Eurocopter has announced a new pair of speed records set by its hybrid helicopter demonstrator, the X3. Piloted by Hervé Jammayrac, the X3 reached a level flight speed of 255 knots (472 km/h) over the south of France on June 7, eclipsing the 250 knots (463 km/h) set by Sikorsky's X2 demonstrator back in 2010. The X3 reached 263 knots (487 km/h) several days beforehand, achieved during a dive rather than level flight, also besting the X2's record in descent – by a single knot.

In a company press release, Eurocopter flight test engineer Dominique Fournier, who was aboard the X3 during its record-breaking flight, reveals how the extra performance was eked out of the machine. "These flights allow us to further explore the behavior of main rotors at high speeds, and enable us to make effectiveness assessments of the fairing we've added to the main rotor hub – which will be beneficial for drag optimization across Eurocopter's overall product range," he said.

Otherwise, Eurocopter reports a familiar specification for the aircraft that flew on June 7. Two adapted Rolls-Royce Turbomeca RTM322 turboshaft engines power the X3's five-bladed main rotor and twin propellors mounted on the X3's stumpy fixed wings which differentiate it from the Eurocopter EC155 on which it is based. This is more or less identical to the X3 that notched up 232 knots (430 km/h) in May of 2011.

Still, it's clear Eurocopter was keen to squeeze every drop of performance out of its technological demonstrator, which, judging by the press material, it is pitching as an sensible choice for search and rescue, border patrol, passenger transportation or special forces military operations.

However, having amassed more than 140 hours in the air since its maiden flight in September 2010, it's thought that the Eurocopter X3 will retire before the year is out. Aviation Week reports that the X3 may live on in the form of LifeCraft, a high-speed helicopter proposed by the European Commission due to fly in

So far as speed records go, we'll be keeping half on eye on Sikrosky and its S-97 Raider, which has superseded its X2, but is yet to make its maiden flight.

Look out for more aviation coverage from the Paris Air Show this week, where Gizmag is in attendance.

Sources: Eurocopter, Aviation Week