Radar Altimeter Identification

Finally the antenna – one on the other side too, the main electronics unit would need to have been close to these hence its location as above.

And mounted between the rear stabiliser spars – well an empty space, but the electronics sat there….. Anti-vibration mounts would have stopped the valves from having a rough time.

The later Stirlings had it fitted – as the aircraft did a lot of ‘gardening’ and so flying low over the sea I assume that it would have been a welcome tool!

Here are the three cockpit parts. The Stirling only need the low flying part and so did not have a range change switch on the height indicator. What you don’t see on the excellent video shown above are the three lights ringed on the photo below, Red White and Green I think. Like the Three Bears you can guess what they indicated.

There is a Youtube video here showing the other parts of the system –
https://www.youtube.com/watch?v=e9nsNCibnC8

Andy

This General Electrics instrument was first used as early as 1943 in a variety of US Navy aircraft… and many non-Navy types.

Fitted to the Gannet too.

The APN-1 was one of the first (and very succesful) Radio Altimeters to be made available. This indicator unit is of course only one part of the system. It was fitted to all sorts of aircraft, both US and British, and doubtless others, both military and civil. Perhaps the Dakota is the most famous.
Andy