Out-of-Control Departures

How to execute an IFR clearance that transitions you from Class G to Class E airspace-safely.

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A reader of IFR Refresher recently inquired about the ATC/Pilot relationship for departures from airports in Class G (uncontrolled) airspace—specifically executing these clearances, and ATC’s expectations of how that aircraft will maneuver. Hailing from an en-route center where mountainous terrain dominates and TRACONS are scarce, I frequently encounter situations where aircraft request departure off one of our numerous non-towered airports, most of which are Class E only upon reaching the typical 700 or 1200-foot AGL mark.

If the transition from Class G to Class E airspace is a bit muddy for the pilot, rest assured, Class G airspace operations are a bit of a mystery for ATC as well—for the precise reason that it is uncontrolled. ATC typically operates on the premise of knowing where an aircraft will be at any given time; however, departures from non-towered airports without Class E surface areas are a bit undefined, with pilots and controllers alike often operating under a set of expectations rather than hard and fast rules.

Altitude Separation

In the center environment, there are often large swaths of landscape where our radar coverage does not reach to the ground, and is often still limited or non-existent at the floor of Class E. Due to this, ATC will typically maximize your safety with altitude separation. We will give an initial altitude that meets our Minimum IFR Altitude (MIA) or Minimum En Route Altitude (MEA) requirements, and also stops you below any overflight traffic in the vicinity. Sometimes, though, that is not enough to avoid what we might see as excessive delay, and we may take advantage of our rules allowing us to issue headings to uncontrolled airport departures.

Let’s draw up a mental scenario that differs from the oft-used “as filed” clearances many pilots receive out in the boonies. Assume there is traffic interfering somewhat with your departure this day, and your departure airport is surrounded by significant, though not prohibitive, terrain. It is an uncontrolled airport with Class E airspace beginning 700 feet AGL.

You have, for better or worse, filed the now-commonplace direct destination flight plan, requesting an altitude well above surrounding OROCAs. Weather conditions are barely IMC, with no icing or convective activity around to preclude a flight. Due to the terrain, a textual obstacle departure procedure (ODP) is present which you have reviewed and would like to execute.

Your departure airport has an FSS RCO, and after your usual pre-flight routine, you call for your clearance requesting the ODP. After a minute on hold, FSS relays the following clearance from Center:

“N12345, cleared from ABC airport to XYZ airport. When entering controlled airspace, fly heading 180. Climb and maintain 8000. Contact Anywhere Center 123.5 on departure, squawk 3456.”

You read back the clearance correctly and finish up with the FSS. Now what? You figured you were going to get “as filed” and just use your textual ODP, but no dice. When do you turn to that new heading? What does ATC expect of you? What happens after the 180-degree heading?

First, as the PIC, you must evaluate whether this ATC-created departure procedure is safe. If this heading is out of your comfort zone, be it an unfamiliar airport, personal minimums, or any significant doubt you have that this ATC instruction puts you in harm’s way, call back and get an amended clearance. ATC won’t try to fly you into terrain, but we don’t know your aircraft’s performance as intimately as you do.

If the textual ODP is more confidence-inspiring, call back and explicitly ask for it. You may be delayed for a few minutes while the sector controller works out a revised plan that takes into account your needs, but better that than launching into a plan you didn’t create and are not sure about.

Class G airspace.

ATC has no legal authority to vector your aircraft while in Class G airspace unless a pilot requests it, and only then as an additional service (meaning it takes a legally-lower priority than, say, vectoring aircraft for sequencing in Class E airspace). FAR 91.123(b) makes an interesting statement that has thought-provoking consequences for uncontrolled airspace:

(b) Except in an emergency, no person may operate an aircraft contrary to an ATC instruction in an area in which air traffic control is exercised.

The contra positive is that in areas where ATC is not exercised (i.e., Class G airspace), a person may operate their aircraft contrary to an ATC instruction. Whether or not this is a safe course of action is very situational and debatable.

Combine the above FAR with this excerpt from FAA JO 7400.9X, Page A-1, Subpart A, 1000.(f):

(f) Airspace not assigned in Subpart A, B, C, D, E, or H of this order is uncontrolled airspace and is designated as Class G airspace. There is no airspace within the United States designated as Class F.

Given the above statements, ATC ultimately carries no authority over your aircraft in uncontrolled airspace.

For the sake of this discussion, let’s presume you are willing to forego your pre-planned textual ODP and follow the given clearance verbatim. After you lift off, when do you turn on course?

The Rest Of The Story

Seeing that the clearance itself explicitly stated “when entering controlled airspace,” ATC is complying with their own regulations which preclude us from issuing departure clearance items that might be construed to apply in uncontrolled airspace. Reference JO 7110.65 4-3-2.c.1.(c):

(c) At all other airports-Do not specify direction of takeoff/turn after takeoff. If necessary to specify an initial heading/azimuth to be flown after takeoff, issue the initial heading/azimuth so as to apply only within controlled airspace.

So the easy answer is turn to the assigned heading when you enter Class E airspace. Nothing says you can’t do it beforehand, but there’s no requirement. You need to have some freedom to maneuver your plane as necessary for safety prior to entering our world. The short version of this: ATC can neither prohibit nor explicitly assign a turn on departure until your aircraft enters Class E airspace. In fact, if you depart an airport with a Class E surface area and a controller gives you a departure heading, they would need to inquire whether the clearance they gave you allows compliance with terrain and obstruction clearance requirements.

This is an option, though not required, for Class G departures. Frankly, don’t expect to be asked. Given that most Class E areas around airports with instrument approaches are 700′ AGL, it’s all but certain you are entering controlled airspace below the MIA or MEA, especially in FAA designated mountainous terrain. Always double-check your departure profile before you taxi out for take-off.

When Is It A Vector?

The reader also inquired about whether the departure heading given is a vector. The Pilot/Controller Glossary defines a vector as: “A heading issued to an aircraft to provide navigational guidance by radar.”

While the first few minutes after departure may be out of radar coverage, the intent here is for ATC to acquire you on radar to provide additional navigation guidance to your destination as necessary. Unlike our TRACON brethren, center controllers can’t issue a new heading below an MIA (except in the rarest of circumstances), so the departure heading might be our only chance to initially get you reasonably on course.

What happens after you are established on the final heading? ATC will clear you on course when appropriate, so absent any communication failure (and associated FAR-defined procedures), just fly the heading as assigned, as ATC has a plan in mind on how to get you on course after you are above terrain and clear of traffic.

To conclude, ATC can use departure headings off non-towered airports legally, and they often will for separation, safety, and efficiency of the operation. If you ever receive a clearance that you question, for whatever reason, get a clarification from the controller.

If you feel an assigned heading will put you in harm’s way, and you wish to use a textual ODP, query the controller for that option and get a revised clearance. Again, no guarantees against it costing you a few minutes on the ground, but the safety of your flight is a joint effort. Fly Safe.

The author is an ATC specialist who regularly handles clearances that transition pilots from uncontrolled airspace.

This article originally appeared in the May 2014 issue of IFR Refresher magazine.

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