Composite Aircraft in the long term...

[Jay Honeck]

Okay, so Cirrus is cooking along at 60 aircraft per month. They're selling
everything they can build, and people who have bought them are ecstatic.

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

Reason for asking: A long discussion with some pilots who were staying at
the inn, who contend that they just won't last. Using as an example the
fiberglass wing tips and cowlings that always crack, flake, and crumble
after 15 years, requiring costly (and usually unsuccessful) repairs, these
pilots are convinced that the composite material in Cirrus will eventually
behave in much the same way. And once your fuselage parts start to crack,
flake, and delaminate, the planes will become essentially large
paper-weights.

So what's the group-think here? Will we by flying used Cirrus' in 20 years?
Or will they all be scrap by then?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Jim]

I'm not a boater, but what happens to 15 year old fiberglass boats? I'd
think some of the pounding they take would be harder than the normal
stresses an airplane goes through. Of course the boat hulls are thicker.

A lot of the trucks we have have fiberglass hoods and front fenders. The
oldest ones are 1979 models. These trucks are used both in the fields and
on the roads and go through a lot of flexing and bending. We don't see any
cracks or damage in them until some idiot backs one into another. Some of
our tractor cabs are fiberglass and of course go through a lot of vibration,
flexing and bending but like the trucks, everything is a relatively slow
speeds.

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

--
Jim Burns III

Remove "nospam" to reply

[Mike Rapoport]

There are plenty of '50s and '60s Corvettes around. Fishing poles and skiis
seem to last too.

Mike
MU-2


"Jay Honeck" > wrote in message
news:WCl5b.344377$uu5.68896@sccrnsc04...
> Okay, so Cirrus is cooking along at 60 aircraft per month. They're
selling
> everything they can build, and people who have bought them are ecstatic.
>
> Fast forward to the year 2018. What's going to be happening to these
> composite beauties?
>
> Reason for asking: A long discussion with some pilots who were staying at
> the inn, who contend that they just won't last. Using as an example the
> fiberglass wing tips and cowlings that always crack, flake, and crumble
> after 15 years, requiring costly (and usually unsuccessful) repairs, these
> pilots are convinced that the composite material in Cirrus will eventually
> behave in much the same way. And once your fuselage parts start to
crack,
> flake, and delaminate, the planes will become essentially large
> paper-weights.
>
> So what's the group-think here? Will we by flying used Cirrus' in 20
years?
> Or will they all be scrap by then?
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"
>
>

[smf]

Jay,

My Glasair II was signed off in 89'. That makes it 14 yrs old. The fuselage
is still in great conditon. It still looks new. It's been hangered except
for being on the ramp on trips. The cowling has a few cracks (hairline)from
the plug wires bumping against it because it is so tightly cowled.

Although, 14 yrs on the ramp would have it looking like an old maid.

Steve

[Paul Tomblin]

In a previous article, "Jay Honeck" > said:
>the inn, who contend that they just won't last. Using as an example the
>fiberglass wing tips and cowlings that always crack, flake, and crumble

Looking at the 5 Pipers on our flight line
(http://www.rochesterflyingclub.com/frames/equipment.html), (and the four
aircraft that we've sold in the time I've belonged to the club) I'd have
to say that Piper wingtips, wheel fairings and cowls are made with
possibly the worst grade of fiberglass ever made. I wouldn't use that
crap on even a non-structural part of my canoe. It looks like the FRP
that they use to roof outhouses in Ontario Provincial Parks, only cheaper.

Composite aircraft are made with much better materials, and more
importantly are coated and treated to avoid ultraviolet and ozone
degradation.

--
Paul Tomblin >, not speaking for anybody
The superior pilot uses his superior judgement to avoid situations in which he
has to demonstrate his superior skill.

[Ted Huffmire]

I feel better about aluminum airplanes,
which bend instead of crack under g-loads
experienced by aircraft in flight.
e.g. AA 587 -- you can't even use the rudder.
Look at these old Cessnas from the 1960s--
you just bend them back when they get a dent.

Fiberglass makes great sense for boats, because
aluminum will rust in the salt water.

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.
This is why the FAA has proposed
the FITS training standards program.
In 2018 I think there will be a lot more Cessna 172's
around.

Just my 2 cents.

Ted

Jay Honeck wrote:
>
> Okay, so Cirrus is cooking along at 60 aircraft per month. They're selling
> everything they can build, and people who have bought them are ecstatic.
>
> Fast forward to the year 2018. What's going to be happening to these
> composite beauties?
>
> Reason for asking: A long discussion with some pilots who were staying at
> the inn, who contend that they just won't last. Using as an example the
> fiberglass wing tips and cowlings that always crack, flake, and crumble
> after 15 years, requiring costly (and usually unsuccessful) repairs, these
> pilots are convinced that the composite material in Cirrus will eventually
> behave in much the same way. And once your fuselage parts start to crack,
> flake, and delaminate, the planes will become essentially large
> paper-weights.
>
> So what's the group-think here? Will we by flying used Cirrus' in 20 years?
> Or will they all be scrap by then?
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"

[Roy Smith]

In article >,
Jim > wrote:
>I'm not a boater, but what happens to 15 year old fiberglass boats?

I've got a 25 year old J-24 (sailboat). It was built using good
quality (but conventional) production techniques for the day:
polyester resin with woven glass cloth, balsa core, and gelcoat. The
basic structure appears to be in as good shape as it was the day it
left the factory. From a cosmetic point of view, it's a mess, but the
hull is sound.

I'm not really sure what you can learn from that, however. The kinds
of construction being used for aircraft today are a world apart from
what was used when my boat was built. Epoxy resin instead of
polyester. Cloth today is kevlar or carbon fiber instead of glass. I
assume aircraft are vacuum bagged and/or kiln baked.

All of these are better techniques, but on the other side, the layups
are a lot thinner. Anything built with the layup schedule of my boat
would be so heavy you'd never get it off the ground.

The only structural fiberglass part on my boat which approaches the
aspect ratio of an airplane wing is the rudder (300mm chord, 20mm max
camber, approx 1100mm unsupported span). Out of the factory, many of
the old rudders were thicker than the class rules allow (thick = more
drag) and in the old days, people tried to fair a few mm off the glass
to make the boats faster. The unfortunate side effect of this was a
lot of broken rudders!

The other high-aspect ratio piece of the hull is the keel. It's made
of lead and weighs 900 lbs. There's probably very little you can
learn about airplane construction from that :-)

[Dennis O'Connor]

Hmmm, a little hostility problem I see...

Denny

"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.

[Thomas Borchert]

Jay,

> cowlings that always crack, flake, and crumble
> after 15 years,
>

Well, you and I know (or could know) that statement is poppycock. Our
Tobago, for example, is still going strong with an over 20 year old
plastic cowling. So there's part of your answer.

--
Thomas Borchert (EDDH)

[Thomas Borchert]

Ted,

> which bend instead of crack under g-loads
> experienced by aircraft in flight.
> e.g. AA 587 -- you can't even use the rudder.
>

no offense meant, but that's a totally clueless statement - and you
probably even know it.

--
Thomas Borchert (EDDH)

[Dylan Smith]

On Wed, 03 Sep 2003 13:01:42 GMT, Jay Honeck > wrote:
>Reason for asking: A long discussion with some pilots who were staying at
>the inn, who contend that they just won't last. Using as an example the
>fiberglass wing tips and cowlings that always crack, flake, and crumble
>after 15 years, requiring costly (and usually unsuccessful) repairs, these
>pilots are convinced that the composite material in Cirrus will eventually
>behave in much the same way. And once your fuselage parts start to crack,
>flake, and delaminate, the planes will become essentially large
>paper-weights.

Our flying club in Houston had an old Arrow 1. The cowling was still in
good (but not perfect) condition. The cowling is in a hostile place -
baking hot engine. The structure of the fibreglass was sound. It had
been around since the 1960s.

As others have noted, plenty of old fibreglass gliders are still beautiful
today. Take care of the paintwork and the composite Cirrus will last too.
You need to take care of the paintwork on a metal plane too (or they
corrode, especially where I live, right next to the sea).

You can't really compare Piper's crappy cowlings from the 60s to the
processes used to make the Cirrus/Lancair/Diamond aircraft today.

--
Dylan Smith, Castletown, Isle of Man
Flying: http://www.dylansmith.net
Frontier Elite Universe: http://www.alioth.net
"Maintain thine airspeed, lest the ground come up and smite thee"

[G.R. Patterson III]

Jay Honeck wrote:
>
> So what's the group-think here? Will we by flying used Cirrus' in 20 years?

I still see a fair number of antique Corvettes on the road.

George Patterson
A friend will help you move. A really good friend will help you move
the body.

[Wallace Berry]

Composite gliders have been around for over 40 years with an excellent
record for structural integrity. My Glasflugel H301 Libelle glider,
N301BW, will be 40 years old in 2004. Made of plain 'ol E glass and
epoxy. Closing in on 3000 hours of flying time, still looks and performs
great. Very few AD's, all on the metal parts.

I have owned and flown old wood, old metal, and old glass. I have had
more problems with the metal than the wood and glass put together.
Corrosion and fatigue. Probably because people are more likely to take
care of wood and plastic and to neglect metal. Fabric covered aluminum
wings are probably the worst for this. Often left sitting out for years
with moisture collecting in wing, not to mention rodent urine, etc. Seen
aircoupe spars that were little more than aluminum oxide powder.

One thing about old glass: Old fiberglass aircraft were significantly
overbuilt to get some rigidity out of the very flexible fiberglass.
Hence, my glider has a 9.5 g wing just to make the wing stiff enough to
keep both tips from drooping to the ground when it's not flying. Carbon
is stiff enough that you can build a stiff structure that is still
pretty weak.

Composite materials tech and fabricating methods are advancing at a high
rate. Eventually, new metal airplanes are going to get rare (says the
guy who just bought a bunch of steel tubes, rags, and sticks with a late
40's Continental to drag it through the air).

[Paul Tomblin]

In a previous article, Foster > said:
>Paul Tomblin wrote:
>>
>> Looking at the 5 Pipers on our flight line
>> (http://www.rochesterflyingclub.com/frames/equipment.html), (and the four
>> aircraft that we've sold in the time I've belonged to the club) I'd have
>> to say that Piper wingtips, wheel fairings and cowls are made with
>> possibly the worst grade of fiberglass ever made.
>
>That's why they're so cheap to replace. ;-)

No, that's why we've got a pair of LoPresti Zip Tips waiting for us when
we take the Dakota to Goderich to get repainted this fall. We're not
wasting another dime of Piper crap fiberglass.


--
Paul Tomblin >, not speaking for anybody
It could have been raining flaming bulldozers, and those idiots would have
been standing out there smoking, going 'hey, look at that John Deere burn!'
-- Texan AMD security guard

[Foster]

Paul Tomblin wrote:
>
> Looking at the 5 Pipers on our flight line
> (http://www.rochesterflyingclub.com/frames/equipment.html), (and the four
> aircraft that we've sold in the time I've belonged to the club) I'd have
> to say that Piper wingtips, wheel fairings and cowls are made with
> possibly the worst grade of fiberglass ever made.

That's why they're so cheap to replace. ;-)

[Rick Durden]

Jay,

The composites used on Cirrus are not anything close to the fiberglass
material you describe. The better comparison is to look at composite
sailplanes that are twenty and thirty years old and have no problems.
The UV issue was dealt with 20 years ago as well.

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.

Warmest regards,
Rick

"Jay Honeck" > wrote in message news:<WCl5b.344377$uu5.68896@sccrnsc04>...
> Okay, so Cirrus is cooking along at 60 aircraft per month. They're selling
> everything they can build, and people who have bought them are ecstatic.
>
> Fast forward to the year 2018. What's going to be happening to these
> composite beauties?
>
> Reason for asking: A long discussion with some pilots who were staying at
> the inn, who contend that they just won't last. Using as an example the
> fiberglass wing tips and cowlings that always crack, flake, and crumble
> after 15 years, requiring costly (and usually unsuccessful) repairs, these
> pilots are convinced that the composite material in Cirrus will eventually
> behave in much the same way. And once your fuselage parts start to crack,
> flake, and delaminate, the planes will become essentially large
> paper-weights.
>
> So what's the group-think here? Will we by flying used Cirrus' in 20 years?
> Or will they all be scrap by then?

[Todd Pattist]

(Rick Durden) wrote:

>The UV issue was dealt with 20 years ago as well.

That's debatable. Improvements have been made, but toxicity
concerns have caused some formula changes. I think the jury
is still out.

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

[Craig]

A good place to start looking at longevity is the Slingsby T-3. It is
probably the one aircraft out there that is really accumulating hours
at a rate with reliable and exacting maintenance standards, that will
give you a good idea. So far it has been a big bust in the training
program for the USAF. It is the only aircraft that I have ever seen
that has a structural temperature limitation. If the structure is over
a certain surface temp, it is prohibited from flight due to structural
degredation at the elevated temp. With the big engine, it is extremely
temp sensitive under the cowling and has what appears to be massive
vapor locking problems despite using multiple fuel pumps. The problems
with the a/c power and structure have become so problematical, that
the USAF grounded the fleet and will probably destroy the a/c rather
than let them get into civilian hands. I know it's only one aircraft,
but the design is certified at a minimum to FAR 23 standards.

What is interesting, is the a/c that are built to the same TC, and
using the smaller engines so far don't have the same problems. Even
those that are in military training programs outside the USAF don't
have the same fuel and structure problems that I've been able to find.

Craig C.

[Kyle Boatright]

"Craig" > wrote in message
om...
> A good place to start looking at longevity is the Slingsby T-3. It is
> probably the one aircraft out there that is really accumulating hours
> at a rate with reliable and exacting maintenance standards, that will
> give you a good idea. So far it has been a big bust in the training
> program for the USAF. It is the only aircraft that I have ever seen
> that has a structural temperature limitation. If the structure is over
> a certain surface temp, it is prohibited from flight due to structural
> degredation at the elevated temp. With the big engine, it is extremely
> temp sensitive under the cowling and has what appears to be massive
> vapor locking problems despite using multiple fuel pumps. The problems
> with the a/c power and structure have become so problematical, that
> the USAF grounded the fleet and will probably destroy the a/c rather
> than let them get into civilian hands. I know it's only one aircraft,
> but the design is certified at a minimum to FAR 23 standards.
>
> What is interesting, is the a/c that are built to the same TC, and
> using the smaller engines so far don't have the same problems. Even
> those that are in military training programs outside the USAF don't
> have the same fuel and structure problems that I've been able to find.
>
> Craig C.
>

The Slingsby's problems are not composite related. They are engine/fuel
system related.

Some (all?) of the Diamona's (sp?) have structural temp limitations as well.
That's why they paint 'em white. Also, the folks who live in Phoenix or
other places that have extreme temperatures often keep 'em hangared.

KB

[Jerry Guy]

Jay Honeck wrote:
> Okay, so Cirrus is cooking along at 60 aircraft per month. They're selling
> everything they can build, and people who have bought them are ecstatic.
>
> Fast forward to the year 2018. What's going to be happening to these
> composite beauties?
>
A recent Hot Topic in the local aerobatic community as the recent
economic situation has driven several 12-14 year old Extra 300 aircraft
onto the market. 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.

Lots of anguish over a recent article in Sport Aerobatics when Bud
Davisson had his 30 year old S2A recovered and found lots of
weakened/broken glue joints in his wings. Everything was repairable
using well established procedures. Nothing like being able to tear off
the old cover and get in and have a look around! Try that with your 300k
dollar composite airplane!

Jerry

[Mike Long]

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

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/F997F6C2309EEA6186256C68004F491E?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...

[Dennis O'Connor]

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?
> >

[[email protected]]

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

[Peter Dohm]

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

[Todd Pattist]

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.

[Gilan]

here is an example of an 18 year old composite going strong.
http://www.geocities.com/CapeCanaveral/Hall/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_gators_annual_fly.htm

[ArtP]

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.

[Dave Katz]

"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.

[Jim Vadek]

"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?

[Jean-Paul Roy]

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/CapeCanaveral/Hall/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_gators_annual_fly.htm
>
>
>