Eurocopter is claiming a pair of unofficial helicopter speed records following the latest test flights of its X3 compound rotorcraft at the beginning of June.

The Marseille-based helicopter manufacturer says that the X3 on 7 June, flown by test pilot Hervé Jammayrac, attained 255kt (472km/h) in level flight. Several days earlier Jammayrac hit 263kt during a descent.

The 255kt record was achieved during a 40min sortie conducted at around 10,000ft (3,050m) over Istres air base in southern France.

"It's no exaggeration to say that the X3 is clearly in its element at high speeds," says Jammayrac. "While flying at both 255 knots and 263 knots, the X3 performed exactly as it has throughout its flight envelope, exhibiting outstanding stability and providing a low vibration level without any anti-vibration system."

Eurocopter X3 plus jet 


Several modifications were made to the aircraft for the latest test campaign, including the addition of a drag-reducing rotor head fairing and landing gear fairings.

Aside from the kudos of breaking the speed record, the flight trials are being used to gather data on the performance of the five-blade rotors at high speed.

Additionally, it will assess the effectiveness of the fairing "which will be beneficial for drag optimisation across Eurocopter's overall product range", says flight test engineer Dominique Fournier.

The X3 demonstrator has accumulated more than 140h since making its maiden sortie in September 2010. This is its final flight-test campaign ahead of retirement following its attendance at the Paris air show, where it will go on the static display.

Eurocopter will now use the data gathered to influence helicopter design for the next decade.

Source: Flight International