Aviation safety is defined in annex 19 to the Chicago Convention, as the state in which risks associated with aviation activities, related to, or in direct support of the operation of aircraft, are reduced and controlled to an acceptable level.
The nature of commercial flight operations – high speeds at altitude in a pressurized environment – means risk cannot be completely eliminated.
In order to achieve and maintain safety, Contracting States have drafted detailed regulations adopted from ICAO annexes to regulate inter-alia; licensing, air traffic control, aircraft operations and maintenance. Such regulations, enforced by state regulatory and oversight agencies, require operational personnel for all aviation organizations to undergo elaborate training (initial and recurrent) so that their competence in risk control and management can be assessed.
Unfortunately, regulations are not sufficient. They are simply words written on paper with limited effect on human behavior. In addition, regulatory and oversight agencies do not run the day-to-day affairs of organizations. To achieve safety, an organization has to continuously promote safety as a core value with practices that support a positive safety culture in its daily operations. Key to this is decision making and internal policies rather than regulatory compliance.
The two illustrations below show accidents caused by poor decision making and internal policies within aviation organizations.
Nigeria Airways Flight 2120
On 11th July 1991, a Nation Air DC-8 operating for Nigerian Airways suffered structural damage caused by a fire, and crashed ten minutes after takeoff from King Abdul Aziz International Airport, Jeddah.
Four days earlier, a mechanic had been stopped by the Nation Air project manager from changing under inflated and partly worn out tires, to enable the aircraft depart on schedule.
The mechanic altered figures on the maintenance log to indicate that the tires had been inflated to normal pressure, whereas not.
On the day of the accident, Nation Air’s lead mechanic told the project manager in Jeddah that there was need to top up the under inflated tires, but the latter directed that the aircraft depart on schedule without servicing the tires.
The underinflated tires led to uneven weight distribution on the left landing gear, damaging the fully inflated tires. This led to intense heat buildup while taxing to the runway. Unknown to the flight crew, two tires on the left main landing gear burst during the take off roll.
Intense heat caused by the wheel assembly scrapping along the runway caused a fire, which spread to the wheel well and aircraft cabin upon retracting the landing gear.
The fire caused massive structural damage and the crew lost control while attempting to return to the airport for an emergency landing. The plane crashed two miles short of the run way, killing all 247 passengers and 14 crew members.
The aircraft accident report prepared by the Saudi Arabian Ministry of Defense and Aviation, attributed the crash to signing off the aircraft as fit for flight in an un-airworthy condition, caused by under inflated tires.
Alaska Airlines Flight 261
On 31st January 2000, an Alaska Airlines MD-83 crashed 2.7 miles north of Anacapa Island, California, after failure of the horizontal stabilizer following collapse of the jack-screw assembly. There were 88 fatalities.
The airline had undertaken reforms to increase revenue. Such reforms included doubling utilization of aircraft and extending service intervals. This put the maintenance schedule under pressure, and as a result, planes were returned into service without proper maintenance. Supervisors were found to have falsified records and passed unfit aircraft as fit to fly.
A maintenance officer had earlier recommended that the Jack screw assembly for the aircraft involved in the accident be replaced. His recommendation was overruled and the plane returned into service. He leaked details of Alaska Air’s violations of maintenance procedures to the U.S Department of Transportation. The airline retaliated by suspending him from work.
The National Transportation Safety Board report determined that the probable cause of this accident was loss of airplane pitch control, resulting from the in-flight failure of the horizontal stabilizer trim system jackscrew assembly’s acme nut threads. The thread failure was caused by excessive wear resulting from Alaska Airline’s insufficient lubrication of the jackscrew assembly. Contributing to the accident were Alaska Airline’s extended lubrication interval and the Federal Aviation Administration’s (FAA) approval of that extension, which increased the likelihood that a missed or inadequate lubrication would result in excessive wear of the acme nut threads.
What the two accidents have in common:
* Maximizing use of aircraft to boost revenue, effectively placing “production” ahead of “protection”.
* Pressure from senior management for aircraft to stay on schedule.
* Management not being aware of the consequences of their actions.
* Fear by junior staff of countermanding their superior’s actions/decisions for fear of retribution. The management style of both airlines was manipulative and authoritarian. Employees were apprehensive of doing anything the airlines considered not in their “best interests”.
* Deliberate falsification of records by maintenance personnel.
* Information regarding unfit condition of aircraft was never shared with the flight crew (although it was never established if the pilots when informed, would decline to fly).
* Both Countries had agencies entrusted with regulatory, oversight and enforcement function: Transport Canada (Canada) and the Federal Aviation Administration (United States of America).
* Both aircraft had operations manuals that indicated when an aircraft was fit to be released into service and approved service intervals. These manuals were known by the airlines and regulatory/oversight agencies as these aircraft were on the respective national registers.
* Hazards were identified and known, but trivialized.
* Crashes were caused by a poor corporate safety culture, not lack of a safety regulatory framework.
The two accidents illustrate that operational personnel in aviation environments do not operate in isolation, but are bound by contractual obligations and interests of higher authorities in the organization’s hierarchy. As a result, their attitudes are influenced by top management and senior administrative personnel who may have limited knowledge and appreciation of aviation’s inherent risks.
Such attitudes constitute the corporate culture which in essence is the personality of the organization. It was part of the corporate culture at Nation Air and Alaska Airlines to “cut corners” regularly, in effect, placing profit ahead of safety, with disastrous consequences.
Regulations, though a good starting point, are not sufficient. An organization’s corporate culture, emphasizing safety ahead of profit, is the only way risks associated with aviation can be reduced and controlled to an acceptable level.