Human Factors and Automation

The Role of Automation and the Pilot

There's been huge debate over whether automation has changed the role of the pilot because of the growth of "autopilots", "autothrottles" and all the other other automated systems in the cockpit. Let's look at and compare their roles first.

Pilot's Roles and Sub-tasks

The main role of a pilot is to maneuver the airplane from A to B safely and efficiently. Other than that, there are five sub-tasks for pilots to perform:

1. to operate, manage, and to monitor the engines and airplane control systems;
2. to avoid inadvertent encounters with either unfriendly terrain or with objects on the ground;
3. to navigate efficiently to the destination airport;
4. to ensure comfort to the passengers and crew by operating and monitoring such systems as pressurization and temperature control;
5. to communicate with company operations and with air traffic control.

(Orlady, 1999¹)

(Picture embedded from Frank on 30 September 2009)

Automation in aviation

The most common automation system in aviation is autopilots. Manual flying, especially on long cruise legs, is a very fatiguing task, autopilots make it much easier to fly smoothly enroute with precision, they are certified for use in all phases of flight except takeoff. (Orlady, 1999¹)

(Picture embedded from Experienmental Airplane on 1 October 2009)

Autothrottles which control thrust from the engines by controlling fuel flow, are used to automatically determine engine parameters and to set engine power for nearly all flight phases, including takeoff. (Orlady, 1999¹)

Anti-skid braking systems are also in wide use, they consist of a pressure modulating system that gives the airplane maximum braking by automatically releasing any braking wheel just before it locks-up and skids as, if a braking wheel locks up, the wheel's traction capability is significantly reduced. The system provides maximum braking for landing or an aborted takeoff, it allows the pilot to select different deceleration rates for automatic braking on landing. (Orlady, 1999¹)

(Picture embedded from Fligh Story on 30 September 2009)

Therefore automation is simply a tool to help the pilot fulfill thier traditional duty. It has not changed the pilot's role in securing the aircraft's safe journey. But the tasks required for a pilot to perform thier role have changed considerably. With the advanced technology nowadays, it is possible to completely automate the airplane and to have a pilotless aircraft, but for both safety and socio-political reasons, it is neither feasible nor acceptable.

Three categories of automation

Modern automation can be divided into
"control automation", which assists the pilot in airplane control tasks or substitutes the pilot's manual manipulation with the automatics, and

"information automation", which includes all of the display and avionics that are devoted to navigation and environmental surveillance and to the digital communications that are a growing part of both air traffic control and airline operations.

The third category is called "management automation", which includes all of those things that aid the pilot in the management of the mission. Management automation guides the airplane, performs the necessary flight functions, and furnishes the pilot with information involving both the state of the airplane and of progress toward the mission's goal.
(Orlady, 1999¹)

In the pilot/computer interface page, the pilot and automation relationship is discussed in detail in relation to aviation safety.

Advantages of Automation²

1. Reduces manual workload and fatigue
2. Relief from small errors
3. Economical utilization of machines
4. Precision in the handling of routine tasks
5. Increased productivity

Disadvantages of Automation²

1. Automation- induced failures
2. False alarms
3. Boredom
4. Increase in mental workload due to additional monitoring of systems
5. Over-reliance, complacency; willing to accept results without scrutinizing them first
6. Silent failures
7. Reduced alertness of operator, by offering a false sense of security

Existing Automation Philosophies

The FAA has offered a summary of 3 manufacturers’ philosophies on automation³;

Airbus³

• Automation must not reduce aircraft reliability, it should enhance aircraft and system economy, safety and efficiency.
• It should maintain the aircraft on its normal flight envelope and not lead the aircraft away from its safe flight envelope.
• Automation must not work against the operator’s input unless when necessary for safety.
• The operator should be able to use the safe flight envelope to its full capacity in cases of extraordinary circumstances.

Boeing³

• The pilot is the final authority in flight operations.
• Important flight crew tasks in rank of priority are flight safety, passenger comfort and efficiency.
• Design systems should be error tolerant.
• Automation is there to assist and not replace the pilot.
• New technology should be used only when the outcome is clear and where the outcome provides efficiency advantage and has no adverse effect on human-machine interface.
• Human fundamental strengths, limitations and differences should be addressed in both normal and non-normal operations.
• Hierarchy of design alternatives should be in the order of simplicity, redundancy followed by automation.
• Flight crew tasks in rank of priority are; safety, passenger comfort and efficiency.

McDonnell-Douglas³

Technology is there to assist the pilot naturally however the pilot is the final authority in flight and he/she should be able to override the computer and use his / her own skills and experience when need be.

References

1. ORLADY, H.& ORLADY, L. (1999). Human Factors in Multi-Crew Flight Operations. Brookfield: Ashgate Publishing Ltd.

2. Weiner, E.L., & Curry, R.E. (1980). Flight-deck automation: Promises and problems. Ergonomics, 23, 995-1011.

3. Orlady, H.W., & Barnes,R.B. (1997).A Methodology for Evaluating the Operational Suitability of Air Transport Flight Deck System Enhancements, Society of Automotive Engineers, Warrendale, Pennsylvania.

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Aimee_Z
Melanie Attan
IWEMcCulloch