In message <memo.825216@cix.compulink.co.uk>, Graham Clarke
<gemin@cix.compulink.co.uk> writes
>Has anyone researched what this means - do they have to be "approved" ,
>conventional mechanical ?, or can they be anything from ones own
>electronic gizzmo to a weighted piece of string. (The latter could do
>both altimeter and ASI (:-))
Three surely, a compass, then again with the big ball of string
measuring height and another by it's pay out rate measuring speed then
so long as you remember to attach the end to a stick driven into the end
of the runway then by vector maths you could work out exactly where you
were and how to get back.
Mind you the cost of certified calibrated string is probably prohibitive
these days and that's why people fit dials, plus of course the
associated nuisance of having to reel in and out a hundred or so feet of
string when one goes from QFE to QNH.
M'thinks you will find the answer in FARs and JARs, I will endeavour to
delve into their arcane delights. From memory the requirements are
deceptively simple though I can't remember any references to twine
technology.
--
Graham E Laucht
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