The altitude was one of only two numbers spoken in the radio call from the center controller, but not one the pilot would want to miss if reception were poor in the low altitudes after departure: “Leaving 3,000 feet,” the controller said, “Turn left to heading 270; when able proceed direct Augusta.”
If you haven’t heard an ATC call like that one, eventually you will, because those are the type of instructions a flight receives from an air route traffic control center on initial call-up after departure from an airport not served by either radar approach/departure control or a control tower. (This airport’s tower is scheduled to close.)
The “altitude leaving” part is there because a controller can’t give you an IFR clearance until you are above the sector’s minimum vectoring altitude (unless you can climb in VFR conditions). That means you remain responsible for obstruction clearance until you reach that altitude.
You could be in radio contact with the distant ARTCC, before radar contact is made during the early stages of the departure—making it a good idea to find out quickly just how well radio calls can be transmitted and received in the area.
Contact with the center is made on a frequency specified in your IFR clearance, as discussed in the Instrument Flying Handbook : “When departing an airport without an operating control tower, the clearance includes instructions such as ‘Upon entering controlled airspace, contact Houston Center on 126.5.’ Pilots are responsible for terrain clearance until reaching the controller’s MVA. Simply hearing ‘Radar contact’ does not relieve a pilot of this responsibility.”
At what altitude did you enter controlled airspace? (When you did, it was likely Class E; said more than 90 percent of readers who responded to the poll question in the April 12 “IFR Fix: Controlled airspace, sort of.”)
On an IFR arrival at this type of airport, not long after you receive approach clearance, the controller will say, “Change to advisory frequency approved.” Do so promptly; if there’s one mile visibility and an aircraft can remain clear of clouds (beneath controlled airspace), someone may be flying in the pattern.
For blue-airport pilots, these maxims for maximizing mastery of magenta may take motivation. But as the FAA points out, the majority of airports with instrument approach procedures “do not lie in terminal airspace.” And that number isn’t getting smaller.