His operational flying career included two tours flying the Jaguar in the reconnaissance and attack roles, a tour as a Qualified Weapons Instructor on the Hawk and command of a Tornado GR1A tactical reconnaissance squadron. In this latter role he saw active service during the First Gulf War, for which he was awarded the Distinguished Service Order. In 1994 he assumed command of Royal Air Force Bruggen in Germany, the largest Tornado base in the Royal Air Force.

Sir Glenn graduated from the Royal College of Defence Studies in December 1997 and the Higher Command and Staff Course in April 1998. He subsequently moved to the UK Permanent Joint Headquarters as Assistant Chief of Staff J3 (Operations), where he was involved in Operation DESERT FOX in Iraq and Operation ALLIED FORCE, the NATO intervention operation in Kosovo, for which he was made a Commander of the British Empire. He spent a short time as Director of Air Operations in the Ministry of Defence before taking over as Assistant Chief of the Defence Staff (Operations).

Sir Glenn became Air Officer Commanding No 1 Group in March 2001, with responsibility for all Royal Air Force Strike Attack, Offensive Support, Air Defence and Reconnaissance forces. During his time at No 1 Group he commanded the 22,000 British Forces participating in Exercise SAIF SAREEA II in Oman, and in 2003 was the UK Air Commander for Operation IRAQI FREEDOM, for which he was awarded the United States Legion of Merit for his part in the Coalition operation. In July 2003 he became Deputy Commander-in-Chief Strike Command before being appointed Chief of Joint Operations at the Permanent Joint Headquarters in July 2004, where he was responsible for all the United Kingdom’s overseas operations, including those in Iraq and Afghanistan. 

Sir Glenn became Chief of the Air Staff on 13 April 2006. He was made a Knight Commander of the Bath in January 2005 and a Grand Knight Commander in June 2008. During his flying career Sir Glenn has amassed some 4300 hours of fast-jet flying, predominately on Jaguar, Hawk and Tornado, but also on Typhoon. He retired from the Royal Air Force in July 2009 and joined BAE Systems as their Senior Military Advisor in January 2011.

Sir Glenn is married to Christine, and for relaxation enjoys playing golf, gardening, cabinet making and reading about military history. He is a Fellow and Council member of both the Royal Aeronautical Society and City and Guild Institute, a Liveryman of the Worshipful Company of Haberdashers and a Governor of Haberdashers’ Aske’s Boys’ School.