Amazon has been given the go-ahead by the UK Civil Aviation Authority to expand Prime Air drone deliveries in Darlington. The number of eligible households rises from around 600 to roughly 8,000.

Amazon says Prime Air is the first operator in the world to receive a SAIL 4 Operating Authorisation and Flightworthiness Validation from the regulator.

SAIL 4 sits at the medium-to-high end of the risk scale the CAA uses for drone operations. The approval covers more of the town, including more densely populated areas.

The service launched in Darlington earlier this year. Under its original authorisation, beyond-visual-line-of-sight flights were limited to quieter, less populated areas.

Deliveries are promised in under two hours, at no extra cost to Prime members. Items must weigh 2.2kg or less and fit in a large shoebox.

Customers need a garden or driveway within 7.5 miles of Amazon’s Darlington fulfilment centre, and they confirm the drop-off point at checkout.

Amazon uses its MK30 drone for the service. It’s fully electric and has a detect-and-avoid system built to spot other aircraft, people, animals and obstacles.

Darlington is still Amazon’s only operational Prime Air site in the UK, and no second location or wider rollout date has been announced.

Tees Valley Combined Authority, which worked with Darlington Borough Council and Teesside International Airport to bring drone deliveries to the area, has confirmed the expansion.