Nose Wheel/Rudder Pedal Steering
The captain’s and first officer’s (if installed) positions are equipped with a nose wheel steering wheel. The nose wheel steering wheel is used to turn the nose wheels through the full range of travel at low taxi speeds. Maintain positive pressure on the nose wheel steering wheel at all times during a turn to prevent the nose wheels from abruptly returning to center. Rudder pedal steering turns the nose wheels through a limited range of travel. Straight ahead steering and large radius turns may be accomplished with rudder pedal steering.
If nose wheel “scrubbing” occurs while turning, reduce steering angle and/or taxi speed. Avoid stopping the airplane in a turn as excessive thrust is required to start taxiing again.
Differential thrust may be required at high weights during tight turns. This should only be used as required to maintain the desired speed in the turn. After completing a turn, center the nose wheels and allow the airplane to roll straight ahead. This relieves stresses in the main and nose gear structure prior to stopping.
Turning Radius and Gear Tracking
During all turning maneuvers, crews should be aware of their position relative to the nose and main landing gear. The pilot seat position is forward of the nose wheels and main gear as indicated in the tables in this chapter.
As the following diagram illustrates, while the airplane is turning, the main gear tracks inside the nose gear. The smaller the radius of the turn, the greater the distance that the main gear tracks inside the nose gear and the greater the need to steer the nose gear outside of the taxi path (oversteer).
Copyright . The Boeing Company. See title page for details.
FCT 737 (TM) October 31, 2006
737 Flight Crew Training Manual
Visual Cues and Techniques for Turning while Taxiing
The following visual cues assume the pilot’s seat is adjusted for proper eye position. The following techniques also assume a typical taxiway width. Since there are many combinations of turn angles, taxiway widths, fillet sizes and taxiway surface conditions, pilot judgment must dictate the point of turn initiation and the amount of nose wheel steering wheel required for each turn. Except for turns less than approximately 30°, speed should be 10 knots or less prior to turn entry. For all turns, keep in mind the main gear are located behind the nose wheels, which causes them to track inside the nose wheels during turns. The pilot position being forward of the nose wheels and main gear is depicted in the table below.
737 Flight Crew Training Manual
737-300 - 737-500
Model Pilot Seat Position (forward of nose gear) feet (meters) Pilot Seat Position (forward of main gear) feet (meters)
737 - 300 5 (1.5) 46 (14.0)
737 - 400 5 (1.5) 52 (15.9)
737 - 500 5 (1.5) 41 (12.5)
737-600 - 737-900
Model Pilot Seat Position (forward of nose gear) feet (meters) Pilot Seat Position (forward of main gear feet (meters))
737 - 600 5.25 (1.6) 42 (12.8)
737 - 700 5.25 (1.6) 47 (14.3)
737 - 800 5.25 (1.6) 56 (17.1)
737 - 900 5.25 (1.6) 62 (18.9)
Turns less than 90 degrees
Use a technique similar to other large airplanes: steer the nose wheels far enough beyond the centerline of the turn to keep the main gear close to the centerline.
Turns of 90 degrees or more
Initiate the turn as the intersecting taxiway centerline (or intended exit point) approaches approximately the center of the number 3 window. Initially use approximately full nose wheel steering wheel displacement. Adjust the steering wheel input as the airplane turns to keep the nose wheels outside of the taxiway centerline, near the outside radius of the turn. Nearing turn completion, when the main gear are clear of the inside radius, gradually release the steering wheel input as the airplane lines up with the intersecting taxiway centerline or intended taxi path.
Turns of 180 Degrees
If the available taxi surface is narrow, coordination with ATC and ground support personnel may be required to complete the operation safely. Reference special aerodrome operating instructions, if available. In some cases (e.g., heavy weight, pilot uncertainty of runway and/or taxiway pavement edge locations and related safety margins, nearby construction, vehicles, potential FOD damage, etc.), towing the airplane to the desired location may be the safest option.
Copyright . The Boeing Company. See title page for details.
FCT 737 (TM) October 31, 2006
737 Flight Crew Training Manual
If a minimum radius 180° turn is necessary, consider using the ground crew to monitor the wheel path and provide relevant information as the turn progresses. The ground crew should be warned of the risk associated with jet blast and position themselves to avoid the hazard. Also ensure that obstacle clearance requirements are met. Since more than idle thrust is required, the flight crew must be aware of buildings or other objects in the area being swept by jet blast during the turn.
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