Alot of chafed wire short circuits occur when an improperly supported wire chafes against the airframe, when that occurs on an aluminum airplane sparks/smoke/fire occur, on a composite airframe that doesn't happen. Composite is not conductive.

But, there are many more wires in a composite airplane, because the airframe is not a ground, so every component has a ground wire returning the current to a ground buss.

Alot of chafed wire short circuits occur when an improperly supported wire chafes against the airframe, when that occurs on an aluminum airplane sparks/smoke/fire occur, on a composite airframe that doesn't happen. Composite is not conductive.

But, there are many more wires in a composite airplane, because the airframe is not a ground, so every component has a ground wire returning the current to a ground buss.

What about Diamond, Epic, and a lot more company's on that train of composites?

It sure makes one think about the longevity




I have also had to purchase a left wing for my Bo, so nothing lasts forever! I see both sides of this debate but I am happy with the old girl. The lines of a Bo, the class, the look, the plane,,,,,,,,poetry in motion!

Cheers,,,

Corvettes have been made of fiberglass, CMIIW but I don’t believe they have had any problems decades later?

The corvette body is basically a giant wheelpant. Not structural

Actually, all of the above. There's an hours limit on the SR series - which I think is still 12,500 hours. (unless it has changed). My Columbia has a 25,000 limit on the airframe.

I haven't looked at the manual for the SR series. My Columbia has a number of mandatory inspections that are required at certain hour intervals. It also has hour/calendar life-limited parts, like the seat belts which must be replaced (not re-webbed or overhauled, but entirely replaced) at 10 year intervals.

I know the SR has the 'chute repack interval, and I'd assume there are other life-limited components and mandatory inspections to accomplish.

While the airworthiness limitations aren't necessarily the nail in the coffin, they do put a date certain on the life of the aircraft and thus, establish the depreciation curve to $0-value.

Mandatory inspections and life-limited components likewise, don't condemn the aircraft, but they do impose a definite cost burden. At some point, the cost of accomplishing mandatory inspections and parts replacement greatly change the value proposition.

These life-limited components and inspections are mandatory, even for pt 91 operations. Thus, there is a cost-curve imposed on any prospective operator.

I think they'll hit economic obsoletion before they hit structural failures.

The long term unknown are the aging of the composite and even more so, the aging of repairs. UV is definitely an issue, as this is a well-known damaging factor to composite materials. Paint chips should be repaired promptly.

The issue of avionics is another problem area. The curious thing is that "steam gauges" will be around forever probably. They're easy to fix and replace. The earliest SR planes had these and I suspect, will be flying a long time.

The Avidyne flight decks are somewhat more modular. The first few years of Columbia aircraft are Avidyne as are the Cirrus line up to 2008. These have easier upgrade paths, as the radios and transponders are all standard avionics as are the autopilots. The flight instruments are not easily replaced though and some components, like the DAU for the Avidyne, have become very difficult or impossible to source or repair already.

The Garmin GFID or G1000 series are more difficult to address. These systems are highly integrated into the aircraft and highly integrated together. Radios, navigation, flight instruments, transponders, autopilot, audio panel, engine indication, all tightly integrated together.

Unfortunately, Textron/Cessna has so far, not issued any updates for the Columbia G1000 lines. We got a firmware update 5 years ago (which mostly had older firmware in it). There's an upgrade for non-WAAS systems, like mine, to WAAS. But that's $40,000.

But no updates to even things like ADS-B have been forthcoming from Textron/Cessna.

There's an STC by Garmin, to install GTX335R or 345R into the G1000.

I think doing any substantial change to the G1000 panel is in most cases, going to be cost prohibitive. Getting the rack out of the plane is likely, impossible.

Cirrus has been a bit better about support. There are more of them out there, but it is still very difficult to make big changes, absent support from the type certificate holder. It isn't impossible, but so far, third party STC's for flight deck systems have been limited to high-dollar turboprops.

So, the writing is on the wall, more or less. This generation of aircraft are unlikely to be flying as long as the last. I don't think they'll fall apart, but become unairworthy due to economic cost of complying with inspections and obsoleted by aging of the avionics to the point they are unmaintainable.

Then there's that whole 100LL thing looming.

Unfortunately I agree.. similar with iPhones & computers these days. It's sad. I deal with it by thinking I'll probably be dead or stop flying before it gets too bad. That doesn't help the future generations though. Maybe experimentals are the future of GA.

Damn right!

Other than chute repacks, the Cirrus doesn’t have the big mandatory structural inspections like the Cessna/Columbia and the Diamond have. Cirrus anticipates extending the 12,000 hour life as planes approach that (an average of 60 years of flying).
http://whycirrus.com/engineering/useful ... tions.aspx

Is there any indication that any Cirrus will ever hit 12,000 hours? Is there any operator that is using them for workhorse service where they are still putting hundreds of hours per year on 15 year old airframes?

Highest time Cirrus for sale on controller.com is 5305 hours, a 2006 SR22-G2.

That'a about 450 hours/year. It will reach 12,000 hours in ~14 years, about 2033 or so at present rate of usage.

Note that a Piper M600 has a life limit of 5,132 hours. The M600 put through the same service would now be end of life. The M600 airframe life limit is not often discussed but is troubling.

Mike C.

I have seen at least one Aerostar airframe that had over 20,000 hrs. on it and many more with over 10,000 hrs. It’s not all that unusual. It’s not hard to maintain an airframe. The key to long life is regular care and maintenance. For aluminum anyway.

But that’s the issue - maintaining present rate of usage. Who has the business case to put 450 hours per year on a 12 year old $150k airplane. In 4 years that’s $150k in avgas plus a new engine.

Rental.

Regular commuter.

Heavy private user.

Charter.

Mike C.

I don't know.

Piper PA38 Tomahawk has an 11,000hr life limit on the wings and a number of them have timed out and some have been fitted with younger wings to keep flying.

On the Cirrus, that isn't possible. The airframe itself times out and that's the end.

Thing is, what happens as the end-life gets closer into view? I mean, if you have a nice plane with 9500 hours on it, but it EOL's at 12,000, what does that do to the value? If it coughed up metal in the oil, would you put $60k into overhauling the engine? Find a used engine, or do you just part it out?