View Full Version : GPWS Pull Up climb gradient

25th Feb 2009, 11:56
This info is probably hard to find in manuals or any generally available written form so I must appeal to those who have more experience in this area:

What kind of climb gradient can one expect from a modern airliner in the terrain escape maneuver, i.e. GPWS Pull Up? This would assume throttles to the firewall, clean, pitch up initially 20 degrees, and then up to the stick shaker. I am mostly interested in the A320/B738 type performance, but any other type info is appreciated.


25th Feb 2009, 12:28
On an A320 or any other modern Airbus you just pull the stick to the rear stop and hold it there until the warning goes away and you are safely above MSA. There is no stick shaker. No idea what the climb gradiant will be be it should be the best the aircraft can give and if thats not enough there's not much you can do about it.

25th Feb 2009, 12:46
On the A320 family you could always try it in the sim with the TRKFPA displayed.

I haven't flown the beast for some years, but can remember being very impressed at the rate of climb with full stick back when settled at protected min speed. I would guess at 5000fpm at 130kts IAS giving about 12degrees climb angle (greater than this whilst trading speed for altitude.

I see no reason why the 737 would not be similar (albeit requiring much greater skill to achieve it).

25th Feb 2009, 12:50
The gradient achievable depends upon your speed (and thus energy) at the time of the pull-up. I can't see the point in knowing any numbers on this, as the gradient you can achieve is as variable as the gradient you are trying to avoid!

25th Feb 2009, 12:54
Are we talking about TAWS i.e, EGPWS, T2CAS predictive, or GPWS reactive?