(Michael) writes:

I'm sure that Canada is the promised land as far as aviation
education goes,

Not at all -- I've just been surprised at how many U.S. pilots don't
seem to know about altimeter temperature errors. On mailing lists,
I've actually had violent reactions from otherwise experienced and
competent pilots when I casually mentioned that pressure altimeters
are routinely off by hundreds of feet at cruise altitude.

I'm sorry if this came across as a "we're better than you" issue --
there are other areas where the U.S. aviation eductation system does
better than Canada's. For example, we do not have to demonstrate any
partial-panel work for our IFR flight test in Canada (good instructors
still teach it, of course, but it's scary that they don't have to).

Let's not forget that the worst case temperature error at 200 ft and
-50C is only 60 ft, while altimeters can be up to 75 ft off in some
cases and still be legal for IFR use.

What if the errors compounded? I agree that it's unlikely (and would
require a very cold day), but using your numbers someone with a 75 ft
altimeter error and a 60 ft temperature error could end up at only 65
ft AGL when the altimeter read 200 ft AGL.


All the best,


David