David Learmount/CAPE TOWN
Pilot disregard of rules has been revealed as the most common primary cause of civil transport aircraft approach and landing accidents (ALAs), according to a just-published report from the Flight Safety Foundation (FSF) Approach and Landing Accident Reduction (ALAR) task force. This exhaustive study of some 350 ALAs of varying severity was presented at an FSF international air safety seminar at Cape Town, South Africa, held on 16-19 November.
The ALAR Operations and Training working group report has studied 287 fatal ALAs in the period from 1980 to 1996 involving Western-built transport aircraft weighing more than 5,700kg (12,500lb) in which 7,185 people were killed. "Omission of an action/inappropriate action by a flightcrew member was identified as the most common primary causal factor," the report found. "This usually referred to the crew continuing to descend below the decision height or minimum descent altitude without adequate visual reference." Some 75% of all ALAs occurred on non-precision approaches.
The second most common primary cause of ALAs, the ALAR task force reports, is lack of position awareness, which includes awareness of height above terrain, and this "generally resulted in controlled flight into terrain". When all factors including contributory causes are taken into account, the other most frequent factors are low energy approaches (low and/or slow flight), flight handling, and "poor professional judgement/airmanship".
Studies of ALAs to CIS-built aircraft showed that the most common cause was "press-on-itis", which the report defines as a decision to continue the approach when conditions indicate higher than normal risk.
The most common circumstantial factors were reported as "non-fitment of presently available safety equipment", particularly ground proximity warning systems, and "failure in crew resource management (CRM)". Inadequate CRM was present in nearly half of the fatal ALAs. The report estimates that the accident rate at night is three times higher than during the day, and that the risk of fatal ALAs for cargo, positioning or ferry flights is eight times that of passenger flights.
Among the 78 fully documented non-fatal ALAs and serious incidents studied, the most common primary cause was "poor professional judgement/airmanship", which involved 74% of the events. "Press-on-itis" was present in 42% of all occurrences. The second most common primary cause was "omission of action/inappropriate action", or inadvertent deviation from standard operating procedures, a factor in 72% of cases.
Source: Flight International
