Airbus said Tuesday it had successfully tested its A400M military transporter as a water bomber as heatwaves cause an increasing number of wildfires during the summer in Europe. 

"Airbus has successfully tested a removable firefighting demonstrator kit on the A400M new generation airlifter during a flight test campaign in Spain," the European plane maker said in a statement.

The test involved dropping 20 tonnes of water in less than 10 seconds, the statement said.

Airbus said that the roll-on/roll-off kit requires no modification to the A400M aircraft. 

The water is stored in a fixed tank in the cargo hold, and retained by two independent doors. These doors are connected to two flood pipes, so when the discharge is triggered, the water is expelled through two sections at the end of the ramp.  

Because of its low-level flight capability and manoeuvrability at low speeds, the A400M can accurately drop payloads of water at very low heights, down to 150 feet (50 metres), Airbus said.

"The development of this firefighting kit is an intrinsic part of our journey towards helping to create a more sustainable and safer world, not only by our actions but also through our products," said Mike Schoellhorn, head of Airbus Defence and Space.

"We strongly believe the A400M can play a vital role in the fight against the ever-increasing threat posed by wildfires and support the restoration of social and environmental systems."

Airbus's deputy head of military aircraft, Jean-Brice Dumont, said that the aim of using the A400M as a water bomber was not to compete with those of rival Canadair, but to complement them. 

Canadair's water bombers have capacity of 6,000 litres -- only a third of that of the A400M. But while the Canadair water bomber can scoop up water from a lake, the A400M needs to land to refill its water tanks. 

Scientists say human-induced climate change is amplifying extreme weather -- including the heatwaves, droughts and floods seen in several parts of the planet in recent weeks -- and say these events will become more frequent and more intense.