Monahan has trained with several non-UK militaries, and serves as the director of the Air Command Operating Model Programme.
4 Squadron flying the Harrier jump jet at RAF Laarbruch in Germany, during which he flew missions over Bosnia and Kosovo.
[6][7] After Germany, he was posted to RAF Valley in North Wales, and then served in an exchange role with the Royal New Zealand Air Force, flying Skyhawk aircraft from RNZAF Base Ohakea.
1 Squadron in Afghanistan, Monahan was called upon to run a mission at very short notice in support of Australian special forces.
[7] He then spent a year training at the Defence Services Staff College in India and,[10] on returning to the UK, took up a post in charge of operations at RAF Leeming in North Yorkshire.
[18] Monahan was diagnosed with myeloma in 2009 and underwent bone marrow transplants at the Royal Marsden Hospital in London.