On Friday, June 15, 2018 at 2:14:31 PM UTC-6, Bob Kuykendall wrote:
On Friday, June 15, 2018 at 12:26:35 PM UTC-7, Paul Agnew wrote:
Meanwhile, the jigs for the Peregrine (Krosnos) are just sitting in shipping containers somewhere in Georgia. Could it be produced cost-effectively?

As I understand it, the problem with the Krosnos is that the engineering and certification are based on material specifications and thicknesses common in Europe but basically unobtanium here in the US. You'd need to either source all your materials from Europe, or re-engineer the aircraft to use US materials and thicknesses.

As a practical matter, it's not that hard. As a regulatory matter, however, it's a huge paperwork effort to go through every single blueprint and justify the change from some metric thickness to the nearest inch size. You basically have to re-engineer the entire structure.

Sourcing materials from Europe is a huge gamble. Here in the US there is a fairly fat supply pipeline supporting the homebuilt aircraft movement that currently produces the majority of all new general aviation aircraft. In Europe, the pipeline is a lot thinner and has a lot more friction and regulatory risk aversion, so it is likely that material costs would be a lot more.

Furthermore, given that prices for carbon fiber in terms of cost per unit mass and cost per unit stiffness are steadily declining, I think that carbon fiber is the way to go for any new design, even for a primary trainer.

Thanks, Bob K.

Yes, materials were part of the problem, Polish aluminum and Russian steel (not stamped but dated with a Sharpie), though Tim seemed to indicate substitution could be done. When surveyed, the majority of operators preferred metal over composites, but that survey is several years old now. Barry Aviation got as far as PMA and had set up the assembly line, but never achieved manufacturing certification. You have to be able to keep the lights on for a year or two at your manufacturing facility. Three have to be built under FAA observation in order to become self-certifying. If they don't like something, they leave and you will not see them again for months. Didn't seem to be a fix it and we'll come back when you're ready, we'll schedule a return when we're ready. In any event, the economy dumped in 2008 and they couldn't keep the facility open. Tim estimated a trained crew could build one per week.

Frank W