The Pilot Monitoring (PM) role is challenging, especially for FOs. One particularly nuanced area is making callouts for unscripted deviations. Before we look at those, we should understand the difference between scripted and unscripted callouts.
From Chapter 19 of Master Airline Pilot:
Scripted Deviation callouts: The simplest PM callouts are procedural deviation callouts. Clearly written in our manuals, they reflect direct readouts from aircraft gauges and displays – “Airspeed”, “Glideslope”, and “Crosstrack”, to name a few. Depending on the airline, PMs are encouraged to add descriptive details such as “Airspeed, plus 15”, “Glideslope, 2 dots high”, and “Crosstrack, 2 dots right.” Typically, the PF responds with an acknowledgment like “Correcting”, and makes an appropriate adjustment to resolve the discrepancy.
Company procedures may direct how often the PM repeats their callouts. They may also direct what to do if the PF fails to acknowledge the callout, if an appropriate correction is not observed, or if the adjustment is insufficient to resolve the deviation. Scripted deviation callouts are effective because they are clearly mandated in written procedures. Generally, PMs aren’t reluctant about making them and PFs aren’t resistant against hearing them. Although, some line cultures discourage them as misguided efforts to promote congenial flightdeck environments.
Unscripted Deviation Callouts: The next class of deviation callouts includes deviation callouts that aren’t specifically scripted in the manuals. These deviation callouts alert the PF of adverse trends or impending errors. For example, if the Captain is distracted while taxiing and starts straying from the taxiway centerline, the PM may call, “Drifting right”. This would alert the Captain of the undesirable trend and return their attention to controlling the aircraft’s trajectory. For another example, consider a PF who is hand-flying a departure SID, becomes distracted by an inside task, and is unaware that they are quickly approaching the assigned level-off altitude. The PM might say, “Approaching level-off”. Like the taxiway drift, this highlights an adverse trend and alerts the PF to redirect their attention toward correcting the flightpath before busting the assigned altitude.
- Unscripted callout verbiage: Since these callouts cover a wide range of pilotage issues, the specific verbiage is left up to the PM. We are empowered to use any informative statements that accurately communicate the nature of the deviation. These callouts tend to be more welcomed when they factually describe a condition and less welcomed when they imply fault. Consider the example of a PF hand-flying a climbout and approaching the assigned level-off altitude. The callout, “Approaching level-off” factually states the condition. Compare this with a more accusatory callout like, “You’re about to bust our assigned altitude.” This option communicates the same information, but with blame. Ratchet it up one step further to get, “You’re about to bust our [expletive] altitude.” On top of the accusation, this callout implies that the PM is upset about the impending error – a “you’re about to get us both in trouble” message.
- Adding corrective directions to the callout: Revisiting our previous example of the taxiway drift, the PM might state, “Come left, you’re drifting.” If the PF is highly distracted, a callout like this eliminates potential confusion. Otherwise, it might take them a few moments to look up, realize what is happening, and apply an appropriate correction. The directive/deviation format streamlines this process. For the impending altitude bust, the callout might be, “Level off now – 300′ to our assigned altitude.” This directs the corrective action, identifies the problem, and communicates the urgency. Make callouts unambiguous and free of accusation or negative undertones. If the PF displays frustration with their error, make an effort rebuild flightdeck rapport. For example, if they successfully correct the trend and smoothly level off, consider adding, “Nicely done”.
A vital consideration governing all callouts is the time available before an adverse trend becomes an error or hazardous situation. If we have plenty of time, the callout can be conversational and informative. “We are starting to drift off the taxi centerline” communicates that the PF (Captain, in this case) has started drifting off of the taxi line. Notice that no directional information is included in this callout. Alerted to the adverse trend, the Captain needs to look up, determine the necessary correction, and make it. Imagining a scenario of how this situation might have evolved, perhaps the PM (FO, in this case) noticed the drift, looked at the Captain and saw that they had become preoccupied with studying their EFB display mounted on their side rail. The callout would alert the Captain to suspend the distracting EFB task, look up, detect the drift, and correct back to taxi centerline.
Increasing the severity of the scenario, perhaps the deviation is sudden and extreme resulting is minimal time to correct the adverse trend. Imagining how this situation can evolve, perhaps the crew was moving along a straight taxiway that transitioned into a curve. If the Captain began their distracting task during the straightaway portion, they might unintentionally believe that they have plenty of time to analyze their EFB. Becoming engaged in the task, they may have lost their sense of time available. In another scenario, perhaps the FO chose that same straight taxiway to engage in their own distractive task. As the FO looked up and detected the drift, they discovered that a significant drift had developed and that they had very little time to recover.
In cases like these, the PM/FO may wish to add a directive component to the callout. “Come right. We are drifting.” Notice that the callout doesn’t mix “lefts” and “rights”. For example, we wouldn’t want to say “We’re drifting left, come right.” As the Captain looks up from their EFB, they need to abandon the previous task (studying the EFB) and assess the outside environment to determine what is happening. They may become momentarily startled and surprised. They may reflexively respond to the first direction they hear (“We’re drifting left”) and jerk the tiller to the left. That is why it is better to make a directive call with only one directional reference – in this case, “Come right.” The rest of the callout explains the reason – “We are drifting.”
As a final dimension, the PM/FO needs to make themselves ready to intervene. Since they lack a way to effective steer the aircraft, their intervention would be to quickly position their feet over the tops of the rudder pedals to be ready to apply emergency braking prior to departing the taxiway.
Unscripted callouts challenge the PM to project their SA forward, anticipate possible adverse trends, detect these deviation events, choose what words to use in their callouts, make the callouts, and determine whether they effectively reverse the adverse trend.
