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Grant (SSSF) Send message Joined: 19 Aug 99 Posts: 13864 Credit: 208,696,464 RAC: 304 |
Apparently icing of control services are being looked at as it flew through some pretty bad weather.Icing may have contributed to the crash, but it won't have (shouldn't have!) been the cause. An aerodynamic stall due to ice doesn't lead to a flat spin. The aircraft may stall start to fall out of the sky with it's nose up (pitch up), a wing could drop (roll) and then the plane turns and heads for the ground. Both are recoverable, although if there is still ice on the wing(s) significant control issues will still remain. But to go into a flat spin (as Gary Charpentier posted stall + yaw)? For a commercial aircraft, it's just not something that happens (and if it does happen, given the altitude of the aircraft when it occurred, only an overload behind the aircraft's CG (Centre of Gravity) would make it pretty much impossible to recover from). I know it's way too early, but unless there was some particularly odd mechanical/control issue i honestly think the pilots experience, training and evaluations are going to end up being the main centre of the investigation and the ultimate cause of the crash. Grant Darwin NT |
Grant (SSSF) Send message Joined: 19 Aug 99 Posts: 13864 Credit: 208,696,464 RAC: 304 |
i honestly think the pilots experience, training and evaluationsAnd add to that- the airline's SOP for icing conditions. Those ATRs are well known for handling icing poorly, and being very susceptible to icing conditions. There was a NOTAM in effect for severe icing in the area they were flying , at the altitude they were flying. Why didn't they fly at a lower altitude? Were they flying at the recommended speed for such conditions (which apparently is a minimum of 30 knots above the minimum speed to avoid a stall under non-ice conditions). Did they attempt to bank at a higher than recommended angle when turning (under icing conditions it's half or less of the maximum angle for non-icing conditions). And even they all of that wrong- how did they end up in a flat spin- Using the rudder to turn, with no banking, at a high AOA resulting in a stall??? It's looking like icing may have been the initiator of this crash (no ice, no crash), but even with the ice, avoiding the crash should have been possible. Or did everything go wrong at once, resulting in sensory overload for the crew, resulting in inappropriate responses to the situation? Grant Darwin NT |
Gary Charpentier Send message Joined: 25 Dec 00 Posts: 31043 Credit: 53,134,872 RAC: 32 |
Juan Browne - blancolireo - has done a good video already. I'm going to take a stab at what likely will be found. They hit top of decent and reduced power to begin the descent, didn't pitch down immediately to maintain speed. May have also been at a way point for a turn, hence aileron and rudder inputs. Enough ice on the wings to stall with even a small reduction in speed. Spin entry happens very quick. Yaw dampener may have been fairly out of trim. (Possible asymmetric ice formation.) Not expecting it the pilot flying didn't instantly go wings level, full nose down, full opposite rudder, throttles to idle. Of course in IMC you don't have ground reference to see WTF is going on. By the time the first rotation was done it may not have been recoverable. Most twin engine prop (including turboprop) airplanes have very bad or no recovery from a spin. Their rudder simply isn't big enough to counter the rotational momentum of the weight of the engines out on the wings. However continued flight in those icing conditions should have never happened. Declare the emergency and descend to warmer and more dense air. This is going to weigh heavily on pilot training, procedures and experience. One thing we will never know is if a large chunk of ice departed one side resulting in asymmetry enough to cause a spin. Perhaps a control input broke it off? |
rob smith Send message Joined: 7 Mar 03 Posts: 22569 Credit: 416,307,556 RAC: 380 |
Link to Blancolirio's video: https://www.youtube.com/watch?v=ozinSmylTmQ Hard - Yes. Impossible - No. Bob Smith Member of Seti PIPPS (Pluto is a Planet Protest Society) Somewhere in the (un)known Universe? |
Grant (SSSF) Send message Joined: 19 Aug 99 Posts: 13864 Credit: 208,696,464 RAC: 304 |
FDR (Flight Data Recorder) & CVR (Cockpit Voice Recorder) have been recovered (hopefully both were fully functional). Also there's some more info on the flight from Flightradar24- the ADS-B ground speed data for that flight was unreliable (to put it mildly), but they do have the reported barometric altitude & vertical rate and the Reported true airspeed as graphs. It's very much looking like ice, and the aircraft with the autopilot on (which apparently is against the aircraft manufacturers requirements for operating in icing conditions). The air speed was gradually dropping, with no change in altitude. Eventually there was a drop in altitude, then a slight increase, some larger increases, and then it started falling out of the sky. 89 seconds from the first signs of trouble, to the last received data. Extremely tragic. ;-( ' Grant Darwin NT |
Wiggo Send message Joined: 24 Jan 00 Posts: 37007 Credit: 261,360,520 RAC: 489 |
Goodness knows what was in his head at the time and we'll likely never know as he died. Up to 400 people have been evacuated from a hotel in Far North Queensland after a helicopter crashed into the roof just after 2am, sparking a massive fireball. A helicopter has crashed into the roof of a Cairns hotel, sparking a massive fireball and the evacuation of up to 400 people.Thankfully no one else was seriously injured. |
Wiggo Send message Joined: 24 Jan 00 Posts: 37007 Credit: 261,360,520 RAC: 489 |
An update on that chopper crash. Stolen helicopter on 'unauthorised' flight crashes into roof of Cairns DoubleTree by Hilton hotel in Far North Queensland. A helicopter that crashed into a Far North Queensland hotel roof was stolen before being taken on an "unauthorised flight", the aviation company it belonged to has confirmed. |
ML1 Send message Joined: 25 Nov 01 Posts: 21325 Credit: 7,508,002 RAC: 20 |
Apparently icing of control services are being looked at as it flew through some pretty bad weather.Icing may have contributed to the crash, but it won't have (shouldn't have!) been the cause. If the autopilot is left on right up until the bitter end right into an iced-up coffin corner, then anything is possible when that autopilot finally gives up eventually too long after all good sense and hope, when already into a deep stall, with all controls already maxed out. Any minor asymmetry can then trigger a spin. And sleepy startled pilots may well take far too long to relearn their training... In my opinion, all autopilots/autothrottles should give a loud warning a useful many seconds BEFORE they approach this-is-impossible-to-fly limits... Even better, give a visual display of how hard the auto-controls are having to work so as to alert well beforehand of any anomalous conditions developing... Fly safe? Martin See new freedom: Mageia Linux Take a look for yourself: Linux Format The Future is what We all make IT (GPLv3) |
Grant (SSSF) Send message Joined: 19 Aug 99 Posts: 13864 Credit: 208,696,464 RAC: 304 |
In my opinion, all autopilots/autothrottles should give a loud warning a useful many seconds BEFORE they approach this-is-impossible-to-fly limits.As i mentioned in a later post- The Auto Pilot is not meant to be used in icing conditions on that aircraft type, so the Pilot Flying can be aware there are issues building up, before they reach the point of no return. Grant Darwin NT |
rob smith Send message Joined: 7 Mar 03 Posts: 22569 Credit: 416,307,556 RAC: 380 |
Partying before flight? https://www.bbc.co.uk/news/articles/c62r7lpx421o Drugs?, alcohol? and flying a helicopter are not a good combination :-( Bob Smith Member of Seti PIPPS (Pluto is a Planet Protest Society) Somewhere in the (un)known Universe? |
Wiggo Send message Joined: 24 Jan 00 Posts: 37007 Credit: 261,360,520 RAC: 489 |
I wonder why it took so long when it was pretty clear at the time that the bus was on the wrong side of the road. Townsville bus driver charged over triple-fatal Bruce Highway Greyhound crash. Police have charged the driver of a Greyhound bus involved in a triple-fatal collision on the Bruce Highway in North Queensland in June. |
Wiggo Send message Joined: 24 Jan 00 Posts: 37007 Credit: 261,360,520 RAC: 489 |
Things now become clearer in superyacht sinking. Italian authorities have opened an investigation into what happened on the doomed superyacht as a Kiwi captain is grilled for several hours. Italian authorities have opened an investigation into what happened on doomed superyacht Bayesian after it sank off Sicily — with the captain grilled for two hours.Now why was the keel raised while it was anchored offshore and who raised it? |
Wiggo Send message Joined: 24 Jan 00 Posts: 37007 Credit: 261,360,520 RAC: 489 |
The builder of the yacht speaks out. Firm that built superyacht Bayesian say ‘human error’ is to blame. The firm that built tech billionaire Mike Lynch’s superyacht Bayesian that sank off the coast of Sicily say “human error” is to blame. |
Wiggo Send message Joined: 24 Jan 00 Posts: 37007 Credit: 261,360,520 RAC: 489 |
Sadly another Cessna Caravan falls from the sky. :-( A plane carrying tourists has crashed shortly after taking off from Bangkok. All nine on board are believed to have died. A small plane has crashed in Thailand and all nine people on board, including five tourists, are believed to be dead. |
Dr Who Fan Send message Joined: 8 Jan 01 Posts: 3358 Credit: 715,342 RAC: 4 |
What's taking so long to see that complete 'autonomous driving' is still science fiction. Questions about the safety of Tesla’s ‘Full Self-Driving’ system are growing Three times in the past four months, William Stein, a technology analyst at Truist Securities, has taken Elon Musk up on his invitation to try the latest versions of Tesla’s vaunted “Full Self-Driving” system. |
zoom3+1=4 Send message Joined: 30 Nov 03 Posts: 66398 Credit: 55,293,173 RAC: 49 |
What's taking so long to see that complete 'autonomous driving' is still science fiction. Agreed, and not much rattles a 16yr old. Savoir-Faire is everywhere! The T1 Trust, T1 Class 4-4-4-4 #5550, America's First HST |
Grant (SSSF) Send message Joined: 19 Aug 99 Posts: 13864 Credit: 208,696,464 RAC: 304 |
It's one accident after another on the Bruce Highway lately. But the latest accident has been the one with the biggest impact, and the result of the diversions due to the accident have resulted in multiple more accidents occurring due to the increased traffic on the detour roads- a detour that adds about 4 hours to the trip. Section of Bruce Highway between Gin Gin and Calliope to remain closed after truck explosion Grant Darwin NT |
Dr Who Fan Send message Joined: 8 Jan 01 Posts: 3358 Credit: 715,342 RAC: 4 |
That is one big hole in the road! From another article that provides more details: The tanker was carrying 42 tonnes of ammonium nitrate, which triggered an explosion. |
Sirius B Send message Joined: 26 Dec 00 Posts: 24920 Credit: 3,081,182 RAC: 7 |
The stupidity of some road users know no bounds. Oh well, at least this idiot will be off the road for 12 months. Coming to a fast food outlet near you soon (UK) |
Grant (SSSF) Send message Joined: 19 Aug 99 Posts: 13864 Credit: 208,696,464 RAC: 304 |
The stupidity of some road users know no bounds.I've been behind cars where the driver is just talking to the passenger & they're spending most of their time looking at the passenger & not the road. And when people use a mobile phone it seems to suck up even more of their attention. But to be texting, while driving a truck, at highway speeds? He shouldn't be allowed to drive at all, not just for the next 12 months IMHO. Oh, and while the people did the right thing in getting out of their car, it goes to show that you should move as far from the edge of the road as you can, and move away from your car towards the oncoming traffic, not away from the oncoming traffic. ie don't have the car between you and the on coming traffic. If the truck had really collected that car, they would have been wiped out like skittles by a bowling ball. Grant Darwin NT |
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