Air Traffic Control

Historical Detail

We have spent more than our share of time in RCAF control towers scattered far and wide. If you look very closely at this particular photo you will note a couple of things that many of us have never seen.

1 - You will note an apparatus that is hanging down from the ceiling of the control tower. We had no ramp floodlighting, so to cover this off they had a floodlight on the roof of the tower that could be rotated from side to side and elevated up or down. This was the control that permitted you to operate the floodlight and spot any aircraft parked on the tarmac for the benefit of aircraft taxiing. This was a great little rig.

2 - Also as a little aside, for a wind indicator on the airfield, we had what they called a Tetrahedron which looked like a pyramid on its side and gave you a very accurate wind direction. It was hooked into the airfield lighting system with running lights along all three sides. I had never seen one before or since, and this was probably something used by the Americans.

Landing Indicators

A device called a Tetrahedron at some airports indicates the active runway. It is a pointed triangular shaped object shown in the diagram below as (T). One end configured in a long point (the front end). The rear end has a short, blunt triangular shape. Most are lighted to be visible at night. It is usually set into a fixed position by the airport personnel to indicate landing direction. It does not necessarially indicate true wind direction. Pilots did not rely on a tetrahedron as a wind indicator. Some are fixed and are not free to swing with the wind.