"Ryan Ferguson" wrote in message
. ..
C J Campbell wrote:

Not true, the SR-22 still is 4350 hours until you can show me a type
certificate that says otherwise. If the airframe life limit has been
extended then Cirrus is sure keeping quiet about it.

Sigh. If it makes you feel better, here ya go.

http://www.fergworld.com/various/4-9...klifelimit.pdf


How come part of this document is blacked out?

There is nothing new, BTW, about fiberglass. It is heavier than aluminum,
more difficult to repair, and subject to solar radiation damage (even the
Cirrus' special 3M fiberglass -- it has to be protected by that white
paint). It does have the advantage of being somewhat tougher than aluminum
(fiberglass does not dent as easily, but it is still subject to abrasions
and cracks.

You can do anything with aluminum that you can with fiberglass or carbon
fiber.

Carbon fiber, though, is both lighter and stronger than either aluminum or
fiberglass. It is also a lot more expensive and even more difficult to
repair. It also can be woven in ways that give infinite combinations of
flexibility and strength. There are very few shops certified to repair
carbon fiber. One of the troubles with carbon fiber is it if it is
over-stressed, it doesn't just gradually crystallize and develop cracks the
way metal does. It fails suddenly and spectacularly. I learned this the hard
way when I was hit head-on by a car while riding my OCLV carbon fiber bike.
Although designed for stresses up to 14,000 pounds, the bike frame exploded
on impact. (I also flew over the car, leaving the soles of my shoes still in
the pedals. I landed on my head on the other side, which some people say
explains a lot about me. Anyway, I am now two inches shorter from having
compressed my neck and spine. The driver, of course, had no insurance, and
got her eighth and ninth outstanding traffic tickets that day. They took
away her license, but no doubt she drives anyway.)

Of course, if money is no object, then carbon fiber is the way to go. No
doubt, this is the reason the Diamond is so expensive for what you get.
Aluminum will always have an economic advantage over carbon fiber.

The Diamond uses fiberglass, too, especially in the wings and skins, no
doubt as a cost saving measure. It uses Kevlar in the seats, so your
passengers can't shoot you in the back (actually, to achieve that 26G
cockpit strength).

I think bicycles are pointing the direction to the future of aircraft. I
think we may eventually see aircraft made of titanium (the stuff is not
rare, just difficult to work with) and beryllium/aluminum alloys. You can
get bicycles made of these materials today, and they are proving their
worth, though I will probably stick with carbon fiber. You will never see a
serious fiberglass bicycle, which is even more dependent than an airplane on
strength and lightness. Fiberglass is for cheap boats, not airplanes or
bicycles.