The final report on the PC6 accident is here
http://mobilit.belgium.be/sites/default/files/downloads/13-08%20EN.pdf
There seems to have been another inflight breakup of a PC-6, this time a parajumper aicraft in Portugal. All jumpers escaped, the pilot was killed.
The ASN report mentions an “explosion in the tailsection”, but other reports speak of structural failure.
alexisvc
The guy at the back saw the wing gone and the fuel coming out so he jumped, the one at the front new nothing so kept of flying. I amsure that if he new he would have also jumped. See if you can watch the video, it is on Utube somewhere.
They discovered that a nut at the trim was completely worn out and not replaced for many years. Hard to understand ... becasue I saw how they would take these planes completely apart for maintenance
and not even the speed ... it was a loose trim tab that fell off under g-load
I would say the trim tab attachment wasn't designed for the load at 500kt.
Peter, I knew that "Reno Pilot" very well, it was Jimmy Leeward and I have visited him in Florida three times to make photos of his Mustangs and other planes. A very nice guy and a very good pilot. What made the P-51 crash was not the shortened wings (all the race Mustangs have that) and not even the speed ... it was a loose trim tab that fell off under g-load, let the Mustang go intoa violent climb that probably let the pilot lose consciousness ... and we know the rest
But the same reports say that 3 divers tried to jump out of the aircraft and were too low for the chutes to open and therefore were also killed. Seems inconsistent with the 10mn
They probably spent most of their descent trying to get out. It may be very hard to exit a spinning aircraft.
There was an incident in the US (I think in Florida) in the late 90s where a Cessna 206 carrying skydivers spun in all the way from 12,000 feet and only one skydiver got out (because she was already outside the aircraft when the pilot lost control). The aircraft in that case didn't even suffer a structural failure - the pilot just stalled it while the skydivers were starting to leave.
Edit: I had a brief look for the late 90s incident, but since I don't remember the exact details I gave up. However, I did find a similar incident where most the skydivers survived to describe the difficulties they faced getting out of a spinning aircraft here:
Is it just me or is the Pilatus PC-6 even uglier than the Fairey Gannet?
On wingtips and damage, it doesn't take a lot to damage the inboard part of the spar. If you think of the torque applied by tagging a wingtip on something on the inner part of the spar, it can be enormous - a wingtip touch that appears to do nothing but superficial damage - perhaps a very shallow dent in the skin - can result in serious damage to the inner spar. When I was living in Houston, someone just caught the wingtip of the club's Cessna 170 on a hangar at no more than walking pace. The damage seemed pretty superficial but when the 100 hour came around, the inspector noted a very slight wrinkle in the upper skin of the wing, near the fuselage. On removing the metal, a pretty significant kink was found in the aft spar.
A friend of mine who has been flying since the Earth cooled nearly died this way back when he was a student pilot. On a muddy and wet airfield he managed to taxi at very low speed into a pole - the wingtip of the Taylorcraft just tagging the pole. After pushing the plane back he thought nothing of it - the aircraft didn't appear to be damaged, but while practising steep turns the angle of incidence of the wing (that had hit the pole) changed suddenly. Very gingerly he flew back. The wooden aft spar had a compression fracture from this very low speed and apparently innocuous incident. Fortunately the externally double-strutted design of the Taylorcraft was otherwise strong enough to stop the wing either moving more or coming off.
Jan - I wasn't comparing the two a/c, but I was and am wondering how much of a wing you can lose before you totally lose control. IIRC there was a Cessna (?) a few years ago, flying from Ireland to Jersey. Somehow they manged to clip a wing on departure and apparently the pilot only noticed a couple of feet missing upon landing. Hard to believe, I know, but still - the a/c arrived minus 2-3 feet of one wing.
lenthamen - as I stated in an earlier post, I'm wondering about the same thing. I usually fly Cessnas and getting one wingtip to hit the ground would involve some serious mishap or very, very aggressive maneuvering close to the ground. Frankly, I can't really imagine how to do it without having an accident. Getting in and then flying the a/c again is beyond belief, at least to me.
Other than that, tend to agree with BackPacker here - a control surface coming off or deploying in an uncontrollable way scares me more than a wing falling off.
If the wind were so strong that a crosswind landing would have a risk of hitting the ground with a wingtip (of a high-winged airplane no less), then I don't think they'd be jumping that day.
Entirely speculative: I've seen jump pilots do some crazy stuff to get the aircraft back on the ground PDQ, to pick up the next load of jumpers. Including aggressive maneuvering close to the ground to get rid of excess airspeed, or to fly a really tight circuit with 60+ degrees banked turns, rolling out on final just feet above from the runway. In those situations, a slight misjudgment may cause you to scrape your wingtip on the tarmac. (But once again, there is zero evidence that this is what actually happened.)
