An increasing number of Part 121 Pilots prefer to continue with an unstable approach in place of executing a go-around, as per a study conducted by Flight Safety Foundation.
Titled “Go-around decision-making and execution project”, the 55 page report find problems with both management oversight and pilot decision-making during unstable approaches among Part 121 Pilots.
The large majority of approaches, nearly 96%, are considered stable. Only 4% are considered unstable and of them only 3% result in a go around, said Greg Marshall, FSF vice president for global programs.
This report highlights the need for revising the final approach and touchdown zone standard operating procedures (SOPs) for pilots and the need to have more management oversight and use of flight data analysis (FDA).
Unstable Approaches are Rare, but Accidents do Happen
William Curtis, a co-author of the report and co-chair of the FSF International Advisory Committee, stated that all unstable approaches are not dangerous, but they can end up in accidents.
The report picks the accident of runway overrun of a 737-300 Southwest Airlines at Burbank-Glendale Pasadena on March 5th, 2000, as an example. A go around would have prevented this accident.
The captain told the NTSB that he was aware that his aircraft was not in the slot when he passed through 500 feet. In this case, the airspeed was more than the one required for safe landing. He was aware that the condition called for a go-around. He was silent when asked why he didn’t performed one.
An analyisis of the data collected in the FSF report indicates that when compared to pilot who make a go-around, pilot who continue with unstable approach to land rated the outcome of their flight as less positive, believed more often that a wrong decision was made, and strongly believed that they should not have made this decision. Even in case no accident or incident resulted, many regretted to continue with the unstable approach.
A Short of Oversight
The study also finds that enough management participation is missing. A large number of mangers who do participate are not aware of the unstable approach and go around compliance and the policies followed by the company.
Both the groups of pilots feel that the criteria for go-around set by their airlines was not realistic for operation on that particular day. The decision made by them was their own as there was little insight available from the management.
For decades, the concept of approach “gates” has been used by the industry. These are the altitudes at which important parameters must be present for an approach to be stabilized and touchdown zone. These approach gates have been set at 1,000 and 500 feet AGL. The FSF states the need for another gate at 300 feet AGL.
Marshall says, the safety analysis indicate that most of the properly loaded aircraft can stop safely even if it is moving at twice the normal rate. From flight idle, it can safely transition to good climb gradient from 300 feet.
Things change quite quickly at and below that altitude. Pilots have to make quick decision and training plays an important role in how the last few seconds before and during touchdown are managed by the crew. Either pilot can execute a go around till the time thrust reverser are deployed.
Deviating from the touchdown zone parameters may caused by contaminated runway or unstable approach, can increase the change of a possible deadly runway excursion.
The reports concludes that with some guided decision-making at the time of approaches and landing, flight crew is in a better position to trust and comply voluntarily with written policies. It is because these policies are framed keeping in mind the changing environment in which pilots work and the risk they face constantly.
Executing a go around has its own set of risks and it is because of this reason active communication is important during landing phase. It is another issue uncovered by the report.
the authors of the report highlights that “Safe Landing Guidelines” published by the Flight Safety Foundation to overcome identified problems in the ALAR Tool Kit risk-reduction tools, is no documented in operations manuals and is not well known by operators.
However, these operators do realize that these recommendations work effectively when properly implemented.
According to Curtis, one operator who worked on these recommendations saw a 90% reduction in go around exposure. Moreover, there was a significant improvement in the rate of unstable approach at 500 feet and below landing.
Considering the number of overrun accidents that happen with chartered and private jets, this study and its recommendations are worth taking note of.