JETPILOT
Topic Author
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Recent Near Collision Arising Frm Tcas Advisories?

Wed Jul 03, 2002 11:41 am

I seem to remeber recently 2 transport category planes (DC10 and 747 I think)in Europen airspace had a neaer collision due to pilots following TCAS advisories.

The incident took place during the day and a collison was prevented by see and avoid.

Can anyone provide further info on that incident?

It sounds earlilly famailiar to yesterdays trajedy over germany.

Is TCAS giving incorrect RA's?

JET
 
TAA_Airbus
Posts: 491
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RE: Recent Near Collision Arising Frm Tcas Advisories?

Wed Jul 03, 2002 11:52 am

I dunno JETPILOT.

If they didnt collide, wouldnt it say that TCAS did its job?
They pump out RAs about 20 seconds before anything will happen, so in that 20 seconds, should you follow them, its still going to be a near miss. But as long as you didnt hit, Id say TCAS did its job.

But I havent read about this incident, and thus cant say to much about it.
 
JETPILOT
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RE: Recent Near Collision Arising Frm Tcas Advisories?

Wed Jul 03, 2002 11:56 am

As I stated the only factor keeping these planes from colliding was the DC10 catching a glimpse of the 747 within 50 feet below it.

The RA issued told the DC10 to descend into the 747.

So did the TCAS do it's job?

I don't think so.....

JET
 
TAA_Airbus
Posts: 491
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RE: Recent Near Collision Arising Frm Tcas Advisories?

Wed Jul 03, 2002 12:00 pm

Like I said mate, I kow nothing of the incident and thus cant say anymore. But from what youve said, you are right, and thus should be looked into.
 
SailorOrion
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RE: Recent Near Collision Arising Frm Tcas Advisor

Wed Jul 03, 2002 3:35 pm

These two planes nearly collided over Japan, not Europe

SailorOrion
 
JETPILOT
Topic Author
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RE: Recent Near Collision Arising Frm Tcas Advisories?

Wed Jul 03, 2002 4:13 pm

Could you contribute a little more insight into the incident?

JET
 
kaitak
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RE: Recent Near Collision Arising Frm Tcas Advisories?

Sat Jul 06, 2002 4:44 am

I believe the 747-400D was flying from Haneda to Osaka and the DC10 (also JAL) was on a flight from Pusan to Narita; they came within a hair's breadth of each other - I've heard 30' mentioned, which for two very large airliners travelling at a very high closing speed is incredibly close.

Apparently, the pilot of the 744 was blamed.
 
AM
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RE: Recent Near Collision Arising Frm Tcas Advisories?

Sat Jul 06, 2002 5:12 am

Talking about TCAS, can it perform some kind of emergency maneuver to try to avoid conflicting traffic all by itself? Maybe an autopilot override? Or is emergency traffic avoidance always performed by the crew following TCAS's advisories either by autopilot or manual inputs?
"... for there you have been and there you will long to return."
 
almbluzman
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RE: Recent Near Collision Arising From Tcas Advisories?

Sat Jul 13, 2002 12:42 am

does anyone think that reduced vertical separation might have had a big impact on these incidents? also, what effect might these incident's have on the proposed reduction of vertical separation minimums in the u.s.?

almbluzman
 
Klaus
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AM, Almbluzman

Sat Jul 13, 2002 2:05 am

AM: Talking about TCAS, can it perform some kind of emergency maneuver to try to avoid conflicting traffic all by itself?

Not as far as I know. The actual course change must still be done by the pilots.


Almbluzman: does anyone think that reduced vertical separation might have had a big impact on these incidents? also, what effect might these incident's have on the proposed reduction of vertical separation minimums in the u.s.?

I´m not an expert, but by looking at the principle I would think that reduced vertical separation would actually decrease the probability of a conflict since the same number of planes would be distributed among a greater number of flight levels.

On the other hand, a deviation from the assigned flight level would be more critical. And that would include the risk involved with evasive action in case a conflict should still occur.

But with increased positioning precision and adapted ATC procedures I would still expect the overall risk to go down rather than up.
 
Guest

RE: Recent Near Collision Arising Frm Tcas Advisories?

Sat Jul 13, 2002 3:23 pm

Just a word here...
I believe, from having a look at official near miss (and collision) reports, that there is more problems with LATERAL rather than VERTICAL separation... except in a few climb/or descent scenarios...
In the new RVSM airspace above FL290, vertical separation is reduced to 1,000 feet... In the original altimeter designs, I doubt that there was much more error above FL290... if compared between FL270/280, or FL290/300...
Maybe it was the case in the higher FL370 or 390 levels... no much change...
I fly in RVSM and non-RVSM airspace... I never notice more level separation or discrepancies in the non-RVSM airspace... separation always seems to be 900 to 1100 feet vertically from "potential" traffic on our TCAS equipment...
I would worry more about LATERAL separation, personally...
(s) Skipper
 
saintsman
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RE: Recent Near Collision Arising Frm Tcas Advisories?

Sun Jul 14, 2002 4:10 am

With regard to the TCAS putting an input to the autopilot. Autopilots don't like sudden large inputs because it causes them to trip out. An alert from the TCAS would by nature call for a large manoever in order to avoid a collision, so the last thing you would want in that situation is for your autopilot to disconnect and leave you with 'nothing'.

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