[time-nuts] Spoofing GPS

[Jim Lux]

On 6/26/12 5:51 PM, Chris Albertson wrote:
> On Tue, Jun 26, 2012 at 3:59 PM, Jim Lux<jimlux at earthlink.net>  wrote:
>
>>
>> I did some calculations last year, and if Los Angeles decided to put up a
>> UAV 24/7 to replace things like helicopters, we could expect a crash into
>> the city about once a week.
>>
>>
> But they could be made very safe for only a little bit of money.   Say you
> add a rocket deployed parachute triggered by ground proximity.   These kind
> of chutes are made large enough for light aircraft.
>
> Lots of other things to do for safety like a video camera that is monitored
> and then you'd know in a minute if the aircraft was going the right way.
>

No, that doesn't make it safe.. it still fails (engine failure is most 
common) it just potentially allows you to crash somewhere less 
obnoxious.  I suspect that the overall system reliability of a UAV is 
*substantially* lower than a military jet.  They're not doing things 
like multiple redundant communication links on different bands, or 
redundant control systems or redundant anything (all of which commercial 
aircraft have)..

Dropping a UAV by parachute onto a school is not quite as bad as 
augering into a pre-school, but not by much.  Or in the middle of the 
freeway during non-rush hour.

When I was getting my pilots license, I used to have bad dreams about 
having an engine failure flying along PCH in Malibu at 1500-2000 ft, and 
trying to decide whether to land on PCH (tons of wires) or the beach 
(tons of people). We used to have discussions about whether it's better 
to land on the freeway going with traffic (lower closing velocity but 
you're coming up on people from behind) or going against traffic (people 
will see you coming and hopefully dive for the shoulder).