Experimental Aircraft End

[Tom-D]

The 172 and the Cherokees had Builder Error rates of 0.3% and 0.4%, respectively.
Ron Wanttaja

Just outa my A$$ here how many 172s were home built?

 

[wanttaja]

The 172 and the Cherokees had Builder Error rates of 0.3% and 0.4%, respectively.

Just outa my A$$ here how many 172s were home built?

Cessna and Piper aren't perfect. They make mistakes. Take a look at this quote from an NTSB Probable Cause:

"Also causal was the manufacturer's inadequate design of the installation and the improper length of the screw."

If this statement was made about a homebuilt in an accident, I would designate it "Builder Error" without a second thought. Since this was on a fully-certified aircraft, shouldn't it still be attributed to the builder?

Ron Wanttaja

 

[Geico266]

Take Geico, that man-about-town RV-10 driver. According to the FAA, he flies his RV 29 hours per year.

Say you convince Geico of the error of his ways. He sells the RV, and buys a Cessna 172.

The FAA now assumes he flies *two hundred* hours per year. Just because he's now flying a certified airplane.

Now there's a thought!




Last year I flew about 200 hours in home builts. I've averaged over 200 hours a year during the course of my flying career for the last 13 years. Clearly, the FAA has the number of assumed flying hours completely backwards in my case.

 

[brien23]

Well...I see the source of a couple of aspects of those quotes, though the paper is just plain wrong on one statistic. Allow me to give you my perspective.

The "Seven Times as Likely" claim came from the Nall Report a few years back. Makes a great quote, but I'm not enamored of their process. The Nall Report computes its figures based on the estimated number of hours flown, by GA aircraft vs. homebuilt aircraft.

They don't make the annual hours estimate. The FAA does. The FAA holds the basis for that estimate very tightly; there's rarely any insight into the process. Several years back, I was in a telecon with the FAA, the Nall Report folks, and a couple of people from EAA. Didn't get much insight, but one aspect is stunning.

Take Geico, that man-about-town RV-10 driver. According to the FAA, he flies his RV 29 hours per year.

Say you convince Geico of the error of his ways. He sells the RV, and buys a Cessna 172.

The FAA now assumes he flies *two hundred* hours per year. Just because he's now flying a certified airplane.

How did the FAA come up with that 29 vs. 200 values? We don't really know. It's a combination of survey inputs and a string of assumptions as to how many homebuilts on the registry are still active. Low estimate for homebuilts, of course. No basis for that, it's just their estimate.

Divide that 200 by 29. You get just about 6.9...which is the amount the Miami paper said that homebuilts are *worse* than production airplanes.

Odd coincidence, that.

The basic problem is that the estimate is based on a stream of unpublished assumptions. You can't check their numbers because you don't know HOW they came up with their numbers. The Nall Report guys just shrug and say, "We used FAA estimates." The FAA guys aren't talking.

The basic problem is what I refer to as comparable use. The FAA probably estimates how many hours privately-owned aircraft fly, adds that to an estimate of how many hour hours charter aircraft flew, adds it to an estimate of how many hours the country's Gulfstreams and Beechjets flew, and divides that by the total number of GA aircraft.

But of course, those homebuilts aren't flying charters. They (mostly) aren't corporate-owned, they aren't flown by pilots specifically hired to fly them. They aren't required to undergo 100-hour inspections, and their upkeep is a matter of a private owner's pocketbook, not a corporation's tax deduction.

Frankly, if you do an accidents-per-100,000-flight-hour comparison between Learjets and Stinsons, the Stinsons will come out far worse.

The fair comparison would be to a Cessna 172 or Piper Warrior, to an estimate of how many hours a private owner flies per year for personal travel and recreational flying...which is all the homebuilt owner can legally do.

But of course, those numbers...other than the 200 hours per year overall average...aren't available.

So, what to do?

How about we *assume* the homebuilt owner and the Cessna owner fly the same number of hours per year?

To me, it's a beautiful solution. Anyone can then compute the "Fleet Accident Rate" (number of accidents per year divided by the number of airplanes of that type). There are no mysterious undocumented assumptions; no "we got the numbers from the FAA" sort of excuses. Number of accidents/number of aircraft. Simple.

The last time I ran this analysis, homebuilts had a 46% higher accident rate than the overall US fleet. They had a lower rate than several types, such as the PA-18. If you eliminated the aircraft still in their test periods, the homebuilt rate dropped to about 15% higher than the overall rate.

When you consider that the aircraft are built, flown, and often designed by amateurs, I don't think 15% is all that bad. Yes, it's higher when you include the airplanes in the test period...but consider: How many production-airplane buyers buy a plane with zero hours? They're all going to have at least one test flight by a company test pilot...and if something happens, a professional test pilot, with scads of experience in that model, is just who you want at the controls to keep from becoming a statistic.

As for the Miami paper's claim that in an accident, "[homebuilt] pilots are seven times as likely to die," that's bull.

For the 1998-2012 period, here are the fatality rates (percentage of accidents with at least one fatality) for the overall US fleet, for homebuilts, and a number of common GA aircraft.

Overall 21%
Homebuilts 27%
Cessna 18%
Cessna 172 13%
Cessna 182 21%
Cessna 210 25%
Cessna 185 15%
Piper 22%
Piper PA-28 20%
Beech 32%
Beech Bonanzas 34%
Mooney 25%
Cirrus 41%
Diamond 18%

You can argue speeds vs. configuration, but there's no way the homebuilt fatality rate is seven times higher.

Ron Wanttaja

Nice write up,Outstanding.

 

[bnt83]

We find fasteners missing all the time in certified aircraft. It's usually when someone notices an empty pilot hole on a bracket and the inspector actually poses the question to the manufactuerer.

One of the dumbest things I see on certificated is replacing parts but not actually fixing the problem. One example that I'm very farmiliar with is the bracket for a hydraulic manifold of the lower rudder system on a Citation X. I could open pretty much any right hand lower pylon on a Citation X and find that bracket cracked. It will be replaced, and eventually found found cracked again later. Then again these airfract are flown about every day.

 

[Geico266]

We find fasteners missing all the time in certified aircraft. It's usually when someone notices an empty pilot hole on a bracket and the inspector actually poses the question to the manufactuerer.

One of the dumbest things I see on certificated is replacing parts but not actually fixing the problem. One example that I'm very farmiliar with is the bracket for a hydraulic manifold of the lower rudder system on a Citation X. I could open pretty much any right hand lower pylon on a Citation X and find that bracket cracked. It will be replaced, and eventually found found cracked again later. Then again these airfract are flown about every day.

BINGO! We have a WINNER!

I wasn't going to name you personally until you said something.

 

[Tom-D]

Cessna and Piper aren't perfect. They make mistakes. Take a look at this quote from an NTSB Probable Cause:

"Also causal was the manufacturer's inadequate design of the installation and the improper length of the screw."

If this statement was made about a homebuilt in an accident, I would designate it "Builder Error" without a second thought. Since this was on a fully-certified aircraft, shouldn't it still be attributed to the builder?

Ron Wanttaja

Don't we have a program in place for manufacturers up grades/retro fit?
does the EXP builders do that?

 

[Tom-D]

One example that I'm very farmiliar with is the bracket for a hydraulic manifold of the lower rudder system on a Citation X. I could open pretty much any right hand lower pylon on a Citation X and find that bracket cracked. It will be replaced, and eventually found found cracked again later. Then again these airfract are flown about every day.

And how many service difficulty reports did you submit?

 

[N801BH]

Don't we have a program in place for manufacturers up grades/retro fit?
does the EXP builders do that?

Yup.... Just less then a month ago a crack was found in the tail feathers of a RV-6.. Within 24 hours the Vans factory put out SB and I think 90% + of the fleet has already done the inspection.......

Try that with any certified plane.... It would take the manufacturer years to even admit there "might" be a problem.....

Now Tom,,,, put that in your pipe and smoke it........

 

[timwinters]

This is like typical arguing with a liberal. Doesn't address the points, just changes the subject or goes off on a tangent...I'm done.
Geico, you're up!

Don't we have a program in place for manufacturers up grades/retro fit? does the EXP builders do that?

And how many service difficulty reports did you submit?

I guess I didn't realize Tom and Brien were such liberals. Each one has, numerous times in this thread, "changed the subject or gone off on a tangent."

Thanks for pointing that out.

 

[bnt83]

It's your airplane, certified or experimental, do whatever you want with it.

There is junk in the experimental world, and there is junk in the certified world.

People often wonder why the FAA Inspectors do such a detailed inspection of an aircraft before conducting a checkride. I've seen my share of airplanes I would never get into and fly.

Bottom line, be responsible for yourself.

This sums it up. I watched a webcast from 40 year tech service veteran for Bell Hellicopter, and the infinite ways to screw up maintenance (human facotors) is mind blowing.

 

[wanttaja]

Don't we have a program in place for manufacturers up grades/retro fit?
does the EXP builders do that?

Certainly, the production world has the AD and service bulletin process. That's one of its advantages.

Things in the homebuilt world are far less structured. Bigger companies, like Vans and Lancair, do issue service advisories. Smaller designs, like the Fly Baby, have to rely on word of mouth.

Doesn't always work, of course. Friend had a part fail on first taxi. Designer said, yeah, forgot to mention to up the wall size on that tube...

One of the reasons I started my homebuilt accident analysis was to try to discover specific recurring issues. That's why it's mechanical-centric.

Ron Wanttaja

 

[wanttaja]

Last year I flew about 200 hours in home builts. I've averaged over 200 hours a year during the course of my flying career for the last 13 years. Clearly, the FAA has the number of assumed flying hours completely backwards in my case.

Like I think I posted here before (damn, these threads keep coming back, don't they...), I make a WAG on annual usage of homebuilts based on the year of construction, the date of the accident, and the number of hours flown. I see an overall average for homebuilts of about 60 hours/year, with the "cross-country" machines (RVs, Glasairs, etc.) about 20-30 hours higher, and the light fun machines a bit lower.

The FAA sorts told me their 29 hours/year number was influenced by their estimate of how many homebuilts were active. Don't know if the production-type hours/year were ALSO adjusted by a similar estimate...or where such estimates might come from. There may well be someone saying, "Well, type-certificated airplanes are valuable, so everything on the register is still flying." We just don't know.

The big issue is the FAA re-registration effort. One goal was to get rid of the deadwood; eliminate the long-gone airplanes that were still registered. About 20% of the homebuilt fleet disappeared.

Do you think the FAA upped that 29 hours/year estimate because a bunch of non-active homebuilts were elminated? I doubt it....

That's why I prefer comparing the Fleet Accident Rates instead of the accidents per 100,000 flight hours. It eliminates a whole mass of assumptions, replacing them with the single (what I think is logical) one that hours per year are set by the pilot, not the machine.

Ron Wanttaja

 

[Fearless Tower]

Is it just me or is it kind of ironic that the only airplane on the list with a parachute is the one with the highest fatal accident rate?

 

[Tom-D]

I guess I didn't realize Tom and Brien were such liberals. Each one has, numerous times in this thread, "changed the subject or gone off on a tangent."

Thanks for pointing that out.

And this post did what?

 

[Tom-D]

Yup.... Just less then a month ago a crack was found in the tail feathers of a RV-6.. Within 24 hours the Vans factory put out SB and I think 90% + of the fleet has already done the inspection.......

Try that with any certified plane.... It would take the manufacturer years to even admit there "might" be a problem.....

Now Tom,,,, put that in your pipe and smoke it........

That's a statement about the company/type club not the EXP aircraft as a whole.

 

[jesse]

Thanks for your insight Ron, always appreciate it. I would likely not have been comfortable buying a Flybaby without your excellent website and loads of information on the type.

 

[N801BH]

That's a statement about the company/type club not the EXP aircraft as a whole.

I respectfully disagree...

Most models of experimentals have a tight knit community and now with the internet there is no shortage of a easy path to share information among fellow builders...

Just name a brand of experimental and I bet there are numerous forums /groups /factory chat rooms etc to share info...

 

[Tom-D]

I respectfully disagree...

Most models of experimentals have a tight knit community and now with the internet there is no shortage of a easy path to share information among fellow builders...

Just name a brand of experimental and I bet there are numerous forums /groups /factory chat rooms etc to share info...

Yer right, there is no end to the information, but a lot of it is BS

like here, every one is an anon expert, with an opinion.

 

[N801BH]

Yer right, there is no end to the information, but a lot of it is BS

like here, every one is an anon expert, with an opinion.

Like you and brien23 about experimentals ............

Can you be so thickheaded that you don't see how deep a hole you are digging.......

 

[bnt83]

I would argue that type clubs are more effective at getting owners motivated to discuss the issues on both sides.


There are tons and tons of pages where owners have been beating the bushes looking for answers on the wing spar cracking of the cantilever winged 210s. What they have uncovered about the repair history of the cracked wing spars has been very interesting including calls to other countries, copy of logbooks and pictures of the aircraft. One member witnessed Cessna’s investigation using a core 210 wing in a load testing fixture and wrote a pretty good article about it.

 

[Tom-D]

Like you and brien23 about experimentals ............

Can you be so thickheaded that you don't see how deep a hole you are digging.......

Are you so bound by your convections that you can't see the weak link?

 

[N801BH]

Are you so bound by your convections that you can't see the weak link?

Good god man...................GET A GRIP.....

 

[brien23]

Certainly, the production world has the AD and service bulletin process. That's one of its advantages.

Things in the homebuilt world are far less structured. Bigger companies, like Vans and Lancair, do issue service advisories. Smaller designs, like the Fly Baby, have to rely on word of mouth.

Doesn't always work, of course. Friend had a part fail on first taxi. Designer said, yeah, forgot to mention to up the wall size on that tube...

One of the reasons I started my homebuilt accident analysis was to try to discover specific recurring issues. That's why it's mechanical-centric.

Ron Wanttaja

How does Vans or Lancair know who the second or third owner is, to send them service advisories?

 

[jesse]

How does Vans or Lancair know who the second or third owner is, to send them service advisories?

That would be incredibly easy to track via the aircraft registration database. I could write a program in a hour that would provide them with an interface to send a written letter via us mail to every owner of all their types. They wouldn't even have to mail a thing just upload a PDF and click a button. No clue if they do it but it'd be trivial to do.

 

[Velocity173]

Is it just me or is it kind of ironic that the only airplane on the list with a parachute is the one with the highest fatal accident rate?

Over aggressiveness knowing they have a parachute and not being familiar with aircraft avionics. 41 % seems high but I'd be willing to bet Cirrus aircraft are some of the most hrs flown per type during that study.

 

[zaitcev]

How does Vans or Lancair know who the second or third owner is, to send them service advisories?

How is it different from certified aircraft? Same database, of course. We are not taking unregistered ultralights here.

 

[Neal Howard]

How does Vans or Lancair know who the second or third owner is, to send them service advisories?

How does Piper, Cessna, Beech, et al know who all their airplanes' subsequent owners are?

*THEY DON'T*

I never got one service advisory from Piper the entire 10 years I owned my Cherokee 140. And I bet that Piper didn't give a rat's patootie who owned or who now owns that old plane either. As pointed out earlier, they can always look up registration info in the FAA's database but that would be knowledge owned and maintained by the FAA, not knowledge owned and maintained by Piper.

I don't know about Lancair, but Vans keeps a database of current owners of completed and flying RVs... participation is voluntary but 100% of everyone I personally know who owns an RV (about 50 of them) whether they built it or bought it already flying, is registered with Vans, and Vans is quite enthusiastic about keeping and maintaining that information too.

 

[wanttaja]

How does Vans or Lancair know who the second or third owner is, to send them service advisories?

As Jesse mentions, it's easy enough to look up the current owner in the FAA registration database. Once you get past the highest tier of companies, though, that's less likely.

You also have to remember how few of a given type there is, once you get past the "biggies". A while back, a Fly Baby issue came up, and I sent a letter to all US-registered owners... all 300 of them. Cost me less than two hundred bucks.

Don't have experience with non-Fly Baby owner communities, but our group is pretty tight with minimal friction. About 700 members, according to Google Groups, but I don't believe that's accurate. We have a few people who are recognized experts and pretty much don't have arguments break out. Bigger groups would have more controversy, of course, but that would certainly apply to production-type interest groups, as well.

Ron Wanttaja

 

[N801BH]

How does Vans or Lancair know who the second or third owner is, to send them service advisories?

The shear fact you are arguing with Ron Wanttaja on this topic is proof that you and Tom are out of touch with reality, the facts and the truth....

No one in the world has researched, studied and published data on this very topic more then Ron.....

 

[Tom-D]

The shear fact you are arguing with Ron Wanttaja on this topic is proof that you and Tom are out of touch with reality, the facts and the truth....

No one in the world has researched, studied and published data on this very topic more then Ron.....

Why do you think I'm arguing with Ron? or that Brien's question was a argument?

You are so fixated that we hate the EXP aircraft you think any post is an argument.

I think you are pizzy because we can work both sides of the industry and make money doing it.

 

[N801BH]

Why do you think I'm arguing with Ron? or that Brien's question was a argument?

You are so fixated that we hate the EXP aircraft you think any post is an argument.

I think you are pizzy because we can work both sides of the industry and make money doing it.

Buddy..... I ain't pizzy.....................

I am enjoying life to its fullest......

And your comments are free entertainment..... ....

 

[Tom-D]

Buddy..... I ain't pizzy.....................

I am enjoying life to its fullest......

And your comments are free entertainment..... ....

then I ask, why do you attack every thing we post like it is an argument?

 

[peppy]

Is it just me or is it kind of ironic that the only airplane on the list with a parachute is the one with the highest fatal accident rate?

The rates posted are percentage of accidents that have a fatality. That is a very different number from fatals per 100,000 flight hours. One way to make the number you reference low is to have a lot of accidents that aren't fatal. Training planes fall into that pattern. Chart out percentage of accidents that are fatal vs. MGW*(VS0)^2. You get a pretty good linear fit. Diamond happens to look be off the line.

 

[N801BH]

then I ask, why do you attack every thing we post like it is an argument?

I don't attack EVERY thing you post... In fact I compliment you on your work often.........

But when you get on a roll of being hardheaded then I really get off on throwing gas on the fire...........
Of course, that is for entertainment purposes only...

Don't try that at home, test driver on a closed course, your mileage may vary, etc etc... And all the other disclaimers you see in life.....

 

[RogerT]

Experimental aircraft owners are great at building informative groups lots of information. A lot of owners do a real good job of building their Aircraft and know how to maintain them. Problem arises when some rogue owners think or don't know or don't care what their letter of authorization is, change engine types, props or other major parts of the plane and still operate it under the original Special Airworthiness Certificate. The Experimental Aircraft group has done a real poor job of getting the word out about what is legal and what is not. Those of you who know what you can and can't do need to get the word out and clean up your own rogue pilots. If you Experimental Aircraft types don't clean up your act, the FAA will step in and you probably wont like new rules and regulations they might come up with.

Okay .. I'll bite .. what's your skin in the game? Us "Experimental Aircraft Types"? Rogue owners? And this is different from "rogue" owners of TC'd aircraft that don't follow the regs just how??? Those of us in Exp/AB know what the Operating Limitations are. We know that's how we have to operate our experimental program. There will always be those in all categories that don't follow the rules. I guarantee you Exp/AB doesn't have a lock on that.

Not sure why I respond to a troll.

RT

 

[RogerT]

My post is not directed at all Experimental operators ..

"If you Experimental Aircraft types don't clean up your act". Sure sounds like it's directed at all of us to me.

RT

 

[jesse]

The experimental part means nothing. Operators not following the rules should clean up their act or they may one day be caught or ruin it for everyone with additional regulation.

Certified and Experimental are both guilty of not following rules. Anyone that can't see that reality, well, I don't know what to say...

 

[RogerT]

User's Agreement and rules of Conduct for the Pilots of America Message Boards.
Personal attacks are prohibited. This specifically means any text/post that is
blatantly attacking another person on or off the forum, especially in personal way.

Some of you should read the rules of conduct again.

So should you .. you came in here attacking a whole segment of aviation and those of us in it.

 

[RogerT]

Believe me Brien is more up to date on the regulations on EXP aircraft than you will ever be.

And he didn't know the difference between a letter of authorization and operating limitations?