A George (GMCPilot) Troll - but serious none-the-less

[aadamson]

George,

I'm just curious. You obviously don't feel that Composite constructions is as good as Aluminum. I'd like to know why? Is it just a personal preference, etc?

I did a little searching on Google and found some interesting factoids. Before I put them here. Is it not true that most of the commercial airlines have adopted composites for their benefits? NASA, Airbus, Boeing, etc. Also, isn't the F22 Raptor all built in composites? Doesn't NASCAR and CART, and the IRL mandate that the "driver capsule" be designed and built to specific safety specifications and those are only met by composite construction?

I'm certainly *NOT* a structural engineer, so I don't know the answer to the following. Is there a dramatic difference between eglass construction and carbon fiber construction that makes carbon *not* have some of the negatives that you've talked about? (NOTE: the racing guys all use Carbon)

Here is a quote I found very interesting, especially in light of your comments about "egg shells" and composite construction.

Why Composite versus Aluminum -
Testing shows standard and reinforced aluminum seats do not withstand multiple impacts like composite seats. Testing of composite seats shows frontal, rearward and passenger lateral impact - incorporating Willans six-point restraints, HANS restraints, bead foam head and body inserts (not shown) - showed impact loads well above survivable. The more rigid design prevents belts from loosening during impact and has higher fatigue resistance. The seat will always try to return to its as-made shape and will not crumple and injure driver as aluminum can. The composite seat is up to eight pounds lighter than comparably equipped aluminum seat.

One final note.... The construction techniques used in Composite Kits today are dramatically different than those used 5-10 years ago. Example, here is the inside of my left wing panel, before closing. You can see the "spars", the ribs and the lower skin.

Outboard wing panel


Top wing skin


Finished wings


Note: the wings were finished in 1 day. so there is a definite advantage to build time with this kit.

Horz stab

[Alex]

I'm making popcorn now! Who wants some?

[TerryPancake]

Alan that looks really great. I think you have a nice flying machine there.
I am not flaming you with this but I do have a question. Why do you come to an all aluminum aircraft site and take exception to someone?s opinion of a composite aircraft? I am a member of a NSX web site and guys with Corvettes come over a get PO'ed when someone with a NSX insults a Vet. Maybe it?s just me but I wouldn?t go to a Lancair web site and get PO?ed if the Lancair guys don?t like RV?s or Pipers. A friend of mine, his grandfather used to say, ?We all can?t like the same thing or we would all be sleeping with your Grandmother?.

[mark manda]

I enjoy Adam's excellent tech advice. I just wish he'd go torment some plastic airplane group forum when he feels the need to do comparisons. Or just plain mention plastic airplanes.

OTOH-- Son, in the RV-10 post brought up Lancairs so-- of course the Plastic airplane guy is going to help out.

down george.

"That's my opinion, should be yours."

[Mike S]

Most interesting thing in Adams quote was about fatigue resistance. Actually your quote can be interpeted as SUPPORTING Georges contention that aluminum a/c absorb energy by crumpling.

Terry, I dont know how long you have been following the "feud", but as I recall the first time I can recall seeing a post from Adam was about avaionoics, and he has repetedly stated that he is perusing this site to gain info about what is oging on in the homebuilt world that is of benifet to him---my phrasing, not his.

The REAL interesting thing is that George and Adam BOTH have a lot of good info, and cant seem to keep from taking offence at something the other says.

Please pass the popcorn, LOTS of butter.

Mike

P.S., Adam, all wet wing, and spoilers?

[Mr. Mikey]

*...walks in the room...starts to say something...decides to shut up and sit down*

I smell popcorn!

[osxuser]

One thing is for certain, that wing needs more access panels. I'm working on a friends Glasair 1 RG, and the lack of access in the wings is a MAJOR problem now that he has a fuel leak!

I think one of the major advantages of composite construction is eliminated by the crashworthiness issue. Basically, most composite airplanes are overbuilt because they have to stay together in a crash, not because they need to be stronger for everyday operations. By very nature composites don't like impact. They tend to just revert to their original form, glue and string.

[aadamson]

See, I'm really good for entertainment value ...

As for some of you... MY NAME IS ALAN . Seriously, I just have too many "A"'s and too many syliables in my name, so I answer to ADAM as well .

As for the access panels comment. The Lancair "Legacy" uses a wet wing that is full length. The only section that isn't wet is the tip. On one side there is an embedded dipole NAV antenna, and the other wig tip is empty. Most put their GPS/WX antennas or Magnetometers out there. The wing is all carbon skin, with Carbon uni making the cap strips on both spars and fiberglass making the web. The Gray you see is a sealer that is used to provide a barrier between the fuel and the laminates.

When the wings are closed, each wing is pressure tested to 10psi to make sure there are no leaks. HySol and flox is used to close the wing surfaces It's a much stronger bonding material than epoxy and yet retains a small amount of flexibility and does not become brittle.

Please accept some of my posts for their intent. Just an alternate view of building. I certainly will never tell anyone here how to pound a rivet or bend or form aluminum. And I will never tell you that your airplane is unsafe either. George decided to resort to that with mine for who know what reason?

[TerryWighs]

Alan...
Thanks for the pictures, and personal insight on composite...

I once built a boat...I built it out of wood...why wood ya say???? Cause I like working with wood. Could have built it out of aluminum, fiberglass...bark even...Enjoyed it alot.
Point being...we all build because we are inspired to do so...Some like rag/dope over tube...some like aluminum...some like glue/solvents/composite...
The best airplane you can build is the one that inspires you to finish it...and love the "process."
Can't remember ever seeing a plane I didn't like in some way???

[aadamson]

Originally Posted by TerryPancake

Alan that looks really great. I think you have a nice flying machine there.
I am not flaming you with this but I do have a question. Why do you come to an all aluminum aircraft site and take exception to someone?s opinion of a composite aircraft? I am a member of a NSX web site and guys with Corvettes come over a get PO'ed when someone with a NSX insults a Vet. Maybe it?s just me but I wouldn?t go to a Lancair web site and get PO?ed if the Lancair guys don?t like RV?s or Pipers. A friend of mine, his grandfather used to say, ?We all can?t like the same thing or we would all be sleeping with your Grandmother?.

Thanks for your comments Terry. I really don't take exception with the comments until someone decides to tell me that airplane A is unsafe compared to airplane B just because it's built of of different materials. There is simply no basis for fact in the statement and I'd hate for someone to make a determination of A vs. B because of it.

BTW, numbers are not proof. Designers for years have built "safe" designs from all kinds of materials. In fact, that is really the specific point. Design goals dictate how a material is used. And either material can be designed in to be safe.

My point, and if you go read my posts is pretty clear. There are those of you that like to build "all purpose" airplanes and those that like to build "specific purpose" airplanes. I'm fine with the RV's being considered "all purpose". But understand the tradeoffs with accepting that. I certainly do understand the tradeoffs with my decision to build a "specific purpose" airplane with plastic.