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Originally Posted by tartare
(Post 10401491)
What happens in a PIO if you simply let go of the sidestick during the roll?
Will the aircraft stabilise at a certain level of roll - or does it all depend on what law you're in? Never understood Airbus's... |
Originally Posted by AerocatS2A
(Post 10401490)
Neither of those seem relevant. The first one was associated with flaps locked at full and the lever selected to 3 in accordance with an ECAM, the second involved ice accretion. As an aside and not directly relevant but more to highlight what pilots are not told as a matter of course: Hamburg A320 LH wing tip scrape in crosswind landing revealed that aileron authority reduced significantly as a/c sensed ground mode even though only one gear on ground and so limiting crew ability to correct the situation more rapidly. Flight Global A320 |
Originally Posted by Sailvi767
(Post 10400319)
That looks like a flight control malfunction to me. Possibly direct law in roll mode. I've wound up in Direct law, and believe me, the airplane flew quite nicely, was like the Pitts S-2 I did a bit of flying in.... |
Originally Posted by AerocatS2A
(Post 10401490)
Neither of those seem relevant. The first one was associated with flaps locked at full and the lever selected to 3 in accordance with an ECAM, the second involved ice accretion. One of the outcomes of this incident and others similar at the time was change to the FBW roll laws with additional data points and proper flight testing of the various configs to confirm certification compliance. The question has been raised in this latest incident as to whether this was sufficient, particularly if the autopilot remained engaged. |
Originally Posted by FCeng84
(Post 10401435)
From the videos that has been linked above it appears that the airplane was well above the ground when the roll oscillations documented occurred. The speed altitude trace shows descent to a very low altitude prior to executing the go-around. I am left with a couple of questions that others may be able to help with:
1. Were there roll oscillations during the final approach that led to the go-around? Did any passengers (particularly those who submitted interior videos) comment on the altitude when worrisome roll oscillations occurred? 2. Did the go-around involve touching down or was it executed without wheel to runway contact? Were there any objectionable pitch or roll motions associated with the flight just prior to initiation of the go-around or during the go-around itself? 3. Has the airline made any statement about this event with regard to either the equipment or the crew? As is often the case, more questions than answers! a) the altitude traces from the flight-trackers clearly aren't relative to a SL datum (i.e. uncorrected for QNH) b) the GA started at around 1.6 nm from the THR (so presumably at around 500' AAL) c) there was no runway contact (the THR was overflown at around 1700') In other words the tracking data is consistent with the video, as one would expect. |
Originally Posted by DaveReidUK
(Post 10401575)
See my earlier post(s):
a) the altitude traces from the flight-trackers clearly aren't relative to a SL datum (i.e. uncorrected for QNH) b) the GA started at around 1.6 nm from the THR (so presumably at around 500' AAL) c) there was no runway contact (the THR was overflown at around 1700') In other words the tracking data is consistent with the video, as one would expect. In my experience, FR24 gives poor altitude information close to airports. Track information is better. When i follow a flight it often stops at a few hundred feet, flies over the runway and then drops straight down to the ground. OMG, it nose dived into the ground! No, just FR24 acting up. |
.PF learns how to not PIO as soon as they transition from W/S escape into G/A and set Config 3. |
Originally Posted by ManaAdaSystem
(Post 10401589)
There had to be a major difference between actual QNH and STD to get that 500 ft difference. What was the QNH at the time?
A QNH of around 1030 would account for that difference. I haven't seen a METAR, so I don't know what the actual value was. In my experience, FR24 gives poor altitude information close to airports. And, regardless of size of the offset, by the time the aircraft was over the threshold it was clearly around 1200' higher than at the lowest point of its approach, so neither the video or the data would indicate any runway contact. |
For those who are interested, QNH in LHR is 1027. You can watch as all aircraft on FR24 are landing short of the runway. Probably the same situation as in Gibraltar. I agree, the difference in QNH can show the opposite, aircraft hanging in the air above the runway in low QNH situations. How would the resulting plunge to the runway show up on a graph? |
Originally Posted by AerocatS2A
(Post 10401490)
Neither of those seem relevant. *the reports cite other previous examples too, also not involving ice, admittedly the details are beyond page 1 however |
While not wanting to get into the detail of this incident it would seem to me that there is an over reliance on autoflight within the industry and with the lack of hand flying the pilots skill at avoiding PIO has become degraded. |
Originally Posted by A and C
(Post 10401644)
While not wanting to get into the detail of this incident it would seem to me that there is an over reliance on autoflight within the industry and with the lack of hand flying the pilots skill at avoiding PIO has become degraded. Very much agree, from what it seems there are far too many pilots who are merely system operators rather than airmen. I recently heard that you're not allowed to remove the Flight Directors in our favourite irish loco airline. Visuals are discouraged in others and more and more outfits are banning visual approaches as they keep messing them up. Unfortunately in times when real pilot/flying skills are required, they're nowhere to be seen. My two cents. |
Originally Posted by geardown1
(Post 10402156)
Very much agree, from what it seems there are far too many pilots who are merely system operators rather than airmen. I recently heard that you're not allowed to remove the Flight Directors in our favourite irish loco airline. Visuals are discouraged in others and more and more outfits are banning visual approaches as they keep messing them up.
Unfortunately in times when real pilot/flying skills are required, they're nowhere to be seen. My two cents. |
Originally Posted by Just the fax maam
(Post 10401643)
Evidence of several* other incidents of uncommanded severe roll oscillations in strong gusty conditions on A320 family aircraft not relevant? Are you absolutely certain about that???
*the reports cite other previous examples too, also not involving ice, admittedly the details are beyond page 1 however |
Hydraulic reservoir and pump capacity
Looks as though too many control inputs depleted control surface hydraulic jack pressure leading to a lag in movement and eventual over control. Known problem.
solution go around or if clever be patient and use smaller stick deflections but knowing how rough the rock can be easier said than done. |
Originally Posted by MichaelKPIT
(Post 10400248)
Here's a video from outside:
or just saying ``hello`` to somebody on the ground..Or a serious problem with the autopilot.. Fly safe, B-757 |
..To me that looks intentional..Maybe a demonstration (for training purposes), or just saying ``hello`` to somebody on the ground..Or a serious problem with the autopilot.. |
Originally Posted by blind pew
(Post 10402678)
Looks as though too many control inputs depleted control surface hydraulic jack pressure leading to a lag in movement and eventual over control. Known problem.
solution go around or if clever be patient and use smaller stick deflections but knowing how rough the rock can be easier said than done. The co-pilot flew the Wind Sheer Go-around. (Capt. hadn't resumed control for the landing) and with little practice in "manual flying" in those conditions, over controlled the sidestick inputs, resulting in the 30deg PIO. Situation was resolved when the gear selected up, which presumably removed the R Alt fault signal and returned the aircraft to Normal FBW Airbus handling. I'm not Airbus qualified so excuse the neccesarily rather non technical description. |
Would like to think the FO is now in the sim .........
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With RA 1+2 fault the Direct Law is tied to the L/G position, i.e. active when down. That piece fits in what cessnapete says.
The bank angles shown on the videos are hard to explain with a simple PIO, even if in direct law. AAIB will tell. |
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