Composite Aircraft in the long term...

The TCDS shows the SR 22 has a 4350 hour airframe life.

http://www.airweb.faa.gov/Regulatory...E?OpenDocument

(Long site name - I don't know if copying and pasting will work)


... Extra 300 aircraft onto the market. These birds have 2000 to 2500 hours on them, with a factory limit life of 5000 hrs...

The real issue Jay, is whether the FAA's airframe life limitations have any
basis in reality... Assuming that the FAA persists in insisting that the
Cirrus airframes time out at 5K, very shortly you will see bunches of them
only accumulating 5 or 10 hours a year on the tach - by various means...

Denny
"Jay Honeck" wrote in message

Fast forward to the year 2018. What's going to be happening to these
composite beauties?

Rick Durden wrote:

snip

Because of the FAA's extremely conservative certification procedures
for composites, the structures are far, far stronger than metal
airplanes, which is why they also weigh as much. The FAA
certification procedures took away the weight advantage of composites,
but what it did was give us airplanes that are evern more overbuilt
than the Grumman Ironworks figthers of WWII.

Generalising quite a bit there a few other issues apart from the
conservative safety factor in strength requirements which tend to increase
weight in composites.

The stiffness issue which often requires extra material (most composites
have 1% strain at yield)

Low work of fracture compared to metals.

Difficulty in inspection for defects especially after minor impact damage
considering that damage can be at some distance from the impact point.


regards

jc

Paul Tomblin wrote:

In a previous article, "Dennis O'Connor" said:
The real issue Jay, is whether the FAA's airframe life limitations have any
basis in reality... Assuming that the FAA persists in insisting that the
Cirrus airframes time out at 5K, very shortly you will see bunches of them
only accumulating 5 or 10 hours a year on the tach - by various means...

I think what's really going to happen is that when the first couple of
Cirrusssessess(sorry) reach 5000 hours, Cirrus is going to buy them back,
and cut them to pieces and test them to prove to the FAA that they're
still as strong as the day they were built, and the FAA is going to
increase the life limit to 10,000 hours and we're repeat the process a few
years later. That's assuming that Cirrus is still in business when it
happens. If not, hopefully there will be a Cirrus owners association that
can perform the work.

Probably all true. With a 300K dollar price tag and loads of avionics, which
would appear to be major theft targets and probably more heat sensitive than
the basic airframe, the new "fast glass" aircraft will probably be kept in
hangars when not in use; except for the occasional overnight stop. Therefore,
most of the the SR22's and similar aircraft should be in pretty good shape at
the end of 15 years and/or 5000 or 10,000 hours.

The new group of composite trainers, which tend to stay out on the ramp when
not in use may prove more about the true service life of composite structures.

Peter

Jerry Guy wrote:

These birds have 2000 to 2500 hours on them, with a
factory limit life of 5000 hrs. These aircraft have been rode hard as
flight demonstration team aircraft and appear fine. But, until someone
puts the requisite 5000 hrs on one and sends it back to be cut up by the
factory for examination it's anybodys guess what the insides look like.

The early composite gliders had hour limits on the
structure. When they reached those limits, the aircraft
were inspected, without any cutting up, and the lifetimes
were all extended by the authorities. I'm not aware of any
composite structures with lifetime limits that had anything
more onerous than an inspection requirement before
extending.

Todd Pattist
(Remove DONTSPAMME from address to email reply.)
___
Make a commitment to learn something from every flight.
Share what you learn.

here is an example of an 18 year old composite going strong.
http://www.geocities.com/CapeCanaver...l/1653/q1.html

think about helicopter rotor blades that last for many many years and flex
like crazy!

--
Have a good day and stay out of the trees!
See ya on Sport Aircraft group
http://groups.yahoo.com/group/Sport_Aircraft/

Flying Gators annual Fly-in
http://www.mitchellwing.com/flying_g...annual_fly.htm

On Fri, 05 Sep 2003 01:22:06 GMT, Angus Davis
wrote:


I heard a rumor that Cirrus wings are only certified for 4500 hours,
after which they must be replaced. Can any Cirrus owners confirm or
deny this rumor?

The SR20 airframe life is 12,500 hours, the SR22 is 4,500 hours.
Cirrus says that by the end of the year further testing will increase
the SR22 number.

"Jim" writes:

Exactly what kind of composite are the Cirrus's made of? Any carbon layers
in them?

Prepreg glass, vacuum bagged and then baked to a golden brown.

"Ted Huffmire" wrote in message
...
The Cirrus makes a great doctor killer.
The people who shell out 300K for one of the
300 HP SR-22 models are the kind of BMW-driving
egomaniacs with more money than brains.
They stare at that computer
screen instead of looking out the window and
flying the plane, which they need to do in an
aircraft that is going so fast.

Cirrus envy?

Gilan, I went and looked at all the pages of your site. Very interesting to
see the amount of worked you put in to that construction project. You have a
plane to be proud of.

J.P.


"Gilan" a écrit dans le message news:
.net...
here is an example of an 18 year old composite going strong.
http://www.geocities.com/CapeCanaver...l/1653/q1.html

think about helicopter rotor blades that last for many many years and flex
like crazy!

--
Have a good day and stay out of the trees!
See ya on Sport Aircraft group
http://groups.yahoo.com/group/Sport_Aircraft/

Flying Gators annual Fly-in
http://www.mitchellwing.com/flying_g...annual_fly.htm