On Apr 16, 9:46*am, Jim Logajan wrote:

I don't think the authors of that NTSB safety letter quite understand
experimental certificates and their ramifications...

Yup. They also don't seem to understand that someone who builds an
aircraft from a kit or from plans is under no obligation to register
that aircraft as having the same type as the kit prototype aircraft.
For example, many of the Schreder HP-series kit sailplanes have types
such as "Drew Two" and "RS-1" and "MR-3" instead of "HP-18" or "HP-11"
or "HP-14." So there are no doubt several CH-601XL aircraft to which
the NTSB's narrowly-worded letter A-09-30 does not apply.

Overall, I think that the NTSB, while perhaps meaning well, is being
too heavy-handed in asking the FAA to take this action. I think that
it would be far more constructive to work with Zenith and with
builders groups to make them aware of the issues and possible
mitigations. I think that it would be well within the FAA's purview to
firmly decline the NTSB's demands.

If they ground every CH-601XL, what else could or might they have
taken action against? Adventurers with their horizontal stabilizer
attachment issues? BD-5As with their marginal takeoff characteristics
and flaky engines? Vari-Ezes (not Long-Ezes) with their somewhat
marginal wing carrythrough strength and attachment plate corrosion
issues? And that's just a few experimental airplanes, to say nothing
about gliders or rotorcraft. In all of these cases the carnage has
been kept to a dull roar by kit makers and builder communities who
(usually) worked together to raise awareness of the issues and to
mitigate them.

Thanks, Bob K.