Message 3309, Jun 30, 2001
Hi Spanner, Yes, the A-13A (A-13A/2) was used briefly by the RAF just after the war, on a trial basis, as the RAF's planned use of the American D-1 02 regulator favoured use of the American mask it was set up for use with. However, the A-13A, despite favourable pressure sealing characteristics, was rejected for several reasons. The RAF's Institute of Aviation Medicine (IAM) developed the M mask as a replacement, using the A-13A/s reversed peripheral seal, eliminating the face cheek flaps in favour of a sulcus-sealing feature, and integration of a lateral ("side")hose feature. This, combined with an improved pressure exhalation valve design using a lateral pressure compensation tube design that permitted a more compact face-cup design (instead of a vertical tube design, as in the A-13A) resulted in a very efficient face-sealing design that stayed well in place during high-G situations.
The M mask was followed by the N, and thereafter by the P and Q series masks, which turned out to be excellent in virtually all respects. An improved mask (the Type W) was subsequently investigated, but this plan was rejected, after limited studies were conducted, in favour of keeping the P/Q series masks in use.
Cheers, DocBoink
----- Original Message -----
Sent: Friday, June 29, 2001 1:20 AM
> Does the A13A come into the British listing? Also anyone know what happened
> to the W mask? It saw it listed a possible replacement for the P/Q but other
> than that have never heard of it.
> Spanner