Yes, I should have written height instead of altitude but I presume everyone understood that I wasn't referencing an approach to La Paz or Denver or Munich.
(PS: you used the term altitude in your thread title)
Reference??? Just the boys talking
over beers in the pub. But maybe, Al Parma mentions it in his "Rules of Thumb" booklet? It's all 60to1 stuff. My navs in the AF used to harp on this stuff whilst doing airborne radar approaches into
airports in the ex-CCCP on nuclear treaty verification flights where there were no published min vis and we had to pick up a Russian nav in Tempelhof to be our radio transmitter. Great fun, especially the arrival lunches with beverage choices of vodka, vodka or vodka. But I digress...
SafetyP, "don't rely on rules of thumb"... No kidding. That's why we have decision heights for Cat 1, 2, and 3A/B. Further, yes, seat height and eye sight and fog type (density) all contribute to everyone's individual point of rwy contact, hence the use of the term "rule of thumb". If it was exact, scientists would be writing about and choosing the apes to do it.