Human Factors in Aviation

The term “human factors” is used in many different ways in the aviation industry. Most people have known it in the context of aircraft cockpit design and Crew Resource Management (CRM). However, those activities are only a small part of aviation-related human factors, as broadly speaking it covers all aspect of human involvement in aviation.

The SHEL model can be helpful to use a model to aid in the understanding of human factors, or as a framework around which human factors issues can be structured. A model which is often used is the SHEL model, a name derived from the initial letters of its components:

• Software (e.g. Maintenance procedures, maintenance manuals, checklist layout.)
• Hardware (e.g., tools, test equipment, the physical structure of aircraft, design off light decks, positioning and operating sense of controls and instruments.)
• Environment (e.g. Physical environment such as conditions in the hangar, conditions on the line, etc. and work environment such as work patterns, management structures, public perception of the industries.)
• Livewire (i.e. The person or people at the centre of the model, including maintenance.

The industry need for Human Factors is based on its impact on two broad areas, which interrelate so closely that in many cases their influences overlap and factors affecting one may also affect the other. These areas are:

• Effectiveness of the system
• Safety
• Efficiency
• Well-being of operational

HUMAN FACTORS APPLICATIONS IN AVIATION
Control of Human Error To contain and control human error, one must first understand its nature. There are basic concepts associated with the nature of human error: the origins of errors can be fundamentally different, and the consequences of similar errors can also be significantly different. While some errors are due to carelessness, complacency, negligence or poor judgement, others are induced by poorly designed equipment, machine, poor maintenance or may result from a normal reaction of a person to a particular situation. The latter kind of error is likely to be repeated and its occurrence can be anticipated.

The control of human error requires two different approaches. First, it is necessary to minimize the occurrence of errors by ensuring high levels of staff competence; designing controls so that they match human characteristics; providing proper checklists, procedures, manuals, maps, charts, SOPs, training etc.; and reducing noise, vibration, temperature extremes and other stressful conditions. Training programmes aimed at increasing the co-operation and communication between crew members will reduce the number of errors (the total elimination of human error is a difficult goal since errors are a normal part of human behavior). The second avenue to the control of human error is to reduce the consequences of the remaining errors by cross-monitoring and crew cooperation. Equipment design which makes errors reversible and equipment which can monitor or complement and support human performance also contribute to the limitation of errors or their consequences.