Sentinel Stories

On March 31, 2021, Sentinel will retire from operational service after 13 years. Since its first mission in November 2008, this surveillance aircraft operated by the Royal Air Force has amassed more than 32,300 flying hours on allied international operations including Libya, Mali, Afghanistan, Syria, Iraq and NATO-led humanitarian missions. To celebrate its history, we asked some of the people who played a key role in the Sentinel story to share their memories.

From a very early age, it was clear to Bill that aviation was in his blood.

“I’ve had the bug since I was five years old,” he said. “Every time I saw or even heard the sound of an aircraft, I would look up. When I left school at 16, I joined the RAF as an apprentice as I thought that was a great way to get an education and a career.”

And so it proved. Bill worked as a technician, an engineer, a flight controller and aircrew member before leaving the RAF in 2000. With this experience under his belt, William was the perfect candidate to join a company developing software solutions for aircrew and pilot training. This set him on a path to join Raytheon UK, where he established the training and testing programme for Sentinel.

The Power of Radar

One of the biggest challenges for the training programme was that the Airborne Stand-Off Radar, or ASTOR, system – a fundamental part of Sentinel’s success – was brand new to the UK.

“As a team we – the company, the military and our partners – were trying to learn how to best employ this new system,” he said. “From the start, it was clear that collaborative working was the key to success. We had a very close relationship with 5 Squadron [operations], 54 Squadron [training] and 56 Squadron [trial], all working together to develop the operational concept of how we use the system. We got to know how they'd actually fly the mission, so we took all that knowledge and rewrote the training programme to reflect that. All of this made us gel really closely as one big team.”

Big Data

One of the aspects that made Sentinel so special was the amount of information it collected. While in theory a huge advantage and an improvement on previous systems, the volume of data also provided new challenges.

“I think the biggest surprise for everyone, including the Royal Air Force, was how much data the Sentinel that could gather in one mission,” Bill said. “Typically, it takes a long time to work out how to use the data and then develop the capability. By the time that capability is developed, technology has marched forward.”

“Toward the end of the Sentinel programme, Bill explored more modern technology – specifically 5G wireless network technology – that could boost the aircraft’s capability in its final years of service.”

“I wanted us as a company to get the forefront of that innovation, and I was lucky enough to be supported to develop a number of products that we can potentially employ on other Raytheon U.K. airborne ISR programmes, to enhance the capability to manage that all of that data,” he said.

Of those 5G products Bill worked on, two are now patent pending.

For Bill, as with Sentinel, retirement will come later this year. While there’s some sadness at the end of an era, he looks back with fond memories and pride.

“Being ex-RAF, getting the chance to fly again and see what the aircrew were doing was fascinating,” he said. “Having been with Raytheon UK for 16 years, it will be hard to leave my friends and colleagues. We've built up really good relationships and ultimately I think that has contributed hugely to the success of the programme.”