From SKYbrary Wiki
Plan Continuation Bias
(Plan) Continuation Bias is the unconscious cognitive bias to continue with the original plan in spite of changing conditions.
Unconscious bias in thinking leads to a pilot or controller following the originally-intended course of action. This bias appears to be stronger as the culmination of a task nears, for example during the flying of an approach to land or the maintenance of the planned separation between aircraft sequenced for approach to a particular runway.
Continuation Bias may have the effect of obscuring subtle cues which indicate that original conditions and assumptions have changed. It may also act in combination with other cognitive biases.
Accidents and Incidents
SKYbrary includes the following reports relating to events where continuation bias was considered to be a factor:
- RJ85, vicinity Medellín International (Rionegro) Colombia, 2016 (On 29 November 2016, a BAe Avro RJ85 failed to complete its night charter flight to Medellín (Rionegro) when all engines stopped due to fuel exhaustion and it crashed in mountainous terrain 10 nm from its intended destination killing almost all occupants. The Investigation noted the complete disregard by the aircraft commander of procedures essential for safe flight by knowingly departing with significantly less fuel onboard than required for the intended flight and with no apparent intention to refuel en route. It found that this situation arose in a context of a generally unsafe operation subject to inadequate regulatory oversight.)
- SH36, vicinity Oshawa ON Canada, 2004 (On 16 December 2004, an Air Cargo Carriers Shorts SD3-60 attempted to land at Oshawa at night on a runway covered with 12.5mm of wet snow which did not offer the required landing distance. After unexpectedly poor deceleration despite selection of reverse propeller pitch, full power was applied and actions for a go around were taken. Although the aircraft then became airborne in ground effect, it subsequently failed to achieve sufficient airspeed to sustain a climb and an aerodynamic stall was followed by impact with terrain and trees beyond the end of the runway. The aircraft was substantially damaged and both pilots sustained serious injuries but there was no post-crash fire)
- C550, vicinity Cagliari Sardinia Italy, 2004 (On 24 February 2004, a Cessna 550 inbound to Cagliari at night requested and was approved for a visual approach without crew awareness of the surrounding terrain. It was subsequently destroyed by terrain impact and a resultant fire during descent and all occupants were killed. The Investigation concluded that the accident was the consequence of the way the crew conducted the flight in the absence of adequate visual references and with the possibility of a ‘black hole’ effect. It was also noted that the aircraft was not fitted, nor required to be fitted, with TAWS.)
- AS65, vicinity North Morecambe Platform Irish Sea UK, 2006 (On 27 December 2006, an AS365 Dauphin 2, operated by CHC Scotia, crashed into the sea adjacent to a gas platform in Morecambe Bay, UK, at night, following loss of control.)
- L410, Isle of Man, 2017 (On 23 February 2017, a Czech-operated Let-410 departed from Isle of Man into deteriorating weather conditions and when unable to land at its destination returned and landed with a crosswind component approximately twice the certified limit. The local Regulatory Agency instructed ATC to order the aircraft to immediately stop rather than attempt to taxi and the carrier’s permit to operate between the Isle of Man and the UK was subsequently withdrawn. The Investigation concluded that the context for the event was a long history of inadequate operational safety standards associated with its remote provision of flights for a Ticket Seller.)
- The “Barn Door” Effect by C. West, Ph.D., NOAA - a paper about pilots’ propensity to continue approaches to land when closer to convective weather than they would wish to get while en route.