Since 1908, when Lt. Thomas Selfridge achieved the regrettable distinction of becoming powered flight's first fatality following the crash of a Wright Model A airplane during a flying demonstration for the U.S. Army at Fort Myer, Va., safety has been the aerial pursuit's foremost priority.

It is drummed into the conscience of every pilot and maintenance tech from the moment training begins, and has culminated in aviation being one of the most scrutinized activities in human history - not to mention the safest form of mass transportation in the modern era. That this relentless monitoring occurs both externally by mandate of various aviation authorities and internally as a voluntary commitment by all categories of operators, from private pilots to business flight departments, the airlines and military aviation branches, is a testament to the aviation community's dedication to safe operations.

For several decades, safety auditing has been a keystone of the monitoring process. This has included periodic - and often unannounced - regulatory audits of commercial operators by aviation authorities as well as voluntary process audits by third-party companies specializing in the activity. During the past 20 years, a proliferation of audits, auditors and safety standards has blanketed the industry.

This became a problem among the airlines in the 1980s and 1990s as carriers formed interlining/code-sharing alliances (when they couldn't merge outright) in the quest for dominating their respective markets. To assure equivalent safety levels, everyone was auditing everyone else according to a plethora of widely varying standards, with some carriers undergoing such evaluations almost continuously. If an airline had 15 code-sharing arrangements, it had to audit all 15 of its partners - and each of them had to audit it - all with consequent expense in terms of personnel workload, loss of productivity and auditing fees. To add this burden, audit results weren't being shared, resulting in an unnecessary redundancy of audits.

Eventually, the carriers appealed to the International Air Transport Association (IATA) to establish a common standard for audits and auditors, and this led to formulation of the IATA Operational Safety Audit, or IOSA. Now, a carrier could be audited once annually according to a universally accepted set of standards and the results of the examination shared throughout the industry via a secure IATA-maintained registry.