时间:2017-11-06 16:55来源:蓝天飞行翻译公司 作者:民航翻译 点击:次
To view this page ensure that Adobe Flash Player version 9.0.124 or greater is installed. Any V2/VS increase leads to (Figure J11):
A decrease in MTOW limited by the:
Brake energy
Tire speed
2.4. Result of the Optimization Process
2.4.1. Maximum Takeoff Weight
The previous section shows how, for a given V2/VS ratio, it is possible to find an optimum MTOW and its associated optimum V1/VR ratio.
For each V2/VS ratio comprised between V2/Vsmin and V2/Vsmax, such a determination is carried out. In the end, the highest of all the optimum MTOWs and associated optimum V1/VR is retained. It therefore corresponds to an optimum V2/VS ratio. The result of the optimization process is, for a given runway and given takeoff conditions:
2.4.2. Takeoff Speeds
The optimization process indicates that MTOW can only be taken off with a single set of takeoff speeds (V1, VR and V2). The use of different speeds would result in an MTOW reduction.
Once the optimum speed ratios (V1/VR and V2/VS) are obtained, the takeoff speeds are obtained as follows:
Note: AFM means that the information is obtained from the Aircraft Flight Manual.
2.4.3. Limitation Codes
The nature of the takeoff weight limitation is always indicated in the takeoff charts (RTOW charts). For that purpose, different codes are necessary (Table J12) which depend on the software used for the computation: TLC or OCTOPUS. For more details on this software, refer to the appendix 3 of this manual (“Takeoff performance software”).
LIMITATIONS CODES
TLC codes A300/A310/A320 OCTOPUS codes A318/A319/A320/A321/A330/A340 Codes 1 2 3 4 5 6 7 8 Nature Structural weight 1st or 2nd segment Runway (OEI)1 Obstacle Tire speed Brake energy Runway (AEO)2 Final takeoff Codes 1 2 3 4 5 6 7 8 9 Nature 1st segment 2nd segment Runway (OEI and AEO) Obstacle Tire speed Brake energy Structural weight Final takeoff VMU
Table J12 : Takeoff Chart Limitation Codes
Most of the time, MTOW is obtained at the intersection of two limitation curves (Figure J13). This is why the limitation codes are always indicated with two digits in a RTOW chart.
1 OEI = One Engine Inoperative 2 AEO = All Engines operative
2.4.3.1. MTOW limited by two limitations
In Figure J13, takeoff weight is limited by obstacles and by the Accelerate Stop Distance (ASD).
An RTOW chart would indicate Limitation Code 4/3.
2.4.3.2. MTOW limited by one limitation
In Figure J14, takeoff weight is only limited by obstacles.
An RTOW chart would indicate Limitation Code 4/4.
2.4.3.3. MTOW limited by three limitations
In this particular case, a V1 range exists. As a result, whatever the selected V1 speed between a minimum V1 and a maximum V1, the MTOW remains the same while the nature of the limitation changes. In this case, the effective takeoff V1 speed remains at the operator’s discretion.
In Figure J15, the nature of the limitation depends on the V1/VR ratio:
At V1/VRmin (Point 1): The takeoff weight is limited by both the TODN-1 and the 2nd segment (RTOW Code: 3/2).
Between V1/VRmin and V1/VRmax: The takeoff weight is only limited by the 2nd segment (RTOW Code: 2/2).
At V1/VRmax (Point 2): The takeoff weight is limited by the 2nd segment and the brake energy (RTOW Code: 2/6).
2.4.4. RTOW Chart Information
3. APPENDIX 3 : TAKEOFF PERFORMANCE SOFTWARE
3.1. P.E.P for Windows
3.1.1. What is P.E.P. ?
The PEP (Performance Engineering Programs) for a Windows’ environment is designed to provide the necessary tools not only to handle the performance aspects of flight preparation, but also to monitor aircraft performance after the flight. It is dedicated to airline Flight operations and design offices. Based on the Microsoft Windows . operating system, PEP for Windows is a standalone application which offers access to all the Airbus aircraft performance programs in a user-friendly and customizable environment.
The following is a list of the available performance programs:
FM : Aircraft Flight Manual (certified performance data)
TLO : TakeOff and Landing computation (MTOW, MLW, speeds)
OFP : Operational Flight Path computation (takeoff and approach paths)
NLC : Noise Level Computation program (takeoff and approach noise)
IFP : In Flight Performance program (climb, cruise, descent, holding…)
APM : Aircraft Performance Monitoring (aircraft performance level)
FLIP : Computerized Flight Planning (fuel calculation)
APPENDIX Getting to Grips with Aircraft Performance
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