EXPERIENCED airmen were ‘tragically’ killed on a tour of duty after their aircraft got caught in a barely-visible balloon cable.

Enemy fire and explosive devices were among the hazards flight lieutenants Alan Scott and Geraint Roberts had expected to face in Afghanistan – but it was a wire the ‘width of a finger’ that sent them spinning out of control.

The RAF Benson servicemen, who lived in Benson and Reading respectively, died on October 11, 2015, alongside three other passengers in their Puma helicopter.

Flight Lieutenant Scott, 32, was pilot of the helicopter with crew including 44-year-old Roberts, who was a dad-of-two.

They were due to make a routine landing on a football field in the capital Kabul, but crashed to the ground after flying into the tether of an observation balloon.

Beginning their inquests at Oxford Coroner's Court today, Oxfordshire Coroner Darren Salter described the deaths as ‘tragic’.

He praised ‘brave and courageous’ witnesses who helped to free trapped survivors from the smoking wreckage.

Four lived but five died: Kabul civilian Gordon Emin, 44, whose inquest was opened today, two US personnel, Flt Lt Scott and Flt Lt Roberts.

They were flying in formation with another Puma, transporting people from Hamid Karzai International Airport to a field next to the NATO headquarters.

The short trip was one they were both familiar with, but unusually they had to overshoot their usual landing spot on the sports pitch as people were playing there.

Sgt Simon Craig, who was in the other helicopter, said they orbited the field to wait for it to clear.

His Puma successfully passed the balloon cable on one corner of the compound, but the other snagged it and suffered a ‘tail-rotor failure’.

Sgt Craig added: “[Their] Puma began pitching and rolling – it was clear something had gone wrong.”

He said during training they were made aware of the danger of the cable, which was marked at intervals with red flags.

Sgt Craig added: “It’s about the width of your finger... it can sneak up on you. We all knew how difficult it was to see.”

A statement from an unnamed crash survivor, who was cut from the wreckage, said: “I heard a loud ‘pop’ noise. The aircraft...started to jerk and drop.

"It seemed we were starting to fall and were whirling to the left.

"The right [of the aircraft] struck first...the cabin filled with smoke and fumes. I was worried we would catch fire.

"My leg was trapped by the aircraft seat.”

They crashed at a crossroads near the compound after radioing ‘mayday’.

The court heard Roberts died of severe blunt head injury and Scott of multiple injuries, including a severe closed head injury.

Sgt Craig praised Scott as ‘a good pilot’ who ‘was prepared for everything’, and Roberts as a 'really experienced operator'.  

RAF personnel who gave evidence at the inquest admitted it was 'not ideal' to have the balloon tether in such close proximity to the pitch, but said they used the base to which it was attached as a marker of its whereabouts.

Sgt Craig has since returned to Afghanistan for another tour and noted there had been changes since the tragedy. 

He told the court: "The balloon is still in the same position but procedures have changed quite radically: there is now a flow system; you have to follow pre-define routes in and out."

The inquest continues tomorrow.