Mumbai, March 29: ?Abhijit?s soul can rest in peace now,? said Kavita Gadgil, who has been waging a campaign questioning the safety of the air force?s MiG-21 fighter aircraft after her son died in a crash two years ago.

Yesterday, Gadgil received a letter from chief of air staff S.P. Tyagi officially acknowledging for the first time that the MiG-21 crash, in which her flight lieutenant son died, could not be blamed on ?pilot error? but could be a result of a critical technical malfunction. The IAF had earlier questioned Abhijit?s flying skills and blamed the crash on September 17, 2001, at the Suratgarh airbase in Rajasthan on his errors.

In 2003, Gadgil began her campaign demanding details of the IAF inquiry into the crash and questioning the use of MiG planes by the air force despite frequent crashes. When the air headquarters dismissed her claims, she gheraoed then defence minister George Fernandes in Mumbai.

In August 2003, President A.P.J. Abdul Kalam granted her personal audience.

She petitioned the National Human Rights Commission in December 2004.

The air force informed her last week that its inquiry into Abhijit?s death did not question his flying capabilities, but blamed the MiG crash on technical factors.