Air Canada A320 loss of control in flight: 14/4/09
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Ground spoilers wouldn't usually move in response to roll control inputs or to flight spoiler selection. I'm not sure how common actually checking the ground spoilers is ...?
Ignore that, it does happen, I just hadn't noticed it
Ignore that, it does happen, I just hadn't noticed it
Last edited by Mad (Flt) Scientist; 22nd Apr 2009 at 04:00.
Mad (Flt) Scientist, cod liver oil:
The flight control check is done very thoroughly, before every flight. The position of the controls is monitored on the Lower Ecam as the check is done.
Here's how the 320 flight control check might go - no particular airline's procedures, just an example:
Prior to performing the rudder pedal check the Captain must press the PEDALS DISC Pushbutton on the Steering Handwheel.
The Captain shall apply full sidestick and rudder pedal deflections. The F/O announces the control deflections as they are seen on the ECAM Flight Control Page.
On the F/CTL page, the F/O will check full travel and correct sense of all elevators and all aileron deflections, the correct deflection and retraction of spoilers, and full travel of the rudder. The F/O will call each position only when fully reached. The Captain silently checks that the F/O calls are in accordance with the sidestick or rudder pedal order.
In order to reach full travel, full sidestick shall be held at full deflection for 2 seconds.
Aileron neutral position when flaps are extended is 5 degrees of aileron droop.
When the Captain's flight control check is complete, the F/O shall apply full sidestick deflections, and will silently check full travel and the correct deflection (sense) of all elevators and all ailerons, and the correct deflection and retraction of all spoilers on the ECAM F/CTL page.
In order to reach full travel, full sidestick shall be held at full deflection for 2 seconds.
Aileron neutral position when flaps are extended is 5 degrees of aileron droop.
When the Captain's flight control check is complete, the F/O shall apply full sidestick deflections, and will silently check full travel and the correct deflection (sense) of all elevators and all ailerons, and the correct deflection and retraction of all spoilers on the ECAM F/CTL page.
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> The airframe vibrations came from the spoilers, that
> started to flutter after the landing flaps were deployed.
Does that imply they were stuck in the deployed or partially deployed position?
> started to flutter after the landing flaps were deployed.
Does that imply they were stuck in the deployed or partially deployed position?
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cwatters, It would be logical that the spoillers would moving between not fully deployed and the almost closed position, as they put the flaps down the air flow above the wing changes modulating the loose spoillers up and down. 
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Here's some questions for you.... (I don't know the answers, insufficient data in FCOMs).
How do the engineers disable/enable the ground spoilers? Through CFDS ?
When you press RECALL before start will a GND SPLR FAULT message appear if they are disabled?
If the Ground Spoilers are disabled, as opposed to faulty, will ECAM show amber ground spoiler indications, and when you arm them after start will you receive a GND SPLR FAULT message? If not, why not?
And why would a ground spoiler problem produce a SPLR FAULT message, or is that just sloppy reporting?
And for your interest there is a note in the abnormal procedure for SPLR FAULT.. If heavy vibrations are felt, CONF 3 may be used for landing in order to reduce the buffeting..
How do the engineers disable/enable the ground spoilers? Through CFDS ?
When you press RECALL before start will a GND SPLR FAULT message appear if they are disabled?
If the Ground Spoilers are disabled, as opposed to faulty, will ECAM show amber ground spoiler indications, and when you arm them after start will you receive a GND SPLR FAULT message? If not, why not?
And why would a ground spoiler problem produce a SPLR FAULT message, or is that just sloppy reporting?
And for your interest there is a note in the abnormal procedure for SPLR FAULT.. If heavy vibrations are felt, CONF 3 may be used for landing in order to reduce the buffeting..
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Such failure is far more rare than loss of control through complete loss of hydraulics, which has resulted in fatal accidents.
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Mad (Flt) Scientist, cod liver oil:
The flight control check is done very thoroughly, before every flight. The position of the controls is monitored on the Lower Ecam as the check is done.
Here's how the 320 flight control check might go - no particular airline's procedures, just an example:
Prior to performing the rudder pedal check the Captain must press the PEDALS DISC Pushbutton on the Steering Handwheel.
The Captain shall apply full sidestick and rudder pedal deflections. The F/O announces the control deflections as they are seen on the ECAM Flight Control Page.
On the F/CTL page, the F/O will check full travel and correct sense of all elevators and all aileron deflections, the correct deflection and retraction of spoilers, and full travel of the rudder. The F/O will call each position only when fully reached. The Captain silently checks that the F/O calls are in accordance with the sidestick or rudder pedal order.
In order to reach full travel, full sidestick shall be held at full deflection for 2 seconds.
Aileron neutral position when flaps are extended is 5 degrees of aileron droop.
When the Captain's flight control check is complete, the F/O shall apply full sidestick deflections, and will silently check full travel and the correct deflection (sense) of all elevators and all ailerons, and the correct deflection and retraction of all spoilers on the ECAM F/CTL page.
The flight control check is done very thoroughly, before every flight. The position of the controls is monitored on the Lower Ecam as the check is done.
Here's how the 320 flight control check might go - no particular airline's procedures, just an example:
Prior to performing the rudder pedal check the Captain must press the PEDALS DISC Pushbutton on the Steering Handwheel.
The Captain shall apply full sidestick and rudder pedal deflections. The F/O announces the control deflections as they are seen on the ECAM Flight Control Page.
On the F/CTL page, the F/O will check full travel and correct sense of all elevators and all aileron deflections, the correct deflection and retraction of spoilers, and full travel of the rudder. The F/O will call each position only when fully reached. The Captain silently checks that the F/O calls are in accordance with the sidestick or rudder pedal order.
In order to reach full travel, full sidestick shall be held at full deflection for 2 seconds.
Aileron neutral position when flaps are extended is 5 degrees of aileron droop.
When the Captain's flight control check is complete, the F/O shall apply full sidestick deflections, and will silently check full travel and the correct deflection (sense) of all elevators and all ailerons, and the correct deflection and retraction of all spoilers on the ECAM F/CTL page.
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Hey MAD, you are correct.
From Transport Canada, the spoiler that was left on Maint. mode was #1, so it is not part of the flight control check, only spoilers 2 +
No big deal, some vibration and back on the ground. TC categorized the occurrence as a level 5; no further action.
All the Airbus haters, sorry all your hopes for a flight control problem down the drain, need to keep hoping!!
G
From Transport Canada, the spoiler that was left on Maint. mode was #1, so it is not part of the flight control check, only spoilers 2 +
No big deal, some vibration and back on the ground. TC categorized the occurrence as a level 5; no further action.
All the Airbus haters, sorry all your hopes for a flight control problem down the drain, need to keep hoping!!
G
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No big deal?
Would the Ground Spoilers (or any spoilers) have worked on an RTO?
Why was there no warning or indication to prevent the crew from taking to the air? (I make an assumption here).
Would the Ground Spoilers (or any spoilers) have worked on an RTO?
Why was there no warning or indication to prevent the crew from taking to the air? (I make an assumption here).
1. Only the isolated spoiler would have failed to extend.
2. It's a mechanical valve which swithes it into maintenace mode. Airbus obviously assumed the post engineering checks would catch this omission.
Still no big deal.
2. It's a mechanical valve which swithes it into maintenace mode. Airbus obviously assumed the post engineering checks would catch this omission.
Still no big deal.
TyroPicard;
Transport Canada has classified this as a "level five" event, the lowest "on their radar". You may take from that what you will but the consensus is that it was not a signficant event. I am not in full agreement with that assessment but not wholly for the reasons you state but for the reasons offered below concerning spoilers 2 to 5 and the comments offered in the article below regarding the control check and human factors. This aside noted, the failure to return the valve to the operational position has occurred before so perhaps changes are needed to ensure failsafe completion of maintenance procedures. The vibration felt, (at Config FULL) is an experienced, known item and guidance for same is provided in the AOM. Returning the flaps to Config 3 greatly reduces the vibration for the reasons cited in this thread and controllability is not affected.
The question I would like answered if anyone has specific maintenance knowledge is, will the ECAM "FCTL Spoiler Fault" message appear during the control check if spoilers 2 through 5 are locked out? In my opinion the message will appear but I have been away from the books for a while now. I think, in other words, your comments would be valid if any spoilers, 2 through 5, would be so affected. That does not appear to be the case here but we don't know.
You'll also recall the Lufthansa flight control reversal; the crew kept the airplane under control and landed without incident. There is an article in Avionics Magazine which describes the incident. If you can get past the the hyperbole and histrionics of "coming within two feet of crashing", (a remarkably stupid comment for a technical magazine), the latter part of the article is worth reading regarding what actually happened. Also, important questions are asked in the article which is worth quoting in full here. Perhaps it should be noted that the causes of the control fault are substantially different from the Air Canada 320 case:
Transport Canada has classified this as a "level five" event, the lowest "on their radar". You may take from that what you will but the consensus is that it was not a signficant event. I am not in full agreement with that assessment but not wholly for the reasons you state but for the reasons offered below concerning spoilers 2 to 5 and the comments offered in the article below regarding the control check and human factors. This aside noted, the failure to return the valve to the operational position has occurred before so perhaps changes are needed to ensure failsafe completion of maintenance procedures. The vibration felt, (at Config FULL) is an experienced, known item and guidance for same is provided in the AOM. Returning the flaps to Config 3 greatly reduces the vibration for the reasons cited in this thread and controllability is not affected.
The question I would like answered if anyone has specific maintenance knowledge is, will the ECAM "FCTL Spoiler Fault" message appear during the control check if spoilers 2 through 5 are locked out? In my opinion the message will appear but I have been away from the books for a while now. I think, in other words, your comments would be valid if any spoilers, 2 through 5, would be so affected. That does not appear to be the case here but we don't know.
You'll also recall the Lufthansa flight control reversal; the crew kept the airplane under control and landed without incident. There is an article in Avionics Magazine which describes the incident. If you can get past the the hyperbole and histrionics of "coming within two feet of crashing", (a remarkably stupid comment for a technical magazine), the latter part of the article is worth reading regarding what actually happened. Also, important questions are asked in the article which is worth quoting in full here. Perhaps it should be noted that the causes of the control fault are substantially different from the Air Canada 320 case:
. . . .
German investigators, Lufthansa officials and representatives from manufacturer Airbus are focusing their inquiry on the maintenance actions that preceded the incident flight. In the process of troubleshooting and repairing an elevator/aileron computer (ELAC–one of two on the A320), Lufthansa Technik personnel found a damaged pin on one segment of the four connector segments (with 140 pins on each) at the "rack side," as it were, of the ELAC mount.
Repair work involving complete rewiring "upstream" of the connector pins was conducted over several work shifts by various technicians. In the process, according to preliminary reports, the polarity inadvertently was reversed on four wires in one connector segment. Two of the wires were for the roll control input and two were for the associated control channel "outputs." It is believed from preliminary accounts that the technicians correctly followed the wiring list. However, BFU officials and maintenance personnel maintained that the wiring lists for individual aircraft may differ. There’s a latent hazard for you, just begging for some technician to perform perfect repairs based on the wrong wiring list.
One pilot observed, "If it were the case that control wiring differed at the ELAC connector between models of the same type, the ELACs would not be interchangeable...and this is not the case." True, but the male/female marriage of connectors and pins (all 560 of them among the four connector segments) is not the issue. Rather, it is the color-coding scheme of the wiring to the backside of the connectors on the rack to which each ELAC is mated.
Before the airplane left the hangar at Frankfurt for return to service, a flight control check was performed using the respective indications on the cockpit ECAM (Electronic Centralized Aircraft Monitoring) display. The BFU confirmed that the mechanic’s flight control check was limited to the first officer’s sidestick, not the captain’s on the left side of the cockpit.
Whether a maintenance technician would be sufficiently astute to catch aileron deflection in the wrong direction is another matter. It is not certain if anyone was standing outside the airplane to double check actual movement of flight control surfaces.
The details of such procedures will be part of the BFU inquiry. The question of any time pressure to get the work done also seems certain to be explored, as well as whether a test flight before the aircraft was returned to service would have uncovered the reversal problem. After all, this was a repair to a primary flight control system (as opposed to a flight management system).
Every crew routinely exercises the flight controls as part of its preflight check. On the A320, the Flight Control page on the ECAM will appear when the sidestick is moved as part of the preflight check. The sidestick must be held about three seconds for full travel to be reached; it takes that long for the ECAM to generate a fault message.
Some confusion exists in the pilot community about whether these checks will be displayed on the ECAM as contro linputs (the position of the sidestick) or control outputs (actual position of ailerons, etc.). The ECAM will display control outputs, as does the comparable system on the Boeing fly-by-wire B777.
One pilot correctly explained the functioning and went on to surmise what may have happened:
"Four position sensors called linear voltage differential transducers (LVDTs–used with aircraft control surface servos) look at the ailerons. This is quite independent of the sidestick positions. This display would not have been affected or reversed because of any miswiring of the sidestick...
"On control checks during taxi out, the pilots saw spoiler movement and aileronmovementin response to commands from each sidestick, correctly displayed on [the] ECAM. It just happened to be in the wrongdirectionfor one stick. Really quite easy to miss at a very busy time, and so unexpected. Every pilot does control checks, thousands of times. It is always correct, isn’t it? Except for this oh-so-rare occasion."
The check often is made during taxi out, a high workload period, rather than before pushback at the gate. Accordingly, the PF is moving his control actuators while keeping his eyes focused on activity outside the airplane, while the PNF is keeping his eyes locked on the ECAM display. In this arrangement, the PNF is not looking at and probably is not able to see the direction in which the PF is testing the sidestick. As such, the PNF may be looking at the ECAM more for confirmation of deflection, but not necessarily for direction of deflection.
In any event, the wiring fault got by at least two safety "filters," as it were. It was not detected during maintenance, and it was not detected during the preflight check.
The fact that this incident did not end with investigators piecing through charred wreckage is fortuitous. In the unfortunate event of a crash, there might not have been sufficient evidence pointing to a connector/wiring fault. Absent such evidence, investigators may have invoked "pilot error" based on a finding of incorrect banking associated with wake turbulence.
To be sure, crossed or reversed flight control cables on conventional aircraft have caused more than one crash. There is a grim history of such events on military and general aviation aircraft. If one control stick is connected backwards, then both yokes are misrigged, and both pilots are faced with the same parlous problem.
However, reversed controls are deemed impossible on transport-category aircraft, with their combination of cables and pushrods. Consider the "conventional" B737. A Boeing official declared it is impossible to reverse the connection of steel cables to hydraulic flight control actuators. Even if done deliberately, the pilots would instantly discover that they could not physically move their flight controls.
In the case of the A320, one aspect of the aircraft’s fly-by-wire design may have enabled the first officer to quickly gain control of the aircraft: the ability to isolate a malfunctioning sidestick and shift command to the other sidestick at the push of a button. As one pilot noted: "I would say that on this occasion, it was because of Airbus technology that a major incident was avoided!"
That may be so. But the case may well illustrate how avionics protections against human error in the cockpit can be reversed into outright hazards by human error on the maintenance floor. The BFU may have "just" an incident on its hands to investigate, but the safety issues are profound.
German investigators, Lufthansa officials and representatives from manufacturer Airbus are focusing their inquiry on the maintenance actions that preceded the incident flight. In the process of troubleshooting and repairing an elevator/aileron computer (ELAC–one of two on the A320), Lufthansa Technik personnel found a damaged pin on one segment of the four connector segments (with 140 pins on each) at the "rack side," as it were, of the ELAC mount.
Repair work involving complete rewiring "upstream" of the connector pins was conducted over several work shifts by various technicians. In the process, according to preliminary reports, the polarity inadvertently was reversed on four wires in one connector segment. Two of the wires were for the roll control input and two were for the associated control channel "outputs." It is believed from preliminary accounts that the technicians correctly followed the wiring list. However, BFU officials and maintenance personnel maintained that the wiring lists for individual aircraft may differ. There’s a latent hazard for you, just begging for some technician to perform perfect repairs based on the wrong wiring list.
One pilot observed, "If it were the case that control wiring differed at the ELAC connector between models of the same type, the ELACs would not be interchangeable...and this is not the case." True, but the male/female marriage of connectors and pins (all 560 of them among the four connector segments) is not the issue. Rather, it is the color-coding scheme of the wiring to the backside of the connectors on the rack to which each ELAC is mated.
Before the airplane left the hangar at Frankfurt for return to service, a flight control check was performed using the respective indications on the cockpit ECAM (Electronic Centralized Aircraft Monitoring) display. The BFU confirmed that the mechanic’s flight control check was limited to the first officer’s sidestick, not the captain’s on the left side of the cockpit.
Whether a maintenance technician would be sufficiently astute to catch aileron deflection in the wrong direction is another matter. It is not certain if anyone was standing outside the airplane to double check actual movement of flight control surfaces.
The details of such procedures will be part of the BFU inquiry. The question of any time pressure to get the work done also seems certain to be explored, as well as whether a test flight before the aircraft was returned to service would have uncovered the reversal problem. After all, this was a repair to a primary flight control system (as opposed to a flight management system).
Every crew routinely exercises the flight controls as part of its preflight check. On the A320, the Flight Control page on the ECAM will appear when the sidestick is moved as part of the preflight check. The sidestick must be held about three seconds for full travel to be reached; it takes that long for the ECAM to generate a fault message.
Some confusion exists in the pilot community about whether these checks will be displayed on the ECAM as contro linputs (the position of the sidestick) or control outputs (actual position of ailerons, etc.). The ECAM will display control outputs, as does the comparable system on the Boeing fly-by-wire B777.
One pilot correctly explained the functioning and went on to surmise what may have happened:
"Four position sensors called linear voltage differential transducers (LVDTs–used with aircraft control surface servos) look at the ailerons. This is quite independent of the sidestick positions. This display would not have been affected or reversed because of any miswiring of the sidestick...
"On control checks during taxi out, the pilots saw spoiler movement and aileronmovementin response to commands from each sidestick, correctly displayed on [the] ECAM. It just happened to be in the wrongdirectionfor one stick. Really quite easy to miss at a very busy time, and so unexpected. Every pilot does control checks, thousands of times. It is always correct, isn’t it? Except for this oh-so-rare occasion."
The check often is made during taxi out, a high workload period, rather than before pushback at the gate. Accordingly, the PF is moving his control actuators while keeping his eyes focused on activity outside the airplane, while the PNF is keeping his eyes locked on the ECAM display. In this arrangement, the PNF is not looking at and probably is not able to see the direction in which the PF is testing the sidestick. As such, the PNF may be looking at the ECAM more for confirmation of deflection, but not necessarily for direction of deflection.
In any event, the wiring fault got by at least two safety "filters," as it were. It was not detected during maintenance, and it was not detected during the preflight check.
The fact that this incident did not end with investigators piecing through charred wreckage is fortuitous. In the unfortunate event of a crash, there might not have been sufficient evidence pointing to a connector/wiring fault. Absent such evidence, investigators may have invoked "pilot error" based on a finding of incorrect banking associated with wake turbulence.
To be sure, crossed or reversed flight control cables on conventional aircraft have caused more than one crash. There is a grim history of such events on military and general aviation aircraft. If one control stick is connected backwards, then both yokes are misrigged, and both pilots are faced with the same parlous problem.
However, reversed controls are deemed impossible on transport-category aircraft, with their combination of cables and pushrods. Consider the "conventional" B737. A Boeing official declared it is impossible to reverse the connection of steel cables to hydraulic flight control actuators. Even if done deliberately, the pilots would instantly discover that they could not physically move their flight controls.
In the case of the A320, one aspect of the aircraft’s fly-by-wire design may have enabled the first officer to quickly gain control of the aircraft: the ability to isolate a malfunctioning sidestick and shift command to the other sidestick at the push of a button. As one pilot noted: "I would say that on this occasion, it was because of Airbus technology that a major incident was avoided!"
That may be so. But the case may well illustrate how avionics protections against human error in the cockpit can be reversed into outright hazards by human error on the maintenance floor. The BFU may have "just" an incident on its hands to investigate, but the safety issues are profound.
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All the Airbus haters, sorry all your hopes for a flight control problem down the drain, need to keep hoping!!
1. Crosswind incidents
2. Overrun incidents due ground spoilers cannot be manually extended
3. A321 incidents in icing conditions (certified without actual flight testing)
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Agreed, Airbus builds an incredible aircraft, I know of no problems with the 321 and icing, personally find it an easy aircraft to control in x-winds...and as PJ2 said...overruns are not an Airbus problem.
Mad (Flt) Scientist;
The information I have, and it is not based upon experience as I am not an engineer or a wrench, is that the 320 AMM cautions that the lockout valve "hex" is fully turned to the "M" position to prevent aerodynamic forces from raising the spoiler, so I assume that the spoiler can be physically locked down, (which only makes sense). Also, apropos the testing of the spoilers when buttoning up only one sidestick is required to be used for testing the spoilers.
We are assuming as well, that the indications for spoiler deployment on the FLT CTL lower ECAM page indicate actual position of the spoiler and nothing else; I raise that point because of comments in the Avionics article posted above regarding indications. Also, (and I thought this had been fixed), the requirement to hold the sidestick in position for at least 2 seconds, (some documents say 3), so give the servos time to reach full travel. Care must be exercised here as well as in actually seeing the ECAM indications, (as opposed to mentally "looking through" the indications because the control check is done so often) - what can appear correct, may not be as was the case with the Lufthansa crew. So there is lots to this, though not all (if even most) may (or may not) apply to the AC case; we just don't have enough information, nor, likely, will we unless it comes from Transport Canada or the CTSB.
The information I have, and it is not based upon experience as I am not an engineer or a wrench, is that the 320 AMM cautions that the lockout valve "hex" is fully turned to the "M" position to prevent aerodynamic forces from raising the spoiler, so I assume that the spoiler can be physically locked down, (which only makes sense). Also, apropos the testing of the spoilers when buttoning up only one sidestick is required to be used for testing the spoilers.
We are assuming as well, that the indications for spoiler deployment on the FLT CTL lower ECAM page indicate actual position of the spoiler and nothing else; I raise that point because of comments in the Avionics article posted above regarding indications. Also, (and I thought this had been fixed), the requirement to hold the sidestick in position for at least 2 seconds, (some documents say 3), so give the servos time to reach full travel. Care must be exercised here as well as in actually seeing the ECAM indications, (as opposed to mentally "looking through" the indications because the control check is done so often) - what can appear correct, may not be as was the case with the Lufthansa crew. So there is lots to this, though not all (if even most) may (or may not) apply to the AC case; we just don't have enough information, nor, likely, will we unless it comes from Transport Canada or the CTSB.
Last edited by PJ2; 23rd Apr 2009 at 21:41.
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Well, post what you will; - It's easy enough to say in an anonymous forum
What is being expressed here is plain old prejudice and not an airman's knowledge or experience.
Transportation Safety Board of Canada - AVIATION REPORTS - 2002 - A02O0406
I'm going to copy a few highlights for those who will not read or comprehend all of it:
Modifications to the A321 ELAC software were made after a landing occurrence in February 2001 in which there was wing-tip damage. This occurrence also involved roll oscillations in a significant crosswind but with no icing.
Findings as to Risk
1.Flight tests in natural icing conditions were not accomplished in any configuration in the A321 to determine if an acceptable level of safety existed in the handling characteristics.
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@ fc101
The cables on the 777 are not driven by computers. There are cables from the flight deck to the stabilizer and to Spoiler #4 and #11. With the cables you are able to keep the AC straight and level until you have re-established electrical power
The cables on the 777 are not driven by computers. There are cables from the flight deck to the stabilizer and to Spoiler #4 and #11. With the cables you are able to keep the AC straight and level until you have re-established electrical power
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Human Factors
So does this mean the AB bashing is finished? Many maintenance mistakes have been made on every type of machine in the air and indeed used anywhere else. It appears to be down to human factors and it is not the first time that this has happened with the A320.
When you lockout the spoilers on the A320 you install a collar with a flag 'REMOVE BEFORE FLIGHT' which in theory remains with the spoiler actuator and can only be removed from the keyway when the spoiler is reactivated IF YOU USE THE CORRECT TOOLING.
It has happened in the past that an alternative procedure has been used when the tools were not available and the result was something similiar. It happened to a G-KMAM Excalibur airways aircraft some years ago but I don't remember the exact details.
Brgds SB03
When you lockout the spoilers on the A320 you install a collar with a flag 'REMOVE BEFORE FLIGHT' which in theory remains with the spoiler actuator and can only be removed from the keyway when the spoiler is reactivated IF YOU USE THE CORRECT TOOLING.
It has happened in the past that an alternative procedure has been used when the tools were not available and the result was something similiar. It happened to a G-KMAM Excalibur airways aircraft some years ago but I don't remember the exact details.
Brgds SB03
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Spoiler
If the ground spoilers were indeed left in maintenance mode, wouldn't the crew have noticed this during their pre-departure flight control checks?
just curious
just curious
How do the engineers disable/enable the ground spoilers? Through CFDS ?
When you press RECALL before start will a GND SPLR FAULT message appear if they are disabled?
If the Ground Spoilers are disabled, as opposed to faulty, will ECAM show amber ground spoiler indications, and when you arm them after start will you receive a GND SPLR FAULT message? If not, why not?
And why would a ground spoiler problem produce a SPLR FAULT message, or is that just sloppy reporting?
When you press RECALL before start will a GND SPLR FAULT message appear if they are disabled?
If the Ground Spoilers are disabled, as opposed to faulty, will ECAM show amber ground spoiler indications, and when you arm them after start will you receive a GND SPLR FAULT message? If not, why not?
And why would a ground spoiler problem produce a SPLR FAULT message, or is that just sloppy reporting?
(If someone knows it better or wishes to make a correction, please do so. I'm using commas when I don't recall the exact names)
Spoilers are mechanically disabled by Maintenance. The process takes about half an hour to 45 minutes. There is a switch in each Spoiler that has to be put in "maintenance position" in order to move it to its closed position and only then it is "locked", in order to keep its retracted position, during flight. I think a "socket" has to be disconnected and therefore amber crosses will appear on ECAM. The opposite side Spoiler must also be disabled.
You will get a SPLR FAULT ECAM Message, as soon as you start-up your first engine, (although amber crosses are always present on the ECAM page before, and after, your start-up).
The STATUS Page will also give a PART SPLRS message, (every time you call that page and) as a recall, as soon as one selects FLAPS 1 for approach.
I don't recall the A320 fleet, but I'm sure it’s the same philosophy. The MEL allows us to take-off with two (pairs) of inhibited spoilers. Penalties are not appalling for just one (pair) off, but may represent lesser payload for the worst case. Penalties also increase in case one decides to use Flap 3 for landing.
I think the system it self is well designed but becomes problematic in case your Maintenance Engineers forget to lock one (or more) of your disabled Spoilers, leaving it in the “Maintenance Position”, therefore receiving hydraulic pressure, but only retracting aerodynamically. In that particular case, the Pilot has no way to know (except visually), that one of his disabled spoilers is in fact receiving hydraulic pressure (and moving up) once the ECAM System Pages will show him amber crosses! Also, since he is flying a FBW aircraft, he will not feel the need for trimming, because the system will automatically compensate for the not retracted spoiler. When you get a SPLR FAULT ECAM message, you will get an amber indication on the FLT CTRLS Page, together with the number of the Spoiler, and if the SPLR is not retracted you will get an arrow showing the faulty one UP.
In the disabled spoiler case, one gets nothing except, aerodynamically induced vibration, higher fuel consumption, a less performant aircraft, and may be some sideslip indication. I find here that there is space for Airbus Industrie to improve this design, although I’m not confident they will. All we would need, is that arrow showing the aviator that, one of his disabled Spoilers is out of the retracted position…
Fly Safe
Join Date: Oct 2007
Location: Miami
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Tree:
I would like to know how close you have been to flying an Airbus FBW to make such a statement.
My guess, not even close!!!
I speak from experience; can you say the same??
G
I would like to know how close you have been to flying an Airbus FBW to make such a statement.
My guess, not even close!!!
I speak from experience; can you say the same??
G