Altimeter errors are greatest when flying over mountainous terrain.
Why is this so?
Come back tonight to see the answer. (It's night already... answer below.)
Olympics from the space needle.
"What are those mountains doing in the clouds?"
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XOX Karlene
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Answer: Wind flowing over and around mountains results in a venturi effect much like air flowing over a wing. This causes wind speed to increase and (static) pressure to decrease, which can cause indicated altitude to be significantly greater than true altitude.
Mountain waves generally causes stronger winds which can cause local lowering of the pressure which creates an altimeter error. Also mountainous regions usually have colder surface temperatures than that closer to sea level, which can cause even more errors. I think I may have missed something with the height there.
ReplyDeleteHigh to low, or hot to cold look out below.
"what's that mountain goat doing way up here in a cloud bank?"
(i cheated, but hey i'm refreshing on these things for two exams i have to write soon)
Karlene, you really had to make me think about this one. My weather theory might be one of the more weak parts of my aviation knowledge. But I am thinking maybe that weather phenomenon associated with mountains like lenticular clouds and heavy mountain wave winds might affect altimeter readings. I haven't had the experience to know the real answer to this. Please post it when the drawing is done!
ReplyDeleteExcellent Ramiel! Keep studying and you'll get all the answers.
ReplyDeleteDaniel, not to worry on weather theory. That is a subject for an entire Masters program. Happy Holidays!!!
ReplyDeleteI live & learn - thank you to all.
ReplyDeletemarypres(AT)gmail(DOT)com
Wow, I love these facts about things I'd never think about otherwise. Thanks!
ReplyDelete