what_next wrote:
Strictly speaking, with certified TAWS, warnings are just warnings (“CAUTION TERRAIN!”). One does not have to react to those other than wake up and have a look at the screen which will automatically display terrain data, even it it had been deselected. But the command “PULL UP!” must be followed instantly. Opinions (and SOPs of different companies) vary if that is also the case when one has visual contact.
As I am still interested in active (i.e. aural) terrain avoidance feature, I have been a bit more into difference between Synthetic Vision (SVT) and TAWS.
SVT includes some aural alerts, but the algorithm is more limited, and won’t take into consideration some significant dangerous conditions. Thus, in the end, you will rely on your interpretation of the 3D-view, and not on an instruction to follow.
That’s why, I tend (without experience :-) to consider the TAWS more as an active safety feature, and SVT as an awareness safety feature. Many users have said that they felt more confident during instrument approaches with it, but being more confident doesn’t mean you’re safer… I guess both increase safety, somehow, but even if less fancy or visible, TAWS is the one you really want to watch above your shoulder.
Here are the different terrain avoidance functions / algorithm, provided by the G1000 (this is from the handbook):
SVT only provides the first function / algorithm: FLTA. Aural alerts are limited to: “Obstacle”, “Terrain”, with preceding “warning” or “caution”.
TAWS, with more functions / algorithms, adds more vocabulary: “Pull up”, “Sink rate”, “Don’t sink”, “Too low” and “Five hundreds”. Each is triggered in precise condition, and provides an order to follow.
That was my saturday penny