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Circling approaches

Don’t go down the drain on an approach

By Bruce Williams

IFR pilots train for an event that they rarely perform in normal operations—circling approaches.

Charts

  • Charts
    Hermiston Municipal Airport in Oregon, has only circle-to-land (CTL) approaches.
  • Charts
    At an airport like Astoria Regional Airport (AST), circling might be preferable to a long approach over open water.
  • Charts
    While circling, you must fly the established traffic pattern even if a shortcut is tempting.
  • Charts
    A circling MDA is often well below the normal traffic pattern altitude.

Circling to land is typically reserved for practical tests and instrument proficiency checks, unless you operate from an airport like Hermiston, Oregon (HRI), where both approaches have only circle-to-land minimums. Even airline pilots don’t routinely circle to land—and then usually only the captain is allowed to do the flying and the weather must be at least basic VMC.

Circle-to-land minimums are established for two common reasons. If the angle between the final approach course and the extended runway centerline exceeds 30 degrees, or if the descent gradient is greater than 400 feet per nautical mile from the final approach fix to the threshold, only circle-to-land minimums are published. You can probably win a beer bet, however, if you ask an IFR pilot (or a CFII) for the third, more obscure, criterion. As the Instrument Procedures Handbook (page 4–11) explains, circle-to-land minimums are also the only option when “a runway is not clearly defined on the airfield,” perhaps because the markings have faded.

We easily recognize circle-to-land-only approaches because they have a letter from A to H in the procedure title, such as the “VOR-A” and “RNAV (GPS)-B” approaches at Hermiston. The title of an approach with at least one line of straight-in minimums includes a runway number; for example, the “RNAV (GPS) RWY 26” at Astoria, Oregon (AST).

Suppose you choose to fly a circling approach. For example, with winds out of the east at Astoria, you might prefer to fly the RNAV approach to Runway 26 and, weather permitting, circle to land on Runway 8 rather than wander far offshore at low altitude to set up for the RNAV (GPS) RWY 8. Leave whale-watching tours to the folks with the boats.

Choosing to circle, however, should still give you pause. Assuming a daytime approach (circling to land at night in anything less than good VMC is not a reasonable option for most GA pilots), how long has it been since you flew a circling approach below low clouds and with limited visibility? Can you confidently maneuver, probably with a tailwind, close to the runway and well below the standard 1,000-foot traffic pattern altitude? For example, at Astoria, the circling minimum descent altitude for the RNAV (GPS) RWY 8 approach in a CAT A airplane is 660 feet msl—646 feet above the runway. At that MDA you’d fly the downwind at an altitude typically associated with a base leg. That’s low—as the Aeronautical Information Manual 5-4-7 explains, a circling MDA provides only 300-foot obstacle clearance within the protected area defined for each aircraft category.

How will you fly the circling maneuver? Advisory Circular 90-66C, Non-Towered Airport Flight Operations, (paragraph 9.11.3) and several legal interpretations from the FAA, such as the 2014 Krug letter, emphasize that you must join and fly the established traffic pattern for a runway unless a procedure specifically calls for another path around the airport. That is, the regulatory left turns required by 91.126(b) apply even when ragged clouds might make an impromptu right-hand pattern more appealing, unless ATC issues specific instructions in Class E airspace.

An airport with crisscrossing runways like Astoria presents a further challenge. Suppose the wind favors landing on Runway 32 after you break out from an approach to Runway 26. The shortest path to the threshold of Runway 32 would be via a right base. But the chart supplement doesn’t specify a right-hand pattern for that runway, so 91.126(b) still rules. AIM 5-4-20 adds that while circling you should “maneuver the shortest path to the base or downwind leg, as appropriate, considering existing weather conditions…[but] there is no restriction from passing over the airport or other runways.” So, after flying an approach to Runway 26, the legal path to a landing on Runway 32 requires overlying the airport at midfield to join the left downwind and base legs.

Of course, you aren’t required to circle at the published circle-to-land MDA. If the weather allows, flying higher, preferably at the normal traffic pattern altitude, helps make a circling approach a familiar procedure. That’s an option even during a practical test or IPC. The ACS for the instrument rating notes that you must “Maintain a stabilized approach…at the MDA, or the preselected circling altitude above the MDA.”

As stipulated in 91.175, whether you land straight-in or circle, you can’t leave the MDA until you are “continuously in a position from which a descent to a landing on the intended runway can be made at a normal rate of descent using normal maneuvers.” Again, if you’re at the MDA, you’re often well below the VFR traffic pattern altitude, so as a rule, don’t descend until you can see a PAPI, VASI, or the familiar, short-final view of the runway markings. During a circle to land, you typically reach that descent point only as you join the base leg. Remember that landing straight-in is an option even on a circle-to-land approach if you can see the paint, pavement, and lights listed in 91.175 and descend smoothly before you start to circle.

The final consideration when preparing to circle to land is briefing the missed approach, specifically which way to turn if you go missed after you leave the final approach course. The instrument rating ACS says only that “If a missed approach occurs, turn in the appropriate direction using the correct procedure.” AIM 5-4-21 Missed Approach provides additional detail: “If visual reference is lost while circling-to-land…the pilot should make an initial climbing turn toward the landing runway and continue the turn until established on the missed approach course.” It’s essential that you brief and plan the direction of that climbing turn before you initiate a missed approach from the downwind, base, or final leg during a circling approach.

Bruce Williams is a CFI. Find him at youtube.com/@BruceAirFlying and bruceair.wordpress.com

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