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Re:Lion Air crash: Boeing 737 plane crashes in sea off Jakarta by angled on Monday October 29, 2018 @03:38AM (#18325641)
fdr wrote on pprune (https://www.pprune.org/rumours-news/614857-indonesian-aircra...)

""" Hmmm.

ADC/Pitot or load....

P/S, Pitot main issue (alt is more stable than speed > static is OK). Maybe.

OK, the DFDR will be telling, probably as much as the CVR. This plane was in distress from 300' AMSL, and has every indication of a longitudinal stability issue, e.g., stick force gradient deal. Immediately, forget about directional issues, this isnt an engine, TR, asymmetric slat, flap or other issue, look closely at the loadsheet, and the load control. The ADSB data is indicating an aircraft with negligible static stability, and that points towards a loading error, with a CG near neutral point. Should you ever have that happen, it is not fun; helicopter pilots get laughed at as that is what they are used to every day, which is why they are generally odd people. If you have an AP, the plane will do better on AP often than a driver at the wheel. If you have flaps, get the TE flaps out, or all flaps the Cp is shifted aft. Don't go to altitude, don't burn CWT gas, move pax fwd if needs be, but mainly, be very careful with your flight control inputs, planes that are unstable are fun to fly for very short times. Do not go fast, unless you have an ejector seat. As an AAI I normally would suggest awaiting data release before sprouting comment pointedly, but this is already shown in the data. Forget suicide etc, this plane had pitch instability from the get go.

I have investigated a number of aircraft loading events, and have also been on the receiving end of 2 of my very own. Have sympathy for the poor flight crew, unless they were form a flight test background it is unreasonable to critique their performance. Could an airline train crews to deal with load errors? I can say that is possible, in fact it is not even hard, and last count, I had investigated over a dozen events... need to dust off the confuser for an exact number, but I can recall 12 offhand. Will airlines train crew to handle such cases? highly unlikely, the industry is not after competency above that mandated by the regulator.

Load error, possible Pitot.

sad day. """

Re:Lion Air crash: Boeing 737 plane crashes in sea off Jakarta by codeduck on Monday October 29, 2018 @11:18AM (#18328173)
Horrendous way to go - in control of an aircraft that is not responding as your instincts and training are saying it should.
Re:Lion Air crash: Boeing 737 plane crashes in sea off Jakarta by coryfklein on Monday October 29, 2018 @03:01PM (#18330239)
Wikipedia tells me that "pitot" refers to the device for measuring airspeed.

Does anybody know what "load" means in this context?

Re:Lion Air crash: Boeing 737 plane crashes in sea off Jakarta by scrumper on Monday October 29, 2018 @03:35PM (#18330574)
Yes, here it means the distribution of passengers and baggage in the aircraft. If the center of gravity after loading is too far forward or aft, you can end up with an aircraft that can take off just fine but then become unflyable.
Re:Lion Air crash: Boeing 737 plane crashes in sea off Jakarta by drhousejr on Monday October 29, 2018 @04:23PM (#18331018)
wow, thats incredibly scary. Would you only know that once its too late? How would it be corrected? Again...very scary..
Re:Lion Air crash: Boeing 737 plane crashes in sea off Jakarta by mrtksn on Monday October 29, 2018 @05:02PM (#18331425)
There's actually a fascinating video if a cargo plane crashing just after a take off due to large cargo not secured properly and moving and changing the center of gravity: https://www.youtube.com/watch?v=M01RmcKsm2k
Re:Lion Air crash: Boeing 737 plane crashes in sea off Jakarta by graedus on Monday October 29, 2018 @06:55PM (#18332400)
To be a little more descriptive, it's a dashcam video from a vehicle driving near Bagram Airfield, and you see the plane crash in a way that makes it clear that the entire crew are killed.

Some more detail from the Wikipedia entry[0]:

"On 2 June 2013, investigators from the Ministry of Transport and Civil Aviation of Afghanistan confirmed the load shift hypothesis as the starting point: three armoured vehicles and two mine-sweeping vehicles, totalling 80 tons of weight, had not been properly secured. At least one armoured vehicle had come loose and rolled backwards against the airplane's rear bulkhead, damaging the bulkhead. This also crippled key hydraulic systems and damaged the horizontal stabilizer components - most notably the jackscrew, which rendered the airplane uncontrollable.[10] Control of the aircraft was therefore lost, with the abnormal pitch-up rotation, stall, and crash to the ground ensuing.[1] The damage made it impossible for the crew to regain control of the aircraft."

[0] https://en.wikipedia.org/wiki/National_Airlines_Flight_102

Re:Lion Air crash: Boeing 737 plane crashes in sea off Jakarta by scrumper on Tuesday October 30, 2018 @02:10PM (#18339660)
You measure up front and plan. Doing a weight and balance calculation is a standard (and critically important) part of flight planning. For light aircraft in particular it is _really_ important because there is very little margin for error. With light private aircraft you're weighing yourself, your passengers, your bags, and the fuel load and you're only taking off if you're within a safe envelope.

I'm not familiar with airline operations because I've never flown anything bigger than a Cessna 172, but from what I gather the airlines assume an average per-passenger weight, and account for number of bags and the ground crew will distribute in the holds accordingly. Ever seen flight crew moving passengers on little regional jets? It's to make the weight distribution safer. The smaller the plane, the bigger the effect of a few passengers.