Police have passed a file to the Crown Prosecution Service after a Red Arrows aerial display team pilot died after he was ejected from his cockpit while on the ground.
Lincolnshire Police confirmed they have handed over the file concerning the death of Flight Lieutenant Sean Cunningham.
Iraq war veteran Flt Lt Cunningham, 35, was a highly-regarded and experienced pilot with the RAF's aerial display team but was fatally injured after being ejected from his Hawk T1 aircraft while on the ground at RAF Scampton, Lincolnshire, on November 8, 2011.
The parachute on the ejector seat did not deploy and the South African-born airman later died in hospital. Following the incident, the RAF grounded all non-essential flying of aircraft fitted with the Mk10 Martin Baker-built ejector seat "as a precaution", but flights later resumed in December 2011, with air chiefs saying they had "no remaining safety concerns".
A Lincolnshire Police spokesman said: "A file has been submitted for consideration by the CPS and as soon as we're in a position to update on that, we will. We are not speculating on the matter of any possible offences."
It is understood the police are expecting a response from the CPS by the end of the month on whether any criminal charges should be brought in relation to the incident.
The Ministry of Defence (MoD) confirmed it was aware a police file was now with the CPS but would not comment further.
An MoD spokesman said: "We are aware that a referral has been made to the CPS in relation to the civil police investigation into this incident. It is not appropriate for the MoD to comment on such matters, any questions should be directed to the civil police and/or CPS.
"Our thoughts remain with the family and friends of Flt Lt Sean Cunningham."
The Red Arrows lost two pilots in 2011, after pilot Flight Lieutenant Jon Egging, 33, from Rutland, was killed when his Hawk aircraft came down after performing at an air show near Bournemouth airport in Dorset in August. An inquest later heard the likely cause of the crash was that he lost consciousness due to the G-Force.