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Haere taka mua, taka muri; kaua e wha.
tdgeek: New develeopments
Half of CVR heard. Normal, nothing to report
They have found that the aircraft ascended at 6000ft per minute, then probably stalled. Could an updraft cause this? This is fighter ascent rate levels. Maybe with high headwinds, full power, pilot controlled it could have? Maybe the rest of the CVR may fill in this gap.
frankv:tdgeek: New develeopments
Half of CVR heard. Normal, nothing to report
They have found that the aircraft ascended at 6000ft per minute, then probably stalled. Could an updraft cause this? This is fighter ascent rate levels. Maybe with high headwinds, full power, pilot controlled it could have? Maybe the rest of the CVR may fill in this gap.
The answer is yes.
From http://www.britannica.com/EBchecked/topic/594363/thunderstorm/218326/Multiple-cell-thunderstorms-and-mesoscale-convective-systems:
Updraft speeds typically peak in the range of 5 to 10 metres (16 to 33 feet) per second, and speeds exceeding 20 metres (66 feet) per second are common in the upper parts of large storms. Airplanes flying through large storms at altitudes of about 10,000 metres (33,000 feet) have measured updrafts exceeding 30 metres per second (5900fpm).
It also tells me that in Supercells, updrafts can reach 40m/s (7800fpm).
Incidentally, headwinds (or tailwinds) are irrelevant to rate of climb.
tdgeek:
Tks for the detail. I assumed a headwind would allow more airspeed over the wing, causing more lift at an angle of attack, but good to know.
Given that the stall speed at close to 40000 feet is very high, easy to see how a stall could occur in this mayhem. And possibly difficult to get the nose down to increase airspeed in varying storm wind conditions?
Lastly, good to see the journos reporting this as not possible. Typically adding to the sensationalism.
joker97: So the final report says the autopilot computer had a cracked solder joint, causing the plane to be upset (pointed up), pilots disabled autopilot and caused it to gain even more altitude by incorrect response, eventually stalling [lift on wings < weight of plane] it leading to crash.
http://edition.cnn.com/videos/world/2015/12/01/report-on-air-asia-crash-released-quest-bpr.cnn
itxtme:joker97: So the final report says the autopilot computer had a cracked solder joint, causing the plane to be upset (pointed up), pilots disabled autopilot and caused it to gain even more altitude by incorrect response, eventually stalling [lift on wings < weight of plane] it leading to crash.
http://edition.cnn.com/videos/world/2015/12/01/report-on-air-asia-crash-released-quest-bpr.cnn
Watching Air Crash Investigation it blows my mind how often pilots do this. Their stick shaker is going off and still they pull up.
My views (except when I am looking out their windows) are not those of my employer.
hairy1: No comment.
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