De Havilland Canada Dash 8: Difference between revisions

On October 13, 2011, [[Airlines PNG Flight 1600]], Dash 8-103 P2-MCJ, was on approach to [[Madang Airport]] when the [[first officer (aviation)|first officer]] accidentally pulled the power levers through the flight idle setting and into the [[Turboprop#Technological_aspects|beta]] setting while trying to reduce airspeed. In beta, which is intended for ground operations and slowing the aircraft after landing, the [[Variable-pitch propeller (aeronautics)|variable-pitch prop]]s transition to flat pitch. In high-speed flight, the rapid airflow through the improperly configured props caused them to overspeed and drive the engines rather than the engines driving the propellers, which caused engine damage and a total loss of engine power. The aircraft crashed during the ensuing off-airport [[forced landing]] attempt; both pilots, the flight attendant, and a single passenger survived with injuries, while the other 28 passengers were killed. The [[Papua New Guinea Accident Investigation Commission]] (AIC) found that the pilots made several other serious errors, including a failure to utilize checklists and a failure to lower the landing gear and [[Flap (aeronautics)|flaps]], which would have slowed the aircraft before impact and reduced the severity of the crash; however, the AIC concluded that a major cause of the accident was the fact that it was possible to actuate beta in flight, coupled with inadequate training for flight crews to recognize and correct this situation. A beta lockout feature was available as an option for the Dash 8, but it had not been installed in P2-MCJ, and the beta warning horn had been inoperative.<ref name=PNG1600/>

 

 

While investigating these two events, the AIC and the [[Australian Transport Safety Bureau]] (ATSB) determined that a number of similar inadvertent in-flight actuations of beta had occurred in the Dash 8, and recommended that steps be taken to prevent it, including more thorough pilot training.<ref name=PNG1600/><ref name=VH-SBV/> In 2012, in cooperation with the AIC and ATSB, [[Transport Canada]] issued an [[airworthiness directive]] (AD) mandating the installation of beta lockout on all Dash 8 aircraft that did not have it, a second AD mandating more frequent testing of the beta warning horn, and a service bulletin requiring a cockpit placard to warn pilots not to move the power levers below the flight idle setting while airborne.<ref name=PNG1600/><ref>{{cite web |title=Dash 8 propeller system design |url=https://www.atsb.gov.au/safety-issues/AO-2011-159-SI-01 |website=atsb.gov.au |publisher=Australian Transport Safety Bureau |date=February 25, 2013 |access-date=July 30, 2024}}</ref>