Why we need 2 Pilots in the Flight Deck

INTRODUCTION

“Safety starts with two.” It’s a quote used by ALPA (AirLine Pilots Association) to help spread the word about what it means to have two pilots in the flight deck; a hot topic as some are pushing for single pilot airline operations. Imagine, you’re ready to board the flight, you grab your belongings and get in line according to the zone. Eventually you get up to the front of the line, scan your boarding pass and off to the bridge you go. The FA at the entrance takes a quick peek at where you sit, and sends you off in the right direction. Just as you are about to make the turn, you notice the flight deck. Amongst a miriade of switches, you notice two pilots diligently working away. You proceed to your seat, and get comfy knowing you are in safe hands, literally. If you’ve ever wondered why there are two pilots in the flight deck, and why that is critical to safety, today I am going to help you answer that very question.

2’S A TEAM, 4’S A PARTY

Boeing Stratocruiser with a 4-man crew, 1950's.

The primary reason we have two pilots in the flight deck is to maximize safety by dividing up the work between them. In the days of past, it was actually common to find four pilots in the aircraft. You’d find the most senior being the captain, followed by a first officer, a navigator, and a flight engineer. Each had a specific role to play. The captain would be responsible for the overall safe handling of the flight, the first officer (who was also second-in-command), would help the captain in their duties. Behind the pilots would be one navigator whose main job was… well pretty self-explanatory. We are talking about a time before GPS was common place, so plotting charts, ground based nav aids, and an expertise in understanding world navigation was a special requirement. It required specialized training to learn such skills, and the importance of the navigator could not be more emphasized. The fourth person in the deck would often be the flight engineer, responsible for the management of complex aircraft systems. The flight engineer would have a large suite of instruments ahead of them, and kept an eye on the health of the plane. This division of work was necessary, as computers and GPS had yet to make their mark in the flight deck.

Fast forward to the modern age, and we got both of those things. The GPS system became very common, making the job of the navigator redundant and an unnecessary requirement. With computers, aircraft systems started to simplify, and negated the reason for a physical person to watch over them; computers could do it themselves. That brings us to today, two pilots in the flight deck.

ONE TO FLY THE BIRD, THE OTHER TO WATCH IT FLY

The point of having two pilots, is to divide the workload of the modern flight deck. And while computers have advanced by a large margin compared to the early days of jet travel, the stellar safety record or airline flying warrants the use of two pilots. While on the ground, roles are divided between the Captain and the First Officer. When we are in the air, these roles turn into Pilot Flying and Pilot Monitoring, irrespective of who is sitting in what seat.

On the ground, the Captain is responsible for overall management of the crew and takes primary lead if issues crop up. If issues do come up, usually the captain is informed first, at which point they can start delegating the workload to the team. For example, if an unscheduled maintenance item comes up, the Captain is notified first. They will start talking with maintenance, while delegating other duties to the First Officer. The First Officer may contact operations control, and request a delay on the flight. This delay will be coordinated with the Flight Attendants and gate agents. They in turn might elect to delay boarding until the issue is resolved. When we start to taxi, the captain is responsible for ground movement of the aircraft, while the First Officer runs checklists, manages communications, and keeps a watchful eye.

As soon as the aircraft lines up for the runway, the duties of the pilots are immediately divided into a Pilot Flying (PF) and a Pilot Monitoring (PM) (already pre-decided). The role of the PF is to essentially maintain safe control of the aircraft, through manual or autopilot flight. The role of the PM is manage communication with ATC, run checklists, modify the Flight Management System as needed, and keep an overall watchful eye on the safe operation of the flight.  For example, after we complete the takeoff the flaps have to be retracted. As the aircraft passes through the minimum flap speed, the PF will ask for a flap selection. The PM will then move the flap lever. Once the flaps are completely up, the PF will ask for the “after takeoff checklist” and the PM will open and complete the checklist. If there is an instruction by ATC to let’s say turn the plane to a given heading, the PM will respond to ATC, acknowledging the clearance, while the PF will make the selection over the autopilot. By dividing up tasks in this manner, we are able to manage the workload effectively, and keep the integrity of the flight. And while all of this sounds like normal work, the effect of two pilots is only more emphasized when things aren’t normal.

“YOU SOLVE ENOUGH PROBLEMS, YOU GET TO COME HOME”

I love that quote above, from one of my favourite sci-fi films, The Martian. In the scene, Mark Watney is giving a lecture about what it took for him to get home to Earth. He shares his greatest tip, which was “you solve enough problems, you get to come home.” Even if it is just a film, the essence of the quote holds true, time and time again.

Airbus A220 with a 2 pilot crew.

Suppose an engine shows signs of degradation, leading to a slow but clear failure. We have on our hands a real emergency. Immidiately, there are 3 main pillars which we use to guide ourselves; Aviate, Navigate, Communicate. The first priority is to "aviate"; that is to fly the airplane. The PF will set max thrust on the operating engine and set the minimum safe speed, thereby maintaining safety of the flight profile. The PM will ensure these two critical actions are complete, and declare an emergency with ATC (the infamous “mayday” call). This will spring ATC into action, providing the flight with priority service, amongst other things. This introduces “navigate” into the mix. ATC will want us to move away from the dense corridors in which we fly, so they may provide headings which the PF will input. We also won’t be able to maintain our altitude, and to make matters worse, could very well be over high terrain. This means drifting down to an altitude that can safely be maintained at one engine, but also keeps us above terrain. Having an accurate idea of what it might be is a PM doing their job well, but also means that the PF has to get the airplane to descend safely. Now comes running checklists, which the PF will call for, and the PM will start to execute. The checklist is read out loud, ensuring both pilots understand the actions, and done at a steady pace; not too fast nor too slow. Then comes “communication”, which I like to further break down into ABC’s (ATC, backend, company). The ATC communication generally happens early on; that’s us declaring the emergency, often done by the PM. Backend communication means talking to the flight attendants about the situation, and addressing our passengers. This is usually done by the Captain but can be done by either crew member. A big part of that communication pillar is the company. Once they are notified, they provide us the legal and operational help needed to divert somewhere safely.

This entire scenario happens within fifteen to twenty minutes, and by the end we have a new plan on how to get the airplane on the ground, safely. There are so many other important factors I did not discuss, such as weather, inoperative systems, geopolitics, etc. As you can see, the amount of workload with emergencies is exponentially more, but with two pilots we are able to manage it so effectively, that almost all emergencies end up in a safe outcome. Even under the worst of conditions, safety is never compromised. Research in the simulator shows that when one pilot is removed even for mundane tasks, task saturation can quickly set in on the remaining pilot, leading to errors, some of which might (and have) cost lives. We practice these, and many other scenarios in the simulator frequently, and put a large emphasis on crew coordination. Like the engine failure scenario; "you solve enough problems, you get to come home."

CONCLUSION

So as you can see, while the number of pilots over time has reduced, we have hit the minimum bar for safety with two pilots. An important distinction, this blog was written in the context of narrowbody, two pilot operations. On larger planes, in the event of an emergency, often all pilots (upto 4) will convene back into the cockpit. Not only are two pilots important for crew coordination on normal days, but they become even more critical when things go wrong. And although we hope each flight should be as uneventful as possible, things can, and do crop up. When that happens, two highly trained pilots start executing their roles to such proficiency, that passengers commonly report that serious events didn't feel all that alarming. It is to that effect, that aviation continues to be the safest mode of transportation. After all, "safety starts with two."