Recovers After 10-Turn Spin Initiated At High Altitude

Pipistrel says that the new four-place Panthera has successfully completed all flights required in the spin-test program for Part-23 certification.

The Pipistrel design team said in a news release that the Panthera behaves "just as expected in all configuration settings" that CS-23 and FAR-23 design codes mandate, including front and back center of gravity, all flaps positions, gear extended and retracted, engine power idle or full, with full or asymmetrically empty fuel tanks.

"The tests revealed that no modifications to the airframe were necessary, no adaptations to the already designed production tooling or to mold-lines," said Ivo Boscarol, general manager of Pipistrel. "The fact that no other on-board systems require any interventions is a testament to this fantastic design. It is remarkable, but even after a full ten-turn spin, Panthera recovers in less than one additional turn just by releasing all controls!

The spin-tests accumulated more than 50 flight hours, all logged using state-of-the-art equipment and cameras. Every spin case also included a chase plane for external monitoring, while Panthera was equipped with three different parachutes; the tail-mounted spin-test parachute, pilot personal parachute and full airframe ballistic rescue system. All doors were equipped with pyrotechnic jettison mechanism.

Since Panthera is to become a full Part-23 (FAR-23 and CS-23) certified airplane under the "Utility", not "Normal" category, a fully developed spin of at least 6 full rotations before recovery is initiated is required in the test flight regimen. Tested were all combinations of centers of gravity, cases of asymmety, flaps and landing gear positions, and engine power variations. The company said that since all cases proved to be non-problematic, they decided to go the extra mile and the testing for spins to 10 rotations, which happens to be the norm for aerobatic aircraft, although Panthera was never conceived to be one. To demonstrate a 10-turn spin is not necessary for certification, but Pipistrel said they chose to do it because of their "commitment to extra safe products."

During the test campaign it was discovered that regardless of the aircraft configuration, spins always fully develop at latest by the 3rd rotation. Once it passes 3 rotations, it is the same if it spins for 4, 6, 10 or 20 rotations. Panthera always recovers using standard technique, with less than 1 turn delay - well inside certification norms. "A 10-turn spin at high altitude, which is what the video shows, is a straight-forward and absolutely safe maneuver for the Panthera," the company said.

(Image from YouTube video)

FMI: Panthera Spin Test Video