Report on my visit to my flying club yesterday:
First I spoke to our recently retired Chief Engineer - he was adamant that tiedowns should NOT be taut and that is the main reason for using ground lines (14/16mm braid on braid pegged out along each aircraft parking line) to allow for pilots who like to yank their lines tight. This applies to both high and low wing aircraft.
But this opinion is only that --albeit from one w/credentials to know...--,
and leaves us no wiser as to
Why ... ?! --a rationale, please!
And our pressing the issue should include pointing to the choice
of line --of stretchy nylon (in perhaps a stretchy construction : hard-laid)
vs. non-stretchy polyester (and braided).
unless the ground speed of the wind over the wing of a tied-down aircraft
is in excess of [35-45 knots, there will be no effective lift]
As one can know reading my posts, I spend some time at Cape May
Point, New Jersey (USA); in the past 5 years there have been two
"hurricanes" that have come up along the coast, and have thus
given me concern about a family house there --some few blocks
from water (pre-hurricane water, that is!). I recall looking over
the
www.Weather.gov "3-Day History" data for several places
along the coast from where Irene landed, in North Carolina,
on northwards ; I was puzzled that --and had great concern--
Irene sustained its "hurricane" rating --sustained winds >65knots
(75mph)-- and NONE of the sites' data showed it much even
near that level, and only a few GUSTS rose to such speeds!?
Huh?! (And i.p. I was happy to find one military? air field giving
data on a small island near the Carolina point Irene touched
land, and thought it surely would be perfect for catching the
full fury. IIRC, top gusts there were in 70s --
gusts.)
((Also puzzling : weather.gov asks for <city>,<state> or <zip code>,
yet using the 08212 zip for Cape May Pt. gets one "15NM NE
of Lewes" --in the ocean!-- information (as though the postal
service might maybe deliver out there, to the fishes?) !? ))
I had similar searches for our recent Sandy, and the highest
GUST was in 60s, IIRC (Atlantic City, Washington D.C. --didn't
check a NYCity-area site). Not to lessen the terrible effect
that that massive (>850mi diameter) storm has wrought,
but it is a puzzling obervation vis-a-vis "hurricane" definition.
A friend who is more intimate with such weather aspects
said something to the effect that wind speeds are measured
at upper altitudes ... . (News media, OTOH, lustily grab for
the highest, most frightening figures they can spew --wind
chill, e.g., peak gust estimates, as though such effects are
commonly felt.)
So, back to Gordon's point : it would be a significant event
to generate such winds. But, OTOH, we do feel some bursts
of wind in non-uncommon, not-occupying-vast-radar-real-estate,
thunderstorms.
--dl*
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