感谢同事的问题。
关于扰流板抑制/自动收上的逻辑，相较于 A320，A350 的描述非常简单，其中存在一些疑问。
A350 FCOM DSC-27-10-10 J AUTOMATIC RETRACTION:
If extended, the speed brakes automatically retract if:
‐ Alpha protection is activated, or
‐ A go-around is initiated.
A320 FCOM DSC-27-10-20 D SPEED BRAKE CONTROL:
Speedbrake extension is inhibited, if one of the following occurs:
‐ SEC1 and SEC3 both are faulty, or
‐ An elevator (L or R) is faulty, or
‐ Angle-of-attack protection is active, or
‐ Flaps are in configuration FULL, or
‐ Thrust levers are above MCT position, or
‐ Alpha Floor is activated.
疑问 1：
A350 只说了复飞会自动收上，A320 的表述则是“Thrust levers are above MCT position”，也就是说在 TOGA 起飞和复飞的时候都会收上。那么 A350 在起飞的时候会自动收上么？
疑问 2：
对两个机型来说，如果 FLEX 起飞（手柄没有 above MCT position），扰流板会被抑制么？
空客的回复是：
对 A350 来说，不管是 TOGA 还是 FLEX 起飞，以及复飞，扰流板都是被抑制的。
对 A320 来说，TOGA 起飞和复飞是抑制的，FLEX 则没有抑制。不过另一方面，为了防止扰流板误展开，在 T.O MEMO 中是有 SPLRS…ARM 这一项的。
其实 A350 的 T.O MEMO 中也有这一条：
也就是说，其实两个机型在起飞/复飞时对扰流板的抑制基本相同，A350 更加优化，在 FLEX 起飞时也会抑制。
不过 A350 手册中的描述过于简单，空客会考虑修改 A350 的描述，尽量和 A320 一致。
原文
Q1
For the A320 and A350, the logic for automatic spoiler retraction is described in the manuals as follows:
A350 FCOM DSC-27-10-10 J AUTOMATIC RETRACTION:
If extended, the speed brakes automatically retract if:
‐ Alpha protection is activated, or
‐ A go-around is initiated.
A320 FCOM DSC-27-10-20 D SPEED BRAKE CONTROL:
Speedbrake extension is inhibited, if one of the following occurs:
‐ SEC1 and SEC3 both are faulty, or
‐ An elevator (L or R) is faulty, or
‐ Angle-of-attack protection is active, or
‐ Flaps are in configuration FULL, or
‐ Thrust levers are above MCT position, or
‐ Alpha Floor is activated.
For the A320, the condition “Thrust levers are above MCT position” appears perfectly logical. However, no equivalent provision exists in the A350 procedures.
Therefore, under this condition, will the spoilers retract?
To consider an extreme scenario: if a TOGA takeoff is performed while the spoiler lever is pulled, will the spoilers deploy?
For the A320, if a FLEX takeoff is conducted (with the thrust levers not ABOVE the MCT position) while the spoiler lever is pulled, will the spoilers deploy?
A1
Answer:
Further to your recent request regarding the inhibition of the speed brakes for your A320 Family and A350 aircraft, Airbus would like to provide the following comments for your information:
- A350
As indicated in A350 FCOM DSC-27-10-10 AUTOMATIC RETRACTION, the speed brakes automatically retracts if the flight crew initiates a go-around.
It means that, if extended, the speed brakes automatically retracts when the flight crew sets the thrust levers (i.e. at least one thrust lever) to the TOGA detent to initiate the go-around.
This logic is also applicable during take-off to give priority to climb performance.
In addition, regarding your scenario, we confirm that, on A350 aircraft, during a TOGA takeoff, the speed brakes extension is inhibited (i.e. do not deploy) if the SPEED BRAKE lever is moved from the retracted position.
- A320
As indicated in A320 FCOM DSC-27-10-20 SPEED BRAKES CONTROL, the speed brakes extension is inhibited if the thrust levers are set above the MCT detent.
As a result, during a FLEX takeoff with the thrust levers at the FLX/MCT detent, if the SPEED BRAKE lever is moved from the retracted position, the speed brakes are not inhibited and extend in accordance with the position of the SPEED BRAKE lever.
As you know, during taxi, the check of the T.O MEMO (i.e. SOP and Taxi checklists) ensures that the ground spoilers are correctly armed (i.e. speed brakes retracted).
Q2
Thank you for your reply. However, I still have two related questions.
First, you mentioned that the spoilers retract during TOGA takeoff on the A350. What about during FLEX takeoff, will the spoiler deployment not be inhibited, just like on the A320?
Second, if the logic for spoiler inhibition above a certain thrust level is indeed the same for both aircraft, could you try to harmonize the description? Currently, the description for the A320 is more detailed, while that for the A350 is overly concise – it only mentions go-around but omits the takeoff scenario.
A2
Further to your recent request regarding the inhibition of the speed brakes for your A350 aircraft, Airbus would like to provide the following comments for your information:
- We would like to confirm, on A350, during a FLEX takeoff with the thrust levers set to the MCT/FLX detent, the speed brakes extension is inhibited. Therefore, the speed brakes do not extend.
In addition, please also note that, during the initial climb, as soon as the thrust levers are set to the CL detent, the speed brakes extension is no longer inhibited. Therefore, the speed brakes will move in accordance with the SPEED BRAKE lever position.
- Please note that Airbus will consider your comment to review A350 FCOM DSC-27-10-10 AUTOMATIC RETRACTION to be consistent with the description in A320 FCOM.
We would like to thank you for your valuable input.
