TonyWilliams

Did you get this FAA ATC bulletin, dated March 2010? I'll bet you'll find it RIGHT NOW in the Read & Initial binders:

http://www.faa.gov/air_traffic/publi...atb_mar_10.pdf

TCAS RAs
/*TRE TCAS RAs can be a recurring phenomenon in busy air traffic control environments. RAs are a feature of TCAS II. Many types of aircraft are being fitted with TCAS II equipment. All commercial turbine powered aircraft, with more than 30 seats, are required to be equipped with TCAS II.

Pilots responding to a TCAS RA will either commence climb or descend. RA climb and/or descent rates can vary dependent on the proximity of detected traffic. RA reversals from climb to descend, or descend to climb, are possible when multiple threats are detected. TCAS is designed to inhibit descending RAs below 1100 feet above ground level (AGL), and all RAs below 1000 feet AGL. Aircraft maintaining visual separation or leveling off at altitudes above or below TCAS II equipped aircraft have been known to trigger RAs without actual loss of prescribed separation. Aircraft responding to an RA will require climb or descent in the 300 to 500 feet vertical displacement range to satisfy a conflict, but other factors can cause the vertical adjustment to exceed this range.

While RAs are designed to enhance overall safety, the effects of an RA can be disruptive. Any unplanned or unanticipated aircraft maneuver can have a ‘ripple’ effect on other traffic.

Understanding aircraft performance characteristics, and recognizing potential TCAS RA scenarios, can help controllers minimize the likelihood and effect of RA events.

Additional information regarding TCAS RAs can be found in FAA Order JO 7110.65, Paragraph 2-1-27, TCAS RESOLUTION ADVISORIES.

TonyWilliams

Here's your 7110.65 language in the Air Traffic Controller Handbook:

2-1-27 TCAS Resolution Advisories

a. When an aircraft under your control jurisdiction informs you that it is responding to a TCAS Resolution Advisory (RA), do not issue control instructions that are contrary to the RA procedure that a crew member has advised you that they are executing. Provide safety alerts regarding terrain or obstructions and traffic advisories for the aircraft responding to the RA and all other aircraft under your control jurisdiction, as appropriate.
b. Unless advised by other aircraft that they are also responding to a TCAS RA, do not assume that other aircraft in the proximity of the responding aircraft are involved in the RA maneuver or are aware of the responding aircraft's intended maneuvers. Continue to provide control instructions, safety alerts, and traffic advisories as appropriate to such aircraft.
c. Once the responding aircraft has begun a maneuver in response to an RA, the controller is not responsible for providing standard separation between the aircraft that is responding to an RA and any other aircraft, airspace, terrain or obstructions. Responsibility for standard separation resumes when one of the following conditions are met:
1. The responding aircraft has returned to its assigned altitude, or
2. A crew member informs you that the TCAS maneuver is completed and you observe that standard separation has been reestablished, or
3. The responding aircraft has executed an alternate clearance and you observe that standard separation has been reestablished.
NOTE -
1 - AC 120-55A suggests pilots use the following phraseology to notify controllers during TCAS events. When a TCAS RA may affect an ATC clearance, inform ATC when beginning the maneuver or as soon as workload permits:
EXAMPLE -
1 - "New York Center, United 321, TCAS climb."
NOTE -
2 - When the RA has been resolved, the flight crew should advise ATC they are retuning to their previously assigned clearance or subsequent amended clearance:
EXAMPLE -
2 - "New York Center, United 321, clear of conflict, returning to assigned altitude."

Captain Tony

Thanks Tony, that was what I was trying to say.

Which goes back to what I said before. Just because you "can" separate by 500' doesn't mean you should.

TonyWilliams

Well, actually, I don't have a problem (from either an ATC perspective or ATP one) with 500 feet separation in LEVEL flight (w/TCAS, in the most current software development).

But.... there is a "donkey blind" mentality on both sides of the microphone. Pilots don't know ATC procedures, and should. And controllers, even if they've received pilot issue training like TCAS, many / most would say, "hey, not my job". Always irritated the crap out of me.

The issues that are shared, like TCAS, need to be fully understood by both parties. One thing I would hope would get controllers attention is that a controller was actually MURDERED over a TCAS event gone wrong.

saab2000

Because that particular controller's lack of attention to detail led to the deaths of about 150 people, including many children. The accident happened while I lived in Switzerland and for a country based on anal retentiveness at all levels, the amateurism of that particular controller was unbelievable.

Not saying he should have been murdered. Not at all. But it was gross, gross on the controller's part negligence which led to that accident.

Starscream

Well, as I understand, that controller was working a massive chunk of airspace, including several satellite airports as well as high altitude RVSM airspace -- all by himself (almost), and in the middle of the night. I understand that this mid-air occured in the high flight levels involving two IFR flights.

TonyWilliams

I'm sure there were failings on the controllers part, but the single biggest failing was the training (or lack of) of the Russian crew who chose to follow the controllers instructions over the established international protocol of following TCAS.

Starscream

Yup. Accidents like this normally do not have a single cause, but several contributing factors in which had anything been different, the accident would have been averted.

dojetdriver

Was that protocol established before that crash? I remember after that accident the flood of revised guidance to ALWAYS ALWAYS ALWAYS follow the RA.

TonyWilliams

The western world was already following TCAS, and of course, reinforcing that it be done.