[Rodolphe42]

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Originally Posted by luthier

3. Lorenz approach aid with fancy hut (fully operational)

Luthier do you mean :

An aircraft approaching the runway would tune his radio to the broadcast frequency and listen for the signal. If the crew heard a series of dots, they knew they were off the runway centerline to the left (the dot-sector) and had to turn to the right to line up with the runway. If they were off to the right, they would hear a series of dashes instead (the dash-sector), and turned left. Key to the easy operation of the system was an area in the middle where the two signals overlapped, where the dots of the one signal "filled in" the dashes of the other, resulting in a steady tone known as the equi-signal. By adjusting their path until they heard the equi-signal, the pilot could align their aircraft with the runway for landing.

Two small radio beacons were also used with Lorenz, one 300 m off the end of runway, the HEZ, and another 3 km away, the VEZ, also broadcast on 38 MHz and modulated at 1700 and 700 Hz, respectively. These signals were broadcast directly upward, and would be heard briefly as the aircraft flew over them. To approach the runway, the aircraft would fly to a published altitude and then use the main directional signals to line up with the runway and started flying toward it. When they flew over the VEZ they would start descending on a standard glide slope, continuing to land or abort at the HEZ depending on whether or not they could see the runway.

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