Rejected Takeoffs Reconsidered

Airline flying is pretty cushy work most days, particularly at the major US carriers, with largely reliable aircraft, a fairly robust support network, and nearly universal procedures that keep everyone on roughly the same page. Most airline pilots, by temperament and long experience, are perfectly content with the atmosphere of ordered boredom that normally reigns on the flight deck. There are, indeed, very few situations that require the Sully-esque nerves of steel and lightning-quick reflexes with which our species is sometimes credited. These attributes are in fact actively discouraged thanks to a long and distinguished history of airline pilots creating emergencies out of benign situations through overly hasty action. There’s an idiosyncratic phrase in common usage at my airline: “Wind the clock!” It refers to old timepieces that needed daily winding, and the idea is that, in most situations, a captain should be calm and collected enough to reach into their flight kit, fetch their trusty gold pocket watch, and leisurely begin winding it while thinking through their plan of action.

There are, of course, a few counterexamples, dramatic events that do require prompt corrective action: engine failures at low altitude, microburst encounters or rejected takeoffs, for example. Because these “no-time threats” (in the parlance of my airline’s CRM program) happen so rarely in modern airliners but require an immediate rote response, we regularly train for them in full-motion flight simulators. Even go-arounds, which aren’t emergencies but are certainly seldom-seen maneuvers that are fairly easy to goof up, have become emphasis items during training, and our crew briefings now include a refresher on go-around procedures.

I’ve experienced a small handful of “no-time” emergencies in 27 years and 14,000 hours of flying: a momentary engine failure in my Piper Pacer because of contaminated fuel, a partial loss of power in a Cherokee at low altitude, an electrical fire in a flight school light twin, smoke in the cockpit of a Horizon Air Q400, and perhaps five or six rejected takeoffs. All but one of those aborts took place while I was in the right seat, basically along for the ride on one of the few maneuvers that remain the captain’s exclusive domain. My sole high-speed abort was thanks to a captain who overreacted to a momentary door light, a big no-no. I didn’t have a single rejected takeoff during six years in the left seat at my last airline, so I was a bit surprised to find myself performing my first RTO as a new Boeing 737 captain this past August, with just over 100 hours in the airplane.

We were on the last leg of a four-day trip, flying from Denver to New York, and we had just picked up a jet from a crew who reported that the No. 1 thrust-reverser light had illuminated during approach. On the 737, this light can mean anything from a minor glitch to an uncommanded reverser deployment. The local mechanics looked at the onboard diagnostics and deduced that the light was caused by a momentary, spurious fault. The ship had no history of reverser problems. After clearing the fault and running the engine at idle, the mechanics couldn’t reproduce it, so they signed off the discrepancy. Half an hour later, we had just started our takeoff run on Runway 34L when the first officer, Clint, announced, “Master caution—looks like the reverser light came back on.” I hesitated for a long moment, declared, “Abort!” and closed the throttles, disconnected the autothrottles and deployed the thrust reversers. The autobrakes delivered a noticeable jolt as they kicked in, but it was otherwise a docile maneuver; we never got above 45 knots.

Even a low-speed rejected takeoff involves quite a bit of cleanup work, including clearing the runway, communicating with flight attendants, informing the passengers, running the post-abort considerations checklist, coordinating with dispatch, maintenance control and local operations, taxiing back to the gate, conferring with tech ops (they disabled and deferred the reverser this time), getting re-dispatched and refueled, making multiple PAs, talking to concerned passengers, and calling the duty pilot. I was fortunate to have a capable first officer who made my job much easier; incidentally, Clint is one of nearly 2,000 pilots at my airline who will be furloughed by the time you read this, unless Congress intervenes. We pushed back an hour after our original departure and made up some time en route to Kennedy International Airport. Along the way, we talked about the abort and worked on our mandatory crew reports.

Read More from Sam Weigel: Taking Wing

Normally, my trips are ancient history as soon as I set the parking brake on the last leg, but I did ponder our low-speed RTO for several days. The decision to abort was the correct one, and we both executed the rejected-takeoff procedure and handled the aftermath very well. However, there was a long, pregnant pause of perhaps two seconds between the time that Clint announced the master caution light and when I initiated the abort. The delay itself wasn’t a big deal as we were still at low speed; the problem was that I hesitated because I was doing something that is somewhat discouraged on the takeoff roll: diagnostic thinking.

There is a very long history of accidents and serious incidents as a result of ill-advised RTOs, and so the FAA, airlines and aircraft manufacturers have put a lot of effort into simplifying the decision process. First, they separated the takeoff into low-speed and high-speed regimes; at my airline, the pilot monitoring makes a callout at 80 knots to signify the transition. Next, they decided that high-speed aborts should be initiated for only the most-serious emergencies, including engine failures, fires or severe wind shear. Aircraft manufacturers incorporated the “dark-cockpit” concept into their designs and inhibited non-severe caution lights during the high-speed takeoff regime. Finally, an aborted takeoff became the default decision for any abnormality in the low-speed regime, especially if the fault cannot be instantly diagnosed.

This is particularly pertinent on the 737, which still doesn’t have the crew-alerting system required of newer designs thanks to its original 1967 certification—an issue that once again reared its head during the Max debacle. Diagnosis requires hunting around the cockpit for the offending fault, perhaps craning your head way back to look at the overhead engine panel where the thrust-reverser lights reside. Thus, at the start of every trip, I brief my first officer, “Prior to 80 knots, I will abort the takeoff for any master caution light.” But that’s not exactly what I did. When the master caution illuminated, Clint immediately thought of the previous reverser fault, glanced up and saw the light, and vocalized the specific fault after announcing the master caution. He wasn’t at all wrong to do so. But instead of hearing “master caution” and initiating the abort, I heard, “Looks like the reverser light came back on.” Those two seconds were how long it took me to think: “Were we expecting that? No. It’s not deferred. It’s probably the same spurious fault, but I can’t guarantee that. It’s a new and unknown occurrence. Abort.”

At 30 knots on a 16,000-foot runway, those extra two seconds represented absolutely no loss of safety. But what if the light came on at 75 knots on a short, narrow runway with a feisty crosswind? Two extra seconds at full power would represent a significant and unwelcome addition of energy. The whole reason professional pilots try to do things the same way every time is so we retain the habit patterns that assure the greatest margin of safety in the most marginal circumstances.

Here’s the thing: This wasn’t exactly an unknown threat. We knew about the ship’s recent maintenance history. I could have prevented the hesitation (“mitigated the threat,” per my airline’s CRM gurus) by anticipating and briefing the potential for a recurrence of the problem on the takeoff roll: “We have a recent history with the No. 1 thrust reverser, and there’s a possibility the fault light will come back on during takeoff. If so, prior to 80 knots, I will abort the takeoff; after 80 knots, I will continue.” This would have prepared me to do the right thing in a potentially ambiguous situation. The main lesson I’m taking away from the incident is to improve my RTO decision-making by incorporating recent maintenance history into my abort criteria briefings.

There’s a lesson here for general aviation pilots as well, I think. We often talk about briefings in the context of multiple-pilot flight crews, as a way to make sure both pilots are on the same page, but they are equally a tool to make sure your own head is straight. Our brains evolved for purposes of pattern recognition, and we arguably do our quickest, clearest thinking when we think in computerlike, Boolean terms (“If A equals true AND B equals true, then condition C equals true; execute action Z”). Briefings essentially pre-load a logic problem into your brain, predisposing you to monitor the variables, predict likely outcomes and execute the desired reaction. I encourage you to think through what the “no-time” threats are in your own flying, brief the most pertinent ones on every takeoff and approach/landing, and review the more general threats (electrical fire, runaway electric trim, open cargo door after takeoff) on a regular basis—perhaps before your first flight of each month. I think you’ll find that the time and effort is a worthwhile investment in making that critical moment of decision a little smoother when things don’t go as planned.

This story appeared in the December 2020 issue of Flying Magazine