Sylvain writes:

No they are not; well, ok, you are half right he they
are considered obsolte but it's a darn shame. You can spot
miles away engineers who did learn with slide rules from
those who didn't, but I digress.

This particular aviation use is a good example of situations in which
slide rules still have advantages, but unfortunately these situations
are rare.

I do; never runs out of batteries, always there, and easy
to use;

True for slide rules in general, but they seem to have disappeared
just the same. People like new and shiny gadgets.

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