For over 25 years, I used a system that prevented launching unless
both the transmitter and receiver were own. Basically, it was a
capture tow hook that had to be opened by radio to hook the towline
to the tow hook and then latched by radio. It was an EK remote
release tow hook with a pin at the back that prevented the tow ring
from coming off. The EK tow hook was activated by a rigid
pushrod. It worked until I ran out of EK tow hooks and began flying
models too large for the light weight EK tow hook. In that time, I
used Rocket City Proto tow hooks that could not easily be modified to
prevent latching with the radio off for Sailaires and larger
sailplanes. When using the Protow, I did launch a Sailaire one time
with the radio off. I was lucky and retrieved it with no damage
after a 45 minute flight.
A standard tow hook could be made into a capture tow hook by
installing a retractable pin at the back of the tow hook to prevent
the tow ring from being attached without the pin being retracted by
radio. The pin would also prevent pop offs if left latched until
just before starting the zoom. I haven't yet tried this because I
am too lazy. Instead I ALWAYS wiggle the controls and see the
controls move just before hitting the peddle no matter how many times
I have done it after turning the radios on. I did launch with the
radio off three times after I quit using capture tow hooks.
Chuck Anderson
At 08:27 AM 2/1/2008, you wrote:
Gentlemen, I would like your feedback on something I created last
season in a bit of a whim. I have been competing at various TD tasks
in the Northwest over the last 3 years. Over this time I have
witnessed far too many launches where the pilot after the fact
admitted that he/she did not turn on the aircraft. Needless to say
most of the aircraft were lost or seriously damaged. So in search of a
solution I went to a local electronics shop and asked a young guy if
he could give me a hand designing a safety component that might help
avoid this scenario.
Basically we designed a switch with a small tilt sensor and some
latching circuitry. The result is this:
If you remember to turn on the plane the switch works as expected. The
plane powers on and off as it would normally.
If you turn OFF the plane and tilt the aircraft in the desired launch
angle ( this is set by the pilot) the plane turns ITSELF on and stays
on until the circuit is reset by disconnecting / interrupting the
battery. The draw is tiny and the circuit and switch itself 1"x"x .25"
or double the size of a typical 20 amp RC switch. I have tested the
product in the lab and i know a shop that could likely get the size
down to half its current size or close to the size of a standard
switch
This would of course cost some money out of pocket but I am not sure
if the target market is too limited to bother creating this solution
for. For the most part, the elite pilots I watch either don't even use
a switch or are very disciplined in their launch methodology. The
target market is more appropriately general pilots who may be
approaching the more "senior" years as well as new pilots.
What do you think people? At your local club have you seen anyone toss
an un-powered glider to its death? Would a product like this be of
value as a replacement for the standard on off switch for your more
senior members or new eager soaring enthusiasts?
David Webb
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