getting to grips with aircraft performance 如何掌握飞机性能 2(26)

曝光台 注意防骗 网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者

The minimum fuel consumption speed is somewhere between the minimum drag speed and the maximum lift-to-drag ratio (Green Dot) speed, which are quite close. As a result, in clean configuration, the standard holding speed is selected equal to green dot.

    Holding patterns may be quite limiting around certain airports due to obstacle proximity. Therefore, green dot is sometimes too high, especially during turn phases where the bank angle can be too significant. As it is not possible to significantly reduce the speed below green dot in clean configuration, slats may be extended and a holding done in CONF1 at “S” speed1.
Note that green dot and S speeds are easy to fly in selected mode, as they are indicated on the Primary Flight Display (PFD), as a function of aircraft weight and configuration:
.  
In clean configuration: “Green Dot”

.  
In configuration 1: “S speed”

3.2. Holding in Operation
A holding pattern can be managed by the FMGS at a selected waypoint during flight. For that purpose, it must be entered on the MCDU Flight-Plan page. Holding pattern data may come from the navigation database, or may be defaulted to standard dimensions (which can be changed), when no pattern is available. In this case, the following default data is proposed (Figure H10):
.  
INB CRS : Inbound course of the holding pattern

.  
Turn : Direction of the turn (Right or Left).

.  
Time: Outbound leg of 1 minute below 14,000 feet, 1.5 minutes above.

.  
DIST: Distance calculated from the predicted TAS which, in turn, depends on the holding speed (speed for max endurance, ICAO speed limit, or constraint speed, whichever is lower).

 

H10: Holding Pattern Data
1 S speed = Minimum slat retraction speed (from CONF1 to CONF CLEAN)

I. FUEL PLANNING AND MANAGEMENT
1. JAR - FUEL PLANNING AND MANAGEMENT
1.1. Fuel policy
The fuel quantity required for a safe trip along the planned route is calculated for each flight. Each operator has its own fuel policy. This policy is based on the loading of minimum regulatory fuel requirements (JAR-OPS 1).
“JAR-OPS 1.255 An operator must establish a fuel policy for the purpose of flight planning and in-flight replanning to ensure that every flight carries sufficient fuel for the planned operation and reserves to cover deviations from the planned operation.”
1.1.1. Standard Flight Planning

Although fuel quantity varies in accordance with national regulations, the JAR-OPS requirements and the various national regulations are very similar.
The minimum fuel quantity (Q) calculated for flight planning is defined as:
Q = taxifuel + TF + CF + AF + FR + Add + XF
Where
.
 TF = Trip Fuel

.
 CF = Contingency Fuel

.
 AF = Alternate Fuel
　
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：getting to grips with aircraft performance 如何掌握飞机性能 2(26)