[smileysteve]

> TCAS Resolution Advisory will give an attentive pilot a good 5 seconds

> "oh, crap, there is a truck stopped 20 feet in front of you that I failed to detect at highway speed.

To appreciate your differences in measurement. 5 seconds in a plane is something about a mile away. A high performance car can still stop from 60-0 at 110ft; which is about 1 second. In context of time; it takes at least .7 second for the human to respond.

(The car or terrain monitoring autopilot can react in <.1 s; which means if the car sees the obstacle at 110 feet away it can stop in time, while, if a car pulls out in the highway in front of a human it would take closer to 200ft to stop.)

[jedmeyers]

> The car or terrain monitoring autopilot can react in <.1 s; which means if the car sees the obstacle at 110 feet away it can stop in time

What happens if the driver expects the car to react upon seeing the obstacle but it fails to do so? Will the driver have enough of the remaining time to react?

[smileysteve]

Nope. And in the case of terrain following airplane algorithms, it's practically impossible to maintain minimum clearance AND allow for any expectation of pilot override.

The >=.7 second human reaction time (with a planned/known reaction such as brakes or jerking steering wheel) is the very reason why Autopilots are safer.