The Forces Commemoration Service is taking place at the Yorkshire Air Museum, home to the Allied Air Forces Memorial, which recognises and commemorates the achievements and sacrifice of allied airmen and women in all conflicts.
The service is being attended by ex-Nimrod personnel and relatives of 'Crew 3', who died when Nimrod XV230 crashed in Afghanistan on September 2, 2006. The crash was the single deadliest loss of military personnel since the Falklands War.
After the service, the Archbishop of York will sit in the cockpit of the Museum's historic Nimrod MR2 XV250 as the engines are fired up on this 'live' aircraft.
There will be a strong contingent from RAF Kinloss, Morayshire, where XV250 was based before being delivered into 'retirement' at Elvington.
A full team of ex Nimrod ground and aircrew will work with volunteers at the Air Museum to maintain the aircraft and keep it in full working order.
Team leader Ken Bannister is confident that the Nimrod is perfectly capable of flying out, unlike the other few remaining Nimrod examples, which with the exception of one, are all static.
The ceremony will conclude with a flypast by a Spitfire from the Battle of Britain Memorial Flight, as the event also forms the annual Allied Air Forces Commemoration Day.