Anti-collision mechanism

On Sat, 1 Jan 2005 16:04:42 -0800, "Peter Duniho"
How many mid-air collisions of commercial airliners not equipped have there
been? Before the mandate, of course (I assume after the mandate there
haven't been any commercial airliners not equipped, right?).

Pete


Don't know the numbers for sure, but it used to be a fairly frequent
occurrence for airliners to hit small aircraft. Of course the press
always got it the other way around. That's why we have to have
transponders is certain airspace in small aircraft. The TCAS will see
our Mode C.

Seems like everything that ends up being mandated is because something
happened. If memory serves it was a Connie and DC-6 in the 50's that
ran in to each other over the Grand Canyon that caused the ATC system
as we know it. AA in Cali Columbia is why we have EGPWS. ValuJet is
why airliners have to have fire suppression in the baggage hold etc.

All commercial airliners are required to have TCAS II with Mode S
transponders; Commuters (up to 30 seats, I think) TCAS I



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On Sat, 01 Jan 2005 19:34:03 -0600, Don Hammer wrote in
::

... it used to be a fairly frequent
occurrence for airliners to hit small aircraft. Of course the press
always got it the other way around. That's why we have to have
transponders is certain airspace in small aircraft.

Here's the MAC that lead to mandatory TCAS:
http://www.ntsb.gov/NTSB/brief.asp?e...13X34444&key=2

Don Hammer wrote:

Also, since TCAS has been mandated, there has been only one mid-air
with equipped aircraft and it was because one crew ignored the
warning. (UPS and Aeroflot in Switzerland)

DHL and Bashkirian Airlines, actually.

On Sun, 02 Jan 2005 00:18:38 GMT, James Robinson
wrotD:

DHL and Bashkirian Airlines, actually

Right you are - gray matter isn't what it used to be.


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Don Hammer wrote:
On 1 Jan 2005 15:17:49 -0800, "george" wrotD:

Also, since TCAS has been mandated, there has been only one mid-air
with equipped aircraft and it was because one crew ignored the
warning. (UPS and Aeroflot in Switzerland)

????? You mean the TCAS only gives a warning, with the pilots having a
say on whether or not to take action?? I was under the impression that
the TCAS sytems talk to each other and take automatic action to avoid a
collision!!

To leave it to the pilots doesn't appear to be too much of an
advantage, with a relative speed of two planes being about 1000 mph
towards each other. Also, given the small reaction time, there's also a
chance, howsoever small, that the pilots could both take action that'll
precipitate a collision instead of avoiding one; both diving, for
example.

If it isn't automatic, I think the TCAS should be. For sure.
Ramapriya

EBME, eye ball measuring equipment is the most important instrument you have
in the cockpit. ALL THE OTHER AIDS ARE ONLY AIDS!

Hope this helps,
Peter

"Ramapriya" wrote in message
oups.com...
Don Hammer wrote:
On 1 Jan 2005 15:17:49 -0800, "george" wrotD:

Also, since TCAS has been mandated, there has been only one mid-air
with equipped aircraft and it was because one crew ignored the
warning. (UPS and Aeroflot in Switzerland)

????? You mean the TCAS only gives a warning, with the pilots having a
say on whether or not to take action?? I was under the impression that
the TCAS sytems talk to each other and take automatic action to avoid a
collision!!

To leave it to the pilots doesn't appear to be too much of an
advantage, with a relative speed of two planes being about 1000 mph
towards each other. Also, given the small reaction time, there's also a
chance, howsoever small, that the pilots could both take action that'll
precipitate a collision instead of avoiding one; both diving, for
example.

If it isn't automatic, I think the TCAS should be. For sure.
Ramapriya

TCAS alerts and instructions are what the pilot is supposed to follow. If
ATC and the TCAS conflict then the pilot is required to follow TCAS.

In the case over Germany the Russian obeyed ATC when they should have
followed the TCAS. The DHL plane obeyed TCAS but still ended up wrecked
because the Russian plane had not taken the action it was supposed to
follow.

As with all accidents measures taken earlier could have eliminated the need
for conflict resolution. There was only one controller on duty that night
covering a couple of sectors and he missed the problem as it was building
up. when he tried to raise the Russian plane he had difficulty and so it all
went on.

In the end the controller was murdered by, its claimed, avenging parents of
the 86 kids killed on the Russian plane.

Every regulation brought in is written in someone's blood.

Chris wrote:

TCAS alerts and instructions are what the pilot is supposed to follow. If
ATC and the TCAS conflict then the pilot is required to follow TCAS.

Of interest, here was the Russian view of the priorities at the time:

http://www.aeronautics.ru/news/news002/news053.htm

I believe they have since changed their instructions to encourage the
pilots to follow TCAS recommendations.

In article .com,
"Ramapriya" wrote:

To leave it to the pilots doesn't appear to be too much of an
advantage, with a relative speed of two planes being about 1000 mph
towards each other. Also, given the small reaction time, there's also a
chance, howsoever small, that the pilots could both take action that'll
precipitate a collision instead of avoiding one; both diving, for
example.

1) Reaction times are less of an issue with TCAS because normally
the system will advise the crew of traffic (called a traffic advisory or TA)
when the conflicting aircraft is (iirc) 40 seconds out. This allows the
crew to begin scanning for the potential conflict.

2) If the two aircraft involved in a potential conflict are both TCAS II
equipped, the systems will coordinate. That is, generally the higher
aircraft will get a "Resolution Advisory" or RA to climb (or possibly not
descend) while the lower aircraft will get a descent (or possibly not
climb).


If it isn't automatic, I think the TCAS should be. For sure.

you have far more faith in automation than I.

btw - since TCAS can only see transponder-equipped aircraft, it
wouldn't be real smart to make the system automatic beause you
wouldn't want the system to fly the aircraft into conflict with
a non-transponder aircraft.

--
Bob Noel
looking for a sig the lawyers will like

Bob Noel wrote:

--
Bob Noel
looking for a sig the lawyers will like

ok, how about "A good lawyer knows the law, a great lawyer knows the
judge"