AC 120-55C Air Carrier TCAS - Code7700

AC 120-55C 2/23/1112. TCAS OPERATIONAL USE.a. General. Operationally, those skills addressed and the guidance provided on TCAStraining in paragraph 9 should be followed and implemented by each operator electing to useTCAS II.NOTE: In no case should a pilot maneuver opposite to a TCAS RA.b. Pilot Responsibilities. A TCAS is intended to serve as a backup to visual collisionavoidance, application of right-of-way rules, and air traffic separation service. For TCAS to workas designed, immediate and correct crew response to TCAS advisories is essential. Delayed crewresponse or reluctance of a flightcrew to adjust the aircraft’s flightpath as advised by TCAS dueto air traffic control (ATC) clearance provisions, fear of later FAA scrutiny, or other factorscould significantly decrease or negate the protection afforded by TCAS. Flightcrews shouldrespond to a TCAS in accordance with the following guidelines when responding to alerts:(1) Respond to TAs by attempting to establish visual contact with the intruder aircraftand other aircraft which may be in the vicinity. Coordinate to the degree possible with othercrewmembers to assist in searching for traffic. Do not deviate from an assigned clearance basedonly on TA information. For any traffic acquired visually, continue to maintain safe separation inaccordance with current regulations and good operating practices.(2) When an RA occurs, the PF should respond immediately by direct attention to RAdisplays and maneuver as indicated, unless doing so would jeopardize the safe operation of theflight or the flightcrew can assure separation with the help of definitive visual acquisition of theaircraft causing the RA. By not responding to an RA, the flightcrew effectively takesresponsibility for achieving safe separation. In so choosing, consider the following cautions:(a) The traffic may also be equipped with TCAS and it may maneuver in response toan RA coordinated with your own TCAS.(b) The traffic acquired visually may not be the same traffic causing the RA.(c) Visual perception of the encounter may be misleading. Unless it is unequivocallyclear that the target acquired visually is the one generating the RA and there are no complicatingcircumstances, the pilot’s instinctive reaction should always be to respond to RAs in thedirection and to the degree displayed.(3) Satisfy RAs by disconnecting the autopilot (if necessary) and auto throttle system,(when required by the airframe manufacturer’s procedures), and using prompt positive controlinputs in the direction and with the magnitude the TCAS advises. To achieve the requiredvertical rate (normally 1,500 feet per minute (fpm) climb or descent), first adjust the aircraft’spitch using the suggested guidelines shown in the table below. Then refer to the vertical speedindicator (VSI) and make all necessary pitch adjustments to place the VSI in the green arc.Page 8 Par 12