.
cold weather altitude correction procedures to be used for published
procedures, to include the table being used
.
a determination of which procedures or routes, if any, that have been
designed for cold temperatures and can be flown as published (without
altitude corrections).
Pilots should note that for very cold temperatures, when flying published minimum altitudes significantly above the airport, altimeter errors can exceed 1000 feet, resulting in potentially unsafe terrain clearance if no corrections are made.
Operation in Icing Conditions
Boeing airplanes are certified to all applicable airworthiness regulations regarding flight in icing conditions. Operators are required to observe all operational procedures concerning flight in these conditions.
Although the process of certifying jet transport airplanes for operation in icing conditions involves many conservative practices, these practices have never been intended to validate operations of unlimited duration in severe icing conditions. The safest course of action is to avoid prolonged operation in moderate to severe icing conditions.
757-300
Note: If the wing anti-ice is selected on at any time during the flight, the flaps up maneuver margin to stick shaker is reduced. Additional airspeed (up to 5 knots) may be added to flaps up maneuvering speed. This additive ensures full maneuver margin (40° bank capability).
Training Flights
Multiple approaches and/or touch and go landings in icing conditions may result in significant ice accumulations beyond those experienced during typical revenue flights. This may result in fan blade damage as a result of ice accumulation on unheated surfaces shedding into the engines.
Recommended Rudder Trim Technique
This section describes two techniques for properly trimming the rudder. It is assumed that the airplane is properly rigged and in normal cruise. The primary technique uses rudder trim only to level the control wheel and is an acceptable and effective method for trimming the airplane. It is approximately equal to a minimum drag condition. This technique is usable for normal as well as many non-normal conditions. For some non-normal conditions, such as engine failure, this technique is the preferred method and provides near minimum drag.
The alternate technique may provide a more accurate trim condition when the roll is caused by a roll imbalance. In addition, this technique outlines the steps to be taken if the primary trim technique results in an unacceptable bank angle or excessive rudder trim. The alternate technique uses both rudder and aileron trim to neutralize a rolling condition using the bank pointer as reference.
Note: Large trim requirements should be documented for maintenance. (Refer to the maintenance manual for guidance.)
Drag Factors Due to Trim Technique
If the control wheel is displaced to the point of spoiler deflection a significant increase in aerodynamic drag results. Additionally, any rigging deviation that results in early spoiler actuation causes a significant increase in drag per unit of trim. These conditions result in increased fuel consumption. Small out of trim conditions affect fuel flow by less than 1%, if no spoilers are deflected.
Note: Aileron trim may be required for significant fuel imbalance, airplane damage, or flight control system malfunctions.
Primary Rudder Trim Technique
It is recommended that the autopilot remain engaged while accomplishing the primary rudder trim technique (using rudder trim only). After completing this technique, if the autopilot is disconnected, the airplane should maintain a constant heading.
The following steps define the primary rudder trim technique:
.
set symmetrical thrust
.
balance fuel if required
.
ensure the autopilot is engaged in HDG SEL or HDG HOLD and
stabilized for at least 30 seconds
.
trim the rudder in the direction corresponding to the down (low) side of
the control wheel until the control wheel indicates level. The indices on
top of the control wheel should be used to ensure a level wheel condition.
The airplane is properly trimmed when the control wheel is level, (zero
index). As speed, gross weight, or altitude change, trim requirements may
also change. In a proper trim condition, there may be a slight forward slip
(slight bank angle indicated on the bank pointer) and a slight deflection of
the slip/skid indicator, which is acceptable.
Alternate Rudder Trim Technique
The alternate rudder trim technique is used if the primary trim technique results in an unacceptable bank angle, excessive rudder trim, or if a more accurate dual axis trim is required.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：757 Flight Crew Training Manual 机组训练手册(15)
