Flt Lt Geraint Roberts (left) and Flt Lt Alan Scott (right) died in October 2015.
A surveillance balloon placed next to an Afghan football pitch, where a RAF helicopter crashed trying to land, was a hazard but did not restrict flying, an inquest has heard.
Flight Lieutenants Alan Scott and Geraint "Roly" Roberts died after a Puma Mk 2 helicopter collided with the balloon's tether and crashed near NATO's Resolute Support (RS) mission headquarters in the Afghan capital Kabul on October 11 2015.
They were among five people killed, while five others were injured.
Families of the two airmen heard evidence at Oxford Coroner's Court about the safety concerns raised with the balloon, known as a persistent threat detection system (PTDS).
The balloon's location was determined after risk assessment, by groups including the mission's rotary wing and the PTDS and it was placed near the football pitch rather than the Canadian embassy, said Air Commodore David Cooper, deputy commander of NATO Air Command in Afghanistan at the time.
"There were very limited options where realistically it could go," Mr Cooper said.
"The preferred site was the one that was chosen - the south-east corner of camp RS."
"In doing their own risk assessments, they came back to us and said 'we are relatively comfortable that risk is understood and mitigated'."
The inquest heard yesterday that the helicopter was unable to land on the pitch itself, as there were players on it.
In bad weather or when there was low visibility, Mr Cooper said commanders would have made the decision whether to launch the balloon or allow helicopters to fly.
He said the weather on the day of the crash was "beautiful".
Georgian soldiers were responsible for marshalling the field and had copies of the flight log, the inquest heard.
Mr Cooper described seeing two Puma helicopters circle the field as they attempted to land.
He said he saw the lead Puma appear to fly towards the balloon tether before turning but the second Puma did not follow suit, hitting the cable and then crashing nearby.
Londoner Flt Lt Scott, 32, died as a result of "multiple injuries including a closed head injury" which were "not survivable".
Flt Lt Roberts, 44, from North Wales died from a "blunt force head injury", which forensic pathologist Dr Nicholas Hunt said in the post-mortem report would have caused him to become "deeply unconscious and effectively dead".