Below is a post made by Marc Gregson, one of the test pilots who flew the Sling before, on Avcom (South Africa’s largest general aviation forum) with regards to the accident that happened over the weekend.
Just to answer a few questions, and clear the speculation…
I did a large amount of the original test flying on the Sling (Did not do the spin tests, however). After many hours of testing, and tweaking on the D6 (first prototype), the “Sling” production prototype, with some major (and minor) improvements, proved to be a really nice aircraft to fly! A nice combination of manouverablity, well balanced controls, and forgiving, predicatable flying characteristics, prompted us to buy a Sling (will be arriving in March )! Second to Mike and James, I have the most hours on the Sling. I have spoken to James in detail, so I am not speculating on this post.
The fact that Mike and James have gone to the effort and expense to put their aircraft through a thorough, and intensive spin testing program, makes me extremely happy and comfortable in the attitude and ideals of The Airplane Factory, and like others have said, shows their commitment to building a safe and reliable aircraft.
Now the facts about yesterday’s spin testing, and accident:
The first set of spin tests were done with one pilot, and half tanks (giving a lighter load and forward C of G. Incipient spins were completed left and right, as well as full turn, and one and a half turn spins both ways, and the recovery was normal, and exceptionally good.
The second set of spins were done with full tanks (normal tanks, not long range), and two test pilots, making it MAUW and rear C of G. Again, incipient spins, full turn, and one and a half turn spins were done, left and right, with normal , and again, exceptional recovery.
At this point, the Sling had passed all the requirements for the spin tests!
On the return flight from the second set of spin tests, the Pilots were so impressed with the spin characteristics, that they decided to enter a sustained spin, to find out if the spin stayed stable. Unfortunately, after the second rotation, the nose pitched up, making the spin flatten out, and rotation speed increased. The pilots tried to recover, but once they hit their hard deck of 4000ft, they decided to abandon recovery. They shut the engine, and deployed the Balistic chute. The rocket fired, but the chute didn’t deploy properly. They then opened the canopy, and bailed out (they estimated just above 3000ft), parachuting to the beach. One of the pilots cracked a vertebrae in his neck when his chute opened. Once the pilots were out, the aircraft recovered itself (probably due to a now forward C of G), and proceded to crash into the sea in a descending turn. The aircraft floated for about 2 hrs, then sank a few hundred metres off shore, before they could tag it with buoys. They seem to have lost the position of the aircraft after sinking!
The reason for doing spin testing, is to make sure that an aircraft is safe for the pilots who will later fly it. Only good can come from what they’ve learnt during this exercise. It is sad to lose such an iconic plane (which I loved!), but good that no one was seriously injured, thanks to the excellent procedure and discipline showed by the test pilots!
Bear in mind, that very few of the light sport aircraft around, are actually spin tested, as this is not a requirement for most European certification processes. In fact, a few people that have tested certain LSA aircraft, found them very difficult, and in fact, almost impossible to recover. The vast majority are not spin tested. I appeal to all pilots, to not spin an aircraft that is not approved for spinning. A spin is a complex aerodynamic situation, with many unknowns. If the manufacturer says don’t do it… DON’T DO IT. I hope that everyone learns a lesson from this.
James has indicated that they wil be getting another aircraft together soon, which they will do further spin testing on. All in the interest of making an already awesome aircraft, even better!
I am really glad that people are viewing this in the positive light in which it should be seen! I’m impressed.
Fly safe, and enjoy!