Dr Mckenna obtained his PhD from the University of Kent in 2005, and in 2011 completed the Postgraduate Certificate in Higher Education. He has previously been a visiting lecturer at City University London, Middlesex University, the University of Surrey, and Canterbury Christchurch University.
He has appeared on BBC Television News, Sky News, the BBC Watchdog programme, BBC South East News, BBC Look North and BBC South discussing issues relating to drone technology. He has also been interviewed by BBC Radio Sussex, BBC Radio Kent, BBC Radio Oxford, BBC Radio Berkshire, BBC Radio Suffolk, BBC Radio Lincolnshire, BBC Radio Surrey, BBC Radio Devon, BBC Radio Humberside, BBC Radio Cambridgeshire, BBC Radio WM, BBC Radio Stoke, BBC Radio Shropshire, BBC Radio Newcastle and BBC Radio Cornwall on issues relating to drones and privacy. His drone related work has also been mentioned in articles in the Guardian, New York Times, BBC Online Website, Miami Herald, Brisbane Times, and the Sydney Morning Herald. He has also helped BBC News, the BBC Breakfast programme, and BBC Crimewatch Roadshow with drone related stories.
The House of Lords EU Internal Market Committee in its Report on the Civil use of drones referred to evidence he had provided, and in the subsequent House of Lords debate on the Report his research was again mentioned. Evidence provide by Dr Mckenna was referenced in the 2019 House of Commons Science and Technology Committee Report into commercial and recreational drone use in the UK.
He has also been quoted In the House of Commons Transport Committee's Report into Operation Stack in June 2016, and he provided evidence to the 2021 House of Commons Select Committee on the Armed Forces Bill. He was in 2016 invited to be an expert participant in a Drone Public Dialogue event organised on behalf of the Ministry of Defence and Department of Transport that is being used to help develop Government drone policies.
In 2017 he organised the very first Action Mesothelioma Day event to be held in Kent, at the Royal Dockyard Church, Chatham.
He has reviewed book proposals for publishers, OUP and Taylor and Frances. He has also acted as a reviewer for journals, Air and Space Law; Human Rights & International Legal Discourse; Geoforum; and the University of New South Wales Law journal.
Asbestos related issues, Information and Communication Law, International Commercial Law, New developing technologies such as Drones, and Privacy and Data Protection.
Dr Mckenna currently teaches modules in: Contract Law; Tort Law; Introduction to Obligations; Privacy, Data Protection & Cybercrime; and Advanced Torts.