Cleared for an approach, then given a different altitude assignment

Today I was practicing a GPS approach and had been cleared for the
approach with the normal, "Cessna XXX, cross ELESE at 3,000, cleared
GPS 15 approach."

A minute or so later the controllers switched positions and another one
took over that slice of airspace.

The new one came on frequency and called my aircraft with, "Cessna XXX,
traffic one o'clock, 2,500 and two miles, southbound" (the traffic was
was crossing my path right to left underneath me).

I replied, "Negative traffic" to which he responded, "Maintain 3,000."

Being momentarily confused, I called to clarify the altitude
restriction. The controller responded rather tersely that he wanted me
at 3,000 for traffic avoidance.

Should the controller have canceled my approach clearance first, then
issued the altitude restriction?

I was initially confused because I still had 5 miles at 3,000 feet
before stepping down to the next altitude as part of the approach, and
it seemed that his first call was simply reinforcing the altitude
minimums on the approach (that is, until he responded in a terse manner
that he wanted to keep me there without ever rescinding my approach
clearance).

--
Peter

"Peter R." wrote:

Today I was practicing a GPS approach and had been cleared for the
approach with the normal, "Cessna XXX, cross ELESE at 3,000, cleared
GPS 15 approach."

A minute or so later the controllers switched positions and another one
took over that slice of airspace.

The new one came on frequency and called my aircraft with, "Cessna XXX,
traffic one o'clock, 2,500 and two miles, southbound" (the traffic was
was crossing my path right to left underneath me).

I replied, "Negative traffic" to which he responded, "Maintain 3,000."

Being momentarily confused, I called to clarify the altitude
restriction. The controller responded rather tersely that he wanted me
at 3,000 for traffic avoidance.

Should the controller have canceled my approach clearance first, then
issued the altitude restriction?

I was initially confused because I still had 5 miles at 3,000 feet
before stepping down to the next altitude as part of the approach, and
it seemed that his first call was simply reinforcing the altitude
minimums on the approach (that is, until he responded in a terse manner
that he wanted to keep me there without ever rescinding my approach
clearance).

--
Peter

When they say "Maintain XXXXX altitude" after having received an approach
clearance you have to maintain the altitude. Obviously, you can't continue
the approach and maintain 3,000. So, you comply with the latest clearance.
No doubt that it is a squeeze play, but the controller apparently had a good
reason. Once he deletes the restriction and, if at the point you are too
high to continue the approach, then you so advise him.

This scenerio will (or should) only happen in a radar environment.

) wrote:

When they say "Maintain XXXXX altitude" after having received an approach
clearance you have to maintain the altitude. Obviously, you can't continue
the approach and maintain 3,000. So, you comply with the latest clearance.

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.

No doubt that it is a squeeze play, but the controller apparently had a good
reason. Once he deletes the restriction and, if at the point you are too
high to continue the approach, then you so advise him.

This scenerio will (or should) only happen in a radar environment.

Thank you for your concise explanation.

--
Peter

"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.

wrote in message ...

When they say "Maintain XXXXX altitude" after having received an approach
clearance you have to maintain the altitude. Obviously, you can't continue
the approach and maintain 3,000. So, you comply with the latest
clearance.
No doubt that it is a squeeze play, but the controller apparently had a
good
reason.


What good reason might there be?



Once he deletes the restriction and, if at the point you are too
high to continue the approach, then you so advise him.


The restriction was superfluous for the next five miles, as he was that far
outside of ELESE and 3000 was the minimum altitude until that fix.



This scenerio will (or should) only happen in a radar environment.


This scenario can happen only in a radar environment because IFR/VFR
separation is not provided in a nonradar environment.

"Steven P. McNicoll" wrote:


This scenerio will (or should) only happen in a radar environment.


This scenario can happen only in a radar environment because IFR/VFR
separation is not provided in a nonradar environment.

I have no experience with that. I related my experience that this happened
several times over the years flying into LAX where practice approaches and VFR
aircraft were not involved.

If you are operating in VMC and practicing approaches you are operating
on IFR and VFR rules. You will have VFR conflicts and a big bang in the
sky is bad, follow the controller.
If you were in IMC this would have been a different story.
Michelle

Peter R. wrote:

Today I was practicing a GPS approach and had been cleared for the
approach with the normal, "Cessna XXX, cross ELESE at 3,000, cleared
GPS 15 approach."

A minute or so later the controllers switched positions and another one
took over that slice of airspace.

The new one came on frequency and called my aircraft with, "Cessna XXX,
traffic one o'clock, 2,500 and two miles, southbound" (the traffic was
was crossing my path right to left underneath me).

I replied, "Negative traffic" to which he responded, "Maintain 3,000."

Being momentarily confused, I called to clarify the altitude
restriction. The controller responded rather tersely that he wanted me
at 3,000 for traffic avoidance.

Should the controller have canceled my approach clearance first, then
issued the altitude restriction?

I was initially confused because I still had 5 miles at 3,000 feet
before stepping down to the next altitude as part of the approach, and
it seemed that his first call was simply reinforcing the altitude
minimums on the approach (that is, until he responded in a terse manner
that he wanted to keep me there without ever rescinding my approach
clearance).




--

Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P

"Elisabeth" a Maule M-7-235B (no two are alike)

Volunteer Pilot, Angel Flight Mid-Atlantic

Volunteer Builder, Habitat for Humanity

Michelle P wrote:

If you are operating in VMC and practicing approaches you are operating
on IFR and VFR rules. You will have VFR conflicts and a big bang in the
sky is bad, follow the controller.
If you were in IMC this would have been a different story.


Why do you think IMC would change it? I've had this very thing happen many
times over the years going into LAX in IMC when they misjudged lateral
separation and had to apply vertical separation on a tactical basis after my
approach clearance was issued. This type of thing occurred a fair distance
out, where my altitude on the extended approach profile was well above the
MVA.