Sgt Glendinning was born in County Durham on 5 th July 1912 and was brought up by his mother and grandfather in the village of Willington.
John joined the RAFVR on 25th January 1937. He carried out his early training at No 12 Elementary & Reserve Flying Training School (EFTS) at Prestwick on the Ayrshire coast.
He was called up on the 1st September 1939 and sent to 32 E & RFTS at West Hartlepool.

After a month flying the school’s various training aircraft such as Tiger Moths, Hawker Harts, Hawker Hinds and Miles Magisters, John moved on to 5 FTS at Sealand on 7th October for an assessment of his flying capabilities after which he moved further into Wales when he was posted on 17th December 1939 to 9 BGS (Bombing & Gunnery School) at Penrhos on the west Welsh coast as a staff pilot.
John Glendinning was one of the men who volunteered for training and on 3rd September 1940 he arrived at 7 OUT Hawarden, another Welsh station, known as the Spitfire School.

After Hawarden John’s first Fighter Command posting in mid September 1940 was to the small airfield of Catterick to join his new unit. A few days previously Al Deere’s 54 Squadron found themselves and their Spitfires there after being taken out of the front line. John’s stay at Catterick was very short lived and he was soon posted on to another Spitfire squadron who had fought from Hornchurch for the first year of the war. He travelled two hundred miles south to Biggin Hill where on the 23rd October he joined 74 Squadron.

While on patrol over Dungeness on Wednesday 12th March 1941, John was shot down and killed. His assailant is believed to have been the famous Luftwaffe ace Major Werner Molders of JG 51. His Spitfire, P7506, crashed at Ivychurch, Kent.