Wind shear is a big deal along the front range of Colorado - it has contributed to or caused accidents and can be a concern at Denver International Airport.

A couple of months ago I was on a B777 that was within a few seconds of touching down in Denver. The landing was abruptly aborted and we started an extremely rapid ascent at what the off-duty pilot sitting next to me in C class called "military power". I didn't know that a B777 could climb like that or had that much oomph!

I suspected something was on the runway - but our captain quickly came on and explained that the windshear alarm had gone off, and that the policy was to abort the landing and get out of there as rapidly as possible.

This has caused me to wonder - do most or all UA or other commercial passenger planes have windshear warning gear? If not, which UA planes have it?