High-risk pilots generally perceive much less risk on unstable approaches and do not feel they will be reprimanded. US Affairs Editor Chuck Weirauch looks at the on-going dilemma of go-around decision-making.

The Pakistani International Airlines Flight PK8303 crash at Karachi on 20 May last year is perhaps the worst imaginable example of a failure to go-around when in an unstable approach. A set of almost mind-boggling flight crew errors led to the disaster, including the Pilot Flying ignoring air traffic controllers’ repeated warnings to go around because the Airbus A320-200 was approaching the Jinnah Airport runway at too high an altitude and too fast a speed. And when the Captain finally did decide to go around, it was after the overspeeding aircraft had touched down without the landing gear deployed. Engines damaged by the impact with the runway failed during the go-around attempt, with the resulting plummet into a nearby neighborhood. An official report blamed the accident on “a confused captain and a hostile cockpit atmosphere.”

While the PIA accident is an extreme example of what can happen even in daylight and near-perfect atmospheric conditions, it highlights that pilots are still reluctant to conduct a go-around procedure when in an unstable approach, in spite of training providers’ ongoing efforts to improve pilots’ go-round decision-making skills.

Another fairly recent catastrophic fatal go-around-related accident occurred in March 2016 when a Boeing 737-800 operated by the low-cost carrier arm of Emirates, Flydubai, crashed during a second attempted landing at Rostov-on-Don, Russia, while fighting against reportedly near-hurricane force winds. All 62 crew and passengers aboard Flight 981 were killed when the airliner suddenly nose-dived into the runway.

On August 6 of that year, Emirates Flight EK521 ended in another go-around-related accident. This accident involved the complete loss of an Emirates Boeing 777-300, with 32 persons injured, as the flight crew was attempting to perform a weather-related go-around at Dubai International Airport. According to the UAE General Civil Aviation Authority (GCAA), which investigated the accident, the flight crew had shown “a reliance on automation” and a lack of training in flying go-arounds from points close to the runway. Emirates stated that it has enhanced its go-around training after the EK521 accident.

In the case of Flight 981, after recommendations by the Russian Interstate Aviation Committee, Flydubai announced that it has enhanced go-around and spatial disorientation training.

Subsequent to the accident, Pakistani International Airlines grounded almost a third of its pilots for holding fake or dubious licenses. Further revelations alleged that 260 of 860 Pakistani pilots had never even taken an exam for flying. In July, EASA issued a six-month ban on all PIA flights to Europe. The UK and USA soon followed suit.

Most airlines and other aviation organisations specify minimum acceptable criteria for the continuation of an approach to land. These vary in detail but the following summary published by the Flight Safety Foundation is one view of the important considerations.

Their Approach-and-landing Accident Reduction (ALAR) Briefing Note 7-1 suggests that “all flights must be stabilised by 1000 feet above airport elevation in IMC and 500 feet above airport elevation in VMC. An approach is stabilised when all of the following criteria are met:

  • The aircraft is on the correct flight path
  • Only small changes in heading/pitch are necessary to maintain the correct flight path
  • The airspeed is not more than VREF + 20kts indicated speed and not less than VREF
  • The aircraft is in the correct landing configuration
  • Sink rate is no greater than 1000 feet/minute; if an approach requires a sink rate greater than 1000 feet/minute a special briefing should be conducted
  • Power setting is appropriate for the aircraft configuration and is not below the minimum power for the approach as defined by the operating manual
  • All briefings and checklists have been conducted
  • Specific types of approach are stabilized if they also fulfil the following:
    • ILS approaches must be flown within one dot of the glide-slope and localizer
    • a Category II or III approach must be flown within the expanded localizer band
    • during a circling approach wings should be level on final when the aircraft reaches 300 feet above airport elevation; and,
  • Unique approach conditions or abnormal conditions requiring a deviation from the above elements of a stabilized approach require a special briefing.

An approach that becomes unstabilised below 1000 feet above airport elevation in IMC or 500 feet above airport elevation in VMC requires an immediate go-around.”

What is a Stable Approach?

The FAA states that a pilot is “flying a stable approach when he or she establishes a constant angle glidepath (with a 3-degree glideslope) towards a predetermined point on the landing runway.” When a flight is above the optimum 3:1 descent ratio, the approach is at risk of being unstable when closer to the runway.”

Worldwide, authorities, manufacturers and airlines use the criteria published by the Flight Safety Foundation in their Approach-and-Landing Accident Reduction (ALAR) Briefing Note 7-1.

FSF says an approach is stable if:

  • The aircraft is on the correct flight path
  • Only small changes in heading/pitch are necessary to maintain the correct flight path
  • The airspeed is not more than VREF + 20kts indicated speed and not less than VREF
  • The aircraft is in the correct landing configuration
  • Sink rate is no greater than 1000 feet/minute; if an approach requires a sink rate greater than 1000 feet/minute a special briefing should be conducted
  • Power setting is appropriate for the aircraft configuration and is not below the minimum power for the approach as defined by the operating manual
  • All briefings and checklists have been conducted

Most airlines specify that the aircraft must be stable at 500 feet in visual meteorological conditions, and 1,000 feet in IMC, or otherwise the pilots must initiate a go-around.

While many in the industry consider “unstable approaches” as a major contributory factor to aviation accidents, there are a number of aviation experts who have stated this viewpoint is not necessarily true. In his 2004 paper, “The Myth of the Unstable Approach,” Ed Wischmeyer, then Associate Research Professor at Embry-Riddle Aeronautical University’s Prescott, Arizona Campus, claimed that “almost no unstable approaches end catastrophically, and thus, it is inappropriate to consider unstable approaches as a causal factor, as an unstable approach is almost always correctable.”

The Non-Compliance Issue

In spite of the fact that the aviation industry considers unstable approaches to be a major factor leading to accidents, pilots continue to be non-compliant with company and industry-standard go-around procedures. Rather than just being willfully non-compliant, Captain Shem Malmquist believes that the vast majority of pilots take action to fly a stable approach with the understanding that minor deviations in the “stable approach” criteria can be corrected, and present less risk than what they consider a more dangerous maneuver, namely the initiation of a go-around. Malmquist is a Visiting Professor at Florida Institute of Technology (FIT), an active Boeing 777 Captain, and co-author of the books Angle of Attack and Grounded - How to Solve the Aviation Crisis.

He agrees with Wischmeyer that too much emphasis is placed on unstable approaches as the major cause of aviation accidents. “I don’t think any of this is as simple as some people make it up to be,” Malmquist told CAT. “One of the problems is that we tend to oversimplify issues. More than 99 percent of unstable approaches do not lead to an accident, and that is why we need to consider it in a different way. And part of that is that the correlation is not what we think it is. It could be that the accident had nothing to do with the unstable approach, and accidents are a combination of a lot of different things happening.”

One thing that pilots know is that go-arounds are really dangerous, and tend to avoid them for that reason, Malmquist emphasized. But are pilots avoiding go-arounds because they are being pressured by the company to avoid the time and cost of doing so, or are they just not taking that action because there will be no repercussions from their management?

“I would say not too often, but maybe sometimes,” Malmquist said. “Do they feel any downside or repercussion from the company or authorities? I’m not so sure that it is so simple as willful non-compliance. What I see is pilots coming in and using the ‘stable approach’ gate as kind of a target. So instead of being stable at that point, they are building their mental model and approach around those criteria. And what that means is that if you are not quite there, but know that it is kind of arbitrary – I think that they will push it a little bit, but not hugely. Pushing 100 feet is safer than a go-around.”

Why a Stable Approach?

Malmquist stresses the importance of flying a stable approach to his students because it provides one thing for them, namely predictability.

“The answer is one thing – it reduces the variability and improves the predictability of the approach – particularly for the Pilot Monitoring, but also for the Pilot Flying,” Malmquist said. “What you are doing is setting up a stable and predictable environment, so that when you go into the more variable environment, such as changing weather conditions, the airplane is behaving in a more predictable way. And that’s why it works to provide a better landing. So part of the problem before anything else is that pilots see stable criteria as a little bit arbitrary, and they are not incorrect.”

We can’t say that there is a direct correlation between unstable approaches and accidents, because accidents are very rare, Malmquist summarized.

“We can’t prove it,” he added. “But what we can say is that if you do fly a stable approach, you will have a more predictable airplane, and it will help your Pilot Monitoring do a better job seeing if anything is out of bounds. Every time you come in, things are different. So reducing the variability really makes the difference in making the airplane easier to land. People are trying to treat the wrong thing (non-compliance), and it’s not working because that’s not what the problem is. People are being very superficial by looking at it as a compliance issue, and it doesn’t work, because we still have the problem.”

Go-Around Research

The definitive study addressing the aviation go-around issue is the Presage Group-Flight Safety Foundation Go-around Decision-making and Execution Report in 2017. The report cites a 16-year FSF study of runway excursions, which concluded that 83% of the excursions, more than likely caused by an unstable approach, could have been avoided with a flight crew decision to go around. It further determined that 54% of all accidents could be prevented by going around.

But the key conclusion of the report is that only 3% of unstable approaches are conducted by flight crews according to industry standard go-around procedures, or making the decision to go around when they determine that the aircraft is in an unstable condition during its final approach to landing. The report shows that 97% of these approaches are made with the aircraft in an unstable condition.

At an FSF International Air Safety Summit, Captain Bill Curtis of the Presage Group and Tzvetomir Blajev of Eurocontrol stated that pilots who ignored unstable approach warnings often also tended to be poor cockpit communicators with the other member of the flight crew. Other presenters pointed out that many of the pilots who chose to land when in an unstable approach scored much lower in every element of situational awareness.

Why Not Go Around?

Just why flight crew members continue to make final approaches and landings under such circumstances is a major focus of the 2017 report. To help determine why, the bulk of the report focuses on the aspects involved in the pilots’ decision-making processes during unstable approaches, or non-compliance with industry-established go-around procedures.

Perhaps the most significant of the conclusions is that airline industry management accepts the pilot non-compliance, since the risk is considered low, and that pilots also have that same opinion. Another key conclusion is that “effective go-around decision-making in flight deck communication is low.”

It’s clear that much can be done to help resolve these attitudes, and the report makes several recommendations to do so. You can access the entire report here. 

The Foundation held a follow-up at its 8th Annual Safety Forum in February 2021, where the theme was its “Global Action Plan for the Prevention of Runway Excursions (GAPPRE)” project. The plan can be accessed here. 

Psychology and Situational Awareness

One part of the FSF go-around report points out that situational awareness is a major factor for pilots involved in situations that call for a go-around/no-go-around decision, merging it with the psychological characteristics of the flight crew. This situational awareness capability includes the mental ability to fly a stable approach, recognize an unstable approach, and make the proper assessment as to when a go-around is required.

Additionally, the report states: “Pristine flight conditions invite a greater tolerance for the belief that the absence of complex environmental factors equates with little or no risk to be managed, and suggests to the unstable approach pilot that on one hand, there is a low probability of the aircraft becoming unstable. On the other hand, should it become unstable, the environmental conditions nonetheless lend themselves to ‘managing’ the instability correctly and landing safely,” the authors concluded.

Dr. Martin Smith, also of Presage, outlined nine characteristics of pilots unlikely to execute a go-around. These high-risk pilots were significantly less likely to discuss potential approach risks. They generally perceived much less risk on unstable approaches, perhaps because most believed their company go-around policy was unrealistic, Smith concluded. They also did not feel they would be reprimanded for an unstable approach.

At an FSF International Air Safety Summit in 2015, Captain Dave Carbaugh cited how pilots might find themselves in an untenable go-around decision-making situation by letting themselves “get behind the airplane,” instead of flying with the correct always-ahead-of-the-aircraft attitude. In this situation, pilots are unable to anticipate what will occur next because of the level of concentration needed for present-time tasks. “You lose your reserve capacity to be able to handle any other activities of concern” that may come up in the immediate future. Carbaugh was Chief Pilot, Technical and Safety for Test and Evaluation, for Boeing before joining APS as a UPRT instructor.

In his “Task-Switching Failure Due to Cognitive Lockup in Airline Pilots” paper presented to the Royal Aeronautical Society, Captain Amit Singh postulates a view similar to Carbaugh. Cognitive lockup is a psychological term describing the reluctance to switch from one task to another until the first task is completed. This is a problem when more than one issue emerges at the same time, since humans tend to deal with events that demand action in a linear manner.

If a pilot has already decided to land, and the aircraft then becomes unstable, due to time pressures the pilot might not be able to take the next sequential step, to go around, due to cognitive lockup, Singh explains. Singh states that training and the mental framing of the go-around task are two ways to eliminate cognitive lockup.

Training Go-Arounds

Captain Jean LaRoche, Director of Research & Development, CQFA Aviation College, recommends that flight instructors must introduce unstabilized approaches to their training curricula, much as they do with stalls and upset recovery, along with proper debriefing. He also advocates repetition of the go-around maneuver until the students have mastered it so that they feel that it is a safe maneuver, rather than a threatening and obscure one.

Perhaps the most important time to teach pilots about the importance of go-arounds is right from the beginning, at flight school ab initio training. Parker Northrup, Chair of the Flight Department at Embry-Riddle Aeronautical University at Prescott, explained that ERAU students are given a three-part introduction to the go-around concept even before they are actually taught the procedure.

“Our training approach centers on the stable approach concept, including the energy management part of it,” Northrup explained. “We teach our pilots before we even talk about go-arounds, or go-around procedures, that we first make sure that they are fully confident in making a stable approach, and understand the elements of the approach that are the most important elements of a safe, efficient landing. We teach that if they are not in a stable approach at 100 AGL, they will execute a go-around. We don’t teach people to save a bad landing. We teach that if you are not stable, you go around and do it again.”

The second phase of the students’ education is how to recognize during the landing phase that a go-around is the appropriate course of action, and analyze anything that would place a safe landing in doubt, Northrup described. The third part is how to perform the go-around procedures themselves.

“With this three-part approach, we think that we have been very successful at reducing and minimizing things like hard landings,” Northrup continued. “Pilots are also required to call out things like ‘100 feet’ AGL during approach so that both the instructor and the student pilot agree, and have made a decision, as to whether this approach is stable for a landing or not. This is a great way for students to practice cockpit communication skills.”