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On slippery runways, crosswind guidelines are a function of runway surface
condition, airplane loading, and assume proper pilot technique.
Note: Reduce crosswind guidelines by 5 knots on wet or contaminated runways
whenever asymmetric reverse thrust is used.
*Winds measured at 33 feet (10 m) tower height and apply for runways 148 feet
(45m) or greater in width.
** Landing on untreated ice or snow should only be attempted when no melting
is present.
*** Sideslip only (zero crab) landings are not recommended in crosswinds in
excess of 26 knots. This recommendation ensures adequate ground clearance and
is based on maintaining adequate control margin.
Runway Condition Crosswind - Knots *
Dry 40 ***
Wet 40 ***
Standing Water/Slush 20
Snow - No Melting ** 35 ***
Ice - No Melting ** 17
October 31, 2004
767 Flight Crew Training Manual
Landing
Copyright © The Boeing Company. See title page for details.
FCT 767 (TM) 6.35
Crosswind Landing Techniques
Three methods of performing crosswind landings are presented. They are the
touchdown in a crab, the de-crab technique (with removal of crab in flare), and the
sideslip technique. Whenever a crab is maintained during a crosswind approach,
offset the flight deck on the upwind side of centerline so that the main gear touches
down in the center of the runway.
De-Crab During Flare
The objective of this technique is to maintain wings level throughout the
approach, flare, and touchdown. On final approach, a crab angle is established
with wings level to maintain the desired track. Just prior to touchdown while
flaring the airplane, downwind rudder is applied to eliminate the crab and align
the airplane with the runway centerline.
As rudder is applied, the upwind wing sweeps forward developing roll. Hold
wings level with simultaneous application of aileron control into the wind. The
touchdown is made with cross controls and both gear touching down
simultaneously. Throughout the touchdown phase upwind aileron application is
utilized to keep the wings level.
Touchdown In Crab
The airplane can land using crab only (zero side slip) up to the landing crosswind
guideline speeds. (See the landing crosswind guidelines table, this chapter).
On dry runways, upon touchdown the airplane tracks toward the upwind edge of
the runway while de-crabbing to align with the runway. Immediate upwind aileron
is needed to ensure the wings remain level while rudder is needed to track the
runway centerline. The greater the amount of crab at touchdown, the larger the
lateral deviation from the point of touchdown. For this reason, touchdown in a
crab only condition is not recommended when landing on a dry runway in strong
crosswinds.
On very slippery runways, landing the airplane using crab only reduces drift
toward the downwind side at touchdown, permits rapid operation of spoilers and
autobrakes because all main gears touchdown simultaneously, and may reduce
pilot workload since the aircraft does not have to be de-crabbed before
touchdown. However, proper rudder and upwind aileron must be applied after
touchdown to ensure directional control is maintained.
Sideslip (Wing Low)
The sideslip crosswind technique aligns the aircraft with the extended runway
centerline so that main gear touchdown occurs on the runway centerline.
October 31, 2004
767 Flight Crew Training Manual
Landing
Copyright © The Boeing Company. See title page for details.
6.36 FCT 767 (TM)
The initial phase of the approach to landing is flown using the crab method to
correct for drift. Prior to the flare the airplane centerline is aligned on or parallel
to the runway centerline. Downwind rudder is used to align the longitudinal axis
to the desired track as aileron is used to lower the wing into the wind to prevent
drift. A steady sideslip is established with opposite rudder and low wing into the
wind to hold the desired course.
Touchdown is accomplished with the upwind wheels touching just before the
downwind wheels. Overcontrolling the roll axis must be avoided because
overbanking could cause the engine nacelle or outboard wing flap to contact the
runway. (See Ground Clearance Angles - Normal Landing charts, this chapter.)
Properly coordinated, this maneuver results in nearly fixed rudder and aileron
control positions during the final phase of the approach, touchdown, and
beginning of the landing roll. However, since turbulence is often associated with
crosswinds, it is often difficult to maintain the cross control coordination through
the final phase of the approach to touchdown.
If the crew elects to fly the sideslip to touchdown, it may be necessary to add a
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767机组训练手册Flight Crew Training Manual (FCTM)767(99)
