, and no reported damage to the external structure of the aircraft.
The report found that the pilot had taken 77 photographs during the flight and had used it as recently as three minutes and 20 seconds before the incident.
It states that although using the camera during the flight was not prohibited, its use "represented a lack of compliance with the policy regarding non-relevant duties".
However, it also says that during the cruise stage of the flight the pilot's workload would have been low, and that taking photographs would have been a way for the captain to maintain his alertness.
It recommends that ways of minimising pilot boredom during less busy periods of the flight should be examined.
Changes to the design of the cabin to prevent a similar incident were not required, but the report recommends that strengthening rules regarding wearing seatbelts could mitigate "future in-flight upsets".
The report concludes: "The loss of the aircraft was not an unrealistic possibility. While at its heart this incident was caused by the simple and unthinking act of placing a loose article close to the aircraft controls, there are broader lessons to learn here.
"Modern technology may be capable of reducing crew workload to historic lows and aircraft can now protect themselves as never before, but the requirement for crews to understand and interact with the aircraft and its systems when things deviate from the norm remains and challenging as ever."
A spokesman for AirTanker, which is responsible for the supply of Voyager to the RAF and the service which underpins it, said: "As an operational issue for the RAF, it would be inappropriate for AirTanker to comment. However, we note the findings of the Service Inquiry Report, which confirm that no technical fault was found with the aircraft."
The RAF started using the Voyager's last year after agreeing to bring in 14 of the planes for military use under a Private Finance Initiative (PFI) contract that is costing more than £10bn.
They were intended to replace the RAF's VC-10 and Tristar planes both as a transport plane, and as an air-to-air refuelling tanker.
- Daily Mail
