By Skies Magazine | July 28, 2016 Estimated reading time 11 minutes, 50 seconds.
If a missed approach procedure is complex and cumbersome, pilots may be reluctant to fly it. A simplified procedure is much easier to remember at a time when cockpit workload is high and a go-around has been initiated. Here, a crew guides Noorduyn Norseman CF-GSR on final for Runway 06 at Hamilton, Ont. Eric Dumigan Photo
Benjamin Franklin likely wasn’t thinking about flying when he coined the idiom “an ounce of prevention is worth a pound of cure,” but it certainly is relevant when it comes to achieving safe flight operations.
It’s better to avoid problems in the first place rather than trying to fix them once they arise. This wise advice, if applied to the dynamic, quick decision-making environment of flying, will generally keep you out of trouble.
Sometimes, however, even the most preventative measures cannot be executed completely and exactly. Published missed approach procedures are clearly a flight profile for which pilots may not always be totally prepared. In fact, missed approaches or go-arounds and the inherent intense “transition workload” could be considered almost as critical as an emergency.
During the past decade, we have experienced exponential growth and change in navigation platforms and procedures. Implementation of satellite technology and area navigation is providing many more options for arrival, departure and approach. Satellite-based precision approach minimums have effectively improved safety while providing greater access to many airports that otherwise would be limited due to higher minima.
With all the progress we have seen in navigation, communications, surveillance etc., which ultimately enhance safety, what about mitigation of pilot workload in the missed approach procedure? What has been done to simplify published procedures to provide a greater safety margin—and maybe more importantly, to create an operating environment that fosters “going around” rather than trying to salvage an unstable approach?
The Flight Safety Foundation’s (FSF) February 2013 edition of AeroSafety World contained an article entitled “Failure to Mitigate: Studying the psychology of decision-making during unstable approaches and why go-around policies are ineffective.”
The article discussed FSF aircraft accident analysis obtained over a 16-year period, and the research clearly indicates that the most common type of accident is runway excursions. The highest risk factor for runway excursions is the unstable approach. According to the article:
“Unstable approaches occur on 3.5 to 4.0 per cent of all approaches, but only 3 per cent of these unstable approaches result in a go-around being called in the cockpit: almost all aircrew in this state—97 per cent—continue to land. It can be argued, therefore, that the almost complete failure to call go-arounds as a preventive mitigation of the risk of continuing to fly approaches that are unstable constitutes the number one cause of runway excursions, and therefore of approach and landing accidents. If our go-around policies were effective even 50 per cent of the time, the industry accident rate would be reduced 10 to 18 per cent. There is no other single decision, or procedure, beyond calling the go-around according to SOPs [standard operating procedures] that could have as significant an effect in reducing our accident rate. Why, then, is compliance so poor?”
I would suggest that the often complex published missed approach procedures add another layer of risk that flight crew must assess. Every pilot has a personal threshold, which is an inherent part of the decision-making process. During the approach pre-planning stage, pilots evaluate the risk factors for the applicable missed approach procedure. If the procedure is complex and cumbersome, there may be a reluctance to fly it.
Another factor which might influence the decision to go-around is the accountability to management. In the FSF’s “Approach and Landing Risk Reduction Guide,” the question is asked: “Does your company practice a no-fault go-around policy?”
For the question to be asked, this must be an issue with some operators.
Missed approaches are relatively infrequent in a pilot’s daily flying operations. Often the only time a pilot is exposed to the go-around procedure is during training in a controlled environment. The lack of exposure to this procedure increases the likelihood that if executed in real time, it will be a stressful endeavour with increased risk. Very few flying manoeuvres involve numerous and simultaneous change in flight path, aircraft configuration, large power adjustments, flight management system (FMS) resets, air traffic control (ATC) communications etc., during which time the crew (or single pilot) must quickly prioritize his/her thoughts and workload. Now that’s a challenge!
Which option carries lesser risk: the possibility of violating airspace, deviating from standard operating procedures and possibly creating another unstable scenario or continuing to land under less desirable and possibly unstable approach conditions?
Most flight departments have SOPs that spell out that the approach and missed approach briefing will be accomplished well in advance of executing the actual procedure. A typical published missed approach procedure could read as follows:
MISSED APCH: Climb to 3500’ heading 300°. Climbing RIGHT turn to heading 045° to intercept outbound on YPB VOR R-010 to 7000’ to AMBER. As required shuttle climb.
Quite a bit of information is contained in this written procedure. What are the chances of remembering all aspects of this procedure, especially when the briefing was accomplished somewhere in the initial descent well prior to executing the approach? Would a simpler procedure not be easier to remember? Would the hazard assessment be less critical if the procedure was less complicated? For example, what if the above published procedure was simplified to read:
MISSED APCH: Climb to 7000’ heading 300°.
Missed approach procedures executed at minimums add yet another layer of risk due to the close proximity to the ground. Missed approaches at altitudes higher than published minimums can present a different hazard. As an example, ATC may instruct the crew to miss due to traffic and the published procedure could then be amended, such as a vector, to keep the aircraft clear of conflict. This again introduces other factors for quick decision-making. SOPs may call for large power adjustments during a normal missed approach; however, in this case the aircraft is already close to the missed approach altitude. To advance power to normal go-around setting may potentially cause the aircraft to climb through the restricted altitude. With modern high thrust-to-weight ratios, aircraft altitude overshoots are another area requiring crew vigilance. The Teterboro, N.J., ILS Rwy 19 missed approach is a classic example of controlling power and quick thinking amidst all the other necessary procedures. With a level-off altitude of 1,500 feet there is less than 1,200 feet from the decision altitude (DA) to the initial missed altitude.
Much thought has been put into the criteria defining a stabilized approach. But what is the definition of a stabilized missed approach?
The FSF uses the following criteria to define a stabilized approach:
The aircraft must be on the correct flight path; Only small heading and pitch changes required to maintain path; Speed must not deviate more than VRef+20kts/-0kts; The aircraft to be in proper landing configuration; A sink rate of max 1000 fpm (unless briefed otherwise); A power setting appropriate for aircraft configuration and not below the minimum power for an approach as defined in the Aircraft Operations Manual; All briefings and checklists must be complete.
Much of the stabilized approach criteria can be applied to a “stabilized missed approach” such as correct flight path, speed deviations, proper configuration, appropriate power setting and execution of calls and checklists. Balancing all the factors during a heavy workload in a critical phase of flight, how difficult is it to proficiently execute a stabilized missed approach? Very!
Many articles and research papers have been published that identify the cause of runway excursions exclusively as pilot error. Safe execution of all aspects of flying is a pilot’s core responsibility, including the execution of a missed approach. If there is a roadblock to consistently achieving this objective e.g.: runway excursions due to “not going around,” then in the spirit of just culture we should look beyond the pilot as being solely responsible. Would reducing the element of risk inherent in complex missed approach procedures foster more missed approaches? Certainly!
In mountainous regions such as Aspen, Colo., or areas where obstructions or runway operations are factors, it is practical to have more complex published missed approach procedures. Published missed approach procedures, similar to published IFR departure procedures, are predicated on all engines operating. Pilots need to consider the possibility of an engine failure during a missed approach. This becomes increasingly important when the published missed approach requires a non-standard climb gradient to be achieved and/or requires turns to avoid obstacles. In all these circumstances, to simply proceed straight ahead and climb to a specified altitude relieves a whole lot of stress.
If a complex published missed approach procedure is part of your approach and the potential of a go-around is a distinct possibility—for example, if weather is just above the approach ban—then ask ATC for an amended procedure. Chances are good that they will try to work out something more favourable for you.
Simplifying published missed approach procedures, either by design or by pilot request, will prove to increase the number of go-arounds and thus reduce runway excursions.
In this case, the ounce of prevention is certainly worth much more than a pound of cure.
Peter Bing is chief pilot of a corporate flight department operating Challenger 300 aircraft. For more than 17 years he was a college aviation institute academic chair, and his previous airline career saw him fly the B737, Bae146, F28, Dash 7/8, and ST-27 aircraft.
