Urges FAA to Require Safety Assessment, Fixes for Excessive Fuel Flow & Power Loss Issue

The NTSB has published a distressing report for Cirrus SR22T owners, recommending action on a possible engine power loss on takeoff. 

In the report, they reference 6 separate accidents involving Cirrus SR22T airplanes which lost engine power during the takeoff climb, in which 5 showed excessive fuel flow rates as high as 50 gph. The designed fuel flow, with the boost pump on, should deliver 19 gph, or, when set to "High Boost/Prime", as high as 42 gph. Excessive fuel flow could only be accurately diagnosed in 3 of the cases, in which 2 revealed the priming position was selected, and that other by an improperly adjusted slope controller. 

In 2018, the issue was somewhat addressed by the manufacturer, who instituted warnings about the incorrect use of High Boost/Prime, followed by a software lockout to prevent its activation at pressure altitudes lower than 10,000 feet. The NTSB is wary, however, stating that although the fixes are helpful to increase the level of safety of the design, they cannot completely rule the problem solved. Of the 6 high-fuel-flow accidents, only 3 have been adequately understood. They recommend that additional study be undertaken, saying 

"We believe that all the potential causes for these failures need to be identified to fully address this hazard. A functional hazard assessment, or FHA, is a top-down process that can be used to examine system functions to identify all potential failure conditions and classify the associated hazards." They note that an FHA was completed early in the SR22T's development and certification, but Cirrus has not performed one specifically targeting excessive fuel flow during takeoff and climb that results in a loss of engine power. They urge the FAA to require implementation to not only complete the study of the problem, but to identify mitigating actions to prevent it going forward, whether through design modification, procedures, or guidance to operators.

FMI: www.ntsb.gov