"Peter R." wrote in message
...
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

What class of airspace were you in?

If Class B or C the answer is probably "Yes, he should have cancelled
approach clearance to be 'book correct." But maybe he decided ensuring
separation was a higher priority task. Or has the view that if he told you
to maintain 3000 it should be obvious to you you're no longer authorized
descend on the approach (not saying it is; saying he thinks it should be
-/ ) .

If Class D or E if either aircraft was VFR, he had no business issuing the
restriction in the first place. Traffic? Yes, altitude restrictions? No

Or there is also the possibility there was a genuine "deal" where standard
separation of 1000ft or 3NM was already lost, and the 500ft/2NM was better
than nothing. That might also explain the controller's "Do something now!
Worry about being "book correct" later" instruction as well as what seemed
to you a terse attitude.