May 26, 2013 3 Comments
The other day at BeechTalk, a forum for owners and operators of Beechcraft (Bonanzas, Barons, and the like) a long, surprisingly contentious, thread started with a simple question: When can I cancel IFR?
The pilot who posed the question described a common situation. An IFR aircraft is approaching an airport that does not have an operating control tower. Other airplanes are en route to the same airport or are waiting on the ground for a release to depart. When the current weather is IMC, ATC can allow only one aircraft at any time to operate under IFR (or special VFR) within the (usually) Class E airspace surrounding the airport. Until an approaching aircraft cancels IFR, either in the air or after landing, no other aircraft can fly an approach or depart under an IFR clearance.
Bowerman Airport (KHQM) on the southwest Washington coast is an example of such an airport. It does not have a control tower, and, as indicated by the dashed magenta lines, it is enclosed by surface-based Class E airspace (as opposed to Class E airspace that begins at 700 ft. AGL). The surfaced-based Class E airspace extends west and east of the airport to protect the final approach paths for the instrument approaches that serve KHQM.
Now, suppose you are approaching KHQM on an IFR clearance. You fly one of published procedures and at some point during the descent, you break into the clear below the clouds. When ATC cleared you for the approach, the controller directed you to report canceling your IFR flight plan either on an ATC frequency or through flight service (in this case, Seattle Radio). You know (or suspect) that other aircraft are waiting to follow you or to depart KHQM, so you are eager to cancel IFR as soon as possible to free up the airspace. It’s often much easier and faster to cancel IFR directly with the controller you’ve been talking to than to use a ground communication outlet or to relay a cancelation through flight service via radio or a cell phone call.
But when can you legally cancel IFR? The basic answer is in AIM 5−1−15. Canceling IFR Flight Plan, viz.:
b. An IFR flight plan may be canceled at any time the flight is operating in VFR conditions outside Class A airspace…
The key to that statement is “operating in VFR conditions.” And that stipulation depends on both the weather and the type of airspace you’re operating in.
If the ASOS at KHQM, which is surrounded by surface-based Class E airspace, is reporting a ceiling less than 1,000 ft. and/or visibility less than 3 miles, you can’t cancel IFR until you are on the ground. That’s because 14 CFR § 91.155 Basic VFR weather minimums stipulates:
(c) Except as provided in § 91.157, no person may operate an aircraft beneath the ceiling under VFR within the lateral boundaries of controlled airspace designated to the surface for an airport when the ceiling is less than 1,000 feet.
(d) Except as provided in § 91.157 of this part, no person may take off or land an aircraft, or enter the traffic pattern of an airport, under VFR, within the lateral boundaries of the surface areas of Class B, Class C, Class D, or Class E airspace designated for an airport—
(1) Unless ground visibility at that airport is at least 3 statute miles; or
(2) If ground visibility is not reported at that airport, unless flight visibility during landing or takeoff, or while operating in the traffic pattern is at least 3 statute miles.
In other words, if the official weather report for the airport indicates that the current weather is less than the minimum for basic VFR in Class E airspace, you can’t legally operate under VFR below the ceiling. In particular, the regulation specifically notes that you can’t take off or land at an airport inside surface-based Class E airspace under VFR when the ceiling is less than 1,000 ft. Flying clear of clouds and having the airport in sight is not the same as “operating in VFR conditions.”
Some pilots argue that, regardless of the weather reported by an AWOS or ASOS, they can cancel IFR or enter the Class E airspace under VFR if their flight visibility allows them to continue under VFR. But the Baginski Letter (2012) from FAA contradicts this notion:
“The pilot’s report of flight conditions cannot supersede the AWOS in this scenario. The determination of the visibility by a pilot is not an official weather report or official ground visibility report. See 14 CFR 91.157(d).”
You have more flexibility if the weather is better. If the ASOS reports a ceiling of, say, 1,300 ft. and more than 3 miles visibility (in other words, KHQM is officially, if only marginally, VFR), you could legally cancel IFR when you reached 800 ft. AGL. (500 ft. below the cloud bases). Of course, throughout the remainder of your approach and landing, you must observe the cloud clearance and visibility requirements for Class E airspace as stipulated in § 91.155:
- 500 feet below
- 1,000 feet above
- 2,000 feet horizontal
In marginal VFR conditions, a few wispy clouds often lurk around the airport. To meet the letter of the law, you must make sure that you can clear all of them by at least 2,000 ft. horizontally and 500 ft. vertically.
It’s important to keep this discussion in perspective. When the weather is marginal and you’re flying an approach, canceling as soon as you break out (even if were legal given current conditions) saves only a couple of minutes versus canceling after landing and clearing the runway. Flying another lap around a holding pattern, slowing down, accepting a delay vector, or idling at the hold-short line at the runway for a few minutes while you wait for a release is occasionally part of flying IFR.
Canceling on the ground can be more cumbersome than speaking directly to the controller who cleared you. But even if the airport doesn’t have good radio coverage on the ground and you have to call flight service on the phone, it’s usually not a big deal. We all have cell phones. Many of us can connect our phones to our headsets or audio panels via Blutetooth. (If you have to call FSS, call the IFR clearance number [888-766-8267] or the main FSS number [800-992-7433] and say “Briefer” as soon as you’re connected so that you can skip the prompts and give the specialist your N-number, location, and intention to cancel IFR.) You can also relay your IFR cancelation through another aircraft that is high enough to communicate directly with ATC.
We all like to help ATC and our fellow pilots by clearing the airspace for the next airplane on approach or to assist the pilot waiting for a release to depart. But trying to sort out the legality of canceling in the air during a critical phase of flight just isn’t worth the risk of distraction or violating the FARs, especially when the delay is so short. If you don’t break out in obvious VMC with plenty of time to juggle canceling, monitoring the CTAF, and keeping an eye out for traffic, land the plane and cancel when you’re safely clear of the runway.
From AOPA Air Safety Institute
Airspace for Everyone (PDF)
Airspace Flash Cards (PDF)
AOPA (members only): Avoiding the Cancellation Trap
Instrument Flying Handbook: Approach to Airport Without an Operating Control Tower (p. 10-13)
Instrument Procedures Handbook: Airports without an Air Traffic Control Tower (p. 5-14)