Experimental Aircraft

Llewtrah381 said:
Somewhere I heard the accident rate in Experimentals is quite a bit higher for the later owners than the builder. Can’t remember where I saw that or any specifics. Has your research shown that? Seems plausible, especially for aircraft considerably different from traditional trainers, etc. (i.e. I’d anticipate it would be true for Lancairs, etc. and less so for RVs maybe). If so, it could suggest a focus for reducing accident rates.
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This is a rather hard analysis, as there's nothing in the FAA to indicate whether the plane is still flown by the original builder, and the NTSB doesn't always indicate whether the accident pilot is the original owner.

Still, I made a cut at the issue about seven years ago for a magazine article. Would flag an accident as being flown by a purchaser if 1) The NTSB report said so, or 2) The "manufacturer name" in the FAA registry was different from the current owner's name (manual process, mostly, to catch variations), or 3) The pilot had less time-in-type than the aircraft total time (with a ~2 hour buffer to account for ground test time).

Roughly half the accidents in my EAB database met these criteria. Accidents due to mechanical failures were down, relative to the builder-flown cases. This was expected, as many of the "teething problems" of new homebuilts are taken care of by the time the airplane is sold.

However, pilot error was, in fact, higher for the purchased airplanes...both the "Pilot Miscontrol" (stick-and-rudder errors) and "Pilot Judgement" (VFR into IFR, Fuel Exhaustion) categories.
purch1.jpg

What was even more interesting was the pilot's time in type at the time of the accident. Purchasers of homebuilts have a higher rate of accidents during the transition period.
purch2.jpg

The builders of homebuilt aircraft are apparently more dedicated to transition training than purchasers. Part of this higher rate is due to more Fuel Exhaustion and Maneuvering at Low Altitude accidents.

Ron Wanttaja
 
All of the aircraft on the list are sound designs, the high ones (Velocity & Lancair IV) suffer from pilot error. Even then, the rate is somewhat misleading because while the Velocity has an unusual number of accidents, it's below most of the aircraft on the list as far as fatal accidents. Below the EAB average as well. So basically you have a fair amount of people dinging up their Velocity aircraft but not many dying from them. PIO on landing comes to mind.
 
brien23 said:
Why would Kitfox be so high, seems like a good design low speed?
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Small, light, inexpensive taildragger. What could possibly go wrong? :)

Kitfox has a higher rate of Pilot Miscontrol (50% vs. 38% for the overall homebuilt fleet), including slightly higher accident rates due to stalls and loss of control on landing. The median pilot hours for Kitfox accidents is about 60% that of the all homebuilt accidents. It's a light taildragger that attracts lower-time pilots.

Its Fleet Accident Rate of 1.06% isn't badly out of bed for small, light homebuilts.

Ron Wanttaja
 
brien23 said:
I kind of wonder about people that rebuild a plane like a Piper or Cessna if those percentages might hold true for the first 10 hours.
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People who rebuild Cessnas or Pipers can get dual instruction in literally identical aircraft. Much more variation in homebuilts.

Also, Cessnas and Pipers are built to certification standards that basically mandate that all aircraft behave similarly at the controls. Nothing like that for homebuilts; the differences tend to catch the unprepared. "Checkout" flights for production airplane are more needed for familiarity with the systems, not the physical ability to control the aircraft.

Ron Wanttaja
 
Ron, I have strong doubts that your numbers for builders vs. owners are actually statistically different. No fault of yours, but I bet those numbers are small. Be happy to be proven wrong.

I doubt its all that facile to get training in your new experimental, given the that most can't be rented for instruction.
 
Llewtrah381 said:
Somewhere I heard the accident rate in Experimentals is quite a bit higher for the later owners than the builder. Can’t remember where I saw that or any specifics. Has your research shown that? Seems plausible, especially for aircraft considerably different from traditional trainers, etc. (i.e. I’d anticipate it would be true for Lancairs, etc. and less so for RVs maybe). If so, it could suggest a focus for reducing accident rates.
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That might be because quite a few E-ABs are built by people that don't fly them much, if at all, and its the later owners that actually put on the flight hours.

Frank Christensen, the creator of the Christen Eagle kit biplane discovered this and spoke about it back in the 1980s. He and his staff became very concerned when they started to see many recently completed Eagles being put up for sale by their builder/owners, and they worried there was something wrong with the plane and how it flew. Turned out when they investigated closer there are three groups of E-AB participants - those that like to build projects and create something with their hands, those that like to fly airplanes (especially sprightly, responsive E-ABs) and a third, much smaller group that do both.
 
steingar said:
Ron, I have strong doubts that your numbers for builders vs. owners are actually statistically different. No fault of yours, but I bet those numbers are small. Be happy to be proven wrong.
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Well, it'd be my fault, because I developed the process to derive the statistics. :)

My database consists of an Excel spread sheet with ~3300 homebuilt accidents. I grab data from the NTSB databases, and add my own assessment of accident causes. So, once accidents are differentiated between "builder owned", "Purchaser owned", and "Unknown", I can easily generate separate versions that have just builder owned or purchaser owned, and slap the statistics together for comparison.

However, the bugaboo here is the ownership differentiation. It's manual in nature...I do use some processes to flag when a plane's manufacturer name is the same as the owner's name, but those flags are used to indicate the "low hanging fruit" that I look at and can quickly assess whether the plane is probably owned by the builder. (Note that I do this process every year, for the ~200 accidents in the preceding year. I'm not trying to make this determination at once for all ~3300 accidents.)

But I still end up stepping manually through most of the homebuilt accidents of that year. If the manufacturer of an RV-6 is listed as "VANS", and the pilot's name is "Smith," I obviously can't assume it's a purchased airplane. But if it's a "Smedly Fly Baby" and the owner was "Frank T. Smedly," there's a real good chance that it was a builder-owned aircraft at the time of the accidents.

Not a perfect chance, of course. It could be the builder's son...which, probably is NOT quite the same as Joe Smith buying Frank Smedly's Fly Baby. The rare times that has come up, I leave the accident in the unknown category.

Stuff like corporate names, etc. end up leaving things in the "unknown" category as well.

That's where the "Time in Type" differentiator comes in. Technically, each individual homebuilt is a unique type, so if the aircraft had 400 hours total time, and the pilot 400 hours time-in-type, it's a good guess that the pilot was the builder.

Good, but not perfect. If I, gods forbid, have an accident in MY Fly Baby, the aircraft will have ~700 hours total time, and I might be listed as ~1100 hours time in type. But I didn't build my airplane.

However, when I do that check, I give two hours of leeway, on the assumption that the aircraft might have two hours of ground run time before its first flight. This wasn't arbitrary...I separately flag accidents where the NTSB said it was the first flight, and looked at the statistics. Two hours was, roughly, the median. Planes had as much as 13 hours total time when they crashed on their "maiden flight."

Once I make my estimate as to the ownership status, I basically ignore it. All the cause assessment is performed without the ownership flags visible. Not because of a conscious effort to avoid bias, but because I need ~50 columns of accident-cause options visible to make the assessment faster and the "purchased" columns are hidden. It isn't until all the cause information is entered that I might split off separate owned and purchased databases for statistics comparison. That's where the "percentage of accidents vs. time in type" plot comes from.

I fully admit it's not a perfect process. But, frankly, it's the ONLY process...I've never seen anyone else even attempting to do this, and, frankly, don't know of any other way to extract the data over so large of a data set.

My sole consolation, accuracy wise, is the fact that the results, for the most part, seem to be reasonable. A reduced rate of mechanical failure is logical, when the airplanes usually have a number of flight hours before they're sold. "Builder Error" cases, in fact, drop in half for the purchaser-owned aircraft.

My results also show purchaser-flown homebuilts have a higher rate for Fuel Exhaustion and Fuel Starvation accidents. A higher rate of Fuel Starvation accidents is logical; these are cases where the airplane HAS fuel but the pilot fails to get it fed to the engine. I'm not as sanguine about Fuel Exhaustion cases, but these might reflect mistrust of fuel gauges/fuel consumption on the part of a new owner who wasn't involved in calibrating the gauges or assessing the fuel burn as part of the initial test series.

The results also show a higher rate for purchased homebuilts in the "Stupidity at Low Altitude" category. My gut likes that, but I'm not sure how logical it is.

Anyway, Steingar, I appreciate your comments, and certainly understand your skepticism. I do enjoy posting information and, especially, discussing the process, as I've gotten a lot of good feedback over the years.

steingar said:
I doubt its all that facile to get training in your new experimental, given the that most can't be rented for instruction.
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That's one of the biggest advantages of the RV world...there's a lot of folks out there assisting in transition training. Good buddy of mine flew his RV-7 for the first time about eight years ago, and he got a very extensive checkout from another builder.

The Vans series have some of the lowest Fleet Accident Rates, in my analysis.

Ron Wanttaja
 
Statistics are great to look at and analyze, until you become one...

For a long time the Sonex had a great safety record compared to the number of those built/flying. I decided to scratch build one in 2002, finishing it in 2012. Since finishing it there have been two factory aircraft (one with fatalities and one with very serious injuries) involved in accidents and I know of another builder who I kept in regular touch with by e-mail who died in his plane. In all three cases the NTSB determined the accidents were caused by a loss of power for unknown reasons. No matter how good you maintain your airplane or how sure you are that you built it right accidents like these are constantly in the back of your mind when flying. There is no way around it that flying a non mass produced airplane built by someone in their garage is always going to be statistically more risky. The design can be solid, the engine can be perfect, but one little mis-step in the build can cost you your life. Factory aircraft are built under controlled conditions with quality checks along the way. Experimental aircraft have none of that. They only require an inspection by a DAR at the end of the buid. The DAR is not going to check to make sure every bolt is tight, every wire is run correctly, all the rivets are set perfectly, etc.

Unfortunately I am starting to come to the realization that I may be ready to sell my plane. The risk/reward just isn't there for me aymore. Statistically I know that there is a better chance of getting in a car accident on the way to the airport, but that doesn't keep me from thinking about the above every time I fly greatly reducing the joy I once had for the hobby.

Keith
P.S. - Anyone want to buy a Sonex?
 
I lost a good friend to a Sonex, but I suspect it was a stall/spin due to a lack of awareness about density altitude leading to the departure stall. Hard to blame that on the aircraft. And he was a purchaser, although he had been building one.
 
kmacht said:
Statistics are great to look at and analyze, until you become one...

For a long time the Sonex had a great safety record compared to the number of those built/flying. I decided to scratch build one in 2002, finishing it in 2012. Since finishing it there have been two factory aircraft (one with fatalities and one with very serious injuries) involved in accidents and I know of another builder who I kept in regular touch with by e-mail who died in his plane. In all three cases the NTSB determined the accidents were caused by a loss of power for unknown reasons. No matter how good you maintain your airplane or how sure you are that you built it right accidents like these are constantly in the back of your mind when flying. There is no way around it that flying a non mass produced airplane built by someone in their garage is always going to be statistically more risky. The design can be solid, the engine can be perfect, but one little mis-step in the build can cost you your life. Factory aircraft are built under controlled conditions with quality checks along the way. Experimental aircraft have none of that. They only require an inspection by a DAR at the end of the buid. The DAR is not going to check to make sure every bolt is tight, every wire is run correctly, all the rivets are set perfectly, etc.

Unfortunately I am starting to come to the realization that I may be ready to sell my plane. The risk/reward just isn't there for me aymore. Statistically I know that there is a better chance of getting in a car accident on the way to the airport, but that doesn't keep me from thinking about the above every time I fly greatly reducing the joy I once had for the hobby.

Keith
P.S. - Anyone want to buy a Sonex?
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Trade for a nice Luscombe?
 
GRG55 said:
...there are three groups of E-AB participants - those that like to build projects and create something with their hands, those that like to fly airplanes (especially sprightly, responsive E-ABs) and a third, much smaller group that do both.
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I think this is very true. When I was shopping for my RV, I noticed a surprising number of completed planes with very low hours, placed on the market by the builder. Several of these didn't even have the flight testing done. I was trying to imagine putting blood, sweat, tears, and all of my spare time, into building an airplane for 4-5 years and then selling it before I flew it 20 hours.... I couldn't. But then again, I couldn't even imagine completing the project in the first place. I have huge respect for those guys and gals that do it and do it right. It would have to be a fantastic feeling of accomplishment and a irreplaceable learning experience.

On getting initial checkout and instruction in an experimental, I agree with @steingar that it can be very challenging, depending on location. At least as a purchaser, you often will have access to the seller who will probably agree to fly with you, but your insurance company typically won't recognize that as instruction in type.
 
Velocity173 said:
All of the aircraft on the list are sound designs, the high ones (Velocity & Lancair IV) suffer from pilot error. Even then, the rate is somewhat misleading because while the Velocity has an unusual number of accidents, it's below most of the aircraft on the list as far as fatal accidents. Below the EAB average as well. So basically you have a fair amount of people dinging up their Velocity aircraft but not many dying from them. PIO on landing comes to mind.
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I see this as the fast E/AB do not have the crash protection that certified aircraft do. So, the fatality rate goes up as the speed does.
 
Tom-D said:
I see this as the fast E/AB do not have the crash protection that certified aircraft do. So, the fatality rate goes up as the speed does.
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The average GA aircraft is about 39 years old. What crash protection features did a 1977 Piper Cherokee have?

The fact is, a large percentage of the GA fleet are Cessnas, and high-wing gives superior occupant protection....for certified as well as experimental aircraft.

Ron Wanttaja
 
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wanttaja said:
The average GA aircraft is about 43 years old. What crash protection features did a 1974 Piper Cherokee have?

The fact is, a large percentage of the GA fleet are Cessnas, and high-wing gives superior occupant protection.

Ron Wanttaja
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I seen some pretty beat up Cherokees and the folks walked away.
The most cheaply built certified aircraft I've dealt with is the pacer/tripacer, yet they are slow enough to nearly kill ya.

The engineering to go fast. seems to be opposite the heavy built crash protection.

JMHO
 
Tom-D said:
I seen some pretty beat up Cherokees and the folks walked away.
The most cheaply built certified aircraft I've dealt with is the pacer/tripacer, yet they are slow enough to nearly kill ya.

The engineering to go fast. seems to be opposite the heavy built crash protection.
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Certainly. Don't disagree. But until the last 10-20 years, crash protection wasn't built in to production GA aircraft. So it's not accurate to claim that the EAB fleet "do not have the crash protection that certified aircraft do." It's a function of mission, not deliberate design choices. The fatality rate for the Glasair and the Cirrus is almost identical, and the Cirrus has a lot of occupant protection.

Will a Wag-Aero J-3 replica naturally have a higher fatality rate than an original J-3, just because it's experimental?

Ron Wanttaja
 
wanttaja said:
Will a Wag-Aero J-3 replica naturally have a higher fatality rate than an original J-3, just because it's experimental?

Ron Wanttaja
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I don't see as it would. unless other factors were involved. some are in light sport, flown by non medically certified individuals.
all factors being equal, there should be no difference.
 
I feel pretty safe in my RV-9A. It'll do 170 KTAS, yet its 39 KIAS stall speed allows for pretty low kinetic energy in an off-field landing situation. And 5-point harnesses have a much better chance of keeping my face out of the panel than 1970s lap belts, especially if you really snug them before impact.
 
SoCal RV Flyer said:
I feel pretty safe in my RV-9A. It'll do 170 KTAS, yet its 39 KIAS stall speed allows for pretty low kinetic energy in an off-field landing situation. And 5-point harnesses have a much better chance of keeping my face out of the panel than 1970s lap belts, especially if you really snug them before impact.
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Hope you like double broken collar bones. but it's better than dead.
 
wanttaja said:
...

Will a Wag-Aero J-3 replica naturally have a higher fatality rate than an original J-3, just because it's experimental?

Ron Wanttaja
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According to Cleveland V. Piper Aircraft, the Wag may even be safer!
 
Want speed how about a single engine jet. The bonanza had a bad rap as a doctor killer how about this, It’s a jet that’s designed to be flown by the owner. Not requiring a full-time professional pilot. Of course, with the exclusive Cirrus Airframe Parachute System™ (CAPS™) the Vision Jet also sets a new standard in jet aircraft safety.

upload_2017-11-10_21-23-33.jpeg
 
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[QUOTE="wanttaja, post: 2397918, member: 4721]The fact is, a large percentage of the GA fleet are Cessnas, and high-wing gives superior occupant protection....for certified as well as experimental aircraft.

Ron Wanttaja [/QUOTE]

Says you, Ron. I’ll take the steel roll cage in my Mooney any day. Recently I saw a crash where the guy got into a departure stall, wound up embedded in someone’s house after ripping off the port wing. Everyone walked away. I’ve seen several crashes where the airplane was destroyed and everyone walked away. Looking at the accidents for my aircraft (Mooney M20c) it is clear that the vast majority of fatalities involved running into mountains. I don’t care what you’re flying, that’s gotta hurt.
 
donjohnston said:
Can you cite a reference for that statement?

Or are you saying that 4 and 5 point safety harnesses are a bad idea?
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Not at all,, but if you hit hard they will break your collar bone.
 
brien23 said:
Want speed how about a single engine jet. The bonanza had a bad rap as a doctor killer how about this, It’s a jet that’s designed to be flown by the owner. Not requiring a full-time professional pilot. Of course, with the exclusive Cirrus Airframe Parachute System™ (CAPS™) the Vision Jet also sets a new standard in jet aircraft safety.

View attachment 57683
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I could barely fly that thing in X-Plane lol. I'm sure I'd smash it in real life without a ton of instruction first.
but that's me...
 
steingar said:
wanttaja said:
The fact is, a large percentage of the GA fleet are Cessnas, and high-wing gives superior occupant protection....for certified as well as experimental aircraft.
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Says you, Ron. I’ll take the steel roll cage in my Mooney any day.
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Mooney (180 mph cruise speed) steel roll cage:
mooney.jpg

J-3 Cub (80 MPH Cruise Speed):
100_0366.jpg

Offhand, I think the occupants of the high-wing aircraft are better protected.....

Ron Wanttaja
 
donjohnston said:
Can you cite a reference for that statement?

Or are you saying that 4 and 5 point safety harnesses are a bad idea?
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Tom-D said:
Not at all,, but if you hit hard they will break your collar bone.
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So someone says that a 5-point harness is better than just lap belts and your response is "Hope you like double broken collar bones. but it's better than dead."?

I suppose that if you were on the radio with a guy that has a parachute who's getting ready to jump from a burning plane that's starting to come apart, you would say: "Hope you like broken legs."

It's almost like you have a quota of posts that you're trying to meet but you don't have anything useful to add.:rolleyes:
 
wanttaja said:
Mooney (180 mph cruise speed) steel roll cage:
mooney.jpg

J-3 Cub (80 MPH Cruise Speed):
100_0366.jpg

Offhand, I think the occupants of the high-wing aircraft are better protected.....

Ron Wanttaja
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Someone could just as easily post pictures of a burned-out J-3 and a slightly dented Mooney.
 
SoCal RV Flyer said:
Someone could just as easily post pictures of a burned-out J-3 and a slightly dented Mooney.
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Certainly. But the burned-out J-3 would still have a HECK of a lot more structure protecting the occupants. The point is the relative sizes of the "roll cages," not how the aircraft met their demises. The J-3 is much slower, but more structure around the occupant's upper torso and head. Both increase survivability.

Mind you, Mooneys will have some aluminum structure backing up what's visible above.

Ron Wanttaja
 
donjohnston said:
Can you cite a reference for that statement?

Or are you saying that 4 and 5 point safety harnesses are a bad idea?
Click to expand...

Tom-D said:
Not at all,, but if you hit hard they will break your collar bone.
Click to expand...

So someone says that a 5-point harness is better than just lap belts and your response is "Hope you like double broken collar bones. but it's better than dead."?

I suppose that if you were on the radio with a guy that has a parachute who's getting ready to jump from a burning plane that's starting to come apart, you would say: "Hope you like broken legs."

It's almost like you have a quota of posts that you're trying to meet but you don't have anything useful to add.:rolleyes:
 
donjohnston said:
So someone says that a 5-point harness is better than just lap belts and your response is "Hope you like double broken collar bones. but it's better than dead."?

I suppose that if you were on the radio with a guy that has a parachute who's getting ready to jump from a burning plane that's starting to come apart, you would say: "Hope you like broken legs."

It's almost like you have a quota of posts that you're trying to meet but you don't have anything useful to add.:rolleyes:
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Even the most perfect device often has its hazards.
 
wanttaja said:
Mooney (180 mph cruise speed) steel roll cage:
mooney.jpg

J-3 Cub (80 MPH Cruise Speed):
100_0366.jpg

Offhand, I think the occupants of the high-wing aircraft are better protected.....

Ron Wanttaja
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Except for where that fuel tank is located.
 
Factory is/can be"junk", as well - short cuts in design, plenty of well known gotchas in even large volume production aircraft, like 172s and Cherokees, etc. Given roughly the same performance envelope and structure, a well constructed experimental isn't inferior in design, construction, or survivability. We can concede there can be more variability in quality control; the modern kits cut down on a lot of that, however.

The statistical universe for all this noise is way too small to draw conclusions with deep meaning - the sample size is too small, and is outweighed by the many variables. Yeah, first (and early flights) are probably more dangerous; but maybe not for a particular individual who is well prepared, with a well designed and constructed experimental of modest to middlin' performance.

If you are prepared, smart, buy or build a well designed and constructed experimental, the stats aren't going to mean much in your particular situation.
 
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