A deep, persistent droning noise from a low-flying aircraft circling Farnham throughout the night has disturbed local residents.

The unusual noise overnight on March 7 has raised concerns among residents, who reported that the sound came from a turboprop aircraft, traced back to Nottingham.

The flight path data showed the aircraft flying back and forth between Guildford and Farnham during the early hours of the morning.

While some on social media speculated that the plane could be a government reconnaissance aircraft, investigations by the Herald reveal that it was actually used for surveying work in the area.

Nevertheless, residents were still annoyed by the plane’s incessant noise. Natasha Gardiner of Farnham said: “I moved from West London, near Heathrow, so I’m not usually affected by aircraft noise. But this was worse than what I’m used to. It went on for hours and only stopped at 3am.”

With a daughter preparing for her A-Levels, Natasha expressed concern about the impact the noise could have on her studies.

“My daughter is studying for her mock exams. The noise left me severely sleep-deprived. I can’t imagine what it would do for her if it returned before an exam.

“When you live in a smaller area, you don’t really have the power to make a fuss,” Natasha added.

She said the deep droning noise, which continued into the early morning, was so loud that even earplugs could not mitigate its effects on her sleep.

The aircraft took off from East Midlands Airport before heading south towards Farnham. It was operated by RVL Aviation, a company that provides charter flights for a variety of clients, including government and private sector.

John Blauth​​​​, head of communication for RVL, said the flight was carrying out survey and mapping work for environmental agencies.

He said the flights could “often only be carried out at night for operational and technical reasons”, which were generally “because of limited availability of access to busy airspace”.

He said night-time flights like this were usually used to gather heat-sensitive or laser-scanned images to create 3D maps of the land. These maps help environmental agencies track changes in the landscape, often to assess flood risks.

The aircraft flies in a back-and-forth pattern because its sensors collect data in narrow strips, explained Mr Blauth. The width of these strips depends on how detailed the images need to be, which is why the plane follows a repeated route.

“As these aircraft are conducting survey work on a specified area, it is rare that we have to cover the same area frequently,” said Mr Blauth.

“However, return visits are sometimes necessary to re-capture data or to further investigate issues identified during previous surveys.

“All our mapping and survey flights over land are carried out in full accordance with all applicable regulations as issued by the UK civil aviation authorities.”

*Story by Jack Baker