The beam approach system didn't have a van. It was a fixed aerial also used for navigation similar to a beacon. It had four segments with the NE and SW radiating 'N's and the opposite radiating 'A's. The idea was to be able to position oneself without an ADF needle as at that time homing was manual with a loop aerial. The beacon would be aligned with the runway but would be some distance away so an approach to either end of the runway would involve remembering whether the 'A's were supposed to be on the left or the right.
The BABS van was parked near the threshold and as I saw at Aldergrove in about 1950 a Halifax undershooting could do a splendid job of flattening it. The Hillman hung on the port undercarriage though so the Halifax ended up sprawled over the side of the runway; never to fly again.
Halifax 1 Hillman 1
Last edited by Fareastdriver; 30th Mar 2018 at 18:04.