The first 39 manufactured DHC-8-100 aircraft had a design problem such that, if the friction control was wound to the full out (friction off) position, the flight idle gate was ineffective in reducing the likelihood of pilots inadvertently moving the power levers below flight idle in flight.
The Service Bulletin addresses the problem with an appropriate fix.
The Civil Aviation Safety Authority (CASA) issued Airworthiness Bulletin (AWB) 61-009 on 12 January 2012 to inform Australian operators of DHC-8 100-300 series aircraft about the design issue.
The AWB recommended an inspection of the power lever quadrant in order to ascertain the ongoing serviceability of the aircraft. Under Civil Aviation Regulations, CASA mandates all ADs from the State of Design. Accordingly, CF-2012-08 became a mandatory requirement for Australian operators on 30 January 2012.
The ATSB is satisfied with the manufacturers safety action concerning this safety issue.
In response to this design problem, Bombardier Inc. issued an alert Service Bulletin A8-76-32 on 24 January 2012, which recommended the modification of the friction lever spring on all aircraft between serial number 001 thru 039 in order to prevent contact between the friction lever spring and the flight idle gate.
The ATSB is satisfied that the safety action addresses the safety issue.
Transport Canada mandated the alert service bulletin with Airworthiness Directive (AD) CF-2012-08 Power lever Friction Brake Assembly Discrepancy on 30 January 2012. That AD mandated compliance with the aircraft manufacturer’s service bulletin.
The ATSB is satisfied with the Transport Canada safety action to address the safety issue.
