US low level altimeters supplied to Britain in WW2
Britain acquired huge numbers of US radio altimeters from early 1943 onwards. These arrived installed in US manufactured aircraft or as sets for installation in British aircraft either during production or as a retrospective fits.
There were three main models.
AYB – pre-production model.
AYD – first mass production model based on the AYB with range of 0-400'.
AYF – development of the AYD with two ranges, 0-400' and 0-4,000'.
So far so good. What I would like to know is the significance of the following variants.
AYB-1
AYB-2
AYD-1 Not actually seen this but seems likely to have existed.
AYD-2
AYD-3
AYD-4 I know the AYD-4 and AYD-5 were the same but from two manufacturers.
AYD-5
AN/APN-1 (aka AYF) This had the double range.
AN/APN-1A (aka AYF) This was limited to the lower range of 0-400'. Both the US and Britain had trouble getting the AYF to operate reliably at the higher end. Based on the TNA files there is no mention of Britain having this version.
All the references are from UK National Archives files. AYD US designation was AN/ARN-1.
Paul
Britain acquired huge numbers of US radio altimeters from early 1943 onwards. These arrived installed in US manufactured aircraft or as sets for installation in British aircraft either during production or as a retrospective fits.
There were three main models.
AYB – pre-production model.
AYD – first mass production model based on the AYB with range of 0-400'.
AYF – development of the AYD with two ranges, 0-400' and 0-4,000'.
So far so good. What I would like to know is the significance of the following variants.
AYB-1
AYB-2
AYD-1 Not actually seen this but seems likely to have existed.
AYD-2
AYD-3
AYD-4 I know the AYD-4 and AYD-5 were the same but from two manufacturers.
AYD-5
AN/APN-1 (aka AYF) This had the double range.
AN/APN-1A (aka AYF) This was limited to the lower range of 0-400'. Both the US and Britain had trouble getting the AYF to operate reliably at the higher end. Based on the TNA files there is no mention of Britain having this version.
All the references are from UK National Archives files. AYD US designation was AN/ARN-1.
Paul