The human element

At the end of the Second World War, my father was flying a Bell P39 Aircobra from the west coast to an Arizona boneyard. After spending the war as a multi-multi-engine flight instructor, he signed up as a ferry pilot for the opportunity to fly different kinds of airplanes. The P39 was a unique airplane in many ways. It was equipped with a tricycle landing gear with a nose wheel instead of the conventional arrangement with a tailwheel. Instead of an opening canopy overhead, the plane had a fixed canopy and doors on both sides of the cockpit. It even had windows that rolled down with hand cranks like automobile windows. Unlike other fighters the engine was located behind the pilot, right over the center of gravity. This design was made around a large canon in the nose of the airplane, which shot through the center of the propellor, which was driven by a gearbox connected to the engine by a driveshaft that ran between the pilot’s legs. Unlike the fighters designed for the European theatre, the Aircobra was not equipped with a supercharger, which meant that the engine could not produce full power at high altitudes. The plane generally flew missions at 10,000 feet or below. The rear engine also meant that the controls for the elevators and rudders, which normally run through the tube of the fuselage, had to be routed down and under the engine.

During this particular flight, the airplane was not armed. There was no need for armament for the journey to the scrapyard. As the plane crossed into Arizona, it experienced a catastrophic engine failure. There were not the advance kinds of accident investigations in those days, so exactly what happened isn’t clear. What did happen was that the engine completely quit. The propellor came to a stop and could not be feathered, creating a great deal of drag. Also the mechanical failure of the engine must have caused some engine parts to interfere with the control connections to the tail. the stick was frozen and had no fore or aft movement. Within seconds the airplane was completely uncontrollable and stalled into a spin. The only way for my father to save his life was to bail out of the airplane and trust his parachute. The gyrations of the plane and the increasing airspeed mede it impossible to open the doors. He had to release his four-point harness, roll down a window and climb out. The plane was falling faster than he and the tail hit him on its way back, but the injury was minor. The chute opened and he became a member of the caterpillar club - those whose lives were saved by a silkworm. I still have the reserve parachute he wore that day. Thankfully, it wasn’t needed. His altitude was too low to allow time to release a primary chute and deploy another.

Within a matter of seconds he had to figure out that his plane was spinning and attempt to control its flight, assess whether or not the plane could be flown and safely landed, make an exit plan, execute that plan, and pull a manual ripcord. When he told the story of the flight, he credited his survival to his practice of memorizing emergency procedures and practicing them on the ground before taking off in any airplane. He didn’t have to think, he could just react and trust his practice and memory to guide him.

Until the recent creation of sophisticated drones, aviation has mostly been dependent upon human pilots at the controls. Their mental and physical capacities have been tested by examiners and the issuers of licenses and they have been an essential part of the incredible safety record of flying. Commercial aviation has achieved an amazing safety record. Millions of passenger miles are flown with incident. People have learned to depend on airline flight as a safe mode of travel.

Part of this remarkable safety record is the practice of equipping modern airplanes with redundant systems. A modern airliner can continue flight even if an engine fails. If an electrical system fails, there is a backup system that can take over. If the hydraulics develop a problem, there is an alternative way of accomplishing the task. In many modern systems there are multiple levels of redundancy - backups to backups. The system is also based on humans who check the work of other humans. The work of mechanics is checked by inspectors. A pilot has a co-pilot even though the airplane could technically be flown by a single individual. The second pilot can watch for and correct mistakes.

As flight becomes more automated, there have been some who have suggested that sophisticated computers can fly more safely than human pilots. Auto landing systems have proven to work well. Autopilots are installed in all modern airliners. Automated navigation systems allow airplanes to fly into weather conditions that had to be avoided with less sophisticated planes.

Removing all human agency from the formula, however, comes with real risks. What happens when a sensor fails? If an airplane is equipped with multiple sensors, how does the computer decide which to trust and which to ignore? My father’s survival depended, in part, upon his capacity to feel fear and the adrenalin rush that gave him the energy to act extremely quickly. A computer doesn’t feel fear and always performs tasks at a consistent speed.

The capacity to make machines that can perform complex tasks does not remove moral agency. Human lives cannot be reduced to algorithms. The human element is still an important factor in the design of aircraft. So far even drones which do not carry human passengers require ground-based pilots to control their flight. Humans decide when and where the machines fly.

Our schools are producing some amazingly competent technicians who can create amazing machines. Equally important in the future will be ethicists and philosophers who will raise the questions of when and how to use the machines we have developed. Boeing is scrambling to come up with a technical fix for its 737 max aircraft. There are ethical and philosophical problems that are just as urgent. The sooner we realize this the safer our skies will be.

Copyright (c) 2019 by Ted E. Huffman. I wrote this. If you would like to share it, please direct your friends to my web site. If you'd like permission to copy, please send me an email. Thanks!