Regarding the Vulcan loss at Heathrow on talkdown refered to much earlier, I recall reading that aside from a talkdown issue it was also partly attributed to the lack of a Pressure Error Correction (correct FW terminology? I use a Helicopter Type Allowance) for the Vulcan's Bar Alt - although hardly the certain truth,
pprune supplies the following:
http://www.pprune.org/aviation-histo...merged-59.html
Thanks AvroLincoln. According to the BoI report, about 7sec before the Vulcan hit the ground,the GCA controller told Podge Howard that he was 80ft above the glidepath. Even after XA 897 struck the ground, the talkdown continued as if the approach had been normal. The BoI concluded that 'the failure to warn the captain that he was going below the glidepath was the principal cause of the accident.' A subsequent Boscombe study of Vulcan altimerer errors revealed that the large delta wing area, plus friction with the altimeter, amounted to a total possible error of 200ft. As Heathrow 10 Left was 80ft above sea leave, even with 300ft indicated on his altimeter Podge Howard was already among the weeds.