An air ambulance service has received approval from the Civil Aviation Authority to operate at night.
The Yorkshire Air Ambulance (YAA) said the approval followed a recent inspection which has enabled it to extend its hours of operation.
The charity said its two Airbus H145 helicopters would now respond to incidents from 06:00 to 00:00 on weekdays and to 22:00 on weekends.
Crews will use night-vision goggles during evening flights.
The YAA serves about five million people across Yorkshire and carries out more than 1,250 missions a year.
Its helicopters are based at the Nostell Estate, near Wakefield, West Yorkshire, and at RAF Topcliffe near Thirsk in North Yorkshire.
Captain Andy Lister, director of aviation, said the approval for night vision flights followed lengthy training.
"Our pilots and crews have worked extremely hard over the last few months to undertake and learn the processes involved in NVIS (Night Vision Imaging System) flying."
He said night-time operations would begin immediately.
"This will mean our crew will be operational for longer periods each day, enabling them to respond to incidents into the hours of darkness.
"This will be particularly beneficial in the winter months, when the nights come in much quicker."
He said pilots and navigational crew would wear NVIS goggles which enable them to identify hazards when approaching a landing site.
Air ambulance flights include two paramedics onboard who will also be trained to wear the special goggles.
Captain Lister said he expected everyone flying with the charity would be approved for NVIS operations by the end of October.
A number of other air ambulances across England already fly at night, including the Great North and the East Anglian services.