Another snowy day, another opportunity to read into the background.
Little progress with the UK's BCARs; there seems to be nothing on line. The National Archives list thousands of documents, hardly any digitised, so the bulk only available by visiting Kew to search and read.
For the US records, though, very different. Following up the link to the DOT archives, there is a treasure trove of material, and a few hours of reading has found some gems.
SR-422A, issued July 2, 1958, and effective for Type Certificates dated after Sep 30, 1958, includes the following significant changes:
1. introduction of VR
2. introduction of all-engine TODR
3. take-off flight path extended to 1500 ft above the field.
The preamble to SR-422A includes lengthy discussion of its changes from the earlier SR-422. Found here
DOT Online Database)
In 1959, SR-422B was introduced, effective Aug29, 1959. Strangely, this does not appear in the DOT archive. The only online record I have found is of para 4T.122, which refers only to landing distance. Was that all there was? I would have thought it to be a complete rewrite of SR-422A.
Some certification dates:
Comet, 22 Jan 1952. The Comet was not bought by any US operator, so was not certificated in the US.
B707-120, Sep 18, 1958 (USA). DC-8, Aug31, 1959 (USA)
Thus it seems that the B707-120 was certified to SR-422, the DC-8 to the later SR-422B.