Stabilized Approach - Civil Aviation Safety Alerts (CASA) No. 2015-04

Purpose

The purpose of this CASA is to stress the importance of, and to outline the elements of a stabilized approach. This CASA also serves to complement CASA 2014-03 which requested Canadian air operators to use existing Safety Management Systems (SMS) to address and mitigate hazards and risks associated with unstable approaches.

Background:

Rushed and unstabilized approaches remain a significant factor in Controlled Flight Into Terrain (CFIT) and other Approach-and-Landing Accidents (ALA). The safety benefits derived from a stabilized final approach have been recognized by many organizations including ICAO, the FAA, EASA and TCCA. 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; and,
• Landing performance consistent with expected performance values.

Air operators have largely adopted stabilized approach criteria into their SOPs, 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 (SOP), 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; and,
• Completion of checklists and flight crew briefings.

Stabilized approach criteria should be defined for all approaches and should include that:

• Approaches be stabilized by no lower than 1,000 feet (ft) above aerodrome elevation (AAE) when in instrument meteorological conditions (IMC);
• All approaches be stabilized by no lower than 500 ft AAE in visual meteorological conditions (VMC);
• A call be made upon reaching 1000 ft AAE in IMC or 500 ft AAE in VMC as to whether the approach is stabilized or not;
• The approach remain stabilized until landing;
• If an approach is not stabilized in accordance with these requirements, or has become destabilized afterwards, a go-around is required.

In summary, maintaining a stable speed, descent rate, and vertical/lateral flight path in the landing configuration is commonly referred to as the stabilized approach concept. Stabilized approach criteria should always be followed and require close monitoring of airspeed, sink rate and energy state during a visual or instrument approach. All available lateral and vertical guidance and visual aids should be used to monitor the aircraft state and flight path.

Stabilized approach procedures should include the required verbal communication about the aircraft state and its progression along the approach. Any significant deviation from planned flight path, airspeed, or descent rate should be announced and promptly corrected. A go-around is required if the approach cannot be continued within stabilized approach parameters.

It is important to note that the decision to execute a go-around is not an indication of poor flight crew performance but rather prudent decision making.

Recommended action:

Air operators certificated under Subparts 702, 703, 704 and 705 of the CARs as well as private operators registered under Subpart 604 should review or institute their own stabilized approach procedures, to include the requirement for a “Stable” or “Unstable” call at the appropriate gate (1000’ AAE in IMC or 500’ AAE in VMC). Furthermore, the application of the stabilized approach concept should be supported by non-punitive go-around policies.

Those air operators not already doing so are encouraged to incorporate stabilized approach procedures into their operations manual, SOP and training syllabus.

Contact office:

For more information concerning this issue, contact a Transport Canada Centre; or contact Roger Gravelle, Commercial Flight Standards (AARTFA) in Ottawa, by telephone at 613-991-3426, by fax at 613-990-6215 or by e-mail at roger.gravelle@tc.gc.ca.

Original signed by

Robert Sincennes
Director
Standards Branch

 

Stabilized Approach
(PDF 478 KB)