I see that both you and I are bieased - I know that I am seeing things in
this light because I hate ATC's "policeman" attitude, irrespective of the
cisrcumstances... I have been a victim of similar attitude, fortunatelty I
am here, angry, but allive and kicking...

So let's get the facts straight -

The ATC instructed the russians to descend as part of the approachg for
landing procedure. At that time, he claims that he did not noticed the
conflict situation because the radar warning system was not operational -
this is bull, as that system is there as an aural warning, and an alert ATC
should have noticed that situation developping himself, not waiting for the
radar to ring a bell to him about it...

The desent instruction coinsided with the TCAS warning and the subsequent
RA. Although the ATC mentiones that there is a potential conflict in his
descent instruction, he fails to advise that the conflict is and will remain
on same FL, he never issues instruction to the DHL traffic although all are
on the same FRQ - that misfortunately makes the russion pilot stay put as he
has to figure out what to do - to to follow the RA (climb) or to follow the
ATC (descent)

The ATC has a 5 sec update (not 12) and the Mode C data error is +/- 100 ft,
sufficiently accurate. At the time the ATC issues his second "expedite"
instruction, the ATC fails to notice that the DHL traffic already has
desended halfway trough - still, no radio contact with the DHL traffic, no
instructions to maintain assigned FL, no query "hey, where are you
going..." - although that information is available cleraly on his radar for
almost 45 sec and the picture is there to show that the DHL is descending
from FL360 into his "other" trafic that he just instructed to descend to
FL350!

Under the pressure, the russion pilot finally decides to follow the ATC
instruction and descend. 30 sec after that decision they collide - now, I
want to know what the stupid ATC was doing for that time - 30 seconds - was
not he seeing on his radar screen ( 6 x 5 sec updates) that the he just
forced one aicraft to descent into another one that was descending on it's
own. Surely he could have just open his mouth and call the DHL traffic and
stop him. Or he could have just open his mouth and changed the clearence to
the russian guy. Or just open his mouth and say something, anything that
would give a clue to the both pilots that they are heading on a collision
course.
You see, the ATC was the only one that had a whole clear picture in front of
him and his job was to keep the things separated and not colliding with each
other... He failed... He should not have...

That's the way I see it.


"James Robinson" wrote in message
...
angry wrote:

Absurd is to see people like you believe in the newspaper stories.

And just where are you getting your information, considering that no
official accident report has been released? I have enough knowledge to
know that information from the media is suspect, particularly their
opinions about what happened and who is at fault.

The ATC did made a mistake by choosing wrong altitude to advice as so to
avoid the collision.

If the Russian plane had followed the ATC instruction, and the DHL plane
had continued without descending, there would have been no collision.
The ATC instruction was incorrect in hindsight, but given the
conflicting information from the collision warning system, the Russian
pilot should have ignored the ATC instruction. Had the pilot done so,
there wouldn't have been a collision.

You are saying that he was unaware of the other aicraft - that's
absurd - he was the only one on duty and he had ALL the aicraft in
his vicinity, their course, and their altitude displayed for him
to make a decision.

He was late in asking the Russian plane to change altitude. That was
part of the problem. However, the collision warning systems are
installed on aircraft for just that eventuality, and the Russian pilot
did not use it correctly.

As far as the altitude display available to the ATC, it is not
necessarily that accurate, since it is only updated on the radar screen
about once every 12 seconds, and relies on the altimeters in each of the
aircraft for data, which can be out of calibration by a couple of
hundred feet. That is why flight levels are at least 500 feet apart, and
automatic TCAS warnings are made earlier at high altitudes.

Beyond that, yes the aircraft were flying at essentially the same
altitude, since they had entered Swiss airspace at the designated
altitudes, which were the same. The controller eventually made the
choice to ask one to descend to avoid the collision. There was nothing
wrong with that instruction by itself, other than it was a bit late.

He made the wrong one.

The ATC likely made the right one, based on the information he had at
hand. However, neither of us can be sure of that, since the official
report has yet to be released.

He further in a tone not allowing any questioning instructed
the russian pilot to obey him and ignore the onboard TCAS
instructions.

Nonsense. Pilots are routinely told to ignore ATC instructions if
following them would endanger their aircraft. In fact, the European
traffic control rules specifically state that pilots are to obey TCAS
advisories over any conflicting ATC instructions. The pilot did not
follow that rule. Pilots have absolutely no obligation to follow ATC
instructions if safety is involved.

The poor pilot did (contrary to what he should have done) and a
lot of people died as a result.

So you are now saying the pilot was primarily at fault?

That's because of the ATC's mistake and attitude.

No. In the first place, the ATC's mistake was in not asking the aircraft
to change altitude sooner. He did not make a mistake in asking the
Russian aircraft to descend, based on the information available to him,
nor was the urgency of his instruction an error, since he was trying to
avoid an imminent collision.

In saying the ATC instruction was a mistake is a gross
oversimplification of a complex set of interactions. The ATC was
certainly involved in the events that led up to the collision, but there
were many other events, such as inadequate support from the ATC's
employer, equipment that was out of service, and questionable training
of pilots on the part of the Russian airline. The ATC was likely not
even primarily to blame. This is where the official accident report will
sort out many of the conflicting events.

Did you get it this time?

I seem to have a much better understanding of the situation than you do.

And further to your earlier suggestion that the ATC instructed the
Russian plane to descend even though he knew that it was contrary to the
advisory from the aircraft's own collision avoidance system, here is a
link to the transcript of the flight data and voice recorders prepared
by the German investigators:

http://www.bfu-web.de/olderinfo/aktuinfo-e28.htm

As you can see, the controller would only have known about the DHL
aircraft descending after the pilot announced it over the radio. This
was 30 seconds after asking the Russian aircraft to descend, and less
than 13 seconds prior to the collision.