wrote in message 
...
Yo Bump,
Are they PMA'd, STC'd or TSO'd? Because my local IA/FAA FSDO/CFI says
I can't install it unless it has the Good Gliderkeeping Seal of
Approval! What about dampening, I hate it when it vibrates back and
forth at 150hZ at the lower speeds.
;-)
Not TSO'd, PMA'd, or STC'd. They are, however, J.C.Whitney, NAPA, and 
McMaster-Carr approved, which is just as good, maybe better (Orville and 
Wilbur didn't give a rat's _ _ _ about acronym groups). But, the MKIV does 
come with the coveted Sham-Wow, Slap-Chop, Energy Star seal of approval 
Damping is excellent at tested speeds below .21 Mach. Much above that, the 
pilot may have other issues with which to concern himself, rather than his 
nice looking yaw string.
bumper