Atlas Air 767 down/Texas
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So, it seems that the gist of this now is that the AP got haywire thinking the aircraft was a Stuka bomber attacking some ground forces. And the crew was not able to or didnt succed in disconnection the AP.
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Even then, what pushed up the autothrottles to max? Both autopilot and autothrottles can normally easily be disconnected and/or overpowered.
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I wouldn't make too much of that wording change.
Maybe it was a reaction to people saying they were blaming the pilots.
I mean they should have the column forces on the FDR readout.
Would surprise me if the person writing "in response to column input" didn't check the column force before writing it.
Maybe it was a reaction to people saying they were blaming the pilots.
I mean they should have the column forces on the FDR readout.
Would surprise me if the person writing "in response to column input" didn't check the column force before writing it.
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On the contrary, I’m inclined to think that if they went to the trouble of changing the wording it’d because it is in some way significant. Curiouser indeed.
AFAIK, control column deflection and control force aren't mandatory FDR parameters per Annex 6.
So it may be that it was inferred from the elevator deflection (which is of course a mandatory parameter) and the inference subsequently corrected.
So it may be that it was inferred from the elevator deflection (which is of course a mandatory parameter) and the inference subsequently corrected.
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A question for 767 knowledgeable crew/engineers. If one of the (two?) autopilots is engaged, and the control columns are pulled fairly/very hard, does the AP disengage at some level of force or does it require positive selection of a button or switch?
I'm thinking of the Eastern Tristar that crashed in the Everglades, in that case gentle pressure on one column was enough to disengage altitude hold but I don't know if that caused the autopilot to release all control surfaces or if it was in one axis. I recall reading that there was a quiet chime that wasn't noticed when this happened whereas I thought that an AP disengaging is indicated in a louder and more attention-getting manner.
I saw up thread that an investigator commented that the Atlas crew "fought the automation" but logic suggests that significant control movement is clearly different from wanting the AP to keep doing what it was previously commanded to do.
I'm thinking of the Eastern Tristar that crashed in the Everglades, in that case gentle pressure on one column was enough to disengage altitude hold but I don't know if that caused the autopilot to release all control surfaces or if it was in one axis. I recall reading that there was a quiet chime that wasn't noticed when this happened whereas I thought that an AP disengaging is indicated in a louder and more attention-getting manner.
I saw up thread that an investigator commented that the Atlas crew "fought the automation" but logic suggests that significant control movement is clearly different from wanting the AP to keep doing what it was previously commanded to do.
Descending In IMC, receives sudden W/S warning. Throttles goes to the stops, aircraft pitches up. Spatially disorientated pilot notices airspeed not building, pushes control column forward and holds it until things 'start feeling right'. Realises what's going on, hauls back on column but too late.
Don't know, just an idea.
Don't know, just an idea.
A question for 767 knowledgeable crew/engineers. If one of the (two?) autopilots is engaged, and the control columns are pulled fairly/very hard, does the AP disengage at some level of force or does it require positive selection of a button or switch?
I'm thinking of the Eastern Tristar that crashed in the Everglades, in that case gentle pressure on one column was enough to disengage altitude hold but I don't know if that caused the autopilot to release all control surfaces or if it was in one axis. I recall reading that there was a quiet chime that wasn't noticed when this happened whereas I thought that an AP disengaging is indicated in a louder and more attention-getting manner.
I saw up thread that an investigator commented that the Atlas crew "fought the automation" but logic suggests that significant control movement is clearly different from wanting the AP to keep doing what it was previously commanded to do.
I'm thinking of the Eastern Tristar that crashed in the Everglades, in that case gentle pressure on one column was enough to disengage altitude hold but I don't know if that caused the autopilot to release all control surfaces or if it was in one axis. I recall reading that there was a quiet chime that wasn't noticed when this happened whereas I thought that an AP disengaging is indicated in a louder and more attention-getting manner.
I saw up thread that an investigator commented that the Atlas crew "fought the automation" but logic suggests that significant control movement is clearly different from wanting the AP to keep doing what it was previously commanded to do.
Not really. Shortly after the NTSB posted the original update with the "control column input" reference, several individuals on their twitter feed started pointing to "an intentional act." Subsequently, the update got updated again with the "column input" deleted. Just another example of social media leading the narrative vs the people who actually know.
This is not even speculation, just a "scenario" that might fit that reported throttle and control-input reading.
Massive incapacitation of PF (bird through the windscreen, medical, other), body pitches forward onto both column and (hand) throttle levers. Nose-over forces make it impossible for the other pilot and jumpseater to clear the controls until too late (that possible last-second attempt to get the nose up).
EDIT: I see I'm not alone - but it would certainly require a "Black Swan" event.
Massive incapacitation of PF (bird through the windscreen, medical, other), body pitches forward onto both column and (hand) throttle levers. Nose-over forces make it impossible for the other pilot and jumpseater to clear the controls until too late (that possible last-second attempt to get the nose up).
EDIT: I see I'm not alone - but it would certainly require a "Black Swan" event.
AFAIK, control column deflection and control force aren't mandatory FDR parameters per Annex 6.
This was an early 1990s build aircraft - and as digital memory was getting cheaper the number of non-mandatory items on the DFDR really exploded in that time frame. Both a benefit and a curse when you were reviewing incident data - with so much data available it could make it a real challenge to sift the wheat from the chaff...
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Descending In IMC, receives sudden W/S warning. Throttles goes to the stops, aircraft pitches up. Spatially disorientated pilot notices airspeed not building, pushes control column forward and holds it until things 'start feeling right'. Realises what's going on, hauls back on column but too late.
Don't know, just an idea.
Don't know, just an idea.
PMFJI, it could be a parameter, along with the force in pounds depending upon the data frame. The B737-400's -5 data frame has control column and control wheel position. This aircraft's data frame will likely have those parameters, and possibly also control column/wheel force in pounds.
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I suspect that the NTSB has a good guess between the CVR and FDR but need to be cagey in their public release of information until they have confirmation.
From today's NTSB update:
A cockpit voice recorder (CVR) group was convened and will complete a transcript of the entire event. The CVR transcript will be released when the public docket is opened.
Having worked in a bureaucracy, the most likely explanation is that someone accidentally posted a version of the press release that didn't include all the edits from the review process (and then corrected their mistake). It seems hard to believe that NTSB is both nimble enough to revise its press release in response to speculation on Twitter, and at the same time stupid enough to think that the revision would make things better.
It also seems hard to believe that those words would have made it into any version unless the FDR data showed column deflection and/or force. Maybe NTSB decided it should formally eliminate any other possible explanation for those readings before publishing the conclusion that there was actual control column input. Or it just didn't want to feed too much speculation ahead of the report (but accidentally did so anyway).
It also seems hard to believe that those words would have made it into any version unless the FDR data showed column deflection and/or force. Maybe NTSB decided it should formally eliminate any other possible explanation for those readings before publishing the conclusion that there was actual control column input. Or it just didn't want to feed too much speculation ahead of the report (but accidentally did so anyway).
From the EgyptAir 990 NTSB accident brief:
p. 25: “The FDR installed on the accident airplane was a Sundstrand Data Corporation (now named Honeywell Aerospace Electronic Systems) Universal Flight Data Recorder…”
“Flight performance parameters recorded by the FDR included the following: pressure altitude; airspeed (computed); engine rpm; pitch; roll; heading; angle of attack; normal (vertical), longitudinal, and lateral acceleration (load factors); left and right elevator positions; left and right inboard and outboard aileron positions; left and right trailing edge flap positions; rudder position; and horizontal stabilizer position.”
“The FDR was not required to and did not record control wheel, control column, or spoiler positions nor did it record control wheel and column forces.”
“Although control column position was not recorded by the FDR, the Safety Board’s testing and evaluation of the 767 elevator system showed that any movement occurring at the control columns would have resulted in concurrent, identifiable movements of the elevators, which would have been recorded on the FDR.”
p. 25: “The FDR installed on the accident airplane was a Sundstrand Data Corporation (now named Honeywell Aerospace Electronic Systems) Universal Flight Data Recorder…”
“Flight performance parameters recorded by the FDR included the following: pressure altitude; airspeed (computed); engine rpm; pitch; roll; heading; angle of attack; normal (vertical), longitudinal, and lateral acceleration (load factors); left and right elevator positions; left and right inboard and outboard aileron positions; left and right trailing edge flap positions; rudder position; and horizontal stabilizer position.”
“The FDR was not required to and did not record control wheel, control column, or spoiler positions nor did it record control wheel and column forces.”
“Although control column position was not recorded by the FDR, the Safety Board’s testing and evaluation of the 767 elevator system showed that any movement occurring at the control columns would have resulted in concurrent, identifiable movements of the elevators, which would have been recorded on the FDR.”