Sport Pilot Talk

drseti wrote:Carbon fiber composites are more difficult to repair than sheetmetal, and take special training, tools, materials, and equipment. So in the event of an incident, an insurance company is more likely to have to total the plane. I would expect insurance rates to reflect this.

This is your opinion, but I can say the same about sheet metal repair. Composite repair takes different training than sheetmetal, but I wouldn't call it special. I wouldn't want someone who hasn't had sheetmetal training working on my airplane. In over 30 years of working on airplanes I always find that I need to borrow or buy some new or different tool(s) with almost every new project, and the list of sheetmetal tools is almost endless. Some of them are quite expensive too.
I have taken some composite training, and in many cases a composite repair is much more simple than a sheetmetal repair. The big difference is with composite it must be done in stages, so you might have a little more downtime.

Tom, I guess the main difference is that all of us old-time mechanics were trained in sheetmetal (and the REALLY old ones were trained on tube and fabric). Yes, you've had composites training, but you're probably the exception. So it may be harder to find a composites mechanic than it is a rivet pounder.

My information comes from avemco.
When i talked with them last they were not insuring LSAs anymore mostly due to landing incidents. He said LSAs with composite gear that get damaged in landing many times are totaled. Very few shops are equipped to do structural composite repair and require a "engineered" repair from the manufacturer.

This is true of cirrus also. Factory's want to sell new airplanes and don't normally go out of their way to approve these repairs.
I am not against composite. The tecnam p2008 i fly is largely composite but has metal continuity between the main and nose gear. The wings and tail are metal also.

Mark

Mark,
Are your control linkages push rod, cable, or what?

That explaines why Avemco said the only LSAs they Insur are J3s, Legacy and the RV12. Easier to repair.

Is Avemco refusing to write liability or only hull?

Tecnam control linkages are a combination of pushrod and cables.

I would be surprised if they were writing policies for the RV-12 but not Tecnams. Maybe they are
are sticking with american made aircraft for now. Last I heard they were not writing any new LSA policies.

Mark

We seem to have drifted quite far from welcoming our new Wisconsin member...

'Composite' is a generic term; it doesn't refer to a single set of materials nor to a single manufacturing process. Lets look at how Flight Design describes the fuselage structure: "The CTLS structure is made from the very latest carbon fiber construction with rigid foam core and epoxy matrix using vacuum technology." Despite having some professional training on GRP repairs and having slathered a lot of WEST System epoxy & polyester resin in combination with a variety of fiberglass weaves, tapes & mats, I wouldn't touch this fuselage. Just the vacuum bagging process alone - let's set aside the relatively exotic materials - makes a full repair very difficult.

Professor Paul is exactly correct. Repairs on many of these composite LSA a/c will be very difficult for the simple reasons that the materials are not off-the-shelf nor is the process(es) used easily replicated in the field. Reskinning a wing or replacing a fuselage panel, by comparison, requires proper training and experience but the materials needed are readily available, as are the tools and the skill sets.

CFRP are being used in so many products these days that it would seem to me the population familiar with working with them would be expanding greatly. Maybe someone should start a new thread that talks about this topic so we can all get up to speed.
In reading a few online articles, it didn't seem to me that it was inherently more difficult to use than fiberglass, for example.
High-end race cars and many other products are made with CFRP.

As the Wisconsin newbie....thank you all. What a good helpful intro.

The Insur Avemco said they were only insuring those 3. I did not hear any distinction between liability vs plane. I did think it odd that the renters/student Insur I bought last week had $1M property damage and only 100k personal injury. Who would buy car Insur like that. Should be the reverse? $1M personal injury! What building will I ever wreck flying over the countryside in WI worth $1m ??

Tim