Vsplat

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Vsplat last won the day on March 22

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  1. I love this. 'without knowing the specifics...this area is known for turbulence'. So, without knowing anything, this is what is known. BS. These people who cannot wait to get their face in front of a camera are an embarrassment. Without knowing the specifics, the message should be, wait for the facts, thoughts for the passengers and crew. Full stop. Vs
  2. Well, I don't think there is any clause in the law that says the victim of a fraud has to trap it immediately or give the fraudster what they want. I don't know why Gabor Lukacs thinks a business can't suspend travel privileges for someone connected to a fraud. How else can they stop the loss? Photo ops make people say just about anything it seems. Vs
  3. I saw the article. Too bad this woman was taken by a fraudster. She seems to think that she should be made whole because she couldn't detect the fraud. Then in the same article, there is this claim that Air Canada should not have any claim on its costs, because it couldn't detect the same fraud. In her own words, she claimed to be buying 'employee discount tickets'. Well, even if real, those would be for employees, right? Hmmmm. I think this is only a story because it's Air Canada and CBC. All just my opinion Vs
  4. Another perspective view
  5. De-icing is gonna be a bear. I guess no question about fuselage anti-icing, but that is gonna be a lot of fluid going into those engines. I would imagine the 'cold dry snow' case wouldn't matter, can't risk shedding a sheet of ice that big. Maybe in-wing sensors would be the answer. Vs
  6. Kip, do you really want to see that bet called?
  7. Agreed. Saved my Dad. 'But', he said with a smile, 'this really is a pain in the ...' Sorry, could not resist Vs
  8. A minor point here. The 737MAX still holds a valid type certificate in most parts of the world. The aircraft is not technically grounded - it is restricted from commercial service. Many have flown since the restrictions came into force, ferry flights to storage for example. Re-certification would require an additional step of revoking the existing certification. Given how much time has passed, I think that still possible, but remote. Reading some of the other threads on this, there does appear to be some smoke to the story about refurbished AOA sensors. Whether that turns into something more, we'll see. That might attract a lot of lightning and split the focus somewhat. None of this takes away from the obvious - serious errors were made in the certification of this design and the prioritization of getting the common type rating seems to have resulted in the introduction of a fatally flawed MCAS system. What I would like to know is, for operators who own only the MAX and for whom a common type rating is unimportant, why have MCAS at all? Can it be disabled at this point? Vs
  9. I think there are two discussions being woven here and that is causing conclusions from one discussion to apply to both. Permit me an attempt to separate the discussions for a bit. First off. I agree with Don that, once the unusual attitude has been reached, the useful time for AoA as a reference in a civilian transport has passed. The purpose of the AoA, if any (and that is the subject of some debate here), is predictive and intended to refine situational awareness in order to avoid an undesired aircraft state. As we have seen, the transition to that state can be rapid and confusing. The AoA provides information directly that must be inferred from other instruments such as airspeed, pitch, etc. That is valuable at times. In the case of MCAS, we have a unique threat, in that an aggressive intervenor may create an unsafe state from safe one. In this case, the first sign of trouble would have been that AoA indication and the associated DISAGREE message. While we will never know for sure, in my opinion a crew faced with that warning ahead of entering the MCAS active zone would have had a leg up. So yes, AoA is a valid countermeasure, but in a proactive, vice reactive sense. WRT the input of thrust couple at high pitch angles, I have to disagree with your assertion that the moment would be constant or not rapid in onset. When airspeed is low, control surface authority is diminished. Higher pitch, decaying speed would lead to lower authority. So the countering effect to a thrust couple would reduce commensurately. Apart from the couple, where the vector below the C of G rotates the aircraft up, the thrust vector becomes more vertical as pitch angle increases, adding an increasing vertical acceleration component. All this adds up to: Apply firewall thrust at a high pitch angle and the effect can be very dramatic and the response would not feel at all linear. On a twin, with all of the excess thrust normally available, this is not going to be a gentle thing. To Don's point, this would be even more evident on the MAX. Vs
  10. boestar, there are other pitching moments in play when the engines are mounted either underwing or above the fuselage. In high pitch, low speed events, firewalling the thrust on aircraft like the MAX will induce a pretty strong upward pitching moment that can worsen the situation. I believe this was one of the guiding forces behind MCAS to begin with. Then there are the swept wing characteristics at mach. There are low and high speed buffet boundaries and a high altitude, unusual attitude event in any direction can lead you to a jet upset in pitch, roll or both, where the forces in recovery can be close to structural limits. While most modern designs should avoid control surface 'blanking' from deep stall, I wonder now how carefully that lesson is applied in modern designs where digital override is seen as an artificial substitute for good aerodynamics. If the stab loses any authority during a deep, very high AOA stall, then recovery can involve roll as well as pitch input. This was spoken to during the ancient (and now discredited) American Airlines Advanced Aircraft Manoeuvring course. Stall avoidance systems for these aircraft tend to incorporate predictive logic, 'phase advance' to start recovery ahead of the onset of anticipated pitch or roll forces that might deepen the stall. The AOA plays an important roll there, not during recovery, but in establishing situational awareness ahead of an event so the crew is not trying to catch up to the aircraft in a deteriorating situation. All IMO. Vs
  11. I have to wonder what happens after the first lightning strike. These aircraft aren't exactly festooned with static wicks. Vs
  12. Thanks Don. Yes, that 20 deg value keeps coming up and while I've seen it associated with full scale deflection in a couple of other places, your AMM reference is definitive. The damage may ultimately hide the true state of that sensor and any installation-induced issues from us, but hopefully the investigators will be able to identify whether a bad ground, perhaps static discharge during installation or some other issue crept into the mix. All the best Vs
  13. Don, when you way the AOA sensor cannot be incorrectly installed, it gives me pause. I've seen so many foolproof systems defeated, I have to think this would be just one more. That said, I know nothing about this particular part number or what connections have to be made (correctly) for it to work. We have a rich history of trouble from bent pins, excessive solder, a pin hole puncture, kink, overtorque, and a couple of dozen I know you could easily add - and all that is assuming that the correct part went into the correct spot - is there a left and right to these things, does the NG take the same part number, etc etc. Vs
  14. No. The computers will only work out what fits their model. If a condition is outside the range of assumptions of the programmer, as the MCAS failure demonstrates, the computers may generate inappropriate solutions or diagnose the situation as something else. When the aircraft is approaching an upset, there is no substitute for raw data and direct control. It may be comforting to suggest that this all goes away when the AP is engaged, but we have to remember that there are limitations on AP engagement. If the aircraft is this far out of trim, is it certain the AP would function? All IMO. Vs