AINsight: Go-around Minded

 - April 29, 2022, 12:47 PM

Pilots’ failure to recognize the need for and execute a go-around is a threat to flight safety and has been a major cause of approach-and-landing accidents. The most perplexing issue with a go-around is that pilots rarely perform this maneuver and often continue an approach to landing even if it is or becomes unstable. 

This decision to continue an aircraft’s unstable approach—rather than performing a go-around—flies in the face of industry guidance. Aviation safety experts overwhelmingly suggest that a go-around is the most effective “reset opportunity” to stack the odds back in the favor of a pilot to safely land an aircraft. 

According to a Flight Safety Foundation (FSF) study that looked at nearly two decades of data, unstable approaches occur on 3.5 to 4 percent of all flights, but only 3 percent of these go around. In other words, flight crews fail to go around in 97 percent of all unstable approaches. That figure is puzzling.

In previous blogs over the past three years, I’ve explored many aspects of the unstable approach and go-around. They include discussions on the complex psychological aspects of continuing an unstable approach, SOP non-compliancebest practices to avoid unstable approaches, and establishing policies and procedures to promote the stabilized approach concept and support the go-around decision. 

In addition, the July 2020 blog was a brief case study on the crash of a Cessna Citation Latitude where a highly unstable approach led to a botched landing and runway excursion, destroying that aircraft. 

Obviously, a go-around from an unstable approach is a complex issue. Overlooked in this discussion are the difficulties of the actual go-around maneuver, which may contribute to the reluctance of a pilot to abandon an unstable approach.

The go-around maneuver involves a highly choreographed sequence of callouts and actions between the pilot flying (PF) and pilot monitoring (PM). Task-sharing between the PF and PM is the most important factor to conduct a safe go-around.

Each step of the maneuver must be properly sequenced. In addition, a go-around almost always occurs during a period of high workload, with numerous distractions from air traffic control—and potentially weather and terrain—and may become more difficult to manage due to the “startle effect.” 

The startle effect includes both the physical and mental responses to a sudden or unexpected stimulus. In the case of a go-around, the physical responses may be automatic and instantaneous, but the mental process is much slower due to the conscious processing and evaluation of sensory information. 

During a study entitled “Airplane State Awareness during Go-Around,” the French BEA examined past go-around-related accidents and surveyed 831 pilots on the challenges encountered during a go-around. Several challenges were identified with some common themes. 

Following the analysis of 10 accidents in the go-around phase, the most common aspects were related to relatively lightweight aircraft with excessive available thrust and the resultant “strong quick-acting nose-up pitching moment.” Also at the top of this list were other human factors issues such as poor active monitoring by the PM, CRM, automation management (including FMA awareness), and “spurious parasitic sensations” such as somatogravic illusions (the sensation of pitching up too much). 

Survey results identified specific difficulties encountered during a go-around such as vertical flight path management, automation management, flight path control (pitch), thrust management, and trim management. In addition, it cited other human factors issues such as CRM—both decision making and task sharing—and coping with acceleration-related spatial disorientation (somatogravic illusions).

The BEA go-around study also included simulator trials, using Boeing 777 and Airbus A330 types, that monitored and evaluated flight crew performance during the go-around phase of flight. 

The simulator trials consisted of three go-arounds scenarios—ATC initiated go-around and two crew initiated go-arounds—flown by 11 different fully qualified flight crews. Each aircraft type required 15 to 16 different actions (examples: select TOGA, callout go-around, call for flaps 10, etc.) to successfully execute a go-around. Of those go-arounds flown during this study, none were flown to perfection. 

Common errors were classified as either callout errors, interactions with ATC, automation mode management, thrust management, aircraft configuration (flaps and gear) management, flight path management and/or manual handling errors.

From the BEA study, there were some specific safety recommendations such as improved monitoring of primary flight parameters (pitch, thrust, and speed) by the PF, enhanced monitoring by the PM, and improved CRM during high-workload environments. 

Teamwork, good CRM, and flight path and FMA monitoring are key to a well-flown go-around. It all begins with a thorough approach briefing prior to the “top of descent.”

In addition to the normal approach-and-landing-related items, crews should discuss in detail procedures and callouts related to either a go-around or discontinued approach to include specific actions and expectations of the PF and PM and the intended use of automation. This briefing provides a clear mental image of the maneuver and reinforces the concept of being go-around “prepared” and “minded.”

Initiating a go-around begins with the PF’s clear callout of “go-around thrust, flaps” (generic procedure) and the PM ensuring that the FMA GA mode is active, go-around thrust is set, and flap retraction is initiated. This initial callout is important since it draws the crew into the “go-around mode” to begin the maneuver and will help overcome the startle effect from this unexpected situation.

Once the go-around is initiated, if visual references are acquired, the PF must immediately transition back to instrument flying. 

The role of the PM cannot be emphasized enough, as the PM’s callouts serve as critical triggers for the PF to perform an action. As an example, a “positive rate [of climb]” callout by the PM is closely followed by a “gear up” call by the PF

Throughout the entire go-around maneuver, the PM must monitor the aircraft flight path (energy and trajectory), proper FMA indications, and make other important callouts. During a go-around maneuver, the PF often may become solely focused on flight path control and tunnel on basic flight parameters.

In this case, it is the role of the PM to provide timely inputs—loud and clear—to help expand the view of the PF to include aircraft configuration (gear and flaps), automation modes, vertical and lateral paths, etc.

To counter the negative effects of too much thrust either due to light weights or initiating a go-around at a higher altitude (close to the missed approach altitude) some manufacturers encourage the use of a “soft go-around” or discontinued approach. Each concept provides a much more controlled option to abandon an approach and limits the extreme changes in pitch and longitudinal acceleration. 

A soft go-around uses either an optimized or climb thrust setting versus GA thrust—typically at a light weight where the aircraft can meet or exceed the required climb gradient by using a lower thrust setting. 

A discontinued approach is a concept where an approach is abandoned without selecting TOGA. Often this is recommended at a higher altitude, typically greater than 1,000 feet above field elevation.

Discontinued approaches take the aircraft out of an approach mode and stabilize the flight path by selecting altitude hold and a safe speed that is appropriate for the current configuration. Once stabilized in level flight, the flight crew can then select an appropriate vertical mode to climb (or descend) the aircraft to the assigned or missed approach altitude.

It is important to note that a go-around is a possibility during every flight up until the time the thrust reversers are deployed. Pilots must have a go-around mindset and be prepared to abandon any approach and once committed, they must fly the complete go-around maneuver through its entirety.

In addition to an unstable approach, other reasons to go around are evenly distributed between weather (at or below approach minimums, gusts, wind shear, etc.) and ATC directed go-arounds (traffic conflicts). 

A go-around is complex, to execute the maneuver safely pilots must be trained to fly a go-around in any situation and fully understand concepts related to decision making and effective teamwork.

The opinions expressed in this column are those of the author and not necessarily endorsed by AIN Media Group.