FCTL check after EFCS reset on ground
Source: Airbus Safety First URL: https://safetyfirst.airbus.com/fctl-check-after-efcs-reset-on-ground/ Published: 2008-07-29 Magazine Issue: 2008-07 Category: Archive PDF: Original PDF
By: Kristjof TRITSCHLER Flight Safety Manager Germanwings
Albert URDIROZ Flight Safety Director Airbus
1 Introduction
Section titled “1 Introduction”need to repeat the Flight Control Check after resetting of an EFCS system computer. Readers interested in the subject may wish to read the paper titled “The importance of the pre-flight Flight Control Check” published in issue #01, dated January 2005, of this magazine.
Recently, an A320 operated by Germanwings experienced an uncommanded spoiler extension in flight.
On review of this event, the authors felt it was worth writing an article to describe the sequence of events that led to this occurrence, and to highlight the
2 iler fault ture Spo cap
Section titled “2 iler fault ture Spo cap”The aircraft was dispatched with a LH spoiler actuator #5 in faulty condition.
When the crew taxied the airplane, the spoiler anomaly was captured during the pre-flight control checks.
The crew performed roll inputs with the sidesticks and the SEC detected the lack of response of LH spoiler 5 by monitoring the difference between the
order given and the position of the spoiler. The EFCS computer SEC2, that controls spoilers 5, disabled the two spoilers 5 as a pair.
F/CTL SPOILER FAULT was triggered, and spoiler shown as FAULT RETRACTED (5) on the ECAM F/CTL page.
Figure 1 illustrates the messages displayed on the F/CTL page of their ECAM.
3 SEC reset
Section titled “3 SEC reset”The crew reset the SEC in an attempt to recover control of spoilers 5. As a result, ECAM indications went back to normal,
i.e. F/CTL SPOILER FA ULT cleared and spoilers 5 were displayed back to GREEN on the F/CTL page ( fig.2 ).
Figure 2: All GREEN after SEC reset
Considering that the systems status was back to normal, the crew then resumed the flight sequence.
Through the SEC reset, the monitoring system of the spoilers was reinitialized and this cleared the fault message. The faulty condition, however, remained.
The capture by the monitoring system, based on the difference between given order and position of the flight control, would have required a second flight control check.
As the flight resumed, aerodynamic forces extended the faulty LH spoiler, forcing the flight crew to counteract the LH roll tendency. The ECAM warning SPOILER FAULT did not appear during the take-off run, nor during the early climb, as it is inhibited in phases 3 to 5 (from takeoff thrust application to 1 500 feet.
Once in level flight, recordings indicate that about 4° of RH rudder trim was necessary to compensate for the uncommanded spoiler extension. The crew was able to fly to its original destination.
Had the crew performed a new flight controls check after the SEC reset, the same spoiler fault ECAM warning would have popped up again.
5 FCOM These TR have been incorporated in the June 2008 revisions (REV 42) of the A320 family FCOM and QRH. improvement
Section titled “5 FCOM These TR have been incorporated in the June 2008 revisions (REV 42) of the A320 family FCOM and QRH. improvement”In order to stress the need to perform a Flight Control Check after the resetting on ground of the EFCS, it was decided to add a note in the “ELAC or SEC malfunction” part of the 3.04.24 Computer Reset Table (P5).
On the A320 family program, TR reference 105-1 was issued in June 2007 ( fig. 3 ). A similar TR reference 568-1 was issued for the QRH 2.38.
On the A310/A300-600 and A330/340 programs the note had already been incorporated in their respective FCOM and QRH.
On the A310/300-600, the note concerns the EFCU reset, which controls the spoilers electrically.
Note: The A380 is, as of today, not concerned by this issue, as FCTL system resets are not authorized.
WARNING :
Section titled “WARNING :”Do not reset more than one computer at a time. . It is possible to reset flight control computers in flight, event if not requested by the ECAM, provided only one reset is performed at a time: For the ELAC only, in case of uncommanded maneuvers during the flight, it is not recommended to reset the ELAC. Note :[. ] When an ELAC reset is performed on ground the crew must check the pitch trim position. . If a reset is performed on ground, the flight crew must then perform a flight control check, as per SOP.
6 Conclusions
Section titled “6 Conclusions”This incident, fortunately, did not have any major operational consequence. It illustrates, however, the message that the authors wish to highlight:
If a reset of an EFCS or EFCU computer is performed on ground, it must be followed by a flight control check
Airbus wishes to thank Kristjof Tritschler and Germanwings for their contribution to this article.
作者：Kristjof TRITSCHLER 飞行安全经理 Germanwings
Albert URDIROZ 飞行安全总监 Airbus
在重置 EFCS 系统计算机后需要重复飞行控制检查。对这一主题感兴趣的读者可参阅本杂志 2005 年 1 月第 01 期发表的题为“飞行前飞行控制检查的重要性”的论文。
最近，德国之翼（Germanwings）运营的一架 A320 在飞行中发生了非指令性扰流板伸出。
在回顾这一事件时，笔者认为有必要撰写一篇文章，描述导致此次事件的一系列经过，并重点强调
2 扰流板故障
Section titled “2 扰流板故障”该飞机在左发（LH）扰流板作动筒 #5 故障状态下放行。
机组滑行时，扰流板异常在飞行前控制检查中被捕获。
机组使用侧杆进行横滚输入，SEC 通过监测给定指令与扰流板实际位置之间的差异，检测到左扰流板 5 响应缺失。控制扰流板 5 的 EFCS 计算机 SEC2 将两个扰流板 5 作为一个组件禁用。
触发了 F/CTL SPOILER FAULT（飞行控制扰流板故障），且在 ECAM F/CTL 页面上显示为 FAULT RETRACTED (5)（故障收回 5）。
图 1 显示了他们 ECAM F/CTL 页面上的信息。
3 SEC 重置
Section titled “3 SEC 重置”机组重置 SEC，试图恢复对扰流板 5 的控制。结果，ECAM 显示恢复正常，即 F/CTL SPOILER FAULT 清除，扰流板 5 在 F/CTL 页面上恢复为绿色显示（图 2）。
图 2：SEC 重置后全部绿色
考虑到系统状态已恢复正常，机组随后继续执行飞行程序。
通过 SEC 重置，扰流板的监控系统被重新初始化，故障信息被清除。然而，故障状态仍然存在。
监控系统的捕获机制基于给定指令与飞行控制位置之间的差异，需要进行第二次飞行控制检查才能再次发现故障。
当飞行恢复时，气动力使故障的左扰流板伸出，迫使机组人员抵消左横滚趋势。在起飞滑跑阶段和初始爬升阶段，ECAM 警告 SPOILER FAULT 未出现，因为该警告在 3 至 5 阶段（从起飞推力施加到 1500 英尺）被抑制。
进入平飞后，记录显示约需 4° 的右舵配平来补偿非指令性扰流板伸出。机组成功飞至原定目的地。
如果机组在 SEC 重置后执行了新的飞行控制检查，相同的扰流板故障 ECAM 警告将再次弹出。
5 FCOM 修订
Section titled “5 FCOM 修订”这些修订已纳入 A320 系列 FCOM 和 QRH 的 2008 年 6 月修订版（REV 42）。
为强调在地面重置 EFCS 后执行飞行控制检查的必要性，决定在 3.04.24 计算机重置表（P5）的“ELAC 或 SEC 故障”部分添加一条注释。
在 A320 系列项目中，2007 年 6 月发布了 TR 参考号 105-1（图 3）。QRH 2.38 也发布了类似的 TR 参考号 568-1。
在 A310/A300-600 和 A330/A340 项目中，相应的注释已分别纳入其 FCOM 和 QRH。
在 A310/A300-600 上，该注释涉及控制扰流板电气操作的 EFCU 重置。
注：A380 目前未受此问题影响，因为 FCTL 系统重置不被授权。
不得同时重置多台计算机。 可以在飞行中重置飞行控制计算机，即使 ECAM 未提出要求，但须一次只执行一次重置： 仅针对 ELAC：在飞行中出现非指令性机动的情况下，不建议重置 ELAC。 注：[…] 在地面执行 ELAC 重置后，机组必须检查俯仰配平位置。 如果在地面执行重置，飞行机组必须随后按照 SOP 执行飞行控制检查。
所幸的是，这一事件未造成重大运行后果。然而，它说明了笔者希望强调的信息：
如果在地面重置了 EFCS 或 EFCU 计算机，必须随后执行飞行控制检查
Airbus 感谢 Kristjof Tritschler 和 Germanwings 对本文的贡献。