Stabilized Approaches or Short Circuits?

October 2015 - If you subscribe to Transport Canada’s (TC) aviation safety alerts, you might have received this. It refers to stabilized approaches and is primarily focused on larger aircraft, but you may agree that it has a lot of relevance.

The meaning of “stabilized approach” is obvious, but it’s easy to forget that being at a point of complete stability early in the final approach has many benefits for GA pilots. You will see many fliers who are proud of their ability to fly very short circuits, but here are some of the reasons in the TC safety alert for a well-stabilized approach. According to the Civil Aviation safety alert (CASA), these benefits include:

• Increased flight crew situational awareness
• More time and attention for monitoring ATC communications, weather conditions, and systems operation
• More time and attention for flight path and energy monitoring
• Defined flight parameter deviation limits and minimum stabilization heights to support the decision to land or to go around
• Landing performance consistent with expected performance values

Air operators have largely adopted stabilized approach criteria into their standard operating procedures (SOP), but practices with respect to flight crew calls (such as a timely “stable” or “unstable” call) and subsequent actions, as required, appear to vary. As stipulated in CASA 2014-03, TCCA plans to direct specific surveillance activities to evaluate operator practices with respect to the stabilized approach concept.

An approach is considered stabilized when it satisfies the associated conditions typically defined by an air operator in their Company Operations Manual or Standard Operating Procedures, as they may possibly relate to:

• Range of speeds specific to the aircraft type
• Power setting(s) specific to the aircraft type
• Range of attitudes specific to the aircraft type
• Configuration(s) specific to the aircraft type
• Crossing altitude deviation tolerances
• Sink rate
• Completion of checklists and flight crew briefings

You may not be convinced to apply extra effort on flying an approach that is even more “stabilized” than you’re used to, since it might involve a longer circuit, more fuel used, and delays to other traffic in the circuit—all of which encourage us to keep it short. However the safety alert was written for a reason—to reduce accidents. Most of us have either had an aviation-related accident, know someone who has, or maybe even lost friends due to one. Stabilized approaches not only produce repeatable results but also give the pilot more time to think about variables like crosswind, wind shear, and gusts.