PPRuNe Forums - View Single Post - 737NG GPWS ("reactive") windshear alerts?
Old 11th Jan 2011, 00:22
  #1 (permalink)  
singletracker
 
Join Date: Jul 2009
Location: Denver CO
Age: 49
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
737NG GPWS ("reactive") windshear alerts?

Hey all...

Quick question about the 737NG's GPWS windshear alerts (not PWS).

The Boeing FCOM says this in the Warning Systems chapter:
Windshear warnings are accompanied by WINDSHEAR on the attitude indicators and voice aural alerts.
Windshear cautions are accompanied by a voice aural alert.
So am I to understand that, a windshear caution has no yellow WINDSHEAR caption on the PFD below the attitude sphere? In other words, just a "WINDSHEAR, WINDSHEAR" aural warning? Then why, during the GPWS test, do we see a flashing WINDSHEAR followed by WINDSHEAR?

Also, the FCOM has no information about what data the GPWC uses to issue the windshear alerts. I assume it's something to to with rate of change of groundspeed versus airspeed... does anyone know for sure?

Last edited by singletracker; 11th Jan 2011 at 05:12.
singletracker is offline