Doc67



This was our circuits day on G-LSAD, January 2011. Sporty, and fun. 4 of us doing circuits for licence issue when we completed type rating course.

ps. The video isn’t of all 4 of us doing 4 circuits each….

Chad Sexington wrote: ↑Sun Apr 10, 2022 9:01 am That must be very unsettling for a pilot.
Layman’s (possibly dumb) question here, what if you emerge through the fog to see runway already under you, how can you tell if there’s still enough runway left for stopping the aircraft?

Chad. Not a dumb question at all.

We have 3 types of precision approach
ILS Cat 1, 2, and oddly 3
Cat 3 has 2 types- 3A and 3B

ILS Cat 1 is a decision height at around 200 feet above the runway elevation, which equates to just over 0.5 miles from the runway. But it’s based on barometric altimeter, and we usually reference to QNH which is sea level pressure, which makes it a decision altitude.
Cat 2 is at based on Radio Altimeter. Decision at 100’. And that’s measured on a surface that is at the same level as the runway. A decision at 100’ height above the runway
Cat3 A is 50’.
Cat3 B is on the runway.

Sorry Doc. The actual glideslope leads to a touchdown which is some 300m/1000’ from the threshold. Roughly the same as the PAPIs

A couple of pics coming up if you’ll bear with me…

This is Lucknow, in India. On a good day.


This is how runway approach lights appear, depending on airport facilities.


So to answer Chads question. In the low visibility approach Cat 3, we actually become visual with the runway under us. In the B737 and 757, and most aircraft for many decades, the landing is automatic. The autopilots land the aircraft, to put it simply. In fact, if the runway isn’t under us, that’s the problem.

One more video for fans of the wooden wonder



Some interesting postwar history, and a poignant tale towards the end.