He previously served as Assistant Chief of the Air Staff from January 2015 to January 2017, Deputy Chief of Defence Staff (Financial and Military Capability) (December 2018 to May 2022) at the Ministry of Defence, and as Deputy Commander Capability at RAF Air Command.

As a university cadet sponsored by the Royal Air Force, he studied engineering at Clare College, Cambridge where he graduated in 1991 with a First.

[1] In his early career, he served as an Engineer Officer, and worked on Nimrod, Harrier, and Tornado F3 aircraft, specialising on airframes.

Promoted to group captain in mid-2007, he moved to RAF High Wycombe in Buckinghamshire to take post as Deputy Assistant Chief of Staff Strategy and Plans at Air Command.

[1][7] In July 2016, it was announced that Knighton would become Assistant Chief of the Defence Staff (Capability & Force Design) with effect from January 2017.

[1] Off duty, Knighton is a "a below-average sportsman", and a keen skier, and confesses a desire to do more sailing, whilst also keeping current with his private pilots licence.