TCAS - air france swissair

[cxi]

Has anyone else had this?
an air france flight in the ltma had a tcas climb yesterday due to high closure, no loss of sep (at least 1000'). Ntohing new there you say, except that the pilot filed an airprox because it is now company policy to file on every tcas ra !!!
Call me bitter, but does the pilot and airline know that the controller involved was withdrawn from controlling until srg could say that the "airprox" was not that persons fault? meanwhile the pilot flew on without a care in the world ignorant of the carnage he had just caused.
Apparantly swissair have the same policy.

I know we dont go on strike just all get suspened for having tcas ra's!!!!

[jtr]

The company I work for has the same policy. i.e. for a RA, submit the paperwork. Makes sense really, you are in controlled airspace, you have to leave your level (if S+L), due to an predicted dangerous situation. A RA on the buses can mean as little as 20 seconds till closest point of approach. Exactly how long would you like us to sit there with the box screaming `CLIMB, CLIMB NOW` then carry on as if a near miss is the norm?

If on the other hand it was a TA, then yeh, thats a bit rough

[2 six 4]

JTR !!!! Does not make any sense whatsoever. Look up the definition of Airprox.

This will cause mayhem.

[cxi]

jtr
tcas does a good job for those nasty little times when it goes wrong. BUT there are also unfortunately those nasty little times when it is all legal 1000' between a/c and horizontal sep when you get tcas ra's and in this case the the pilot thought oh i'd better file an airprox for the stats and the controller was suspended until the pen pushers go through there life history to decide if the controller should be allowed to keep his job

Not quite what the pilot had in mind I hope.

[Shazbat]

Dear jtr

I can understand your company's need for paperwork.....NATS ATCOs, too, have to do the same - but they fill out a form that is especially designed for TCAS RA's.

It would be helpful if your company, and others, would realise that - in a busy environment like the London TMA, for example - TCAS RA's happen a lot, with the tight sectors and high climb rates that are sometimes asked for.

Surely it might be prudent to go along the same lines as NATS (God forbid I support NATS management, but this time - for a change - they have things right) and have a separate form for this.

My colleagues has a very good point....if an Airprox is filed everytime there is a TCAS RA, then the Operation at LATCC (for one) will soon grind to a halt - not to mention the affect that such a trial has on the controllers involved.

Thanks for posting by the way....it's nice to know that pilots read our side of the Forum :)

[fart]

We also have to fill in the paperwork for either TA or RA's , but the supervisor on shift can decide whether or not it is serious and if you should get relieved from duty or not. I personally think TCAS is ok and have had a few nuisance alerts, but have seen some hairy stuff and if it was not for TCAS, then we would have had some serious close calls at our unit.
I would like to ask shazbat if it is possible to get a copy of their TCAS form. I am employed by a pvt company in the ME and we really need to be educated more about these things. It is interesting to note that in the last 3 years, all the incidents at our unit were TCAS RA related. I am just wondering how different things would have been if not for TCAS and how many times in the past did we all get away with close calls that were never reported. I find that I would now give traffic info to aircraft when I anticipate that there could be a possibility of a TCAS ta/ra. It just improves everybodies situational awareness and I think it is really great. I would like to find out how you all deal with these kinds of incidents and particularly those situations where the 2 TCAS's did not give a co-ordinated response. This can iniatially reduce the separation even further before corrective action/advisories are generated. Shazbat, I would really appreciate your help here with your reporting procedures as we still learning as we go.
Thanks
We also find that pilots operate TCAS whilst on final or immediately after departure and so trigger a lot of nuisance alerts. I believe most airlines have a policy of not operating TCAS within 15 nm of the field to avoid nuisance alerts. We have had several go-arounds because of TCAS RA's against helicopter traffic close to the approaches. We also find that ships squawking over the ocean with no mode C will trigger high flying aircraft TCAS ra's. Likewise for VFR flights with no mode C below controlled airspace.

[Shazbat]

hi fart *sniff*

I'd only be too happy to help....let me know a contact email addy and away we go http://www.pprune.org/ubb/NonCGI/redface.gif)

[10W]

fart

The UK Reporting for ACAS is detailed in the CAA Manual of Air Traffic Services Part 1 (MATS Pt 1). Maybe you can get a hold of that from somewhere ? (sorry Shazbat, it's not been issued by NATS management so you'll just have to go on not supporting them !!)

Copies of the form are also available in the UK's AIC published on ACAS which you can find here:

http://www.ais.org.uk/Uk_aip/pdf/aic/4Y308.pdf


Some more info on a few of the other points you covered:

Co-ordinated Response

For TCAS II equipped aircraft, the responses should be co-ordinated using the Mode S transponders fitted to the aircraft. Obviously this only works where both actually have TCAS fitted and operating.

The system does this by checking to see if it has received an intent from the threat aircraft (i.e. is it going to climb or descend). If it has an intent, then it will do the opposite. If it does not, then it will treat the aircraft as being non TCAS equipped and make it's own decision based on the conflict information. The first aircraft to get it's interrogation in will normally determine the resolution.

Occasionally both aircraft's TCAS will do the above simultaneously (thinking they are first to spot the threat) and in this case each may select the same resolution (e.g. in level flight both may choose a descent). If this happens, the aircraft with the higher Mode S address (each box has a transmitted serial number in effect) will reverse it's course of action. Interestingly the fleets with the lower range of numbers are those based in the USA ;) Great you might think, the aircraft is going to go down then up. Not so. For TCAS/TCAS encounters of this type, the aircraft with the higher address will delay output of the resolution for the pilot for up to 3 seconds to allow the intent from the lower addressed aircraft to be received.

Of course for a TCAS aircraft against someone squawking only Mode A/C with no TCAS fit, then there is no co-ordination. There is only one piece of kit which will be making the decision.

In The Vicinity Of The Airfield

There TCAS II box will inhibit RA's below 1000'AGL (from the Rad Alt presumably). All pilots should get is a TA. Also, if the TCAS believes that the threat is within 340 feet of the ground, it will not provide an alert, assuming the threat is on the ground.

Non Mode C Targets

Ships and VFR traffic will not generate RA's unless they also have a Mode C output. At most they will generate TA's.


The UK CAA issue a 'TCAS & The Controller' Pack. Try [email protected] to see if you could get a full copy.


------------------
10 West
UK ATC'er
[email protected]

[twrboy]

We have had the stupid situation of an inbound aircraft being provided with visual separation with outbound traffic, both given traffic and sighted each other and the jet driver still files a TCAS RA report when the darn box went off.

Not much sense having separation standards if we are going to get written up each time we use them.:confused

[Dehavillanddriver]

It is mandatory under Australian rules to file an Air Safety Incident Report for every RA - they are considered an immediately notifiable incident.

It wasn't all that long ago that a TA was also notifiable (though only within 24 hrs).

Interestingly enough though I believe that many regional pilots in Oz disregard up to half of the RA's that they get - prefering to wait and see if it is real! For my money that is undoing any safety benefit that may arise from TCAS....

[fweeeeep]

DH Driver,

Does the mandatory reporting of RA's include when ATC has provided traffic information regarding traffic that is restricted above/below, but climbing/decending toward you ?

[Capt H Peacock]

Those of us who are still allowed to exercise some airmanship reduce rates of climb/descent in the TMA so that RA's can be avoided. Mosr regular customers appreciate that average achieved rates on the BIG arr and MID deps are usually less than 1500fpm. That should be enough to avoid a TA/RA for AF and SR, and save them a deal of 'travail du papier'

[Chatterbox]

Funny old thing but TCAS and STCA (A RADAR kind of TCAS for those that are unfamiliar) can cause the same problems.

If a pilot takes action on an RA then as any controller will know it can lead to a further loss of separation with a different aircraft. If a controller takes action on an STCA alert (particularly close to an airfield) it can also lead to the same problem.Who is now responsible for separating the following aircraft?

Back to the point.......
the whole problem needs highlighting but suspending people is not the way to go.
Whoever mentioned the TCAS form might be on the right lines if the airlines can be persuaded to adopt them too.
Not that an ATCO is supposed to file on every single level bust though are they?

[fart]

Shazbat and 10W - Thank You Sirs!
I got hold of the info and am much obliged. Thanks for making us outside your system aware of these issues. Much appreciated!
Cheers

[Shazbat]

Hi Chatterbox

According to NATS Safety department, every NATS ATCO is supposed to file on EVERY level bust !!

SRG are very hot on this apparently - I just wonder how true-to-life the number of reported levels busts are as opposed to those that actually happen ?

And, perhaps, if there wasn't a blame-culture prevalent within NATS management (and other managements) whether more reports would be filed ??