Sonerai structural failures/homebuilt responsibility
Dan Bergmen
airplane. There is an article in Kitplanes, April, 1992 in the
"Around the Patch" column concerning in flight structural
failures of 5 of these planes. A state licensed aeronautical
engineer was hired to analyze the design, and he found some
design weakness in the mainspar web and some unstable wing elements.
His name is Bill Welch, and he was subsequently fired by the present
president of Sonerai for "unsatisfactory work and too conservative
conclusions." There is a mod done by the original designer, John
Monnet to add some angles and vertical members. No failures
have occured in planes with this mod. I hope the Sonerai
about to fly has these mods, if not, I sincerely hope the builder
checks out the story with diligence and good sense. A project near
first flight gets very intense and there is a lot of momentum to complete.
The other side of it is your life! Please excuse the alarm, but we homebuilders
have no AD network to support and distribute flaws in designs. I am
amazed constantly by people building IFR Kitfoxes, when every Kitfox
owner I know has experienced multiple power failure forced landings.
Flying IFR with a Rotax 2-stroke is sheer madness! Maybe I'm missing
something here, but I don't know how to land if you can't see the ground!
This could be the kernal of a valuable publication, collecting and
publishing all known homebuilt accidents and incidents, with at least
the NTSB reported cause. I receive two accident report newletters, and in the
last two years I can remember less than 5 homebuilt accidents. With the
number of EAA members and planes at Oshkosh, I would hope to see some
better responsibility on the part of some of these kit manufacturers.
No regulation attracts scoundrels, and I know some do exist out there.
Okay, I'm finished for now. So Mr Sonerai builder, whoever you are,
I wish you only the best, I expect to first fly my Skybolt in a few
years myself. I plan to have a test pilot do the first one, I hope you do
too. Blue Skies, bud!
Richard
thomas.e.lester
>I recall someone on the net near to completion of a Sonerai II
>airplane. There is an article in Kitplanes, April, 1992 in the
>"Around the Patch" column concerning in flight structural
>failures of 5 of these planes. A state licensed aeronautical
>engineer was hired to analyze the design, and he found some
>design weakness in the mainspar web and some unstable wing elements.
The failures were in aircraft flown by 2nd or 3rd owners.
They were over gross and doing aerobatic manuevers when the wings
sheared. John had the analysis and came out with the mod and a "new"
S wing design with 3 more ribs and the spar stiffeners you reference.
This occured several years ago. (about 1985 ??)
>His name is Bill Welch, and he was subsequently fired by the present
>president of Sonerai for "unsatisfactory work and too conservative
I know of no "Sonerai" president or company. Plans are currently
available through Great PLains Aircraft Supply (Steve Bennet)
I am not aware of any "analysis" by Steve or anyone else.
since Johns withdrawal from business.
>conclusions." There is a mod done by the original designer, John
>Monnet to add some angles and vertical members. No failures
>have occured in planes with this mod. I hope the Sonerai
>about to fly has these mods, if not, I sincerely hope the builder
Yes, I have the new design. Thanks for your concern.
>checks out the story with diligence and good sense. A project near
>first flight gets very intense and there is a lot of momentum to complete.
You hit the nail on the head here!
>The other side of it is your life! Please excuse the alarm, but we homebuilders
>have no AD network to support and distribute flaws in designs. I am
Sport Aviation lists ADs issued against all recognized kits and
plans. When John was notified of these failures, he issued warnings
to all plans holders. After the conclusion of study, he issued an AD
mandating the change for the reinforcment. The system is there.
you just need to be in the network. A "stolen" set of plans will
keep you from learning of many such fixes.
>amazed constantly by people building IFR Kitfoxes, when every Kitfox
>owner I know has experienced multiple power failure forced landings.
>Flying IFR with a Rotax 2-stroke is sheer madness! Maybe I'm missing
>something here, but I don't know how to land if you can't see the ground!
>
>This could be the kernal of a valuable publication, collecting and
>publishing all known homebuilt accidents and incidents, with at least
>the NTSB reported cause. I receive two accident report newletters, and in the
FAA and EAA already do this. Just call Ben Owens at EAA and ask
for the accident history for your type (members only, please)
He will send a complete listing of all incidents/accidents
>last two years I can remember less than 5 homebuilt accidents. With the
>number of EAA members and planes at Oshkosh, I would hope to see some
>better responsibility on the part of some of these kit manufacturers.
>No regulation attracts scoundrels, and I know some do exist out there.
Yes it does. But please, tone down the negative comments.
Most "scoundrels" are found out and short lived (in business terms
at least) Stick to designs with at least a few flying examples
built by other than the designer.
Many designers are truely out to have a good solid design.
They try to provide the best support finances will allow.
Lets not give net lurkers the idea this is a bunch of profit crazed
jerks selling garbage to every unsuspecting sucker.
That simply is NOT my experience.
>
>Okay, I'm finished for now. So Mr Sonerai builder, whoever you are,
>I wish you only the best, I expect to first fly my Skybolt in a few
>years myself. I plan to have a test pilot do the first one, I hope you do
>too. Blue Skies, bud!
After 8 yr.s there is no way in HELL that I would give that honor
to someone else. Of all the builders I have talked to, I know of NONE
that have had someone else test hop their bird. I'm sure as you finish,
you will most likely change you mind. Perhaps not, but odds say you
will either NOT finish, or will test hop it yourself.
Please let us know how far along you are.
--
-----------------------------------------------------------------
Tom Lester att!cblph!tel
Sonerai IIL (under construction) (614) 860-3259
N4LX (614) 927-8106
Matthew L. Ginsberg
> After 8 yr.s there is no way in HELL that I would give that honor
> to someone else. Of all the builders I have talked to, I know of NONE
> that have had someone else test hop their bird. I'm sure as you finish,
> you will most likely change you mind. Perhaps not, but odds say you
> will either NOT finish, or will test hop it yourself.
Just a data point: I had someone else test fly my plane and, if I had
to do it again, would make the same decision. My test pilot (Dave
Morss; I'll give a phone number to anyone interested) is simply an
incomparably better pilot than I am -- especially so at handling
airborne disasters. I have no inflight structural failures under
my belt; he has many.
Sure, flying the first flight would have been fun (especially because
he got to be on the local news doing it!). But Dave was simply better
qualified for the job.
Matt Ginsberg
Steve Pennypacker
> I hope that somebody else out there know hard numbers, but I heard at a
> forum at Oshkosh that in the BD-5 the death rate is 50% on FIRST FLIGHTS.
> The speaker stated that after the first 40 hrs, homebuilts have been safer
> that certificated aircraft in the hands of GA pilots. It seems to depend
> VERY much on which homebuilt. Keep in mind that the overall safty of GA
> compares with riding a motorcycle ... which to my mind is not very good.
For those of you who read the BD-5 figures above and decided (or
reconfirmed your beliefs) that homebuilts are dangerous: PLEASE READ
THIS.
I just spoke with Ben Owen at the EAA in order to get some factual data
about homebuilt safety. Here's what he told me.
First, look at insurance rates for different aircraft types. On the
whole, rates for homebuilts are approximately the same as for production
aircraft (by the way, this matches my own experience). Insurance
companies don't like to lose money, and their rates are a good indicator
of risk. The companies simply do not see excess risk with homebuilts.
Homebuilts have a slightly higher accident rate than production aircraft.
However, the fatality rate is LOWER. These figures were recently
confirmed by the FAA Administrator (you know, the guy who's appointed
by the president to help us ;-).
Safety among types of homebuilts varies widely (as do the insurance
rates). Racing, aerobatics, and high-performance planes have higher
accident rates, while others have lower.
-end of conversation with Ben-
Although I don't have figures, I would bet that if we compared only
comparable performance planes and uses, that the safety record of
homebuilts would be excellent.
Don't judge the safety of homebuilts by the BD-5 example. It just not
representative.
--
Steve Pennypacker PP-ASEL
David Doshay
forum at Oshkosh that in the BD-5 the death rate is 50% on FIRST FLIGHTS.
The speaker stated that after the first 40 hrs, homebuilts have been safer
that certificated aircraft in the hands of GA pilots. It seems to depend
VERY much on which homebuilt. Keep in mind that the overall safty of GA
compares with riding a motorcycle ... which to my mind is not very good.
personal chances are much better.
David dos...@ursa.arc.nasa.gov
Paul Stafford
Well, to add one more data point, I flew my own test flight in my RV4.
Before I did that, I became super-taildragger current, reviewed and made
lists of emergencies and the proper responses, had umpty million people
check my plane ( 6-pack to anyone who found problems- got to motivate 'em!)
and only flew for about 15 minutes the first flight, well within gliding
distance of the airport. Also, I waited until that perfect time- Zero traffic,
zero wind, a chase plane to watch for bad leaks, streaks of oil, things
flapping/falling off, etc.
An incomparable experience, to be sure. I am glad I did it. For the rest of
the test program, I followed a syllabus prepared by an ex-test pilot for
McDonnel Douglass, and it was a very slow, conciencious, conservative
process indeed. But afterwards, I knew that I had explored the envelope
completely, had no worries about the airplane(a good thing- flew to Alaska
the following month...)and learned an awful lot about flying precisely,
and making measurements while airborne. I think I decowled it after almost
every flight, too, for inspection.
Another RV4 builder at my airport ( STS) had a flight instructor do his
first few flights, and he regretted it. The guy "wrung it out", progressing
much too fast, and in both of our opinions, dangerously. He fired him after
the first 5 flights.
I feel that if you are reasonably competent in type (or similar a/c), research the problem thoroughly, and wear a chute so you don't make dumb decisions,
there is no reason not to do your own test flights. Your SO may feel
differently, though... :)
One of the problems that many builders face is that during the building
process, they don't fly much- hard to spend that kind of money or time...
Well, obviously, this is a mistake. Get current first, preferably in type,
or at least contact other owners of type, to get some typical numbers to
use for that first flight, for t/o., Vy, Vapp, etc. Hopefully, the builders
manual will cover this.
Well, enough rambling. Good luck!
Paul Stafford, N84PS ( only 6 years in the making)
Gary A. Braun
> publishing all known homebuilt accidents and incidents, with at least
> the NTSB reported cause. I receive two accident report newletters, and in
the
> last two years I can remember less than 5 homebuilt accidents. With the
> number of EAA members and planes at Oshkosh, I would hope to see some
> better responsibility on the part of some of these kit manufacturers.
> No regulation attracts scoundrels, and I know some do exist out there.
>
I remember reading somewhere that the chances of dying in a plane you built
yourself was 1 in 85. Could it really be that bad? I had always hoped to
build my own airplane, but now I'm not so sure...
--
Gary A. Braun
gbr...@beech.mitre.org
Mary Shafer
Society of Experimental Test Pilots' symposium on the ffight testing
of home-built aircraft. The title was "The Far Side (Flight Testing
Homebuilt Experimental Aircraft" by Chuck Berthe and Dick VanGrunsven.
--
Mary Shafer DoD #0362 KotFR NASA Dryden Flight Research Facility, Edwards, CA
sha...@rigel.dfrf.nasa.gov Of course I don't speak for NASA
"There's no kill like a guns kill." LCDR "Hoser" Satrapa, gunnery instructor
"A kill is a kill." Anonymous
Peter Theune
>There was a very good article by Chuck Berthe (of Calspan) at the last
>Society of Experimental Test Pilots' symposium on the ffight testing
>of home-built aircraft. The title was "The Far Side (Flight Testing
>Homebuilt Experimental Aircraft" by Chuck Berthe and Dick VanGrunsven.
It's great to see that Chuck is still contributing to the field...
I worked with him in the early 80's out of Pax River on a pilot workload
study with the Calspan T-33 and a little computer for memory tests.....
somehow they didn't much like having to load up the pilot until he
could'nt do the terain following mission any more.. never could figure
out why..
Do you know how to get in touch with him? Did he ever finish the
homebuilt he was working on?
I didn't know anything about homebuilts at the time, but I think it
might have been one of the RV series.
Anyhow, best wishes to him if you have contact.
Peter Theune
Johns Hopkins University, Applied Physics Lab.
Johns Hopkins Rd. Laurel Md. 20723
Dan Bergmen
I am relieved to know that Tom's Sonerai is updated, more sothan I am
as it turns out. I am rather a neophyte at flying ( 2 years, 200 hours)
and at home building as well. I did make the trip to Idaho and rode in
Kitfox, Avid, and came home empty. I don't fault either of these designs,
I just am too big for these little planes. (6 ft., 200 lbs.) Next pilgrimage
was to Arlington, '91. Oshkosh just seemed too overwhelming for my quest.
I rode with Dick VanGrunsden in his RV-4, rolls, immelman, and it was very fun.
Then I rode in Dave Baxter's Starduster, and it was love! There is a special
sense of majesty in an open cockpit bi-plane that has to be experienced to
understand. So I started to look and found a Skybolt project, in Washington.
I sent a mechanic to check it out, and then bought it and a friend trucked
it down to me in Felton, CA.
I am at a early stage, fuselage welded, wing kit and the rest in parts.
I had to backtrack some to learn to weld. I spend most of my time hacksawing
(anyone want to armwrestle?!). I have connected with an A&P + welder who
built Wayne Hadley's Raven, Gene Stisser. I will want to do most of the work myself
but I'm struggling with decisions at this point. I am very glad to have
decided on the Skybolt, since it is the size I like, strong, but a bit more
docile than a Pitts (I'm told). I have no plans to compete with it, I just
want a bi-plane that I can play around in. I have had 6 hours of aerobatic
instruction, enough to know I enjoy it. I hope to reach a point where I
don't have to wonder which way to do something, every time I start a part.
Maybe this is a continual dilemma.
Sorry if my tirade drifted into negatives. I am committed (but not incarcerated)
to the homebuilding movement. Thank you, Tom for enlightening me about accident
history records. My decision to use a test pilot is the same as Matt's.
I don't feel qualified to handle it if things go weird. I don't want to
buy the farm trying to save the plane.
This will be my last entry for a while, I am changing jobs and may not have
access to the net. I will miss this terribly. I hope I haven't annoyed anyone
with my awkward nettiquite or blundering postings. My ignorance seems to expand
exponentially relative to my curiosity. But then life is for learning, huh?
Please feel free to call..........
Richard Hankey
(408) 335-9487
ps. IO-540/360 needed..
t
Charles K. Scott
> After 8 yr.s there is no way in HELL that I would give that honor
> to someone else. Of all the builders I have talked to, I know of NONE
> that have had someone else test hop their bird. I'm sure as you finish,
> you will most likely change you mind. Perhaps not, but odds say you
> will either NOT finish, or will test hop it yourself.
There have been quite a few articles written over the last 5 years in
both Kitplanes and Sport Aviation about the "first flight". The
conclussion of the ones I remember best is that it is unsafe to do your
own first flight if you are not an experienced test pilot. I also
recall reading that most Homebuilt fatalities occurr on the first
flight.
I'm not going to try to dissuade anyone from making their own first
flight, very few people are going to change their minds by simply
reading a rec.aviation posting, but the facts speak for themselves.
I'm not sure I could make the right decisions if I was making that
first lift off in my own airplane, I would definately be distracted.
I'm willing to pay someone who does this all the time to make the
flight, come back and tell me what he, as an expert in flight
characteristics, thinks about the way the thing flies and what should
be done to correct it, if necessary. Too much is at stake and LOTS of
pilots have bent their babies badly when making that first flight for a
demanding audience. No thanks.
Corky Scott
David Doshay
|> In article <1992Mar19....@news.arc.nasa.gov>, dos...@ursa.arc.nasa.gov (David Doshay) writes:
|> > I hope that somebody else out there know hard numbers, but I heard at a
|> > forum at Oshkosh that in the BD-5 the death rate is 50% on FIRST FLIGHTS.
|> > The speaker stated that after the first 40 hrs, homebuilts have been safer
|> > that certificated aircraft in the hands of GA pilots. It seems to depend
|> > VERY much on which homebuilt. Keep in mind that the overall safty of GA
|> > compares with riding a motorcycle ... which to my mind is not very good.
|>
|>
|> For those of you who read the BD-5 figures above and decided (or
|> reconfirmed your beliefs) that homebuilts are dangerous: PLEASE READ
|> THIS.
|> Although I don't have figures, I would bet that if we compared only
|> comparable performance planes and uses, that the safety record of
|> homebuilts would be excellent.
|>
|> Don't judge the safety of homebuilts by the BD-5 example. It just not
|> representative.
|>
I agree completely. There are a few homebuilts out there that are ruining
the statistics for the rest of us. Actually, I should say home-builders and
pilots. Note that I do say that after the first 40 hrs are flown off ( a
dividing point in the statistics because of FAA regs for the first 40) it
is my understanding that homebuilts are slightly safer. The insurance
probably stays a little higher because of the lack of large numbers in the
homebuilt field, and because the insurance companies also do not mind making
a little more money when they know they can.
It is also true that GA statistics would be much better if head strong
pilots would stop flying VFR into IFR weather.
In my opinion, the two are related: too many pilots think that they are
MUCH better than they really are, and are so stubborn that they kill themselves
proving to the rest of us how good they are. The BD-5 is loved by a few
extremely experianced pilots, but too many not so great pilots who thought
themselves test pilots ended up dead when they got in over their heads.
The whole thing should not reflect on homebuilts. It should get all pilots
to really know themselves.
David dos...@ursa.arc.nasa.gov
charles.a.keskimaki
>owner I know has experienced multiple power failure forced landings.
>Flying IFR with a Rotax 2-stroke is sheer madness!
>
My Kitfox, N89CK, has been flying for 2 years and 150+ hours -- no
power failures, no forced landings. The 2-stroke Rotax 582 hasn't
missed a beat.
Power plants in all homebuilts are, after-all experimental; the
builder/pilot must carefully plumb, wire, and then monitor the
package, on an ongoing basis, to maximize reliability (Lycoming
and Continental included).
Maybe the Rotax 2-stroke (at least the 582) doesn't have to be
unreliable. In fact, ... none of the Kitfox owners I know have
experienced multiple power failure forced landings!
Chuck
G A Venkatesh
>In article <2204...@hp-ptp.ptp.hp.com> da...@hp-ptp.ptp.hp.com
>(Dan Bergmen) writes:
>>I am amazed constantly by people building IFR Kitfoxes, when every Kitfox
>>owner I know has experienced multiple power failure forced landings.
>>Flying IFR with a Rotax 2-stroke is sheer madness!
>>
>>Richard
>
>My Kitfox, N89CK, has been flying for 2 years and 150+ hours -- no
>power failures, no forced landings. The 2-stroke Rotax 582 hasn't
>missed a beat.
He probably means the earlier Rotax 532s which doesn't have all that great
(not bad but not something you really want to trust in IFR) a record.
However, the failures seem to be bunched in the take-off phases than in
cruise.
The oil injection was a big step up for the 582 and I am sure prevented a
lot of owner related failures.
>
>Power plants in all homebuilts are, after-all experimental; the
>builder/pilot must carefully plumb, wire, and then monitor the
>package, on an ongoing basis, to maximize reliability (Lycoming
>and Continental included).
>
>Maybe the Rotax 2-stroke (at least the 582) doesn't have to be
>unreliable. In fact, ... none of the Kitfox owners I know have
>experienced multiple power failure forced landings!
As long as you follow the golden rule for Rotax engines - change spark
plugs and often.
venky
Ron Wanttaja
> In article <2204...@hp-ptp.ptp.hp.com> da...@hp-ptp.ptp.hp.com (Dan Bergmen) writes:
> > There is an article in Kitplanes, April, 1992 in the
> >"Around the Patch" column concerning in flight structural
> >engineer was hired to analyze the design, and he found some
> >design weakness in the mainspar web and some unstable wing elements.
> >president of Sonerai for "unsatisfactory work and too conservative
>
> I know of no "Sonerai" president or company. Plans are currently
> available through Great PLains Aircraft Supply (Steve Bennet)
Welch was hired by the Formula V Racers association. The association was
rightly concerned after the "Jersey Devil" crash last year... the vast
majority of Formula V racers are Sonerais. Great Plains had no connection
with the hiring of the outside analyst.
Welch also writes a column for KITPLANES on homebuilt aircraft design and
analysis... and I think he wrote the "Stress without Tears" series a while
back.
Racing Association was looking for reassurance; what they got was someone
telling them their airplanes were unsafe. Welch had started redesigning
the wing by the time he was fired.
KITPLANES, of course, has maintained serious interest in the Sonerai
controversy. One of the regular writers had written an article about the
aircraft soon after the Jersey Devil crash. The editor was aware of the
ongoing analysis and declined to print the article until more information
was available on possible flaws. Somehow, this (to me, quite reasonable)
action was distorted in word-of-mouth until it got back to the Great Plains
people in the form of "Kitplanes won't talk about Sonerais because they
crash!" Bennet, of course, got ticked and blistered KITPLANES in the
Sonerai newsletter.
Then came along ANOTHER unsuspecting writer; one who happens to drive a Fly
Baby. HE writes an article on a local Sonerai and sends it into KITPLANES.
The editor calls back and explains the situation. The writer doesn't like
it (basically because he'd shot some NEAT air-to-air) but agrees it's a
reasonable course of action.
Of course, he has to break the news to the owner of the local Sonerai that
his pride-n-joy won't be gracing the cover of KITPLANES anytime soon. And
of course, the Sonerai owner passes the situation to the other local
builders. And then the editor at KITPLANES gets a letter that says, "Ron
Wanttaja says you won't publish articles about Sonerais because they crash!"
Sigh.
> >There is a mod done by the original designer, John
> >Monnet to add some angles and vertical members. No failures
> >have occured in planes with this mod. I hope the Sonerai
> >about to fly has these mods, if not, I sincerely hope the builder
>
> Yes, I have the new design. Thanks for your concern.
And according the word I got (third hand), Sonerais with the mod are safe,
as long as they're operated in normal category.
> >The other side of it is your life! Please excuse the alarm, but we
> > homebuilders have no AD network to support and distribute flaws in designs.
> Sport Aviation lists ADs issued against all recognized kits and
> plans. When John was notified of these failures, he issued warnings
> to all plans holders. After the conclusion of study, he issued an AD
> mandating the change for the reinforcment.
The EAA also has a computer bulletin board for homebuilt safety issues.
Information is contained in most issues of Sport Aviation.
Ron Wanttaja
prang@ssc-bee
...rutgers!uw-beaver!ssc-bee!prang
pr...@ssc-bee.boeing.com
thomas.e.lester
>In article <1992Mar19.1...@cbnews.cb.att.com>, t...@cbnews.cb.att.com (thomas.e.lester) writes:
>> In article <2204...@hp-ptp.ptp.hp.com> da...@hp-ptp.ptp.hp.com (Dan Bergmen) writes:
>> > There is an article in Kitplanes, April, 1992 in the
>> >"Around the Patch" column concerning in flight structural
>> >failures of 5 [Sonerais]. A state licensed aeronautical
>
>And according the word I got (third hand), Sonerais with the mod are safe,
>as long as they're operated in normal category.
The final wing design by John Monnet is rated +/- 7G single passenger.
The design is approved for limited aerobatics (no snap manuevers)
All of these mods occured in less than a years time.
Ed Sturba covered the progression in detail in his most recent
newsletter.
In brief: Original wing 9 ribs +/- 6 Gs
After crash, derated to normal category temporarily
about 3 months later Mods required add stiffiners &
back up to aerobatic.
about 1 year later : New 11 rib design (S wing, S for stretch)
with reinforcments (full +/- 7 G rating)
wingwalk and inboard counterbalance also available
Status update: Moved the plane to paint shop last Saturday.
Now have wings in primer. putty REALLY shows up after getting it
in one color :-( More sanding and touch up to go.
HINT: Don't try to fill rivet dimples on wings. The time speant is
driving me NUTS.
(sigh, patience, I need more patience)
Ed Wischmeyer
One homebuilder recently posted
>HINT:Don't try to fill rivet dimples on wings. The time speant [sic] is
driving me NUTS.
Aside from the obvious discussions about whether it is possible to drive a
homebuilder nuts or whether they already have to be nuts to be a
homebuilder (doesn't apply to me, of course!! :-) ), everyone I've talked
to states that filling rivet holes is *a bad idea.* The thinking is that
if a rivet starts to work loose, you will want to know about it. A rivet
head that is circled by cracks in the paint shows a loose rivet, but
a filled rivet head won't give this warning.
Ed Wischmeyer
col...@akro.austin.ibm.com
> From: wi...@Apple.COM (Ed Wischmeyer)
> Subject: Re: Sonerai structural failures/homebuilt responsibility
>
> homebuilder (doesn't apply to me, of course!! :-) ), everyone I've talked
> to states that filling rivet holes is *a bad idea.* The thinking is that
> if a rivet starts to work loose, you will want to know about it. A rivet
> head that is circled by cracks in the paint shows a loose rivet, but
> a filled rivet head won't give this warning.
>
NOT that loose rivets will be hidden. The filler material used (Bondo or
other equivalent) is not structural and will in fact crack if the rivet does
become loose. In fact Bondo will crack even if the rivet stays tight if there
is suficient flexing of the skin. The result, in the filled case, is typically
a large chunk of paint flaked off rather than a few crack in the paint in the
unfilled case.
Of course this is all predicated on the assumption that the filler material
is less than .050 inch thick. If the filler is thicker (i.e. the rivet dimple
looks like a dent from a hail stone) a different question of airworthiness
might arise. :-)
John Collier Voice: 512-838-4675 or t/l 678-4675
IBM AWD-Austin/2830 Fax: 512-838-4851 or t/l 678-4851
col...@akro.austin.ibm.com or col...@austin.vnet.ibm.com
#include <std/disclaimers.h>