7/7 radio problems 'had been known about since 1987'
Some of the problems which hampered the 7 July 2005 rescue operation were noted in 1987, the inquest has heard.
Sir Desmond Fennell's report into the King's Cross fire in 1987 had made several recommendations which were not followed through, the inquest was told.
London Underground staff's radios were still not fully compatible with those of the emergency services 18 years later.
It meant rescuers could not pass requests for help to the surface.
Four suicide bombers targeted three Tube trains and a bus, killing 52.
Hugo Keith QC, counsel to the inquest, said: "Some of the things that went wrong on 7/7 were direct reflections of issues identified by Fennell which had not been corrected or addressed fully by the time of July 7."
The fire at King's Cross Tube station in November 1987 killed 31 people.
Geoff Dunmore, London Underground's operational security manager, said: "The root causes of a lot of the problems was the fact that we couldn't get communication directly from the trains to the outside world, including our own controls."
Since the 2005 bombings London Underground has got a new radio system, Connect, which is now fully compatible with the emergency services, said Mr Dunmore.
"Of course with these type of incidents you can never guarantee that a communications system will stand up totally but it is a lot more resilient than anything we've had previously," he said.
Mr Dunmore said London Underground had learned lessons from the King's Cross fire before 2005.
"If you consider for a moment the overall response to July 7, a lot of what we had in place in terms of emergency planning and training and things like rendezvous points is a direct outcome of Fennell," he said.