Note: Flaps 1 and 5 (-800/900) takeoffs have the least clearance. Consider using a larger flap setting for takeoffs at light gross weights. Because of the short fuselage, aft fuselage contact is unlikely in the 737-600.
Copyright . The Boeing Company. See title page for details.
3.10 FCT 737 (TM) October 31, 2006
737 Flight Crew Training Manual
Effect of Rotation Speed and Pitch Rate on Liftoff
Takeoff and initial climb performance depend on rotating at the correct airspeed and proper rate to the rotation target attitude. Early or rapid rotation may cause a tail strike. Late, slow, or under-rotation increases takeoff ground roll. Any improper rotation decreases initial climb flight path.
An improper rotation can have an effect on the command speed after liftoff. If the rotation is delayed beyond V2 + 20, the speed commanded by the flight director is rotation speed up to a maximum of V2 + 25. An earlier liftoff does not affect the commanded initial climb speed, however, either case degrades overall takeoff performance.
The following diagram shows how a slow or under rotation during takeoff increases the distance to a height of 35 feet compared to a normal rotation.
Slow or Under Rotation (Typical)
737 Flight Crew Training Manual
Center-Of-Gravity (CG) Effects
When taking off at light weight and with an aft CG, the combination of full thrust, rapid thrust application, and sudden brake release may tend to pitch the nose up, reducing nosewheel steering effectiveness. With CG at or near the aft limit, maintain forward pressure on the control column until 80 knots to increase nosewheel steering effectiveness. Above 80 knots, relax the forward control column pressure to the neutral position. At light weight and aft CG, use of reduced thrust and rolling takeoff technique is recommended whenever possible. The rudder becomes effective between 40 and 60 knots.
Operation with Alternate Forward Center of Gravity Limit for Takeoff
Takeoff performance is based on the forward CG limitations as defined in the AFM. However, takeoff performance can be improved by taking credit for an alternate (further aft) forward CG limit if shown in the AFM. Use of this data provides higher performance-limited takeoff weights than the basic AFM performance data.
Typically alternate forward CG is used to increase performance-limited takeoff weight for field length, climb or obstacle limited departures. Another potential benefit of alternate forward CG is to allow greater thrust reduction which increases engine reliability and reduces engine maintenance costs. However, this improved performance capability is only available if the operator has the certified data in their AFM and has approval from their regulatory agency to operate the airplane at an alternate forward CG limit.
A more aft CG increases the lift available at a given angle of attack due to the reduction in nose up trim required from the horizontal stabilizer. This allows VR and V2 to be reduced, which in turn reduces the field length required for takeoff. Reduction in field length required can also permit an increased field length limited weight. In most instances this reduction in nose up trim also results in a decrease in drag which improves the airplane’s climb capability.
Note: The FMC calculated takeoff speeds and QRH takeoff speeds are not valid
for operations using alternate forward CG. Takeoff speeds must be
calculated using alternate forward CG performance data normally
provided by dispatch or flight operations.
Copyright . The Boeing Company. See title page for details.
3.12 FCT 737 (TM) October 31, 2006
737 Flight Crew Training Manual
Crosswind Takeoff
The crosswind guidelines shown below were derived through flight test data, engineering analysis, and flight simulator evaluations.
Note: Engine surge can occur with a strong crosswind or tailwind component if takeoff thrust is set before brake release. Therefore, the rolling takeoff procedure is strongly advised when crosswinds exceed 20 knots or tailwinds exceed 10 knots.
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