Jon Wright asked: > Is this how TCAS is supposed to work--issuing coordinated instructions > to the different planes in conflict to maximize evasive manuevers? What > are pilots trained to do when given instructions from ATC that are > counter to a TCAS TA? Allan9 answered: > Most if nnot all US Airlines mandate the TCAS resolution be followed. ...and Walter Wilson added: > ..and...all that is 'normally' required is to notify ATC as soon as possible > after the avoidance maneuver that it was a TCAS deviation..and it will be > forgotten. The situation is the same in Europe. Whatever the controller tells you, always do what the TCAS system is demanding, and as soon as possible call out "TCAS climb/descent" on the frequency. Unfortunately the Ukrainian pilot chose to obey the 'wrong' part of the system this time with fatal consequenses... The hesitation while deciding who to trust also explains the 16 second delay in reading back and carrying out the descend instruction. Walter says that if ATC is informed that the deviation was due to a TCAS RA (Resolution Advisory), everything is forgotten. Not so, at least in Europe. Whenever a TCAS RA is carried out, we need to file a report, as this indicates that two aircraft have been well below minimum separation, a situation which, even when they don't hit each other, must be investigated as it is a clear violation of the rules. (Of course sometimes the RA is triggered by an aircraft with a high rate of climb approaching its cleared level 1000 feet below another aircraft, as the system is tricked into believing that with this rate of climb, the 'intruder' is not going to stop below. So please, all you pilots on the list, keep that in mind when you're out there!) I don't know if it has made the international news yet, but here in Denmark it is reported in the media that the controller involved was a Dane - a former colleague of mine (we have actually known that within the company since right after the accident but of course not been allowed to tell to protect his family from the reporters!). Back in the mid-90'es, the Swiss had a shortage of controllers, while we had a surplus here in Denmark, so 20-some of my colleagues were 'leased' to Swisscontrol (as it was known back then) for 3 years. On completion of their contract, the Swiss offered them all permanent positions and 17 chose to stay. (This just to explain why a Danish controller was working Swiss airspace!). The person in question had held his Swiss rating for around 5 years at the time of the accident. The thoughts of everyone in Danish ATC is with this guy and his family. Finally: I note that the international media are no different than the Danish ones: When will journalists learn that controllers working flights at 36000 feet are sitting in Area Control Centers, not control towers!!!??? Rgds Jan Broe EKCH ATC