At my airport We have CRJ's from United and Northwest. My question is,why do all CRJ's do Rudder Checks before leaving the stand whereas no other aircraft does(MD-80,DC-9,717,ATR,BAe146,Saab 340,J-41's)
At our carrier the rudder is checked on the Taxi checklist as the airplane taxis out to the runway. We do a check of the flight controls which include the ailerons, spoilerons and elevator. We also check that the rudder will operate through its full range of motion. As a matter of fact, all surfaces should move in their full range of motion. The information is displayed on the Flight Control page on our EICAS Secondary display, since you cannot see the control surfaces outside of the flightdeck window. The reason the check is preformed is to check if the controls are functioning properly and that they are within tolerances.
Uh Jet Joc, the CRJ does have a "tiller" that is used to steer the airplane on the ground. The tiller is turned on during the Before Taxi checklist and is turned off during the Parking checklist. The nosewheel steering on the CRJ is a 'steer-by-wire' system which is electrically controlled and hydraulically actuated through dual push-pull actuators mounted on the nose landing gear. The tiller provides 70 degrees of travel left or right and the rudders can provide 7 degrees left or right for steering.
Every aircraft I have ever flown, from a C-152 to a Saab, requires a flight control check. We do this to make sure they are operative, and nothing is blocking there movement. Either outside, or even in the cockpit. It is a quick check, we just go throw the full range of the flight controls.