A Smooth Hand-Off

There are many models we could use in this short piece to describe the importance of a smooth transition from one mode of aircraft control to another – namely, the transition between manual flight (that characterized by no support from the autopilot, autothrottles or both) and coupled flight (that in which physical control of the flight path is under autopilot or autothrottles, or both). Because it can generate almost universal appeal, we’ll use competitive sports to help communicate the vitally important but little-emphasized concept of making these transitions both smooth and effective.

Nothing can be more frustrating as a sports fan than watching players on your favorite team mishandle the ball so that it ends up in the hands of the other team. And that goes for just about any sport, whether you’re a fan of American Football, Soccer (or Football to the international audience), Rugby, Hockey, Basketball, or countless other sports. This action, commonly referred to by at least a dozen similar terms as a “fumble,” “interception,” “steal,” “turn-over” or “dropped ball,” can suddenly turn the tide of competition in favor of the opponent, and often results in an undesirable outcome to the contest.

On the contrary, teams whose players and coaches manage these undesired events to a minimum are hailed with terms like “superior ball control,” “superior in protecting the ball (or puck),” and other related terms. And few things in sport are as fun and exhilarating to witness as a carefully executed hand-off, pass, or throw that advances the entire team towards the goal.

We have long suggested that the ability to make these smooth handoffs with ease and even elegance on the automated flight deck is one hallmark of superior Automation Airmanship. This ability is not as well understood or as attention-getting as when this is done poorly, and aviation has its terms to describe a poor hand-off, just like competitive sports: “Upset”, “Automation Surprise,” and more recently, “Startle” – and countless accidents involving automated aircraft bear the markings of a breakdown in the transition from coupled flight to manual handling.

We suggest that just a few steps can make these hand-offs smoother, including:

  1. Knowing the autopilot and autothrottle connect/disconnect “logic” – everything from how to smoothly cancel aural and visual warnings and alerts to what flight modes trigger disconnects – provides a solid framework for smooth hand-offs;
  2. Prior to connecting or disconnecting autoflight, take a few seconds to assess the state of the aircraft – trim, configuration, flight guidance, and powerplant modes – to ensure that no sudden flight path deviations are created as a result of the connect/disconnect action.

Just as a smoothly executed pass or hand-off is a sure sign of superior teamwork and integration, smooth transitions on the flight deck are a signal to your fellow crewmembers that you’re executing a high level of airmanship.

Until our next report, fly safe, and always, fly first.

San Juan, February 25th, 2013

Leave a Comment