Extra 300 SHP Formally Announced at Oshkosh
Aircraft designer Walter Extra and airshow legend Mike Goulian co-announced the Extra 300 SHP at a morning forum during AirVenture Oshkosh. The 300 SHP (Super High Performance) is an advanced version of the recent 300 HP.
The design was a collaborative effort between Extra and Goulian which began last September. The motivation was to move manned aerobatic potential towards current capabilities in the RC aircraft world - expanding the low speed envelope. RC aircraft achieve their immpressive performance through a combination of high thrust-to-weight (often 2.5-1) ratio and large control surfaces. A similar philosophy was used to guide the 300 SHP development.
Goulian’s custom 300 SHP boasts larger elevator surfaces for additional pitch control at low airspeeds. Extra eliminated an impressive 100lbs of aircraft weight via advances in composite materials and manufacturing processes. This may not seem like much, but this is nearly a 10% reduction for an aircraft which must withstand brutal g forces. To improve ‘tumbling’, the aircraft CG was moved aft. Power is provided via a Lycoming Aerobatic IO580 engine rated for 350HP swinging a Hartzell 3-blade composite propeller.
Both Mike and Walter were in good spirits during the forum and it was interesting to hear them discuss the design and testing process from their respective rolls. Mike has been flying the Cap 232 until recently due to its ‘tumbling’ prowess, but he has retained a fondness for Extra designs used in his earlier competition days. It was a natural choice to seek out Extra for his next aircraft.
For his part, Walter is very interesting in pushing the state of the art in performance capabilty - especially in the low speed regimes. At the same time, he required that the resulting aircraft retain certifiable stability characteristics and not require any special handling on the ramp. While both admitted long cross-countries are tedious in most aerobatic show planes, the 300 SHP remains fundmentally well behaved aerodynamically.
The exact transition path of the 300 SHP into the Extra lineup was unclear from the forum. Mike’s 300 SHP is intended to remain certified under FAA Experimental rules. In response to an audience question, Walter indicated that some of the elevator designs and composite weight reductions would likely find themselves in future versions of Extra’s certified aircraft.
We wish both Mike and Walter success with the Extra 300 SHP and look forward to Mike’s new routine next spring.