The launch of the 2014 Red Bull World Championship has seen a host of modifications to the rules and regulations. Along with the standardised racing engines comes a similar amendment to the propellers. But what exactly does the new propeller policy entail?
In previous years, each team could choose its own propeller. But for the 2014 season, each plane will be fitted with the Hartzell 3-bladed 7690 structural composite propeller. Hartzell is renowned for its commitment to innovation, performance and safety and has led the aviation industry for nearly 100 years. The propeller, nicknamed 'The Claw' by Red Bull Air Race pilot Michael Goulian, is noted for its low gyroscopic forces and inertia and incredible thrust. By the end of the last Red Bull Air Race season, all of the competing teams had converted to the 'Claw'.
But although the Hartzell propeller may be standardised for the Red Bull Air Race, it is by no means a standard propeller,
"The airfoil and propeller system is designed to maximise aircraft performance and will enable pilots to achieve greater performance than any other available propeller," reveals Sam Gascho, a Hartzell representative. "This is why so many of the pilots chose 'The Claw' during the prior race series."
"The propeller has seen many years of proven service in the aviation world," Gascho explains. "We have performed propeller vibration and strain surveys in order to measure the loads and strains the propellers see in operation. We then compare these loads to the established blade fatigue allowables that were obtained as part of our FAA certification testing."
In addition, Hartzell will also provide lightweight governors, carbon fibre composite spinners and technical support and maintenance services for each team.
All for one, one for all
The decision to use the standardised propeller was taken in order to improve the safety of the aircraft, in case of engine failure. The new propellers will be fitted with counter-weights, which will determine what the blades will do if oil pressure is lost during flight. In the event of a loss in oil pressure and without the counter-weights, the propeller blades will twist and become flat against the airflow, creating drag and causing the plane to slow down and descend at a rapid pace. But with counter-weights in place, the blades are prevented from twisting, enabling them to remain inline with the airflow - therefore allowing the plane to glide for longer.
With all aircraft now on a level playing field, the biggest variable will now be in the skill of each pilot.