Best homebuilt for ~700 nm commute

[[email protected]]

Re the Tango (composite) and RV (metal) an article in July Sport
Aviation (pg 54) addresses Drag Coefficient as a function of
construction process. The multiplier for the Drag Coefficient for
composite is 1.0-1.05 and for flush rivet metal is 1.10. Composite
can reduce drag then by 5 - 10% over a metal constructed aircraft.
Food for thought.

[Jay Maynard]

On 2008-07-07, > wrote:
> Re the Tango (composite) and RV (metal) an article in July Sport
> Aviation (pg 54) addresses Drag Coefficient as a function of
> construction process. The multiplier for the Drag Coefficient for
> composite is 1.0-1.05 and for flush rivet metal is 1.10. Composite
> can reduce drag then by 5 - 10% over a metal constructed aircraft.
> Food for thought.

The flip side: what happens when it collects hangar rash? Repairing aluminum
is well known; repairing composites is not.
--
Jay Maynard, K5ZC http://www.conmicro.com
http://jmaynard.livejournal.com http://www.tronguy.net
Fairmont, MN (FRM) (Yes, that's me!)
AMD Zodiac CH601XLi N55ZC (got it!)

[Gig 601Xl Builder]

Jay Maynard wrote:
> On 2008-07-07, > wrote:
>> Re the Tango (composite) and RV (metal) an article in July Sport
>> Aviation (pg 54) addresses Drag Coefficient as a function of
>> construction process. The multiplier for the Drag Coefficient for
>> composite is 1.0-1.05 and for flush rivet metal is 1.10. Composite
>> can reduce drag then by 5 - 10% over a metal constructed aircraft.
>> Food for thought.
>
> The flip side: what happens when it collects hangar rash? Repairing aluminum
> is well known; repairing composites is not.


Exactly, which along with the health related issues associated with
building a composite aircraft is why any of us still work with aluminum.

[Paul Hastings]

"Jay Maynard" > wrote in message
...
> On 2008-07-07, > wrote:
>> Re the Tango (composite) and RV (metal) an article in July Sport
>> Aviation (pg 54) addresses Drag Coefficient as a function of
>> construction process. The multiplier for the Drag Coefficient for
>> composite is 1.0-1.05 and for flush rivet metal is 1.10. Composite
>> can reduce drag then by 5 - 10% over a metal constructed aircraft.
>> Food for thought.
>
> The flip side: what happens when it collects hangar rash? Repairing aluminum
> is well known; repairing composites is not.
> --
> Jay Maynard, K5ZC http://www.conmicro.com
> http://jmaynard.livejournal.com http://www.tronguy.net
> Fairmont, MN (FRM) (Yes, that's me!)
> AMD Zodiac CH601XLi N55ZC (got it!)

Could you clarify that Jay?

The way I read it your saying that composite repair is not possible or much
harder than aluminum repair.

There are well established methods for repairing composite damage, without any
annoying rivet bucking noise.

Paul

[Jay Maynard]

On 2008-07-07, Paul Hastings > wrote:
> The way I read it your saying that composite repair is not possible or much
> harder than aluminum repair.
>
> There are well established methods for repairing composite damage, without
> any annoying rivet bucking noise.

Why, then, can't you get composite factory aircraft repaired short of
sending the broken part back to the factory?

Yes, I know the discussion is around homebuilts, but if composite repairs
are well understood, then there should be no reason to require all repairs
to be done at the factory.
--
Jay Maynard, K5ZC http://www.conmicro.com
http://jmaynard.livejournal.com http://www.tronguy.net
Fairmont, MN (FRM) (Yes, that's me!)
AMD Zodiac CH601XLi N55ZC (got it!)

[Paul Hastings]

"Jay Maynard" > wrote in message
...
> On 2008-07-07, Paul Hastings > wrote:
>> The way I read it your saying that composite repair is not possible or much
>> harder than aluminum repair.
>>
>> There are well established methods for repairing composite damage, without
>> any annoying rivet bucking noise.
>
> Why, then, can't you get composite factory aircraft repaired short of
> sending the broken part back to the factory?
>
> Yes, I know the discussion is around homebuilts, but if composite repairs
> are well understood, then there should be no reason to require all repairs
> to be done at the factory.
> --
> Jay Maynard, K5ZC http://www.conmicro.com
> http://jmaynard.livejournal.com http://www.tronguy.net
> Fairmont, MN (FRM) (Yes, that's me!)
> AMD Zodiac CH601XLi N55ZC (got it!)

Not knowing which factory you are speaking of, my guess is more of a company
policy issue for liability reasons. I know Northwest(I live in MN too) isn't
sending parts back to Airbus they are repairing them onsite.

So are many homebuilders with composite planes, imho composite repairs are
easier. Especially in your example of hangar rash, if you ding the leading edge
in aluminum How many rivets do you have to drill and rebuck if it is a single
piece leading edge. It gets even worse if you bend an aluminum spar.

Paul

[Jay Maynard]

On 2008-07-07, Paul Hastings > wrote:
> Not knowing which factory you are speaking of, my guess is more of a company
> policy issue for liability reasons. I know Northwest(I live in MN too) isn't
> sending parts back to Airbus they are repairing them onsite.

I was thinking of the LSA market, as well as being told of one DA20 that
took out a landing light and was down for six months while waiting on
Diamond to fix it.

> So are many homebuilders with composite planes, imho composite repairs are
> easier. Especially in your example of hangar rash, if you ding the leading edge
> in aluminum How many rivets do you have to drill and rebuck if it is a single
> piece leading edge. It gets even worse if you bend an aluminum spar.

OTOH, damage that would bend an aluminum spar would break a composite wing
in half.

I don't mean to minimize the repairs required with aluminum, certainly...but
any A&P can deal with an aluminum repair. That's a major reason I ruled out
composite aircraft when I was looking. I would expect the same would go for
composite homebuilts. Sure, the builder might well be able to fix it - but
how well would the fix work, especially in the long run? How well would it
stand up to sun and weather?
--
Jay Maynard, K5ZC http://www.conmicro.com
http://jmaynard.livejournal.com http://www.tronguy.net
Fairmont, MN (FRM) (Yes, that's me!)
AMD Zodiac CH601XLi N55ZC (got it!)

[Vaughn Simon]

"Jay Maynard" > wrote in message
...
> The flip side: what happens when it collects hangar rash?

So who has a hanger? Perhaps it is because I started out in sailplanes, but
I would not be comfortable parking a glass bird out in the sun for years at a
time, especially one finished in jellcoat.

> Repairing aluminum is well known; repairing composites is not.

Sorry, I can't agree. I have seen some torn up sailplanes repaired so well
you can't see where anything ever happened. It all a matter of finding the
right repair station.

[Peter Dohm]

"Paul Hastings" > wrote in message
.. .
>
> "Jay Maynard" > wrote in message
> ...
>> On 2008-07-07, Paul Hastings > wrote:
>>> The way I read it your saying that composite repair is not possible or
>>> much
>>> harder than aluminum repair.
>>>
>>> There are well established methods for repairing composite damage,
>>> without
>>> any annoying rivet bucking noise.
>>
>> Why, then, can't you get composite factory aircraft repaired short of
>> sending the broken part back to the factory?
>>
>> Yes, I know the discussion is around homebuilts, but if composite repairs
>> are well understood, then there should be no reason to require all
>> repairs
>> to be done at the factory.
>> --
>> Jay Maynard, K5ZC http://www.conmicro.com
>> http://jmaynard.livejournal.com http://www.tronguy.net
>> Fairmont, MN (FRM) (Yes, that's me!)
>> AMD Zodiac CH601XLi N55ZC (got it!)
>
> Not knowing which factory you are speaking of, my guess is more of a
> company policy issue for liability reasons. I know Northwest(I live in MN
> too) isn't sending parts back to Airbus they are repairing them onsite.
>
> So are many homebuilders with composite planes, imho composite repairs are
> easier. Especially in your example of hangar rash, if you ding the leading
> edge in aluminum How many rivets do you have to drill and rebuck if it is
> a single piece leading edge. It gets even worse if you bend an aluminum
> spar.
>
> Paul
>
From what I've heard around my local chapter, composite repairs are not much
of a problem--at least as long as the spars and fuel tanks are still OK.

OTOH, you really can't beat the pre-punched aluminum from VanGrunsven for
assembly time. If you already have some wiring and systems knowledge from
your work experience, you could almost make an argrument to build an RV to
fly while you are building something that fit your "ultimate" solution. If
you don't have that experience, you will have to deal with the "90% done and
90% remaining" problem, but the same will sitll be true of the composites.

Peter

[Paul Hastings]

"Jay Maynard" > wrote in message
...
> On 2008-07-07, Paul Hastings > wrote:
>> Not knowing which factory you are speaking of, my guess is more of a company
>> policy issue for liability reasons. I know Northwest(I live in MN too) isn't
>> sending parts back to Airbus they are repairing them onsite.
>
> I was thinking of the LSA market, as well as being told of one DA20 that
> took out a landing light and was down for six months while waiting on
> Diamond to fix it.
>
>> So are many homebuilders with composite planes, imho composite repairs are
>> easier. Especially in your example of hangar rash, if you ding the leading
>> edge
>> in aluminum How many rivets do you have to drill and rebuck if it is a single
>> piece leading edge. It gets even worse if you bend an aluminum spar.
>
> OTOH, damage that would bend an aluminum spar would break a composite wing
> in half.
>
> I don't mean to minimize the repairs required with aluminum, certainly...but
> any A&P can deal with an aluminum repair. That's a major reason I ruled out
> composite aircraft when I was looking. I would expect the same would go for
> composite homebuilts. Sure, the builder might well be able to fix it - but
> how well would the fix work, especially in the long run? How well would it
> stand up to sun and weather?
> --
> Jay Maynard, K5ZC http://www.conmicro.com
> http://jmaynard.livejournal.com http://www.tronguy.net
> Fairmont, MN (FRM) (Yes, that's me!)
> AMD Zodiac CH601XLi N55ZC (got it!)

So, it is a personal issue that you have with composites. I'm glad we cleared
that up :^)

[Jay Maynard]

On 2008-07-07, Paul Hastings > wrote:
> So, it is a personal issue that you have with composites. I'm glad we cleared
> that up :^)

Oh, I don't dispute that the choice is one that every aircrafy buyer or
builder needs to make for himself. In the end, it's a huge investment, be it
time, money, or both, and the owner needs to be comfortable with the
decision. My point is that composites have significant drawbacks, and they
need to be clearly understood during the decision process.
--
Jay Maynard, K5ZC http://www.conmicro.com
http://jmaynard.livejournal.com http://www.tronguy.net
Fairmont, MN (FRM) (Yes, that's me!)
AMD Zodiac CH601XLi N55ZC (got it!)

[denny]

On Jul 7, 5:29�pm, Gig 601Xl Builder >
wrote:
> Jay Maynard wrote:
>
> > The flip side: what happens when it collects hangar rash? Repairing aluminum
> > is well known; repairing composites is not.
>
> Exactly, which along with the health related issues associated with
> building a composite aircraft is why any of us still work with aluminum.

[denny]

On Jul 7, 5:29�pm, Gig 601Xl Builder >
wrote:
> Jay Maynard wrote:

>
> > The flip side: what happens when it collects hangar rash? Repairing aluminum
> > is well known; repairing composites is not.
>
> Exactly, which along with the health related issues associated with
> building a composite aircraft is why any of us still work with aluminum.

I can't speak for other composite airplanes, but in building a
Tango 2 or Foxtrot 4, the whole construction process teaches you to
repair any hanger rash or major damage. In one case we had an
airplane damged that the insurance adjuster said to repair. He said
he would have scrapped it if it had it been aluminum. What does this
prove? Not much. One could throw corrosion into the discussion. If
one material was universally better than the other, the other would
disappear. Health issues? We haven't seen any.

Denny

[Steve Foley]

"Gig 601Xl Builder" > wrote in message
m...

> Exactly, which along with the health related issues associated with
> building a composite aircraft is why any of us still work with aluminum.

Aluminum is not necessarily good for your health either. The guy who used to
rebuild Piper Cherokee fuel tanks (Sky-something in NH) could not lift his
right arm over his head. He had spent too much time with a rivet gun.

[BobR]

On Jul 7, 6:33*pm, "Vaughn Simon" >
wrote:
> "Jay Maynard" > wrote in message
>
> ...
>
> > The flip side: what happens when it collects hangar rash?
>
> * *So who has a hanger? *Perhaps it is because I started out in sailplanes, but
> I would not be comfortable parking a glass bird out in the sun for years at a
> time, especially one finished in jellcoat.
>
> > Repairing aluminum is well known; repairing composites is not.
>
> * *Sorry, I can't agree. *I have seen some torn up sailplanes repaired so well
> you can't see where anything ever happened. *It all a matter of finding the
> right repair station.

Agreed, repairs on the non-structural parts is not any more of an
issue than repairing the non-structural parts of any other aircraft.
Structural parts are a problem rather it is a metal or composite. In
many ways, the composite is much more forgiving of hangar-rash and
even more severe problems because the damage is generally much more
localized. I had a bird strike in a 182 that resulted in having to
replace the entire wing. The same on a composite would have been a
localized repair. I have seen composite planes repaired from hard
landings including one that flipped that would have totaled metal
birds.