Lufthansa Hamburg
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@ CONF iture
Let's assume that was the Captains mindset. He wanted the F/O to have the experience under his supervision and was sure if things go wrong he could interfere anytime, basically acting like an instructor.
Taking the Airbus philosophy into account, isn't that intention flawed by the simple fact, that since the CPT did add to the sidestick input the F/O wouldn't know how the plane reacts to her own input alone? If the sticks were connected the F/O could feel the correction from the CPT and know the total input. Not in an Airbus.
So basically the F/O was helped by the CPT, but she didn't effectively learn what she did and how the aircraft reacted? She wouldn't fly better then the next time. Nothing would have been learned, actually the next approach in these conditions would be even more dangerous with her. (For sure she will get simulator training though after this)
So would you agree, that in an Airbus in order to have the experience under real conditions and learn from it, you need to fly the thing alone?
Cross wind handling only request time + practice, effective practice, when under supervision you go and manipulate these flight controls, you control and over control, you test the reactions, you test the limits, or at least your own limits … but can you afford that from the right seat of your Company Airliner in the day to day operation ?
Taking the Airbus philosophy into account, isn't that intention flawed by the simple fact, that since the CPT did add to the sidestick input the F/O wouldn't know how the plane reacts to her own input alone? If the sticks were connected the F/O could feel the correction from the CPT and know the total input. Not in an Airbus.
So basically the F/O was helped by the CPT, but she didn't effectively learn what she did and how the aircraft reacted? She wouldn't fly better then the next time. Nothing would have been learned, actually the next approach in these conditions would be even more dangerous with her. (For sure she will get simulator training though after this)
So would you agree, that in an Airbus in order to have the experience under real conditions and learn from it, you need to fly the thing alone?
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So would you agree, that in an Airbus in order to have the experience under real conditions and learn from it, you need to fly the thing alone?
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Lack of flying experience...
One of the big benefits of the introduction of the MPL, will be that more and more pilots with less and less hands-on experience will take control of some real airplane to fight some real weather... that's gonna be fun 
Please fasten your seat belts and let the show begin!
live 2 fly 2 live
Please fasten your seat belts and let the show begin!
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Let's assume that was the Captains mindset. He wanted the F/O to have the experience under his supervision and was sure if things go wrong he could interfere anytime, basically acting like an instructor
To that day, he probably never fully realized how much the Airbus sidestick philosophy is detrimental to proper supervision. He is an experienced pilot with 10000 hours from which 4000 on type and probably did already encounter kind of similar situations in the past but with proper landing in the end. He probably thought that a few "discreet" inputs on its own sidestick (as he did 4 times before the first touchdown) would "help" his FO to maintain the overall situation on track … But that day, FO inputs were more unconventional and CAPT having absolutely no way to monitor such strange inputs at very low altitude … got finally caught.
Taking the Airbus philosophy into account, isn't that intention flawed by the simple fact, that since the CPT did add to the sidestick input the F/O wouldn't know how the plane reacts to her own input alone? If the sticks were connected the F/O could feel the correction from the CPT and know the total input. Not in an Airbus
So would you agree, that in an Airbus in order to have the experience under real conditions and learn from it, you need to fly the thing alone?
But yes, interference is worse than anything.
A Pilot Monitoring on FBW Airbus, whatever his grade, title or qualification must be aware he does not have the proper tool to monitor Pilot Flying inputs on flight controls. Therefore his capacity to evaluate aircraft behavior is diminished not knowing if the developing aircraft attitude is a consequence of pilot flying input or a consequence of external conditions or even a mix of both … ?
I see this event as a reminder, or should I say WAKE UP CALL for all CAPT, future CAPT and FO
Airbus should be lucid about this flaw and honest enough to publish a Caution Advisory as part of Flight Crew Training Manual.
Also, and obviously, the actual limited awareness regarding TAKE OVER PUSHBUTTON is not sufficient.
I can agree with this point, as a person gets more proficient controlling the Airbus it tends only to match the overall flight experience of that pilot, after I had figured it out, I had 10,000 hours flight experience behind me, so a pilot of her experience is only as good as one would expect and had no business being the operating pilot
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What did I say? Here we go again... CONF with his
There is *nothing* wrong with the sidestick for training purposes - it did just fine in the F-16 trainers, long before one was ever fitted to an A320. There is no proof that the dual input was what caused the excessive bank angle either, but the Airbus-haters will never accept that.
The need for feedback-linked controls went out with the introduction of RAT-powered hydraulics - you don't need two pilots "feeling" the aircraft and what each other are doing if it's all being done by actuators with no manual reversion. If the LH Captain messed up by going against training and failing to press the override switch before taking control, or even by having his F/O do an approach in weather that nasty in the first place, that is his lookout and no-one else's.
Waa... Asseline was innocent... Norbert Jacquet is a great man... Airbus are evil and hate pilots...
The need for feedback-linked controls went out with the introduction of RAT-powered hydraulics - you don't need two pilots "feeling" the aircraft and what each other are doing if it's all being done by actuators with no manual reversion. If the LH Captain messed up by going against training and failing to press the override switch before taking control, or even by having his F/O do an approach in weather that nasty in the first place, that is his lookout and no-one else's.
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The following is a summary of a crosswind landing incident to an A340 landing at Melbourne, Australia. As an observer I find myself thinking that there is some thing a little more basic going on than the often said "follow SOP's" or "more training required" in dealing with the Airbus philosophy.
Full report at http://www.atsb.gov.au/publications/...505311_001.pdf
At 1200 Eastern Standard Time on 26 October 2005, the outboard bead heel of the number-1 wheel tyre on the left main landing gear (MLG) of an Airbus A340-642 (A340) aircraft, registered HS-TNA, separated from the outboard rim of the wheel assembly during a landing on runway 16 at Melbourne Airport, Vic. The landing was conducted during gusting crosswind conditions.
The number-1 wheel tyre deflated immediately after the bead heel separated from the wheel rim. The tyre then partially disintegrated during the remainder of the landing roll, and the tyre tread detached from the tyre casing. Following the number-1 wheel tyre deflation, the crew maintained control of the aircraft and, apart from some minor deviations to the left and right of the runway centreline, tracked along the centreline.
The aircraft touched down with 15-degrees of yaw as a result of its handling by the flight crew. That yaw angle was greater than recommended by the aircraft manufacturer, and increased the risk of damage to the MLG at touchdown. It also increased the risk that the resultant groundslip angle of the MLG tyres would exceed the ‘saturation’ point at which they entered a fully-skidded state.
The pilot in command made dual side stick inputs during the latter stages of the approach intending to assist the copilot to maintain the attitude and trajectory of the aircraft. Those dual inputs compounded the handling difficulties being experienced by the copilot and increased the associated risks. Those risks could have been mitigated by the pilot in command taking control of the aircraft and pressing the side stick priority pushbutton at the point where he appeared to have become concerned about its attitude and trajectory, instead of making dual side stick inputs.
Side stick operation – dual inputs
The operator’s A340 FCOM also contained information that the PNF should not make control inputs to correct the handling of the aircraft by the PF. The lack of a direct mechanical linkage between the side stick controllers meant that there was no tactile feedback provided to the PF if the PNF was making concurrent or dual side stick inputs. (The aircraft manufacturer indicated that the interconnection of the aircraft’s side sticks ‘would be operationally not beneficial and technically not efficient’)
The aircraft was, however, fitted with a warning system to alert the crew of simultaneous inputs on both side sticks in the event that the side stick priority system was not activated. A 2-degree deflection of the PNF’s side stick in any direction from the neutral position resulted in the illumination of the green SIDE STICK PRIORITY warning lights on the glareshield in front of each crew member. In addition, the ‘DUAL INPUT’ synthetic voice message was activated by the flight warning system.
The aircraft manufacturer has examined the reasons for dual sidestick inputs during line operations. Advice received from the manufacturer included that, in normal flight conditions, the practice should not occur if ‘…proper airmanship and CRM [crew resource management] applied.’
An analysis by the manufacturer of reported instances of dual sidestick inputs has revealed they may be ‘spurious’, ‘comfort’, or ‘instinctive’ interventions on the part of the PNF. Those inputs can be defined as follows:
• Spurious dual inputs. Spurious dual inputs are unintentional, are of short-term duration and small in magnitude, and result in only marginal effects on an aircraft’s pitch and roll.
• Comfort dual inputs. Comfort dual inputs are intentional, short-term interventions by the PNF. The intention of the PNF is to correct or improve the aircraft’s attitude or trajectory during a precision manoeuvre, such as a landing approach or landing flare. Comfort inputs are normally small deflections, and may be the same as, or opposite to the PF’s sidestick inputs. They usually result in only minor effects on an aircraft’s altitude and/or trajectory, and are ‘…thus in most cases unnecessary.’ In most cases, the PF was unaware of any ‘comfort’ inputs by the PNF.
• Instinctive dual inputs. Instinctive dual inputs are ‘reflex’ interventions by the PNF, acting out of surprise at some unexpected event that may occur during a dynamic flight manoeuvre, such as the landing flare. Those interventions are significant in terms of stick deflection, and are usually initially in the same direction as the PF’s stick inputs. They have the potential to affect an aircraft’s behaviour, and may lead to over-control of an aircraft. As with comfort dual inputs, in most cases the PF is unaware of any ‘instinctive’ dual inputs by the PNF.
Previous incidents involving dual sidestick inputs on ‘fly-by-wire’ aircraft
The investigation examined three reports on previous dual sidestick input occurrences involving Airbus fly-by-wire aircraft types. Those reports revealed that, because neither crew member is provided tactile feedback of any sidestick inputs made by the other, dual sidestick inputs are problematic. (My bolding)
On 21 June 1996, the crew of an Airbus A340 aircraft enroute from Dallas/Fort Worth Airport to Houston Intercontinental Airport received a “descend” resolution advisory from the aircraft traffic collision avoidance system. The copilot was the PF. The US National Transportation Safety Board (NTSB) factual report19 on the incident revealed that:
The Captain initiated an immediate descent. The Captain did not make a verbal announcement that he was taking command of the left side stick control.
In that incident, the dual inputs from the pilot in command’s and copilot’s side stick controllers continued until the copilot noticed that the pilot in command was providing sidestick input, and returned the right side stick controller to the neutral position.
At the time of that occurrence, the ‘DUAL INPUT’ side stick warning system was not available on A340 aircraft.
On 21 June 2000, an Airbus A321 aircraft was involved in a tailstrike accident during a landing at London Heathrow. The copilot was the PF. The UK Air Accidents Investigation Branch (AAIB) investigation report20 included information that:
The aircraft touched down at an airspeed of 130 kt CAS, with a pitch attitude of 7.4° nose-up and a normal acceleration of 2.0g. The FO's sidestick position was 92.5% nose-up demand with an upelevator angle of 12.3°. The FO's sidestick demand then reduced, towards 46.8% nose-up demand.
The ground spoilers deployed automatically; this is designed to occur when both the main landing gear oleo switches are compressed. The FDR showed that these switches then 'unmade' indicating that the aircraft had rebounded into the air. The pitch attitude continued to increase to a maximum of 9.8° nose-up, which was reached just as the aircraft mainwheels touched the ground again. The tailscrape occurred at this point. The second touchdown recorded a normal acceleration of 1.6g at which time the commander's sidestick moved forward to a 56.3% nose-down demand.
The analysis section of the AAIB investigation included information that:
The commander did not anticipate a problem until after the aircraft's initial touchdown. He could not have been aware of the control inputs applied by the FO21, in particular the continued aft sidestick input late in the landing, because his own sidestick showed no movement.
and that:
The sidestick control authority logic requires a different method of intervention by commanders from that which they may have experienced on other aircraft types. Because of the difficulty of detecting the inputs made by the other pilot (My bolding) early takeover of control based on flight characteristics is required.
On 9 October, 2000, another Airbus A321 aircraft was involved in another tailstrike accident during a landing at London Heathrow. The copilot was the PF. The AAIB investigation revealed that, during the latter stages of the landing approach, the pilot in command became concerned at the high rate of descent. The pilot in command then applied aft sidestick, which ‘progressed to nearly full aft sidestick by a height of 10 feet, in order to arrest the rate of descent but he did not activate his sidestick takeover push button.’
The AAIB investigation report22 included a conclusion that:
As with other such incidents the commander could not see the control inputs of the FO and his first indication was a high rate of descent at about 40 feet shortly after the flare was initiated. He did not activate his sidestick takeover button and, given the circumstances, this action would not have prevented the tail of the aircraft contacting the runway. This occurred following the bounce on the second touch down when the commander was using aft sidestick to prevent the nose wheel coming down heavily.
During the latter stages of the landing approach, the pilot in command, who was the pilot not flying (PNF), commenced dual sidestick control inputs. Those dual sidestick inputs contravened the instructions relating to the operation of the aircraft’s fly-by-wire and side stick systems, which were contained in the operator’s A340 Flight Crew Operating Manual (FCOM).
The passage of the strong westerly winds over the Box Forest area to the north-west of Melbourne Airport would probably also have resulted in lee turbulence in the vicinity of the touchdown zone of runway 16. That turbulence was likely to have contributed to the aircraft’s unexpected roll deviations, including the recorded sudden roll to the left shortly after the aircraft passed through a height of about 70 ft. The pilot in command’s dual sidestick input at that point seemed to have been a ‘comfort’ intervention to correct the aircraft’s attitude or trajectory at that stage of the approach.
The pilot in command’s dual sidestick interventions became more significant in terms of stick deflection as the aircraft neared the ground, and were in mostly the same direction as the copilot’s stick inputs. Those dual sidestick would have provided ‘global’ electronic demand ‘orders’ to the flight control computers that were greater than those ‘ordered’ by the copilot. Consequently, the aircraft’s response to those ‘global’ demand ‘orders’ would likely have been greater-than-expected by the copilot. Moreover, the unexpected magnitude of aircraft’s response seemed to result in both crew members applying opposite sidestick inputs to counteract that unexpected response, leading to an over-control of the aircraft.
The investigation was unable to determine whether the copilot was aware of the pilot in command’s dual sidestick inputs, even though they resulted in aural ‘DUAL INPUT’ synthetic voice messages from the flight warning system (FWS). It was likely that, during the latter stages of the approach, the copilot’s attention was focussed on the external visual cues in order to maintain the aircraft tracking on the extended centreline of the runway in the gusting crosswind conditions. In addition, the copilot’s attention seemed also to have been focused on countering the unexpected magnitude of the aircraft’s roll and pitch that resulted from the ‘global’ demand ‘orders’. The copilot’s focus on correcting the aircraft’s attitude and trajectory, together with the numerous FWS synthetic voice messages, may have resulted in the copilot not comprehending the significance of the aural ‘DUAL INPUT’ warnings, and that they were a cue to the reason for the aircraft’s unexpected handling response.
The application of two-thirds full right rudder during the landing flare increased the yaw angle to more than that recommended by the manufacturer for a ‘…a safe crosswind landing…’ where the crosswind component exceeded 15 to 20 kts. The right yaw resulting from the application of that rudder would have increased the aircraft roll to the right, and therefore increased the risk of a right wingtip or wing-mounted engine pod strike. The right roll was countered by rapid and large left sidestick inputs by both crew members that resulted in an effective full left sidestick input in what appeared to be an instinctive ‘reflex’ response by both crew members to prevent that risk.
There was no attempt by either crew member to partially ‘decrab’ the aircraft during the landing flare. That was contrary to the advice provided by the manufacturer for the performance of ‘…a safe crosswind landing…’ in higher crosswind conditions. The lack of any ‘decrab’ therefore decreased safety margins and increased the risk of main landing gear (MLG) damage at touchdown. It also increased the risk that the resultant groundslip angle at touchdown would be of sufficient magnitude that the MLG tyre side forces exceeded the ‘saturation’ point at which they entered a fully-skidded state.
Full report at http://www.atsb.gov.au/publications/...505311_001.pdf
At 1200 Eastern Standard Time on 26 October 2005, the outboard bead heel of the number-1 wheel tyre on the left main landing gear (MLG) of an Airbus A340-642 (A340) aircraft, registered HS-TNA, separated from the outboard rim of the wheel assembly during a landing on runway 16 at Melbourne Airport, Vic. The landing was conducted during gusting crosswind conditions.
The number-1 wheel tyre deflated immediately after the bead heel separated from the wheel rim. The tyre then partially disintegrated during the remainder of the landing roll, and the tyre tread detached from the tyre casing. Following the number-1 wheel tyre deflation, the crew maintained control of the aircraft and, apart from some minor deviations to the left and right of the runway centreline, tracked along the centreline.
The aircraft touched down with 15-degrees of yaw as a result of its handling by the flight crew. That yaw angle was greater than recommended by the aircraft manufacturer, and increased the risk of damage to the MLG at touchdown. It also increased the risk that the resultant groundslip angle of the MLG tyres would exceed the ‘saturation’ point at which they entered a fully-skidded state.
The pilot in command made dual side stick inputs during the latter stages of the approach intending to assist the copilot to maintain the attitude and trajectory of the aircraft. Those dual inputs compounded the handling difficulties being experienced by the copilot and increased the associated risks. Those risks could have been mitigated by the pilot in command taking control of the aircraft and pressing the side stick priority pushbutton at the point where he appeared to have become concerned about its attitude and trajectory, instead of making dual side stick inputs.
Side stick operation – dual inputs
The operator’s A340 FCOM also contained information that the PNF should not make control inputs to correct the handling of the aircraft by the PF. The lack of a direct mechanical linkage between the side stick controllers meant that there was no tactile feedback provided to the PF if the PNF was making concurrent or dual side stick inputs. (The aircraft manufacturer indicated that the interconnection of the aircraft’s side sticks ‘would be operationally not beneficial and technically not efficient’)
The aircraft was, however, fitted with a warning system to alert the crew of simultaneous inputs on both side sticks in the event that the side stick priority system was not activated. A 2-degree deflection of the PNF’s side stick in any direction from the neutral position resulted in the illumination of the green SIDE STICK PRIORITY warning lights on the glareshield in front of each crew member. In addition, the ‘DUAL INPUT’ synthetic voice message was activated by the flight warning system.
The aircraft manufacturer has examined the reasons for dual sidestick inputs during line operations. Advice received from the manufacturer included that, in normal flight conditions, the practice should not occur if ‘…proper airmanship and CRM [crew resource management] applied.’
An analysis by the manufacturer of reported instances of dual sidestick inputs has revealed they may be ‘spurious’, ‘comfort’, or ‘instinctive’ interventions on the part of the PNF. Those inputs can be defined as follows:
• Spurious dual inputs. Spurious dual inputs are unintentional, are of short-term duration and small in magnitude, and result in only marginal effects on an aircraft’s pitch and roll.
• Comfort dual inputs. Comfort dual inputs are intentional, short-term interventions by the PNF. The intention of the PNF is to correct or improve the aircraft’s attitude or trajectory during a precision manoeuvre, such as a landing approach or landing flare. Comfort inputs are normally small deflections, and may be the same as, or opposite to the PF’s sidestick inputs. They usually result in only minor effects on an aircraft’s altitude and/or trajectory, and are ‘…thus in most cases unnecessary.’ In most cases, the PF was unaware of any ‘comfort’ inputs by the PNF.
• Instinctive dual inputs. Instinctive dual inputs are ‘reflex’ interventions by the PNF, acting out of surprise at some unexpected event that may occur during a dynamic flight manoeuvre, such as the landing flare. Those interventions are significant in terms of stick deflection, and are usually initially in the same direction as the PF’s stick inputs. They have the potential to affect an aircraft’s behaviour, and may lead to over-control of an aircraft. As with comfort dual inputs, in most cases the PF is unaware of any ‘instinctive’ dual inputs by the PNF.
Previous incidents involving dual sidestick inputs on ‘fly-by-wire’ aircraft
The investigation examined three reports on previous dual sidestick input occurrences involving Airbus fly-by-wire aircraft types. Those reports revealed that, because neither crew member is provided tactile feedback of any sidestick inputs made by the other, dual sidestick inputs are problematic. (My bolding)
On 21 June 1996, the crew of an Airbus A340 aircraft enroute from Dallas/Fort Worth Airport to Houston Intercontinental Airport received a “descend” resolution advisory from the aircraft traffic collision avoidance system. The copilot was the PF. The US National Transportation Safety Board (NTSB) factual report19 on the incident revealed that:
The Captain initiated an immediate descent. The Captain did not make a verbal announcement that he was taking command of the left side stick control.
In that incident, the dual inputs from the pilot in command’s and copilot’s side stick controllers continued until the copilot noticed that the pilot in command was providing sidestick input, and returned the right side stick controller to the neutral position.
At the time of that occurrence, the ‘DUAL INPUT’ side stick warning system was not available on A340 aircraft.
On 21 June 2000, an Airbus A321 aircraft was involved in a tailstrike accident during a landing at London Heathrow. The copilot was the PF. The UK Air Accidents Investigation Branch (AAIB) investigation report20 included information that:
The aircraft touched down at an airspeed of 130 kt CAS, with a pitch attitude of 7.4° nose-up and a normal acceleration of 2.0g. The FO's sidestick position was 92.5% nose-up demand with an upelevator angle of 12.3°. The FO's sidestick demand then reduced, towards 46.8% nose-up demand.
The ground spoilers deployed automatically; this is designed to occur when both the main landing gear oleo switches are compressed. The FDR showed that these switches then 'unmade' indicating that the aircraft had rebounded into the air. The pitch attitude continued to increase to a maximum of 9.8° nose-up, which was reached just as the aircraft mainwheels touched the ground again. The tailscrape occurred at this point. The second touchdown recorded a normal acceleration of 1.6g at which time the commander's sidestick moved forward to a 56.3% nose-down demand.
The analysis section of the AAIB investigation included information that:
The commander did not anticipate a problem until after the aircraft's initial touchdown. He could not have been aware of the control inputs applied by the FO21, in particular the continued aft sidestick input late in the landing, because his own sidestick showed no movement.
and that:
The sidestick control authority logic requires a different method of intervention by commanders from that which they may have experienced on other aircraft types. Because of the difficulty of detecting the inputs made by the other pilot (My bolding) early takeover of control based on flight characteristics is required.
On 9 October, 2000, another Airbus A321 aircraft was involved in another tailstrike accident during a landing at London Heathrow. The copilot was the PF. The AAIB investigation revealed that, during the latter stages of the landing approach, the pilot in command became concerned at the high rate of descent. The pilot in command then applied aft sidestick, which ‘progressed to nearly full aft sidestick by a height of 10 feet, in order to arrest the rate of descent but he did not activate his sidestick takeover push button.’
The AAIB investigation report22 included a conclusion that:
As with other such incidents the commander could not see the control inputs of the FO and his first indication was a high rate of descent at about 40 feet shortly after the flare was initiated. He did not activate his sidestick takeover button and, given the circumstances, this action would not have prevented the tail of the aircraft contacting the runway. This occurred following the bounce on the second touch down when the commander was using aft sidestick to prevent the nose wheel coming down heavily.
During the latter stages of the landing approach, the pilot in command, who was the pilot not flying (PNF), commenced dual sidestick control inputs. Those dual sidestick inputs contravened the instructions relating to the operation of the aircraft’s fly-by-wire and side stick systems, which were contained in the operator’s A340 Flight Crew Operating Manual (FCOM).
The passage of the strong westerly winds over the Box Forest area to the north-west of Melbourne Airport would probably also have resulted in lee turbulence in the vicinity of the touchdown zone of runway 16. That turbulence was likely to have contributed to the aircraft’s unexpected roll deviations, including the recorded sudden roll to the left shortly after the aircraft passed through a height of about 70 ft. The pilot in command’s dual sidestick input at that point seemed to have been a ‘comfort’ intervention to correct the aircraft’s attitude or trajectory at that stage of the approach.
The pilot in command’s dual sidestick interventions became more significant in terms of stick deflection as the aircraft neared the ground, and were in mostly the same direction as the copilot’s stick inputs. Those dual sidestick would have provided ‘global’ electronic demand ‘orders’ to the flight control computers that were greater than those ‘ordered’ by the copilot. Consequently, the aircraft’s response to those ‘global’ demand ‘orders’ would likely have been greater-than-expected by the copilot. Moreover, the unexpected magnitude of aircraft’s response seemed to result in both crew members applying opposite sidestick inputs to counteract that unexpected response, leading to an over-control of the aircraft.
The investigation was unable to determine whether the copilot was aware of the pilot in command’s dual sidestick inputs, even though they resulted in aural ‘DUAL INPUT’ synthetic voice messages from the flight warning system (FWS). It was likely that, during the latter stages of the approach, the copilot’s attention was focussed on the external visual cues in order to maintain the aircraft tracking on the extended centreline of the runway in the gusting crosswind conditions. In addition, the copilot’s attention seemed also to have been focused on countering the unexpected magnitude of the aircraft’s roll and pitch that resulted from the ‘global’ demand ‘orders’. The copilot’s focus on correcting the aircraft’s attitude and trajectory, together with the numerous FWS synthetic voice messages, may have resulted in the copilot not comprehending the significance of the aural ‘DUAL INPUT’ warnings, and that they were a cue to the reason for the aircraft’s unexpected handling response.
The application of two-thirds full right rudder during the landing flare increased the yaw angle to more than that recommended by the manufacturer for a ‘…a safe crosswind landing…’ where the crosswind component exceeded 15 to 20 kts. The right yaw resulting from the application of that rudder would have increased the aircraft roll to the right, and therefore increased the risk of a right wingtip or wing-mounted engine pod strike. The right roll was countered by rapid and large left sidestick inputs by both crew members that resulted in an effective full left sidestick input in what appeared to be an instinctive ‘reflex’ response by both crew members to prevent that risk.
There was no attempt by either crew member to partially ‘decrab’ the aircraft during the landing flare. That was contrary to the advice provided by the manufacturer for the performance of ‘…a safe crosswind landing…’ in higher crosswind conditions. The lack of any ‘decrab’ therefore decreased safety margins and increased the risk of main landing gear (MLG) damage at touchdown. It also increased the risk that the resultant groundslip angle at touchdown would be of sufficient magnitude that the MLG tyre side forces exceeded the ‘saturation’ point at which they entered a fully-skidded state.
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Of course, with force-feedback the famous incident where the controls were cross-connected would have probably ended up as a fatal accident, with the force feedback forcing the stick in the opposite direction on the correctly-wired side, with the pilot finding it considerably harder to correct.
It's a complex issue, and this is why issuing recommendations on a purely reactive incident-based level needs to be thought about very carefully.
It's a complex issue, and this is why issuing recommendations on a purely reactive incident-based level needs to be thought about very carefully.
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with force-feedback the famous incident where the controls were cross-connected would have probably ended up as a fatal accident
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It should have showed up in a control check anyway on the MFD while the a/c was on the ground, but it would appear that one was not performed.
Like I said, a complex issue that has no simple answers. I know there's a tendency to insist the "old ways" were better, but even Boeing are using computer-controlled back-driven force feedback in their new aircraft rather than mechanical connections, which is in itself a complex system that has more scope for problems than the older system. I think Airbus went with the old engineering maxim that the less complex a system is, the fewer parts there are to go wrong.
Like I said, a complex issue that has no simple answers. I know there's a tendency to insist the "old ways" were better, but even Boeing are using computer-controlled back-driven force feedback in their new aircraft rather than mechanical connections, which is in itself a complex system that has more scope for problems than the older system. I think Airbus went with the old engineering maxim that the less complex a system is, the fewer parts there are to go wrong.
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GREAT reading Brian !
I was aware of a few cases but not all of them. They all point to the same direction, exactly the one I want to emphasize, not to bash Airbus but more to make FBW Airbus drivers aware of that specificity.
You mention S76, I believe this being a helicopter (?) Surprised you show a manifest interest in that 2 wings subject … but I take that opportunity to ask you the following:
In your domain, I think to understand that movement amplitude of the different flight controls are very tiny (?)
The sticks are mechanically coupled (?)
If you operate in dual crew, how do you appreciate the flight control inputs from your PF ?
And how is it important for the Pilot Monitoring ?
Coming back to Hamburg, and taking in account your comments, I believe the first 4 interferences from the Captain could be qualified as "Comfort dual inputs" and probably trigger at most a warning light (?) but the fifth one was an "Instinctive dual input" with the associated DUAL INPUT synthetic voice.
The proper procedure SIDESTICK PRIORITY PB was applied 20 seconds after the first visible interference.
GDL, unless you see something I don’t (?), to me your 737 video landing is perfect and that rebound is not much to worry about.
DW, I have no objection to be quoted, but PLEASE, do it carefully: Except from the fact that Norbert Jacquet is a GREAT MAN, I have nothing to see with your quote !
I’m afraid you don’t really get it: The problem is not the question to "feel" the aircraft, but merely to be simply aware of what your partner is trying to do with the airplane you’re seated in !
Is that really too much asking ?
In Hamburg if the PM would have known the PF was applying that unwanted LEFT control command coupled to the LEFT rudder input he would have just blocked and reversed that crazy move ... Hamburg was a non event ... Young FO would have learned a lot !
As you can see through the many "anecdotes" many Captains seem to mess up by failing to press the override switch … Hamburg is far to be an isolated case … It could even be called a … trend.
So, as Brian said, is there something else going on !?
I suppose you’re a FBW Airbus Pilot as well (?) and don’t look even in the slightest way bothered by the Airbus sidestick philosophy … GOOD FOR YOU … but maybe one day your partner will mess it up as well ?
You probably know over confidence is not our best ally in a flightdeck.
And … did you finally have a serious look at the FDR readings as promised … !?
Do you maintain your position ?
… Standing by for your comments !
I was aware of a few cases but not all of them. They all point to the same direction, exactly the one I want to emphasize, not to bash Airbus but more to make FBW Airbus drivers aware of that specificity.
You mention S76, I believe this being a helicopter (?) Surprised you show a manifest interest in that 2 wings subject … but I take that opportunity to ask you the following:
In your domain, I think to understand that movement amplitude of the different flight controls are very tiny (?)
The sticks are mechanically coupled (?)
If you operate in dual crew, how do you appreciate the flight control inputs from your PF ?
And how is it important for the Pilot Monitoring ?
Coming back to Hamburg, and taking in account your comments, I believe the first 4 interferences from the Captain could be qualified as "Comfort dual inputs" and probably trigger at most a warning light (?) but the fifth one was an "Instinctive dual input" with the associated DUAL INPUT synthetic voice.
The proper procedure SIDESTICK PRIORITY PB was applied 20 seconds after the first visible interference.
GDL, unless you see something I don’t (?), to me your 737 video landing is perfect and that rebound is not much to worry about.
DW, I have no objection to be quoted, but PLEASE, do it carefully: Except from the fact that Norbert Jacquet is a GREAT MAN, I have nothing to see with your quote !
I’m afraid you don’t really get it: The problem is not the question to "feel" the aircraft, but merely to be simply aware of what your partner is trying to do with the airplane you’re seated in !
Is that really too much asking ?
In Hamburg if the PM would have known the PF was applying that unwanted LEFT control command coupled to the LEFT rudder input he would have just blocked and reversed that crazy move ... Hamburg was a non event ... Young FO would have learned a lot !
As you can see through the many "anecdotes" many Captains seem to mess up by failing to press the override switch … Hamburg is far to be an isolated case … It could even be called a … trend.
So, as Brian said, is there something else going on !?
I suppose you’re a FBW Airbus Pilot as well (?) and don’t look even in the slightest way bothered by the Airbus sidestick philosophy … GOOD FOR YOU … but maybe one day your partner will mess it up as well ?
You probably know over confidence is not our best ally in a flightdeck.
And … did you finally have a serious look at the FDR readings as promised … !?
Do you maintain your position ?
… Standing by for your comments !
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Cover up!
"German investigators believe that lack of clarity over crosswind operating limits contributed to a Lufthansa Airbus A320's suffering a serious wing-strike while landing at Hamburg two years ago.
Analysis of the incident - particularly the decision to continue an approach despite strong gust conditions - has revealed discrepancies by pilots in the interpretation of crosswind limits as presented in operating manuals.
Flight LH044's left wing-tip was damaged after it struck the surface of runway 23 when the A320 suddenly rolled to the left just as it touched down. The crew executed a go-around and subsequently landed safely.
German investigation agency BFU, in a final report into the incident today, states that the crew had opted to make the de-crabbed approach after being informed that winds were at 28kt, gusting to 37kt.
Airbus' A320 flight crew operating manual, under the term 'maximum crosswind demonstrated for landing, gives a figure of 33kt gusting to 38kt.
During LH044's final approach, however, the crew was told that the winds were still around 28-29kt but gusting to 47kt.
BFU says that a go-around would have been "reasonable", but states that the crew "did not interpret" the operating manual information prescribing a limit for the aircraft.
Concerned over the possible lack of clarity regarding operating limits, the investigators questioned 81 pilots from five carriers to understand how the term 'maximum demonstrated crosswind' is interpreted in practice.
The survey found that while half of respondents viewed the term as a limit, the other half considered it only a guideline.
BFU says this is "evidence of a considerable information deficit", adding that the terms used in the operating manuals - and by the carrier itself - are not adequately defined or explained.
"The answers to the questions on the permissibility of landings in gusty conditions call for clarification," it says.
Among 12 recommendations in its final report into the 1 March 2008 incident, BFU has recommended revisions to the nature of the crosswind information presented by Airbus in its operating manuals. It also says that airlines should set crosswind limits for their own specific operations."
Smells a cover up IMHO..........how many of the German BFU guys are ex Lufthansa?
and yeh... they even managed to blame a part of it on Airbus
Didn't LH had "crosswind limits for their own specific operations" before this incident? Don't all airlines do?
A crosswind limit is a LIMIT.......end of story!
Analysis of the incident - particularly the decision to continue an approach despite strong gust conditions - has revealed discrepancies by pilots in the interpretation of crosswind limits as presented in operating manuals.
Flight LH044's left wing-tip was damaged after it struck the surface of runway 23 when the A320 suddenly rolled to the left just as it touched down. The crew executed a go-around and subsequently landed safely.
German investigation agency BFU, in a final report into the incident today, states that the crew had opted to make the de-crabbed approach after being informed that winds were at 28kt, gusting to 37kt.
Airbus' A320 flight crew operating manual, under the term 'maximum crosswind demonstrated for landing, gives a figure of 33kt gusting to 38kt.
During LH044's final approach, however, the crew was told that the winds were still around 28-29kt but gusting to 47kt.
BFU says that a go-around would have been "reasonable", but states that the crew "did not interpret" the operating manual information prescribing a limit for the aircraft.
Concerned over the possible lack of clarity regarding operating limits, the investigators questioned 81 pilots from five carriers to understand how the term 'maximum demonstrated crosswind' is interpreted in practice.
The survey found that while half of respondents viewed the term as a limit, the other half considered it only a guideline.
BFU says this is "evidence of a considerable information deficit", adding that the terms used in the operating manuals - and by the carrier itself - are not adequately defined or explained.
"The answers to the questions on the permissibility of landings in gusty conditions call for clarification," it says.
Among 12 recommendations in its final report into the 1 March 2008 incident, BFU has recommended revisions to the nature of the crosswind information presented by Airbus in its operating manuals. It also says that airlines should set crosswind limits for their own specific operations."
Smells a cover up IMHO..........how many of the German BFU guys are ex Lufthansa?
and yeh... they even managed to blame a part of it on Airbus Didn't LH had "crosswind limits for their own specific operations" before this incident? Don't all airlines do?A crosswind limit is a LIMIT.......end of story!
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Although it´s a "non event", the accident report was published today. Interesting read, indeed.
http://www.bfu-web.de/cln_007/nn_223...indlandung.pdf
Unfortunately the 86 page report is in German, but there is a summary on the Flight page.
Inquiry: Crosswind limit clarity needed after A320 wing-strike
With regards,
Stubenfliege
http://www.bfu-web.de/cln_007/nn_223...indlandung.pdf
Unfortunately the 86 page report is in German, but there is a summary on the Flight page.
Inquiry: Crosswind limit clarity needed after A320 wing-strike
With regards,
Stubenfliege
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English Version
A320 Hamburg Xwind Report-English
Courtesy of 20milesout as posted in the Tech Log Forum
Courtesy of 20milesout as posted in the Tech Log Forum
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Whatever happened seconds or minutes before, when most needed, the aircraft deprived the crew from the controls full deflection !?
"At this point I will only give you half deflection and do not question"
... This Airbus is a really strange animal, with many little secrets … how many more ?
"At this point I will only give you half deflection and do not question"
... This Airbus is a really strange animal, with many little secrets … how many more ?
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"At this point I will only give you half deflection and do not question"
Now what kind of BS is that and how were we supposed to know??
Good thing it is clarified now, but it will change with the next software update, no doubt, and it will, again, not be communicated until the next accident.
As CONF iture says, strange kind of animal but still some pilots like it.
Strange kind of pilots, RCPs ('remote controlled pilots') I call them.
But they're happy, that's all that matters .....
Don't like three-twenty, oh no.
I love her!
(with apologies to 10CC)
A320 is jolly good girl. She was boldly taken by 579 hr TT F/O where no test pilot has gone before, she was treated with left stick in right crosswind decrab, she was landed on the downwind gear.
Result?
One bent wingtip fence.
I'm not sure whether it was Randy Cunningham or Robin Olds that, referring to F-4, said: Airplane is like your wife, you have to love her good sides and learn to live with the bad ones. Applicable to any aeroplane, I'd add.
Despite the rumors to the contrary, 320 is still full-blooded aeroplane and will happily chew any SysOp foolishly buying the hype of "You needn't be pilot to fly A320". Our love affair was brief and happy, a couple of quarrels between us. most of them were my fault, were quickly resolved by using both red buttons. Worked like a charm every time.
I love her!
(with apologies to 10CC)
A320 is jolly good girl. She was boldly taken by 579 hr TT F/O where no test pilot has gone before, she was treated with left stick in right crosswind decrab, she was landed on the downwind gear.
Result?
One bent wingtip fence.
I'm not sure whether it was Randy Cunningham or Robin Olds that, referring to F-4, said: Airplane is like your wife, you have to love her good sides and learn to live with the bad ones. Applicable to any aeroplane, I'd add.
Despite the rumors to the contrary, 320 is still full-blooded aeroplane and will happily chew any SysOp foolishly buying the hype of "You needn't be pilot to fly A320". Our love affair was brief and happy, a couple of quarrels between us. most of them were my fault, were quickly resolved by using both red buttons. Worked like a charm every time.
@gretchenfrage: The bus switched into ground mode as the left main gear touched down. The right MGL had no ground contact during the whole incident (page 47 of the report).
@cllandestino: The manufacturer didnt specify the correct procedure for strong crosswinds in the manual He mentioned different methods. So the pilot flying held the wings level (no low wing in the wind) and tried to decrab. --> Not the best procedure for this conditions.
greetings
and many happy landings
Thomas from germany
@cllandestino: The manufacturer didnt specify the correct procedure for strong crosswinds in the manual He mentioned different methods. So the pilot flying held the wings level (no low wing in the wind) and tried to decrab. --> Not the best procedure for this conditions.
greetings
and many happy landings
Thomas from germany
Last edited by krohmie; 12th Mar 2010 at 17:57.
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One more time, an incident, as it happened in HAM, can bring questions on the Airbus technical options.
I can see a serious issue with that roll rate demand coupled to the side sticks the way Airbus opted to implement them :
What about keeping things simple ?
HAM is remarquable on that regard.
I can see a serious issue with that roll rate demand coupled to the side sticks the way Airbus opted to implement them :
- The PF has no way to evaluate the amount of deflection on the flight control surfaces in relation to his own side stick displacement.
- The PM has no way to know what the PF request is.
- And now on top of it we learn that the flight controls deflection can be suddenly reduced by 50%
What about keeping things simple ?
- Linked side sticks to keep the PM in the loop
- Direct law to keep both PF and PM in that same loop
HAM is remarquable on that regard.
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@krohmie
Thanks, but I had stated that in my contribution already ...... and still think such programming is bs.
@PJ
It might not be an issue to you, fine. But it might be an issue to others.
There is a big difference between those who merely state their oppinion and suggestions, dismissed by you with "too much unknown, too much guessing", and yourself proclaiming to know what shall be an issue and what not.
What are your merits or credentials to do so? This devaluates your contributions, at least for me.
Thanks, but I had stated that in my contribution already ...... and still think such programming is bs.
@PJ
Quote:
1. The PF has no way to evaluate the amount of deflection on the flight control surfaces in relation to his own side stick displacement.
It isn't an issue.
Quote:
2. The PM has no way to know what the PF request is.
True. It isn't a serious, high-risk issue.
1. The PF has no way to evaluate the amount of deflection on the flight control surfaces in relation to his own side stick displacement.
It isn't an issue.
Quote:
2. The PM has no way to know what the PF request is.
True. It isn't a serious, high-risk issue.
There is a big difference between those who merely state their oppinion and suggestions, dismissed by you with "too much unknown, too much guessing", and yourself proclaiming to know what shall be an issue and what not.
What are your merits or credentials to do so? This devaluates your contributions, at least for me.