Completely agree with this. One other point I might add is that by
blindly using a calculator or some program that does all the computations
for you, it is very easy to become a victim of a "garbage in - garbage out"
scenario. I've seen this happen more than once: people would plug in some
numbers, get some numbers back, and just take those numbers as the answer,
even though they're completely wrong because of an error made in the input.
When you do things by hand, you get a much better feel for how sane your
results are, because you see all the intermediate steps, and there's many
more places that would raise a red flag for you if you made a mistake.
Besides, I could never fully trust the completeness and correctness of the
airnav data that online planners use: after all, if one blunders into a
restricted airspace, or scratches a mountainside because of an error in
such a planner's database, that would be pretty sad, and totally that
person's responsibility.

Andrey


In rec.aviation.piloting Alan Gerber wrote:
One of the hazards of calculators, and of electronic computation in
general. Nobody understands the concept of "significant digits" any more.
Just last week, I saw somebody build a spreadsheet with single-digit
input, but triple-digit comparisons in the output. I had to explain that
there was no way that "4.89" and "5.12" were actually different results,
and that there was no reason to prefer one over the other based on those
calculations.

... Alan