Inclusion of instructions for the manual selection of the TLU’s standby system in the ATR FCOM and in other relevant instructions

When it comes to a TLU fault neither the Quick Reference Handbook nor the FCOM include an instruction for the flight crew to switch on the TLU’s standby system by manually setting the TLU to the appropriate mode. Such an instruction is given for an ADC fault and a DUAL GEN fault: “TLU……..MAN MODE LO SPD”.

Safety recommendation 1 (checklists): Safety Investigation Authority, Finland recommends that the manufacturer of the ATR aircraft include instructions for the manual selection of the TLU’s standby system in the FCOM and in other relevant instructions.

When it comes to a TLU fault neither the Quick Reference Handbook nor the FCOM include an instruction for the flight crew to switch on the TLU’s standby system by manually setting the TLU to the appropriate mode. Such an instruction is given for an ADC fault and a DUAL GEN fault: “TLU……..MAN MODE LO SPD”.