I thought we were talking "certificated" here.Â* That would mean, to me
at least, that a licensed mechanic's signature is required in the log
book.Â* I think there are also regulations about transponder
installations which, to me, are ridiculous, e.g., I can remove and
replace a radio as the owner/operator of the aircraft, but not a
transponder.Â* So, if you can find a mechanic who's willing to put his
license on the line to save you a hundred bucks, have at it. But if you
have a near miss with another aircraft while your transponder is
reporting that you're on the ground...

I know it's silly, but those are the rules.

On 1/7/2019 10:44 AM, wrote:
On Sunday, January 6, 2019 at 10:15:39 AM UTC-8, Darryl Ramm wrote:
Yes better be differential, have the right trip point, tolerance, longevity, and some basis for knowing the thing is suitable to install in an aircraft in critical pitot plumbing... or... I know pay $125 for the Pereguine kit and spend time worrying about more important stuff.
Does anyone know why a $125 squat switch is important for a glider (other than the FAA saying so?)

I found several uncertified pitot pressure switches online, eg MDS-0, MDA111, PSF100A. They can be found for less than $20, rated for about 20 million cycles. A suitable trip point pressure is 1" H20 column, which corresponds to 39kts airspeed. Or 0.5" corresponds to 28kts.

--
Dan, 5J