Any aircraft undercarriage or mechanical item for that matter will fail if
impacted
with enough force; damage to the mono undercarriage from excessive side loaded
touchdowns can be mitigated by several ways; one being thought about this
afternoon may find its way into the chapter shortly... or be relegated to the
graveyard of great ideas.
Keep in mind the undercarriage will not lock up if the bungee tension is less
than
required to hold the undercarriage above its parked position; the weight of
the wheel and gravity is what brings the assembly out of this scenario each
time, however the force needed to close out the undercarriage remains constant.
The force required to action the undercarriage through the retraction stage
is not the same.
Somebody mentioned about the operational over center specification; this is an
adjustable setting that needs to be maintained regardless.
Dave upstream there asked about how I go about doing this and what software is
used... great to hear you are building a model; wishing you well with that!
Regarding
software; they all provide the same result; buttons are often in different
places, same as politicians and beer... I use a few very special ancient
tools that few these days know exactly what they each do... A piece of string
is the most highly valued, next is a plumb bob, a spirit level but i have been
known to use a glass of water during desperate moments, cardboard (cardboard
is your best friend), protractor, calipers, a roll of masking tape, good even
lighting, a clean floor, a sharp pencil, a blunt pencil, a white board marker,
a rheem of plain A4 paper, an adhoc laser pointer on an adjustable tripod, a
ruler and tape measure, lots and lots and lots and then some more time, lots of
coffee hamburgers, about 30,000 hrs playing CAD, and about 45years of analytical
experience.
The model here has taken about 300 hours to measure and a further 1100 to
accurately
model from the data collected.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=509453#509453
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