What was found
PHX - FLT 98 - FLT CREW REPORTED, A RUDDER FLUTTER WHEN CHECKING THE STANDBY RUDDER. PERFORMED RIGHT CHECKS ON NORMAL RUDDER SYSTEM, ALL CHECKS NORMAL. STANDBY SYSTEM CHECKS OK. FOUND STANDBY ACTUATOR DEAD BAND CHECK OUT OF LIMITS. COULD NOT RIG ACTUATOR. REMOVED AND REPLACED RUDDER STANDBY ACTUATOR PER R6B27001 RIGGED AND OPS CHECK PER BMM 27-21-141. (M)