Cancel with care
IFR doesn’t abolish all airspace limitations
By Bruce Williams
One of the benefits of operating IFR is having ATC usher you past the velvet ropes that surround controlled airspace. But although an IFR clearance means you can usually ignore airspace alerts that pop up in your GPS or electronic flight bags, you still need to be aware of potential gotchas.
The most frequently misunderstood scenario is canceling IFR when landing at an airport with surface-based Class E airspace. After clearing an aircraft for an approach, ATC often reminds—or urges—pilots to cancel IFR as soon as possible, noting that others are awaiting their turn to land or depart. But that request doesn’t mean that you can always cancel as soon as you have the runway in sight.
Aeronautical Information Manual 5−1−15: “Canceling IFR Flight Plan” says that “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,” a stipulation that depends on both the weather and the type of airspace you’re operating in.
At an airport with Class E to the surface, FAR 91.155 limits VFR operations when the ceiling is less than 1,000 feet and/or the ground visibility is less than 3 statute miles. That rule explicitly says that “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” unless both those conditions are met. Of course, while operating VFR in Class E airspace, you must also always be able to remain at least 500 feet below, 1,000 feet above, and 2,000 feet horizontally from clouds.
In other words, if you are approaching an airport with surface-based Class E when the latest METAR or one-minute weather report indicates less than basic VFR, you can’t cancel IFR until you are on the ground, even if the runway appears as soon as you dip below the clouds. Some pilots argue that, regardless of the weather announced by an AWOS, they can cancel IFR in Class E airspace if their flight visibility allows them to continue under VFR. But the Baginski Letter (2012) from the lawyers at the FAA contradicts this notion. That legal interpretation states: “The pilot’s report of flight conditions cannot supersede the AWOS…. The determination of the visibility by a pilot is not an official weather report or official ground visibility report.”
Waiting until you’re on the ground to cancel is easier now that the chart supplement lists phone numbers to contact ATC directly at most airports with instrument approaches. To have that information ready, during preflight planning I transfer the numbers to the airport diagram, always in view as I taxi to the runway for takeoff. That chart also appears automatically as I roll out after landing. If an airport diagram isn’t published, I add the ATC phone number to charts for departure procedures and approaches.
The stipulations in FAR 91.155 are there to protect both IFR and VFR aircraft when marginal weather limits the ability to see-and-avoid traffic. But Class E to the surface isn’t established at every airport with RNAV (GPS) approaches. Today, most non-ILS runways capable of supporting LPV approaches offer decision altitudes of about 250 feet with visibilities as low as 3/4 sm. But if the airport doesn’t meet FAA criteria to designate Class E to the surface (see JO 7400.2, Procedures for Handling Airspace Matters, Chapter 18), the rules for operating in Class G begin at 700 feet agl. That means during the day you could emerge from the murk on short final at a nontowered airport to discover an aircraft with no radio legally flying the pattern while remaining clear of clouds and with only 1 sm visibility. So, cancel IFR with care, and proceed with caution. 
Bruce Williams is a CFI. Find him at youtube.com/@BruceAirFlying and bruceair.wordpress.com
