MARIGNANE, France, May 15 (Reuters) - Airbus Helicopters

showcased an experimental half-plane, half-helicopter

on Wednesday in a quest for speed as competition heats up to

define the rotorcraft of the future.

The Racer is a one-off demonstrator model that combines

traditional overheard rotor blades with two forward-facing

propellors in a bid to combine stability and speed, shortening

response times for critical missions like search-and-rescue.

"There are missions where the quickest possible access to

the zone is vital. We often talk about the 'golden hour',"

Airbus Helicopters CEO Bruno Even told Reuters, referring to the

window considered most critical when people need urgent medical

attention.

Airbus Helicopters was due to fly the aircraft at its

Marignane base outside Marseille in front of 150 industry

officials, politicians and representatives from the European

Union, which gave support through its Clean Sky 2 initiative.

The demonstration comes months after Italy's Leonardo

and U.S. manufacturer Bell agreed to

co-operate on enhancing existing tilt-rotor technology.