From May 2, the FAA will start publishing new instrument approach plates that include an enlarged segment of airspace to protect aircraft during circling approaches. The new airspace also offers pilots additional obstacle clearance while considering their MSL altitude above the MDA, which affects true airspeed.
The boundaries of protected airspace for circling approaches are defined by arcs drawn from the threshold of each runway at an airport. The larger the aircraft, the larger the arc.
Previous versions of the FAA’s terminal instrument procedures (Terps) used a radius of 1.7 nm from the end of the runway for a Category C aircraft such as a Hawker 800. Under the new criteria that radius will increase by 65 percent, to 2.7 nm.
Chart providers U.S. Terminal Procedures and Jeppesen both plan to use new chart symbology to identify the updated approaches. The government plates will show an inverse “C” in a black box in the approach minimums area of the plate, while Jeppesen will use a “C” inside a black diamond.
Charts without the new designation will continue to be guided by the old, smaller-radii criteria.