Event Description
From bad weather events to VFR mountain flying to SFRA and airspace avoidance, BVA's Challenge event is designed to put aviation knowledge to practice. Challenge is about learning through experience. Each event involves a specific activity, or series of activities, for pilots to complete. Past Challenge events have included the Washington and New York SFRAs, Class B airspace avoidance, landing competitions, IFR procedures, and Pilot Ratings Program flights.

This event is not about flying missions or winning points. It's about exercising your multi-tasking ability in challenging and unfamiliar situations—something pilots have to do all the time.
Event Briefing

In this Challenge, three airports that regularly use circle-to-land procedures will be staffed up in and around the Boston Class B airspace. Bedford (KBED), Norwood (KOWD), and Lawrence (KLWM) and all located nearby Boston's busy Logan International Airport. As a result of traffic landing and departing at Boston, aircraft landing at these three regional airports regularly fly an instrument approach to one runway, then break off the approach and fly a visual maneuver to line up with another runway. This is known as 'circling'.

During the event, ATC will be advertising circling approaches at each of the three featured airports. Participating pilots should file IFR, or fly VFR practice approaches, into the three airports, using circle-to-land techniques. If you're up for the extra challenge, conduct a missed approach while you are mid-circling. Of course, anyone is welcome; if you prefer to fly the straight-in approach, just advise the controller. We also welcome VFR closed traffic and operations between these three controlled airports.

Circling approaches may be in use for a variety of reasons. At some airports where terrain prevents flying a standard, straight-in approach, an instrument approach might end in a letter (for example, "VOR-A" instead of "VOR RWY 36"). The "-A" at the end of the approach means that, rather than being attached to a specific runway, the approach is for the airport. Pilots need to circle to whichever runway is in use at the time. 

At Norwood Airport (KOWD), the only instrument approaches available to the airport are to Runway 35. But what happens if the weather is low, but there is a strong wind favoring Runway 17? Fly our Circling Challenge event to find out!

Let's use the LOC RWY 35 procedure at KOWD as an example. Unlike a lettered approach, this is a straight-in procedure that also has circling minimums published, so a pilot can either fly the approach straight-in (and land on Runway 35) or could elect to fly a circling approach to land on another runway. If the approach ended in a letter (e.g., "LOC-A"), there would only be circling minimums published, and the pilot would have to fly a circling maneuver to land.

First, let's review the published minimums that are available on the approach. For now, we'll ignore the DIKEY fix minimums and just use the focus on the other set of minimums. (The DIKEY fix minimums are published because the only way for a pilot to identify DIKEY is by the I-OWD 2.5 DME, and not all aircraft would have DME. If you don't have DME, and therefore don't know where DIKEY is, then you have to level off a little sooner on the approach.) 

As you can see, there are two sets of minimums. The first set (S-35) is for straight-in approaches to Runway 35. As you likely remember, the minimum depends on your approach category, or aircraft's speed on final. In this case, if you are flying the final approach segment at 120 knots or less, then you are Category A or B, and use those minimums. If you fly faster than that, you need to reference the C and D minimums.

Let's say we are in a C172, and are flying the approach at 90 knots. If we fly it "straight in", then the minimums are 580-3/4, which means 580' MSL, and 3/4 miles visibility. To the right, the smaller number (531') represents that 580' altitude above the ground. So, if you were flying the approach straight-in, you would descend on the procedure to 580', then level off until you see the runway. By comparison, if you are flying the circling procedure as this same C172, the minimums are a little higher (600-1). This is because circling involves maneuvering around the airport, so the airspace that is protected from terrain is larger. 

Initially, flying a circling approach is the same as any other procedure. You start by either getting vectors onto final or getting cleared along a transition route. The only difference in your approach clearance will be the circling instruction: "cleared Localizer Runway 35 Approach, circle to Runway 17". Once you are on the approach, you would descend to the circling minimums (in this case, 600' for a Category A like a C172). At this point, if you have the runway in sight, you can commence the circling maneuver. In plain terms, this means that you will maneuver the aircraft visually from being lined up with Runway 35 to a landing on a different runway.

The actual circling maneuver will depend on which runway is active and instructions from air traffic control. In some cases, ATC may simply advise you to "circle your discretion". This gives you the opportunity to circle however you wish. Maneuver the shortest path to the base or downwind leg of the runway you are landing on. There is no restriction from passing over the airport or other runways. If the airport is busy, the controller may specify a restriction like "circle east" or "enter left downwind", in which case your circling maneuver would need to be adjusted to comply with the instruction. In some cases, the instrument approach itself might specify an area where circling is not available due to terrain or noise abatement considerations. 

From the time that you leave the instrument approach, you should remain at the circling minimums (for a C172, 600') until the time that you can make a continuous descent at a normal rate, using normal maneuvers, to land on the runway. You also need to remain clear of cloud, and keep the runway in sight. 

In the event that you inadvertently re-enter cloud or lose sight of the runway while circling, a missed approach must be conducted. Because you won't be on the final approach segment, you may have to be a little bit creative in re-establishing yourself on the approach and then conducting the missed. First, start a climb from the circling minimums up to the missed approach altitude. Then, navigate toward the middle of the airport. From there, you can re-join the published missed approach procedure. 

Circling procedures require maneuvers at low altitude, at low airspeed, and in marginal weather conditions. Pilots must use sound judgment, have an
indepth knowledge of their capabilities, and fully understand the aircraft performance to determine the exact circling maneuver since weather, unique airport design, and the aircraft position, altitude, and airspeed must all be considered. Good luck!

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