A330/A340 »ú×éѵÁ·ÊÖ²á FCTM Flight Crew Training Manual 1(60)

Æعą̂ ×¢Òâ·ÀÆ­ ÍøÆØÌìèµê¸»ÃÀ½ðÊ¢¼Ò¾ÓרӪµê¿ÓÃɹÕÆ­ÆÛÕ©Ïû·ÑÕß

This technique allows an altitude constraint to be matched with minimum use of speedbrakes. When regaining the descent profile, the speedbrakes should be retracted to prevent the A/THR applying thrust against speedbrakes. If the speedbrakes are not retracted, the "SPD BRK" message on the ECAM memo becomes amber and "RETRACT SPEEDBRAKES" is displayed in white on the PFD.
A/C above descent path
 
¬ø If the aircraft gets low on the computed descent path
The speed will decrease towards the lower limit of the speed range with idle thrust. When the lower speed limit is reached the A/THR will revert to SPEED/MACH mode and apply thrust to maintain the descent path at this lower speed. The path intercept point will be displayed on the ND, to indicate where the descent profile will be regained.
A/C below descent path
 
 
NORMAL OPERATIONS
DESCENT
 

 
¬ø If selected speed is used:
The descent profile remains unchanged. As the selected speed may differ from the speed taken into account for pre-computed descent profile and speed deviation range does not apply, the aircraft may deviate from the descent profile e.g. if the pilot selects 275 kt with a pre-computed descent profile assuming managed speed 300 kt, VDEV will increase.
SELECTED DESCENT MODE
There are 2 modes for flying a selected descent, namely OP DES and V/S. These modes will be used for pilot tactical interventions.
V/S mode is automatically selected when HDG or TRK mode is selected by the pilot, while in DES mode. Furthermore, in HDG or TRK mode, only V/S or OP DES modes are available for descent. To initiate a selected descent, the pilot should set the ATC cleared altitude on the FCU and pull the ALT selector. OP DES mode engages and is annunciated on the FMA. In OP DES mode, the A/THR commands THR IDLE and the speed is controlled by the THS.
Speed may be either managed or selected. In managed speed, the descent speed is displayed only as a magenta target but there is no longer a speed target range since the pre-computed flight profile does not apply.
The AP/FD will not consider any MCDU descent altitude constraints and will fly an unrestricted descent down to the FCU selected altitude.
If the crew wishes to steep the descent down, OP DES mode can be used, selecting a higher speed. Speedbrake is very effective in increasing descent rate but should be used with caution at high altitude due to the associated increase in VLS.
If the pilot wishes to shallow the descent path, V/S can be used. A/THR reverts to SPEED mode. In this configuration, the use of speedbrakes is not recommended to reduce speed, since this would lead to thrust increase and the speed would be maintained.
MODE REVERSION
Applicable to: ALL
If a high V/S target is selected (or typically after a DES to V/S reversion), the autopilot will pitch the aircraft down to fly the target V/S. Thus the aircraft will tend to accelerate, while A/THR commands idle thrust to try to keep the speed. When IAS will reach a speed close to VMO or VFE, the autopilot will pitch the aircraft up, so as to fly a V/S allowing VMO or VFE to be maintained with idle thrust.
¡¡
Öйúº½¿ÕÍø www.aero.cn
º½¿Õ·­Òë www.aviation.cn
±¾ÎÄÁ´½ÓµØÖ·£ºA330/A340 »ú×éѵÁ·ÊÖ²á FCTM Flight Crew Training Manual 1(60)