Terrain Avoidance at Night

"BTIZ" wrote:
know where you are know where the ground is and if lights in the
distance start blinking or disappearing there is either a cloud between
you and the light or solid ground

This is a crucial point. I am always amazed when I fly licensed pilots at
night and they don't understand BTIZ's point.

At HPN, 29 has a displaced threshold due to trees just beyond the airport
boundary, and no VASI. If you're on final, the trees are invisible, but
the threshold lighting is bright and clear. If the threshold lights
suddenly disappear, that means you've fallen below a flight path that keeps
you clear of the trees.

When this happens, I'll say something like, "You're too low". If that
doesn't get a reaction pretty fast, the next hint is a much more emphatic,
"You need to climb NOW", quickly followed by my taking the controls. Some
people just don't seem to get it.

In a situation like this, the first glimpse you'll get of the trees is when
branches start coming through the windshield.

BTW, if the lights straight below you start blinking, that's because you're
looking straight down through a thin layer of ground fog. You take off a
little before sunset on a clear evening with a small temp/dewpoint spread.
The sun goes down, radiation cooling drops the surface temp 5 or 10
degrees, and suddenly there's fog. Maybe not in Pheonix, but it happens a
lot around here. This is bad news. A 100 foot thick layer of fog makes
the lights twinkle when you're looking straight down through it. On final,
when you're looking through it at an oblique angle, it's zero-zero landing
conditions.