BUCS ON Procedures

TM 1-1520-238-10 Change 9 2-48.3/(2-48.4 blank) (b) Severance engagement. 1 The crewmembers will most likely dis- cover the aircraft to be in BUCS after the flying pilot moves the controls enough to satisfy the mistrack engagement criterion causing the MASTER CAUTION light and BUCS ON and ASE (ASE not applicable for collective) caution/ warning lights to illuminate. 2 Fly the aircraft. Some control will be available immediately and full control will be phased in over a one (1) second period. (3) BUCS ON Procedures (a) If the BUCS ON caution/warning light is il- luminated, pilot and CPG coordinate to determine in which station and axis (axes) BUCS is activated (affected axis (axes) should be indicated by a disengaged SAS channel switch(s) and an ASE caution/warning light illumi- nation; if no SAS channel switch(s) are disengaged and the ASE caution/warning light is not illuminated, the sev- erance is in the collective control system) and transfer control as necessary. (b) Perform aircraft emergency procedure for BUCS ON. (4) BUCS FAIL Procedures (a) If the BUCS FAIL light illuminates, avoid rapid or erratic flight control inputs. (b) Pilot attempt to reset the BUCS FAIL by toggling the appropriate SAS channel on the ASE panel. (c) Perform aircraft emergency procedure for BUCS FAIL. g. BUCS FD/LS. BUCS is monitored continuous- ly. If a BUCS failure is detected, BUCS will not engage in the affected axis and the BUCS FAIL warning light in each crew station illuminates. To assure that BUCS is fully op- erational, a preflight self-test is provided in addition to the on-command DASE FD/LS test. The self-test verifies the integrity of BUCS before starting engines. The BUCS self- test requires primary hydraulic pressure within normal lim- its, RTR BRAKE switch set to BRAKE, flight controls cen- tered, collective friction off, both PWR levers in the IDLE position or below, the helicopter on the ground and BUCS not engaged. All DASE channels must be off. h. Control Locks. The control locks protect the shear pins in the pilot and CPG cyclic longitudinal and lat- eral SPADS, and pedal directional SPADS (fig 2-25) from accidental breaking when the helicopter is on the ground without hydraulic power. They consist of two rig pins to prevent cyclic longitudinal and lateral movement and two pedal lock fixtures to prevent pedal movement, one set for the pilot station and one for the CPG station. The two sets, comprising four rig pins and four pedal locks, are in a pouch located in the crew station. Each rig pin and pedal lock are attached together by a lanyard with a warning streamer. CAUTION When installing and removing the con- trol locks, hydraulic power must be on the helicopter to prevent damage to the SPAD shear pins. One rig pin is installed in the left side of the cyclic stick base to prevent longitudinal movement. The other rig pin, to prevent lateral movement, is installed in the lower right side of the cyclic stick shroud cover where it has been cut away to allow access for rig pin installation. After each pedal is moved forward, the pedal lock fixture is installed through the brushes and cutout in the floor so it rests on the edge of a shelf. The pedal lock fixture is aligned so that when the pedal is moved aft, the pedal support fits into the fork of the pedal lock fixture. The pedal is then moved aft so the fork tightly engages the pedal support to prevent movement and the pedal adjust is tight- ened.