That's a great graph, thank you. It's interesting that the Wheelers are higher than the L-IV. From everything I had seen documented they were by far the worst loss by percentage of fleet of anything like your graph shows but again there's so few Wheelers it may skew the numbers by sample size as has been mentioned.
Yes, you picked up the main problem...the small sample size. A couple fewer accidents over that 26-year period would have had a good drop in the percentage. This is why I normally don't look at homebuilt types with fewer than 50 accidents.
Other factors are involved as well. Pilot experience is one. Some types, typically the simpler aircraft, attract those with less flying time. This can skew the results. The median pilot total time for the PIC in homebuilt accidents is a thousand hours....in Cessna 172 accidents, it's about a quarter of that.
The mission of the plane is a factor, too. Normally, in the plot I posted, I would not have flagged the higher-rate aircraft like the Lancair IV. But I *knew* people would look at the worst-case dot and assume it was the Lancair. It was actually a small homebuilt....an AMPHIBIOUS homebuilt. Several accidents involving hidden logs, etc. in the water. Not really something the Lancair encounters. Similarly, the Zenair CH-701 scores above average...but it's a STOL plane, and you find a lot of accidents with less-experienced pilots.
It makes you wonder how much people were expecting a more docile, slower airplane and thus simply flew it slower as originally recommended (70 Kt Vy) and were close to stall speed, slow with less effective and smaller tail, then over-controlled the yaw?
It doesn't *appear* from the flight test PDF you posted earlier that it's inherently more unstable when flown within a normal envelope. Or did I miss something?
It's all down to the fundamental nature of homebuilt aircraft. Almost every one of us here learned to fly on an aircraft certified to Part 23 or its CAR equivalent. The regulations specify a lot of details on how the plane should react to the controls. Switching from a Cessna to a Piper is mostly just a matter of learning where the switches are and what the airspeeds should be. When you manipulate the controls, all the aircraft respond in a reasonable, expected fashion.
Not so (mostly) in the homebuilt world. There was once a homebuilt on the market (think it was actually an ultralight) where the pedals were connected to the ailerons and the yoke to the rudder. Yet, if the airplane had crashed, the NTSB would probably have put the blame on the pilot's handling of the plane.
There's NOTHING that requires a homebuilt handle like the planes we're used to. Good designers try. Others...well, they figure if THEY could get used to it, anyone else should be able to. One homebuilt designer was interviewed about his plane's stall characteristics. "I've never stalled it," he said. "In fact, I doubt it can recover from a spin."
The usual pushback I get is this: "But we don't WANT our homebuilts to handle like trucks. We want sporty handling, not like driving a stodgy old Cessna.
The Pitts Special is an aircraft fully certified under Part 23. No one ever accused a Pitts of stodgy handling.
In contrast, about 30 years ago, one man posted about his experience in a demo ride with another new homebuilt design:
“I got a chance to fly in the prototype at Tullahoma in 1980. I have flown in a number of homebuilt aircraft, but this is the only one that I refused to allow any other member of my family fly in... The demo pilot was supposedly an airline pilot with tens of thousands hours experience, yet he seemed to have his hands full with this little monster.”
Now, this is a classic example of homebuilt Darwinism: Prospective builders would go for a demo flight, and get scared away. Only ~45 of these airplanes were ever built, and only two remain on the registry. Many were modified to try to tame their characteristics.
In contrast...look at the Vans series. Thousands built, thousands flown. Back in the '90s, I went to the company to test fly the then-new RV-8 for a review in Kitplanes (from the back seat, I hasten to add). Met Dick Van Grunsven. He was fretting a bit. The RV-8 was not meeting the stick-force-per-G requirement of Part 23. Note that it didn't HAVE to meet the requirement. But Vans wanted handling to match a certified airplane.
Most homebuilts, even the successful ones, fall somewhere between the RVs and the Polliwagons. Generally their handling is good...but, sometimes, there's a corner of the envelope where it'll bite. 99.99% of the time, you may never encounter it. Until you do.
Pinky: "Are we going to go to the edge of the envelope?"
The Brain: "No, but we might reach the sticky bits."
And that, I think, is the basic issue with the Express. Does everything right, until you reach the sticky bit of the envelope.
Finally, I should note: The RV-8 I rode in for the article eventually crashed fatally. Apparently, the pilot getting the demo ride pulled the stick too hard and ripped the wings off. Makes one wonder about that stick-force-per-G.....
Ron "Narf!" Wanttaja
