Re: Near miss Australia

From: (David T. Medin)
Organization: Rockwell Avionics - Collins, Cedar Rapids, IA
Date:         15 Jun 95 14:25:24 
References:   1
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In article <airliners.1995.774@ohare.Chicago.COM>, The Nut <> writes:

[article on near-miss deleted]

> My question is, I know that this B747 had a collision avoidance radar and
> that the B737 did not. The first question is do all B747 have these
> radars or is it only the -400 ? The second question is, what is the range
> that the radar works at, that is how close does another plane have to get
> to a B747 before the warning is sounded and how long do the pilots have
> to react?
> And finally, why are more planes not fitted with this radar?
> Being a pilot myself, I know that closing to within 150 metres would
> scare me brainless.

I think that the "collision avoidance radar" was not true radar, but
TCAS, which uses transponder signals to avoid collisions by issuing
advisories and indicating approximate position and altitude of
conflicting aircraft. Whether TCAS has to be installed or not (and
what features it has) depends on the size and type of aircraft, and
the regulations observed by the countries whose airspace it flies in.
In the US for example, the 737 would have been required to have TCAS
installed and both aircraft would have been issued advisories to avoid
a collision.

       David Medin            Phone: (319) 395-4498
   Rockwell Collins ATD	      Internet:
     Cedar Rapids, IA