Cleared for an approach, then given a different altitude assignment

"Peter R." wrote in message
...

Which I did. Having heard "Aircraft XXX, cancel previous approach
clearance, maintain current heading" or some such instruction to other
aircraft many times now, I mistakenly assumed that the controller was
required to cancel the approach clearance first. That history is what
prompted my confusion.


While "cancel previous approach clearance" is probably a good idea for
clarity, it is not required.

Steven P. McNicoll wrote:
While "cancel previous approach clearance" is probably a good idea for
clarity, it is not required.

What instructions/clearances can ATC issue to a flight after issuing
an approach clearance which wouldn't automatically cancel the approach
clearance?

Some instructions obviously don't: "Contact tower 123.45", for
example. I would think that any instruction which included an
altitude restriction, or a heading/route to fly, would. Any other
cases which I haven't thought of?

"Roy Smith" wrote in message
...
Steven P. McNicoll wrote:
While "cancel previous approach clearance" is probably a good idea for
clarity, it is not required.

What instructions/clearances can ATC issue to a flight after issuing
an approach clearance which wouldn't automatically cancel the approach
clearance?

Some instructions obviously don't: "Contact tower 123.45", for
example. I would think that any instruction which included an
altitude restriction, or a heading/route to fly, would. Any other
cases which I haven't thought of?


Speed restrictions. An altitude restriction can also be issued that
wouldn't prevent the completion of the approach. For example, let's say an
aircraft was issued clearance for the approach under discussion here with
"cross PAGER at or above 3000, cleared RNAV RWY 15 approach." Then a VFR
aircraft east of PAGER requests an IFR popup, so the aircraft on the
approach is instructed to cross PAGER at or above 4000. 3000 feet is now
available for the popup clearance, and the arrival aircraft can still
complete it's approach.

Steven P. McNicoll wrote:

"Roy Smith" wrote in message
...
Steven P. McNicoll wrote:
While "cancel previous approach clearance" is probably a good idea for
clarity, it is not required.

What instructions/clearances can ATC issue to a flight after issuing
an approach clearance which wouldn't automatically cancel the approach
clearance?

Some instructions obviously don't: "Contact tower 123.45", for
example. I would think that any instruction which included an
altitude restriction, or a heading/route to fly, would. Any other
cases which I haven't thought of?


Speed restrictions. An altitude restriction can also be issued that
wouldn't prevent the completion of the approach. For example, let's say an
aircraft was issued clearance for the approach under discussion here with
"cross PAGER at or above 3000, cleared RNAV RWY 15 approach." Then a VFR
aircraft east of PAGER requests an IFR popup, so the aircraft on the
approach is instructed to cross PAGER at or above 4000. 3000 feet is now
available for the popup clearance, and the arrival aircraft can still
complete it's approach.

But, how do I tell, just from what the controller says, if it will
prevent the completion of the approach or not? It seems reasonable in
the scenario under discussion, that "cross PAGAR at or above 4000"
should not be a problem. But what about "Cross ELESE at or above
4000", or "Cross NADSY at or above 4000", or "Cross PAGER at or above
15,000"? Do any of those imply "cancel previous approach clearance?"

"Roy Smith" wrote in message
...
Steven P. McNicoll wrote:

"Roy Smith" wrote in message
...
Steven P. McNicoll wrote:
While "cancel previous approach clearance" is probably a good idea for
clarity, it is not required.

What instructions/clearances can ATC issue to a flight after issuing
an approach clearance which wouldn't automatically cancel the approach
clearance?

Some instructions obviously don't: "Contact tower 123.45", for
example. I would think that any instruction which included an
altitude restriction, or a heading/route to fly, would. Any other
cases which I haven't thought of?


Speed restrictions. An altitude restriction can also be issued that
wouldn't prevent the completion of the approach. For example, let's say
an
aircraft was issued clearance for the approach under discussion here with
"cross PAGER at or above 3000, cleared RNAV RWY 15 approach." Then a VFR
aircraft east of PAGER requests an IFR popup, so the aircraft on the
approach is instructed to cross PAGER at or above 4000. 3000 feet is now
available for the popup clearance, and the arrival aircraft can still
complete it's approach.

But, how do I tell, just from what the controller says, if it will
prevent the completion of the approach or not? It seems reasonable in
the scenario under discussion, that "cross PAGAR at or above 4000"
should not be a problem. But what about "Cross ELESE at or above
4000", or "Cross NADSY at or above 4000", or "Cross PAGER at or above
15,000"? Do any of those imply "cancel previous approach clearance?"


You use your knowledge and experience as a pilot.

In article . net,
Steven P. McNicoll wrote:

"Roy Smith" wrote in message
...
Steven P. McNicoll wrote:

"Roy Smith" wrote in message
...
Steven P. McNicoll wrote:
While "cancel previous approach clearance" is probably a good idea for
clarity, it is not required.

What instructions/clearances can ATC issue to a flight after issuing
an approach clearance which wouldn't automatically cancel the approach
clearance?

Some instructions obviously don't: "Contact tower 123.45", for
example. I would think that any instruction which included an
altitude restriction, or a heading/route to fly, would. Any other
cases which I haven't thought of?


Speed restrictions. An altitude restriction can also be issued that
wouldn't prevent the completion of the approach. For example, let's say
an
aircraft was issued clearance for the approach under discussion here with
"cross PAGER at or above 3000, cleared RNAV RWY 15 approach." Then a VFR
aircraft east of PAGER requests an IFR popup, so the aircraft on the
approach is instructed to cross PAGER at or above 4000. 3000 feet is now
available for the popup clearance, and the arrival aircraft can still
complete it's approach.

But, how do I tell, just from what the controller says, if it will
prevent the completion of the approach or not? It seems reasonable in
the scenario under discussion, that "cross PAGAR at or above 4000"
should not be a problem. But what about "Cross ELESE at or above
4000", or "Cross NADSY at or above 4000", or "Cross PAGER at or above
15,000"? Do any of those imply "cancel previous approach clearance?"


You use your knowledge and experience as a pilot.




My knowledge and experience as a pilot can tell me whether *I* think I
can safely complete the approach or not. They cannot tell me whether
my clearance to do so has been revoked.

"Roy Smith" wrote in message
...

My knowledge and experience as a pilot can tell me whether *I* think I
can safely complete the approach or not. They cannot tell me whether
my clearance to do so has been revoked.


This isn't that hard. If you can comply with the restriction and still
complete the approach your clearance hasn't been revoked. That should be
obvious to you.