Sdruvss,
No problem. I'm glad we seem to have sorted out our communications. We seem both to be interested at getting at the heart of this matter.
You want to discuss it in detail. OK, let's try.
Originally Posted by Sdruvss
1. Legacy was leaving a point-to-point section -- I don't know the english word for that -- (S.José to Brasilia) to enter a RVSM airspace in UZ6. No one RVSM authorized aircraft flies from Brasilia to Manaus at FL 370. All pilots know that. If they were engaged in appropriate pre-flight planning, Legacy pilots would have known that. That is why their original flight plan informs to descend to FL360 at Brasilia.
The Legacy joined UZ6 at a waypoint. I would assume the pilots knew what the usual westbound/eastbound flight levels on UZ6 are, because they are worldwide the same.
And, as you correctly surmise, they filed an appropriate FL in the flight plan.
Originally Posted by Sdruvss
2. “[…] before communications were lost” – From 15:51, last contact, until 16:26, there was no contact attempt, when Brasilia begins trying to contact them.
Communications were lost.
Originally Posted by Sdruvss
3. 16:02 Brasilia looses Legacy transponder signal.
That's what I understand, but I haven't specifically checked the time.
Originally Posted by Sdruvss
4. Brasília assumed they were at right level FL 360,
Now, here begins a problem. Why would ATC assume that?
There has to be a two-sided understanding of how an aircraft is going to behave under lost communications.
According to the IFR of many countries in the world, including the U.S. (whose rules I know best), but also including Germany and the U.K., then when you are cleared by ATC for a particular FL or altitude, you remain at that cleared altitude until you receive and acknowledge an amended clearance.
Cleared altitudes by ATC always take priority over what is in the flight plan. I don't think I have ever flown my filed flight plan under IFR. ATC always says something different at some time, and then it's for them to direct the flight through further clearances (they may also say "proceed as filed" but that itself is a further clearance).
So, what are the Brazilian IFR under lost communications?
Originally Posted by Sdruvss
all pilots knows what authorized levels from Brasilia to Manaus are. They don’t need to be cleared and, if they want to fly another authorized level, they don’t need clearance because they are under radar surveillance.
*Yes they do* need to be cleared. Every minute of the time they are flying IFR they need to be cleared.
It occurs to me that you may not understand what a clearance is.
A clearance is a two-sided contract between ATC and pilot, in which ATC undertakes to keep a particular block of airspace free of other (IFR) traffic, and the pilot accepts this undertaking or rejects it. If heshe accepts, heshe undertakes to fly within that block of cleared airspace until it terminates, or until another clearance is received and accepted.
This is all pretty routine until one no longer has two-way communications. Then one needs conventions, understood by both sides, as to what the pilot is going to do, and the controller will then keep other traffic out of the way of the airspace that the pilot is anticipated to be using.
These conventions exist in most jurisdictions (including those with which I am familiar).
Originally Posted by Sdruvss
5. There was a turn shift meanwhile. New operator isn’t alerted by this issue, but is not a big issue for him, the pilots should be at correct level.
What is the "correct level" depends in this case on convention. Legacy was last cleared to FL 370. He was not flying his flight plan, but following ATC clearances. This should be on the flight strip that the new controller took over.
Originally Posted by Sdruvss
6. Pilots should check transponder before entering RVSM airspace. If fails they should tell ATC “RVSM NEGATIVE”. ATC would take care of them.
Exactly what here does a transponder check consist in?
7. Last Legacy/Brasília dialog upsets me. It should be (but it isn’t):....
Are you aware of how often pilot-controller communications fit the precise standards, and how often they do not?
I don't buy your suggestion of how the communications "should" have proceeded. There is too much there that is not ICAO-standard terminology.
Originally Posted by Sdruvss
It is expected that they should descend!!! They shouldn’t confirm that.
Well, now, that is the crucial point, isn't it. If you are a U.S., or British, or German pilot and you are flying under ATC clearances, you fly your last cleared level, unless ATC clears you to "proceed as filed", in which case you then follow your flight plan.
And if it is so simple as that the Legacy pilots failed to follow Brazilian procedures, why are four controllers being charged with manslaughter (including "voluntary manslaughter" in one case)?
PBL