All Nimrods whose hot air ducts had not been replaced have been grounded
Defence firm Qinetiq has said its chief executive is stepping down, a day after it was criticised in connection with a fatal Nimrod aircraft crash in 2006.
The company said Graham Love is standing down with immediate effect after eight years with the group.
A review of the Nimrod crash by the MoD, BAE Systems and Qinetiq was called "lamentable" by an independent review.
A Qinetiq spokesman told the BBC that Mr Love's resignation was "not related at all" to the Nimrod review.
The crash killed 14 service personnel when the plane blew up after air-to-air refuelling over Afghanistan, when leaking fuel made contact with a hot air pipe.
Mr Love will remain a consultant to Qinetiq.
Leo Quinn, the former head of currency printer De La Rue, will take over as chief executive from 16 November.
"The board has been in succession planning for over a year," the Qinetiq spokesman said.
Qinetiq was formerly part of a UK government defence and research agency, spun off in 2001 with the government holding a minority stake.
The firm will announce its results for the six months to September on 25 November.