Two British air force members killed in a helicopter crash in Afghanistan have been named as Flight Lieutenants Alan Scott and Geraint "Roly" Roberts, the Ministry of Defence (MoD) said.
The RAF pair died after a Puma Mk 2 helicopter crashed while landing at Nato's Resolute Support mission headquarters in the Afghan capital Kabul.
Group Captain Simon Paterson, station commander at RAF Benson, said the men were "two of our most capable and dedicated colleagues and friends".
Flight Lieutenant Scott, from London, was 32, and Flight Lieutenant Roberts, from North Wales, was 44.
They were among five people killed, while five others were injured.
The MoD insisted Sunday's crash was an ''accident'', while an Afghan security guard said the aircraft appeared to strike an observational balloon as it landed.
Both officers were members of the Puma helicopter force based at RAF Benson in Oxfordshire.
In a statement, Captain Paterson said: "Today we mourn the loss of two of our most capable and dedicated colleagues and friends, both of whom were exceptional men who made a massive impact on the Puma Force and, indeed, the station.
"They will be greatly missed by all and we send our heartfelt condolences to the families of Flight Lieutenant Alan Scott and Flight Lieutenant Geraint "Roly" Roberts.
"A well-respected pilot, Alan was part of the core team which make up the Puma Force. His experience and level-headed nature made him an ideal pilot to go to Afghanistan on operations.
"His passion and enthusiasm for the job were second to none and he was a large part of the success that the Puma 2 has become.
"I completed my Puma 2 conversion course with Roly last year and have known him as long as I have been flying Support Helicopters. He was a military man to his core and was the epitome of all that the RAF represents. It was an honour to have served and flown with him."
A tribute from Flight Lieutenant Scott's family said: "There are no words and no justice. Yesterday my wonderful, beloved husband Alan Scott was killed in a helicopter crash in Kabul.
"My heart is broken at the fact that such a vivacious, young and amazing person can be taken so cruelly and suddenly.
"Nothing I can say here - or anywhere else - could ever do justice to the thoroughly excellent man I'm proud to call my husband. Rest in peace, my love. Manylots, every day."
Flight Lieutenant Scott - known as "Scotty" - was described by his commanding officer, Wing Commander Mark Biggadike, as "one of the most dependable and intelligent officers I have had the pleasure of working with".
Flight Lieutenant Roberts, who was married with two children, has served in Bosnia, the Falkland Islands, Iraq and Afghanistan.
He was described by his commanding officer, Wing Commander Toby Sawbridge, as "an extremely experienced, loyal and dedicated loadmaster".
Friend and colleague, Flight Lieutenant Kevin Hare said: "He cared about his job so much, constantly pushing the rest of us and never accepting mediocrity. His was always the passionate voice in any debrief.
"On the ground he was equally passionate about his stories of flying experiences and his family. He spoke with such joy about his time growing up in North Wales, and strove to ensure he gave his own children the best opportunities and experiences."
Major General Richard Felton, the commander of Joint Helicopter Command, said: "This accident is a reminder of the dangers our service men and women face in military service; I'm extremely proud of their unwavering professionalism, courage and commitment to serve and protect the nation."
Secretary of State for Defence, Michael Fallon, said: "The heartfelt tributes paid to Flight Lieutenant Scott and Flight Lieutenant Roberts demonstrate that they were both highly respected and professional members of the RAF."
Resolute Support is a Nato-led mission to train and assist Afghan security forces and institutions, following the stand-down of the International Security Assistance Force (Isaf) last year.
The MoD said around 500 British troops remain in Afghanistan as part of the mission.
All five people killed in the crash - which happened at around 4.15pm on Sunday - were Resolute Support personnel, a spokesman for the mission said.
The latest deaths bring the total number of British forces personnel or MoD civilians killed while serving in Afghanistan since the start of operations in October 2001 to 456.
The helicopter crash happened hours after a convoy of UK military vehicles was attacked in Kabul in a separate incident. Three civilians - said to include a woman and a child - were wounded but no-one was killed.