SONAS Aviation will directly employ its own internal resources to manage the key functions required to control and monitor the operation of its client’s aircraft to provide the service levels expected and deserved.

The leadership team for this enterprise are already identified and offer a wide range of complementary skills and experience.


Graham Williamson

Chief Executive Officer & Founder

Until recently Graham was the President responsible for Aircraft Management and Charter Operations for one of the World’s leading Business Aviation Operators.  He joined the company in November 2005 as Director of Operations and was later promoted to Managing Director of the newly formed UK entity with additional responsibility for Flight and Ground Operations across Europe.  He was subsequently promoted to President Europe in 2009 and in his 14 years with this operator he grew the core business from less than 10 managed aircraft to more than 90 along with helping to create Operations in Hong Kong, Bahrain and Malta.

Prior to joining this company, he was the CEO of a start-up airline in India and in a 35-year career has held Executive posts in airlines in central Europe, the United Kingdom and the Middle East.

He is a member of the EBAA Board of Governors and has been an Accountable Manager for several Airlines and operators.

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The Air Law Firm


The Air Law Firm LLP is a boutique aviation law practice providing international legal services to the aviation industry. The practice model sets us apart: we offer a bespoke and focused service from an agile and responsive team who can react quickly to the changing demands of your business environment. The Air Law Firm’s legal services are partner-led and we are proactive not reactive. Their lawyers are passionate about aviation, recognised internationally as being experts in their fields, focused and unique. As a legal partner in aviation, they offer a different experience.

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Capt. Russell Allchorne MA MSc FRAeS


As COO SONAS Aviation, Russ has overall responsibility for the safe and compliant conduct of all ground and flight operations. He is responsible for the conduct of all operational staff, the establishment and oversight of all operational contracts, and the conduct and supervision of all matters relating to the maintenance, growth and evolution of the SONAS operational output.

Russ joined SONAS Aviation from TAG Aviation (UK) Ltd where he was the Vice President Flight Operations for TAG Aviation Europe, and the Director Flight Operations for TAG Aviation UK.  Prior to this appointment, Russ served as the Accountable Manager and Quality Assurance Manager for TAG Aviation Middle East, and as the Client Aviation Manager for a VIP Challenger 605 aircraft operating out of The Kingdom of Bahrain. Russ was responsible for establishing the Company of TAG Aviation Middle East in Bahrain and for obtaining the company’s initial Air Operating Certificate in the region. Russ joined TAG Aviation following a 25-year career in the Royal Air Force where he flew F4 Phantoms, F-15E Strike Eagles (USAF Exchange tour) and Tornado aircraft amongst others; he retired from the RAF as a Group Captain in July 2008. Russ also displayed Spitfire and Hurricane aircraft with the RAF Battle of Britain Memorial Flight for 3 years and also displayed Spitfires privately on the UK Airshow circuit prior to moving to Bahrain. He was a Qualified Weapons Instructor in the RAF and an Instructor Pilot with the USAF, and served on ground tours for the UK Ministry of Defence, the UK Defence Procurement Agency, and the RAF Air Warfare Centre. Russ is a graduate of the UK Joint Services Command and Staff College, and holds 2 Masters Degrees; the first in Defence Studies from King’s College, London, and the second in Air Transport Management from City University, London. Russ is rated on Hawker 800XP, Hawker 800XPC, Challenger 604/605 and Boeing 757 aircraft and is a Fellow of the Royal Aeronautical Society.


Keith Brennan

Technical DIRECTOR

Keith heads up the Technical and Airworthiness section of SONAS Aviation, responsible for managing and implementing all technical aspects of the company’s AOC. Leading a team to ensure SONAS Aviation’s philosophy of providing unrivalled customer service reinforced with the highest and most robust safety standards.  

Keith joins SONAS Aviation from Eirtech Aviation Ltd. where he was the nominated post holder for Continuing Airworthiness (CAMO Manager) responsible for the management and safe transition of multiple aircraft types from end of lease deliveries to induction into the next operator’s fleet. As an ARC signatory, EASA Form 4 holder, on A320, A330, A340, B737, B757, B777 and ATR72-212A aircraft types he has overseen and worked closely with Ireland’s guild of lease companies and SPV’s whom manage and transition aircraft on a global scale. Prior to his time in Eirtech Keith worked for Aer Lingus in Line Operations, Lufthansa Tecknik (formerly Shannon Aerospace) in heavy maintenance and project managed B747 and B777 delivery checks out of Rome, NY and Mirabel, Montreal for transfer into, Russian airline, Transaero’s fleet.

With more than 26 years’ experience in the aviation industry he has been involved with the major Aviation Authorities including (Authorities within) EASA, the FAA, Bermuda and Guernsey and holds licences under EASA Part 66 and FAA A&P, certificates with the Law Society for Leasing and Finance and London City and Guilds in Aircraft Maintenance.  


Tissa Davis

DIRECTOR of Compliance & SAFETY

Holding the position of Director of Compliance & Safety, Patricia is responsible for oversight of regulatory compliance while facilitating high safety standards and a solid safety culture across the organisation.  The safety and security of all aspects of SONAS operations are a core business focus that she is passionate about.

Patricia has a wealth of aviation experience which saw her operating as a commercial pilot for over 20 years.  Her flying career began in 1989 flying in and around East Africa and culminated in her flying B747-400s for Cathay Pacific based in Hong Kong over two decades later. 

Following a move back to the UK, Patricia decided to make a career change and moved in to Compliance & Safety. In 2013 she joined the Compliance Monitoring Department of TAG Aviation (UK) Ltd, operating a large fleet of business jet aircraft based at Farnborough Airport.  Patricia rapidly earned significant professional acumen for her reputation as a subject matter expert within the business jet compliance discipline and took over the position of Compliance Monitoring Manager.  In 2016 Patricia accepted the newly created role of Head of Compliance & Safety and, from there, integrated the Compliance Monitoring and Safety Departments in to one strong and effective Compliance & Safety Team.  Patricia held dual Form 4 positions of Compliance Monitoring Manager (AOC) and Quality Manager (Part M) until she left TAG Aviation (UK) Ltd to become part of the SONAS team.

Patricia joined SONAS in early 2019 as one of the vanguard senior management team members responsible for driving this new innovative business jet management company forward.