Friend of mine just landed his fine airplane gear up.
How about all you single chip microcomputer programmers out there
build a gear up landing alarm.

If the RPM is below 4000 and during the last three
15 seconds consecutive periods the altitude has
steadily decreased and the gear is still up turn
on the alarm.

Paul Lamar ...No rotor no motor.


That could work.  Or how about taking GPS output and alarm if the plane is
within, say 1 1/2 miles from an airport, and less than 1000' AGL and the
gear is up.

The AOA pro is nice; so are radar altimeters; but we need something for
about a third of that cost.

Al



Paul,
Al Wick has already done this, his system shows you how to build a
system that will check and log anything that you want using off the
shelf equipment.
http://www.maddyhome.com/canardpages/pages/alwick/index.html


Regards
Andrew Martin

Well Al Wick does mention it but he does not say what logic he
uses to warn of gear up when landing so I don't think he has
it implemented yet. It does not appear to be linked to a data base.

Al Gietzen is suggesting knowing at what airport you are near and how
high you are above the airport to warn you about the gear.

Here are a few screens from my moving map software written
in the early 90's. Kind of crude but it was written in DOS days.
Ahead of its time :) I used an early Lowrance boat GPS receiver
that put out only an NEMA 0183 RS232 ASCII data stream.

From this FAA data base you know where you are and how high the
airport is so you can be warned on approach about the gear.