Anti-collision mechanism

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.

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"

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.

Bob Noel wrote:

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.

You know I'm not an aviator, but 40 secs don't appear that much. A few
secs to initially notice a warning and a few more till it properly
registers would take away much of the 40 secs. Moreover, the pilots
could easily be doing other things at the time - a loo break, chatting
up passengers while on autopilot, munching a snack, even flirting with
a hostess (hope I don't get flamed for suggesting that )...

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

you have far more faith in automation than I.

and why is it that you don't have faith in automation, Bob? Not having
to use brains, and doing something by rote instead, isn't necessarily a
disadvantage always. The chances of a well-programmed software
consistently doing a collision avoidance routine correctly are better
than two pilots doing so, I'd imagine.

Ramapriya

Ramapriya wrote:
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.

20+ years ago I knew one of the early developers of TCAS. She told me
about some of the attempts at conflict resolution. For example, they
started off with a rule that said if two planes were heading directly at
each other, "pass with the other plane on the right". Fortunately,
they did simulations: the result is the colliding planes form a
decreasing-radius spiral about each other, always with the other plane
on the right.

"Larry Dighera" wrote in message
...
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



Correct Larry,

The thing that gets me is that this collision would still have happened
because,

"N4891F'S X-PONDER WASN'T DISPLAYED DUE TO EQUIP CONFIGURATION."

IOW, stand-by mode.

Marty

On Sun, 2 Jan 2005 11:31:26 -0600, "Marty"
wrote:

The thing that gets me is that this collision would still have happened
because,
"N4891F'S X-PONDER WASN'T DISPLAYED DUE TO EQUIP CONFIGURATION."
IOW, stand-by mode.

I read this as a configuration "error" on the controller's display
(filtering out VFR targets, or targets above/below a certain
altitude).

Tobias

Ram, if I recall that incident correctly, ATC had repeatedly requested a
heading change and direction of turn (don't recall actual numbers) but the
flight crew repeatedly read back incorrectly. In the end the controller
deferred to the "obviously" more experienced and knowledgeable captain - and
gave in...

With respect to the capability of TCAS - it only interrogates the
transponders of nearby airplanes. It then figures out their distance away,
bearing and delta altitude (assuming a mode C or S transponder). It will
give a Resolution Advisory (Climb or Descend) instruction. It does not give
any terrain warning.

Anthony Quick

"Ramapriya" wrote in message
ups.com...
Bob, guess I didn't frame the Q properly enough.
While I knew about the GPWS and TCAS individually, I wasn't sure
whether TCAS was equipped to deal with purely traffic or whether
accidental straying into terrain would also be taken care of.
I'm asking this because I remember an incident of many years ago where
an idiot in the ATC asked an Indonesian aircraft to turn 'left' when he
had to say 'right' and the unsuspecting blokes ran into a mountain. I
was wondering if that kinduva incident can be avoided with the TCAS...

Cheers,

Ramapriya


Bob Moore wrote:
"Ramapriya" wrote

Does this get activated only when there's an aircraft in the
dangerous
vicinity or will it also trigger if the aircraft is hurtling
towards
some terrain such as a hill?

In my generation of aircraft, (B-727) they are two different systems.
First came the GPWS (Ground Proximity Warning System) and then some
time later came the TCAS (Traffic Alert and Collision Advoidance
System).

And does every aircraft have this system these days, regardless of
size?

No, only passenger jets are required to have them.

Bob Moore