Re: [Drip] ADSB

[Robert Moskowitz <[e-mail]>]

On 7/12/23 06:45, Carsten Bormann wrote:
> On 2023-07-12, at 11:52, Alexandre Petrescu <[e-mail]> wrote:
>> why not 400m
> This is not a domain where we get to invent boundaries.
>
> (Also, generally speaking, of course we should have a strong bias to using SI units, but in a domain where regulation is widely based on furlongs per fortnight, we’ll have to adapt.)

And anyway it would be 125M to be a bit more than the Imperial 400'.

Why 400'?

I think it was to keep general aviation some reasonable distance above 
people on the ground.  As the ceiling for UA that is a consequence.  
"They can't go any lower, you can't go any higher."

It is called boundaries to keep unequal players apart.

One of the interesting debates in this is that the 400' floor is to 
ground obstacles like radio towers.  Thus since big birds have to stay 
400' from that 700' radio tower down the block, you can take your UA up 
to 1100' right next to it...  Or so some claim.

And speaking of Imperial vs Metric...

Civil aviation separation is 1000'.

This has already caused incidents where a lesser  Metric distance was 
used by one aircraft against one using the greater separation of Imperial.

Fun!

Not.

Bob