Flight Lieutenant Nathan Jones, 34, fractured his back and was left with several other injuries after the incident, and was medically downgraded.
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But his actions saved the lives of those on board by steadying the Voyager aircraft after it was sent into a 4,400ft dive in just 29 seconds.
The court heard how he was initially pinned to the ceiling by the sudden dive and had to be extremely careful as he pulled back the controls for fear of 'snapping the wings off.'
A camera belonging to his co-pilot and captain of the flight, Flt Lt Andrew Townshend, had jammed the controls as he moved his seat forwards, sending it plummeting, the court heard.
Flt Lt Jones' actions helped save the lives of those on board, who were "pinned to the ceiling and thought they were going to die".
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He will captain Great Britain at this year's Invictus Games in Canada - an event created by Prince Harry which sees injured servicemen and women from 17 allied nations compete against each other in a range of adaptive sports.
He today told Bulford Military Court, Wilts, that on that day on February 9, 2014, he had left his seat to fetch a cup of tea when the plane suddenly "rumbled" and he "hit the ceiling".
He described how the aircraft - previously cruising at 33,000ft over the Black Sea as it flew from the UK to Camp Bastion in Afghanistan - was violently shaking, and he could hear the rush of wind outside.
Describing how it began, Flt Lt Jones said: "It felt like a rumble, a bit of turbulence, and then suddenly I hit the roof.
"There had been turbulence throughout the flight, so you would initially think that but when you're pinned to the roof you know it's not turbulence.
"When you're on the roof, you know it's going to be nose down. I remember there being lots of sounds, the main sounds felt like a rush of wind on the outside of the aircraft."
He went on: "I then crawled along the ceiling, and as you have seen the doorway into the cockpit is lower than the ceiling.
"So I had to climb through the opening. Then when I got into the cockpit, that was when I saw everything was pitch black.
"I could see we were going into the sea, or something very dark.
"There were a lot of flashing lights in the cockpit, everything was stuck to the ceiling and Flt Lt Townshend was shouting "get back into your seat, I can't get the auto pilot out"."
He continued: "The aircraft was violently shaking. I had never experienced anything like that before."
Amazingly, he recovered the aircraft from the dive by pulling back on the side stick - but did it gently as he was "aware that if I pulled back hard it would most likely snap the wings off".
With one hand he gripped on the cockpit overcomb, and with the other he pulled the joystick.
Eventually, he was able to regain control, and the plane levelled out as he fell into his seat.
The plane then diverted to the nearest airfield at Incirlik Air Base in Turkey, so casualties could be treated and the cause could be diagnosed.
Flt Lt Jones said at the time he believed it to be an auto-pilot malfunction - even though it appeared to be a "perfectly functioning aircraft".
He was badly injured with a fractured back, a prolapsed disc and nerve damage, and there was blood pouring from a split in his head and fingers.
He is still getting treatment today after undergoing surgery and other lengthy procedures, and has been medically downgraded since the incident.
Once the plane was levelled, they then began to recover their belongings while calls were put out for a doctor on board the flight to tend to a passenger.
The court has heard Flt Lt Townshend was "bored" and "practicing taking photos" when his camera jammed the controls, causing the plane to dive in a matter of seconds and leaving those on board fearing for their lives.
While flying, he took photos of the views, passing aircraft, the inside of the cockpit, instruments used by pilots and the speed and altitude dials.
He claims the camera fell from a shelf to block the controls, but the prosecution alleges the camera had been place in front of an arm rest and wedged against the joystick as he moved his seat.
The trial heard that after diverting to an airbase, 49-year-old Townshend lied when filing a tech-log in which he attributed the cause of the incident to a mechanical fault.
He allegedly then lied days later while under oath at a service inquiry, by insisting the incident was a result of a technical error.
Flt Lt Townshend denies two counts of perjury and making a false record in relation to lying, but admits negligently performing a duty in relation to causing the camera to collide with the side-stick.
The court heard he deleted photos he took in the cockpit after the incident.
Flt Lt Jones recalled Flt Lt Townshend, based at RAF Northolt, taking photos on the flight, and occasionally showing him the screen of his Nikon DSLR to show off his pictures.
He also overheard him having a "geeky" conversation with someone on board about photography prior to the incident.
The court today also heard a recording of the terrifying moment the plane went into its dive as Flt Lt Townshend screams: "Shit. Jesus Christ."
After a few seconds, he's heard yelling at Flt Lt Jones: "Get into your seat!" An alarm started sounding as the autopilot is disengaged and there were audible yells of "Mayday. Mayday."
Eventually, the aircraft begins to level out, when one of the pilots is heard saying: "Holy Shit. What the hell just happened."
After a minute or so passes, Flt Lt Townshend says over the speakers: "Ladies and Gentlemen, we're not quite sure what happened there. If you could remain in your seats with your seat belts tightly fastened."
Flt Lt Jones, from Colwyn Bay but based at Brize Norton, said he had flown with Flt Lt Townshend many times previously.
Yesterday, the board went on a site visit to explore a Voyager aircraft and the evidence resumed today.