"Robert M. Gary" wrote in message
oups.com...
On Mar 27, 11:50 am, "Bob Gardner" wrote:
I used to handle that by saying to the new controller "BuzzBomb 234X,
7000
feet, on a vector." A previous controller can't issue an instruction that
has any effect in a subsequent sector, to the best of my knowledge,

But that clearly isn't the case. My original clearance was to go out
to a VOR, then follow one airway, turn 90 degrees go up another airway
etc. A previous controller changed my clearance to be direct (a much
different route), which had great affect on not only the subsequent
controller but about 3 controllers after that as well.

-Robert

Something to keep in mind is an IFR clearance doesn't really have much of
anything to do with separation.

It's simply the route and altitude ATC has assigned to get the aircraft from
A to B. It's in the computer and there's enough of it on each sector's
strip so that controller knows where the aircraft is coming from and where
it needs to end up.

There may be (probably are) a dozen or more built-in conflicts with other
aircraft on the same or different routes and altitudes. Controllers
deconflict and ensure separation in real time. So long as the controller
gets the aircraft to the required fix and altitude at the edge of his
airspace without any conflicts he's done his job.

Another thing worth knowing is some controllers will "bet on the come" with
semi-routine route changes. They'll issue them to the aircraft *then*
effect the required coordination. Sometimes this doesn't work out exactly
right and they have to re-re-route or sometimes the ball gets dropped
completely :-/ As long as it doesn't create a "deal" there isn't usually
much of a fuss.

So all it really takes to change a route is to issue it. As long as each
subsequent controller accepts the aircraft nobody much cares what happens
three sectors down the road.

The new route should be entered into the ARTCC computer so the necessary new
info gets forwarded to each controller as the aircraft progresses along the
new route. That new route may (probably will) have its own set of a dozen
or more built-in conflicts but again, nobody really cares. Those conflicts
will be fixed when they need fixing.

Ideally, the first controller approving any route change will enter it into
the computer. But sometimes that doesn't happen. Maybe the first
controller is too busy, too far from the ARTCC computer keyboard, or some
other reason. In that case the first controller will call the next sector
on a landline to coordinate the change prior to handoff. If the next sector
accepts the handoff with the new route then the first controller has done
all he needs to do. Now that second controller is obligated to either enter
the change into the ARTCC computer or verbally coordinate with the next
sector before *he* does a handoff. It goes on that way until *somebody*
puts it in the computer or the aircraft reaches its destination.

As for issuing instructions that affect other sectors that's concerned with
real-time situations when a controller has an aircraft *in another
controller's airspace.* In these situations the controller either has to
coordinate what he wants to do (many LOAs allow limited control without
additional coordination after a handoff but before the aircraft crosses the
actual sector boundary), wait until the aircraft crosses into his own
airspace, or handoff the aircraft to the controller who's airspace the
aircraft is actually in (very common when an aircraft pops up on the wrong
freq).