Avionic Proximity Warning

Avionic Proximity Warning

[Bob Wells #402]

G'day,
What is the name of this piece of equipment that tells a pilot the
evasive action he should take to avoid a possible collision with
another detected plane? Such advice is given locally, and is totally
independent of any ATC instruction (making it a bit dangerous IMHO).

It is currently in use (I believe) in the US? And I think its
acronym starts with the letter T.

Anyone know what language it was written in?

Thanks,
Bob W. (-:

Re: Avionic Proximity Warning

[Bob Wells #402]

Thanks Richard and Pass,
The system I was thinking of is TCAS (T????
Collision Avoidence System).

Now anyone know what language it was written in?

Thanks,
Bob W. (-:

Re: Avionic Proximity Warning

[CONDIC]

From: Marin David Condic, 407.796.8997, M/S 731-93
Subject: Re:Avionic Proximity Warning
Original_To:  PROFS%"SMTP@PWAGPDB"
Original_cc:  CONDIC



Bob Wells #402 <wel@EUROCONTROL.DE> writes:
>
>What is the name of this piece of equipment that tells a pilot the
>evasive action he should take to avoid a possible collision with
>another detected plane? Such advice is given locally, and is totally
>independent of any ATC instruction (making it a bit dangerous IMHO).
>
I worked on programming such a radio device called TCAS which (if
the two remaining brain cells are still functioning after the New
Year's parties...) stood for Traffic Collision Avoidance System.
Our implementation was for a radio called ICNIA and was written
in JOVIAL. (Other implementations could have - and probably were
done in just about any other language. It's a radio protocol. Not
a specific piece of hardware.)

Basically, it worked by having two planes trade off
positional information and if they agreed that they were in
immanent danger of collision (something under a mile, if memory
serves) they'd take a vote on which direction each plane should
move in.

Its independence from ATC instruction wasn't dangerous in the
sense that it only went off when the danger was immanent and
presumably, this meant that the pilots or air traffic controllers
had already screwed things up. The airlines *did* refuse to give
full authority over the airframe to the TCAS (enabling a flight
control to take automatic evasive action) and insisted that it
provide only a "suggestion" to the pilot because they were
worried about liability. I don't know if they were right or wrong
on this, but other devices on airplanes can and do take authority
away from the pilot under some conditions.

Hope this enlightens.

Pax,
Marin

Marin David Condic, Senior Computer Engineer    ATT:        407.796.8997
M/S 731-93                                      Technet:    796.8997
Pratt & Whitney, GESP                           Internet:   CONDICMA@PWFL.COM
P.O. Box 109600                                 Internet:   MDCONDIC@AOL.COM
West Palm Beach, FL 33410-9600
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Re: Avionic Proximity Warning

[Joe Rodnite]

I worked on  unit testing the TCAS system at Bendix in Fort Lauderdale.

It is written in INTEL PL/M.

Re: Avionic Proximity Warning

[IanMaclure]

Bob Wells #402 <wel@EUROCONTROL.DE> writes:

>Thanks Richard and Pass,
>The system I was thinking of is TCAS (T????
>Collision Avoidence System).

>Now anyone know what language it was written in?

PASCAL

IBM
-- 
################ No Times Like The Maritimes, Eh! ######################
# IBM   aka      #    Ian_Maclure@QMGATE.arc.nasa.gov           (desk) #
# Ian B MacLure  #    maclure@(remulak/eos).arc.nasa.gov   (currently) #
########## Opinions expressed here are mine, mine, mine. ###############

Re: Avionic Proximity Warning

[Robert I. Eachus]

In article <9412311351.AA10354@eurocontrol.de> Bob Wells #402 <wel@EUROCONTROL.DE> writes:

 > What is the name of this piece of equipment that tells a pilot the
 > evasive action he should take to avoid a possible collision with
 > another detected plane? Such advice is given locally, and is totally
 > independent of any ATC instruction (making it a bit dangerous IMHO).

   TCAS, and yes, the air traffic controllers don't like it one bit,
but the pilots love it.  Since the pilot has "total responsibility for
the safety of the aircraft," he can (and many would say automatically
should) choose to follow a TCAS directive instead of ATC instruction.
But this can mess up all the ATCs nice pretty plans for lots of
airplanes. 

   Fortunately, this seems to be an administrative issue so far.  I
don't think there are any cases where TCAS is alleged to have made the
safety situation worse, just that "false" TCAS alerts cause extra
workloads for the ATC system and for the controllers.

 > Anyone know what language it was written in?

   Bsst! Wrong question.  TCAS is really an implementation independent
protocol, you would have to ask the manufacturers of avionics
equipment what they used for their TCAS boxes.  I wouldn't be
surprised if you find Ada implementations, as well as others.


--

					Robert I. Eachus

with Standard_Disclaimer;
use  Standard_Disclaimer;
function Message (Text: in Clever_Ideas) return Better_Ideas is...

Re: Avionic Proximity Warning

[Norman H. Cohen]

In article <INFO-ADA%95010309592615@VM1.NODAK.EDU>, CONDIC@PSAVAX.PWFL.COM
writes: 

|> Basically, it worked by having two planes trade off
|> positional information and if they agreed that they were in
|> immanent danger of collision (something under a mile, if memory
|> serves) they'd take a vote on which direction each plane should
|> move in.

A two-voter vote?  That sounds fishy, given the high probability of a
tie.

--
Norman H. Cohen    ncohen@watson.ibm.com

Re: Avionic Proximity Warning

[Robert Dewar]

"A two-voter vote [on which way to fly to avoid collision"

no problem, I execute that algorithm on the street frequently:

let me go to the right, oh, you want to go to the right, ok I'll go to
the left, oh, you changed your mind too, never mind, I'll go to the right
after all, oh ....

Re: Avionic Proximity Warning

[Dave Funk]

The Collins TCAS system in use by many airlines is written in Ada.  
We have been using Ada in coomercial avionics systems since 1984.

Regards,
Dave Funk
Collins Commercial Avionics
Rockwell International

---
"Common sense is not so common" - Voltaire

Re: Avionic Proximity Warning

[CONDIC]

From: Marin David Condic, 407.796.8997, M/S 731-93
Subject: Re: Avionic Proximity Warning
Original_To:  PROFS%"SMTP@PWAGPDB"
Original_cc:  CONDIC



"Norman H. Cohen" <ncohen@WATSON.IBM.COM> writes:
>
>In article <INFO-ADA%95010309592615@VM1.NODAK.EDU>, CONDIC@PSAVAX.PWFL.COM
>writes:
>
>|> Basically, it worked by having two planes trade off
>|> positional information and if they agreed that they were in
>|> immanent danger of collision (something under a mile, if memory
>|> serves) they'd take a vote on which direction each plane should
>|> move in.
>
>A two-voter vote?  That sounds fishy, given the high probability of a
>tie.
>
All citizens are created equal, but some citizens are more equal
than others!

Maybe they used "Rock/Paper/Scissors." It's been a rough week and
the memory fails.

Pax,
Marin

Marin David Condic, Senior Computer Engineer    ATT:        407.796.8997
M/S 731-93                                      Technet:    796.8997
Pratt & Whitney, GESP                           Internet:   CONDICMA@PWFL.COM
P.O. Box 109600                                 Internet:   MDCONDIC@AOL.COM
West Palm Beach, FL 33410-9600
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