HANGZHOU - Traffic used to be a frequent headache for medical workers in Hangzhou, capital of East China's Zhejiang province. They have been considering ways to improve deliveries for medical emergencies between city buildings, and they have now discovered a "nature path" -- the air.

A white, six-axis drone, carrying several blood bags and ice packs, arrived at the Second Affiliated Hospital under Zhejiang University School of Medicine on Wednesday.

The unmanned aerial vehicle took off from the Blood Center of Zhejiang Province, about 3 km or a 12-minute drive away from the hospital. Staff at a flight control center inspected the machine online before letting it land.

It was a trial blood delivery by the drone maker Antwork Technology, a startup based in Hangzhou, which obtained China's first license for the test-running of drone deliveries in 2019.

Dubbed Antwork RA3, the UAV with a payload of 5 kg and a range of 15 km made the journey in less than five minutes. In the past, it would take two medical workers at least 30 minutes commuting from a blood center to the hospital for one delivery.

Compared with ordinary aerial vehicles, the aircraft for blood deliveries has more accurate drone navigation and higher wind resistance. It can also fly in rain and snow. The drone container is capable of maintaining a constant temperature. It will ensure the quality of blood samples, said the drone company founder Zhang Lei.

Drone deliveries can transport up to 4,000 ml to 5000 ml of blood for an adult at a time. The drone service also costs less than road traffic, he added.

More than saving manual labor, drone deliveries can avoid time delays from road traffic congestion. It earns patients in critical condition crucial minutes that could make the difference in their doctor's ability to save their lives in an emergency, said Zhang Mao, director of the hospital's Emergency Medicine Department.

Last year, Zhang Lei's company used drones to deliver emergency medical supplies for county hospitals during the COVID-19 epidemic. It also pioneered drone deliveries of life-saving devices, such as automated external defibrillators for marathons.

After the trial delivery, the drone maker launched 24/7 all-weather blood delivery services for all medical institutions in Hangzhou, and it plans to expand these services to other cities.