Two Lock Rule?

Short length of padded chain locked around the propeller hub?


"T o d d P a t t i s t" wrote in message
...
"Slick" wrote:

A lock on the door of your hangar and a throttle lock would suffice.

My Champ doesn't have a needle type throttle, and AFAIK,
there's no easy way to fit a throttle lock.

"It is possible to fly without motors, but not without knowledge and skill."
Wilbur Wright

Greg Farris wrote:

Funny - the "best places to live" sites list the income tax at 2.something,

They are roughly 20 years out of date. It was 3.5% when I moved here, but Florio
jacked it to something like 8% back around '87. It got reduced to the current
level under Whitman about 10 years ago.

George Patterson
"Naked" means you ain't got no clothes on; "nekkid" means you ain't got
no clothes on - and are up to somethin'.

So you land at TEB with your Gulfstream. Since they have a door lock
only, the FBO installs a Denver Boot-type device on the nose wheels.

Typical government crap. Anyone intent on stealing a jet can surely
stop by the local Depot and pick up some bolt cutters.


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In article ,
Don Hammer wrote:

So you land at TEB with your Gulfstream. Since they have a door lock
only, the FBO installs a Denver Boot-type device on the nose wheels.

Typical government crap. Anyone intent on stealing a jet can surely
stop by the local Depot and pick up some bolt cutters.

Some years ago, thinking about the problem of bike theft on our
university campus (generally local teenagers with small bolt cutters, or
outsiders coming in with a U-Haul truck), I "invented" the fiber optic
lock: small rugged sealed metal box with a keypad, a few ICs inside, and
an attached fiber optic pigtail of any desired length coming out whose
other end plugs into a receptacle on the same box.

Gives essentially zero physical protection; but once the fiber is
wrapped around something and plugged back in and the gadget is armed by
keying in a lock code, it starts sending optical pulses around the loop,
thru the fiber, and disconnecting or cutting the fiber without keying in
an unlock code will either (depending on how the gadget is designed and
set up):

* Set off audible alarm inside the (in this case somewhat larger)
lock gadget itself.

* Wirelessly trigger either an audible alarm somewhere close by
(e.g., under a hangar roof) or a silent but flashing warning light
visible to others (e.g, on the hangar roof)

* Wirelessly signal a detection unit in a nearby location (bike owners
campus office, airport tower, nearby police station)

The electronics would always have been trivial to implement for an
undergrad IC circuit designer; the needed fiber optics components are
now at the Radio Shack level; and the remote signalling would be
trivial with Wi-Fi or Bluetooth technology. The point to alarm
signalling rather than physical protection is to, depending on your
choice, scare off the bad guys, and/or know its happening immediately,
and/or alert someone who might catch 'em. The reasons for a fiber optic
rather than electrical wrap-around cable/signal loop are (a) these days,
very cheap and very low power consumption; (b) impossible to tell from
looking or "sniffing" if fiber is actually armed and carrying a signal;
(c) impossible for even a sophisticated thief to "scrape off the
insulation" and bypass the signals in the fiber cable loop.

Hmmm -- maybe I should be going into business.

The electronics would always have been trivial to implement for an
undergrad IC circuit designer; the needed fiber optics components are
now at the Radio Shack level; and the remote signalling would be
trivial with Wi-Fi or Bluetooth technology.

I won't argue what RF technology would be best for remote signalling. I
argue that small current loops (on the order of microamperes) is much more
efficient of power AND money than optics. I'm not really sure how you
"scrape off the insulation" when the "wire" can be the chain (or better yet,
cable) itself.

Jim

"RST Engineering" wrote in message
...
I won't argue what RF technology would be best for remote signalling. I
argue that small current loops (on the order of microamperes) is much more
efficient of power AND money than optics. I'm not really sure how you
"scrape off the insulation" when the "wire" can be the chain (or better
yet, cable) itself.

I think the point is that with a regular conductor, the signal can simply be
rerouted very easily, assuming someone knows that there's a signal to be
rerouted. Fiber optic makes the job a LOT harder (and probably out of the
skillset of the random person looking to steal an airplane).

You could try to address signal rerouting by monitoring not just its
presence, but other characteristics (voltage or current, for example), and
assume that minor changes are evidence of someone rerouting the signal. But
then the alarm is much more sensitive to things that aren't related to
someone trying to break the lock.

Certainly if you were going to use a physical restraint to conduct a signal,
you'd want cable, not chain. Too much likelihood of one chain link becoming
briefly out of contact with another and breaking the signal, resulting in a
false alarm.

It seems to me that there are enough issues with a electrical conductor,
that fiber optic isn't a bad way to go at all.

Of course, all of this assumes that applying additional locks to an airplane
satisfies a basic cost/benefit analysis, which I think is far from being a
foregone conclusion.

Pete

In article ,
"RST Engineering" wrote:

The electronics would always have been trivial to implement for an
undergrad IC circuit designer; the needed fiber optics components are
now at the Radio Shack level; and the remote signalling would be
trivial with Wi-Fi or Bluetooth technology.

I won't argue what RF technology would be best for remote signalling. I
argue that small current loops (on the order of microamperes) is much more
efficient of power AND money than optics. I'm not really sure how you
"scrape off the insulation" when the "wire" can be the chain (or better yet,
cable) itself.

My argument would be that if the wire is a current loop and is
physically accessible (and of course if the protected item is valuable
enough) a moderately competent thief can literally shave the insulation
off the side of the wire with a razor blade or Exacto knife; attach a
longer bypass wire that doesn't encircle the protected goods with a
couple of alligator clips; snip the original wire; and be home free.

This might fail -- that is, the alarm might still go off -- if the
electrical signals in the wire are high frequency enough, or the
measurement of the impedance of the wire itself, or the capacitance from
wire to ground, is sensitive enough, or . . .

But if you're using techniques that sophisticated, then the alarm is
also likely to be triggered by temperature changes, or by some large
object going by (a fork lift in a hangar), or by EMF from a nearby radio
or computer, or by . . .

A fiber loop would (in my judgment) be much less sensitive to all of the
above problems, and I believe the optical source, detector, and fiber
technology involved is now really cheap and simple.

As for the power consumption question, well, I have an optical mouse on
my desk that's been in use (putting out a lot of light, as well as
communicating constantly with the Bluetooth adaptor on my laptop) for
8-10 hours/day for many weeks now, and never turned off 24/7, on just a
couple of AA batteries.

AES -

If you aren't going into business - somebody should. I think it is a
neat idea although it would need a way to detect that the electronic
box is being crunched or shot at etc etc.

Cool------

The easy way to do that is with a positive signal system. That is, the
little transmitter chirps once every couple of seconds when things are
"good". When it stops chirping (batteries low, shot, crunched, or alarm
triggered) you light the alarm fuse.

Jim




"nrp" wrote in message
oups.com...
AES -

If you aren't going into business - somebody should. I think it is a
neat idea although it would need a way to detect that the electronic
box is being crunched or shot at etc etc.

Cool------

In article ,
"Peter Duniho" wrote:


You could try to address signal rerouting by monitoring not just its
presence, but other characteristics (voltage or current, for example), and
assume that minor changes are evidence of someone rerouting the signal. But
then the alarm is much more sensitive to things that aren't related to
someone trying to break the lock.


Thanks -- my point exactly, and better said.