5 ms·

No it doesn't. No reason backed by facts available to the public for decertifying the airplane have arisen. The worst case scenario (for Boeing), at this point

by cmurf 7y ago

No it doesn't. No reason backed by facts available to the public for decertifying the airplane have arisen. The worst case scenario (for Boeing), at this point, is the FAA and/or other aviation regulators, decide that the differences require different type certification for the aircraft and therefore mandate a unique type rating by pilots to fly the plane. That would require they be trained about those differences.

chvid 7y ago
Would that not have all the companies that bought the MAX asuming that they would not have to retrain their pilots asking for some $$$ or even cancelling?
- cmurf 7y ago
  I'm not sure I'm parsing this question correctly, but it sounds like a contracts question, and I'm not at all privy to the contract between any airline and Boeing, whether they have any contingency for this. The actual risk is complex, an airline with more capacity depending on the new model has more risk as they take on new planes and retire old ones, but does the contract reflect that complexity? I have no idea. For all I know, there's generic terms for handling all certification problems that crop up, including airworthiness directives from the FAA that affect A&P's rather than pilots. It might be the two sides split the cost 50/50 for all I know, or maybe they use binding arbitration to keep the airing of dirty laundry as much out of the public view as possible.
salawat 7y ago
If I may direct your attention to FAR 25.173... And https://www.seattletimes.com/seattle-news/times-watchdog/the-inside-story-of-mcas-how-boeings-737-max-system-gained-power-and-lost-safeguards/ https://www.seattletimes.com/seattle-news/times-watchdog/the... There are more than enough reasons to reasonably decertify the aircraft. When you start doing things that "fly-in-the-face" of industry best practice, and begin requiring the most liberal interpretation possible of regulations as written, it's time to start dialing back what you're willing to let slide. Even with these "minor tweaks" to every fuselage, the airframe can reasonably be assumed to have further problems. As a for instance, what happens if a dual flameout in flight occurs? Does the Ram Air Turbine make enough power to run the Flight Control Computer and all it's dependencies to ensure the MCAS functionality stays intact until the plane can be safely touched down? If not, will there be simulator training so pilots are prepared? There is more than enough publicly available information to be cause for concern.
- dunmalg 7y ago
  >As a for instance, what happens if a dual flameout in flight occurs? Does the Ram Air Turbine make enough power to run the Flight Control Computer and all it's dependencies to ensure the MCAS functionality stays intact until the plane can be safely touched down? Isn't MCAS a solution to address greater nose pitch-up due to stronger thrust vectoring effects from the new engines? In a dual engine flameout where all thrust is lost, doesn't thrust vectoring cease to be an issue?
  - salawat 7y ago
    It's not actually the thrust MCAS counters; that is counterable by elevator alone. MCAS counters extra lift generated by the nacelles shape and position at high Angle of Attack. No thrust is required to reproduce the aerodynamic effects MCAS is intended to counter. That's why this damn kludge of a system is so concerning. It's an active airworthyness hack to counter a passive aerodynamic characteristic of the airframe. So if a double flameout occurs, killing all power, and killing the Flight Control Computer due to unreliable voltage being supplied from the Ram Air Turbine, the pilots are stuck flying a glider that'll try to pitch into a stall on them if they aren't careful. Again, normally wouldn't worry about something like this, but they missed/intentionally left out the single AoA sensor... So...yeah... I have severe concerns about this design, and the effort put into known, unlikely, but highly severe failures.
    - t0mas88 7y ago
      > So if a double flameout occurs, killing all power, and killing the Flight Control Computer due to unreliable voltage being supplied from the Ram Air Turbine, the pilots are stuck flying a glider that'll try to pitch into a stall on them if they aren't careful. Maybe you shouldn't post such strong statements about a technology you know very little about. First: The 737 does not actually have a RAT. Second: On types that have a RAT (e.g. the A320) it isn't electrical, it provides hydraulic power to operate the flight controls. If you need emergency electrical power from a RAT equipped aircraft it will be from an haudraulically driven AC generator through a constant speed drive. It will not have voltage fluctuations, only risk is frequency being off and aircraft systems are designed to deal with that.

by cmurf 7y ago

chvid 7y ago

Would that not have all the companies that bought the MAX asuming that they would not have to retrain their pilots asking for some $$$ or even cancelling?

cmurf 7y ago
I'm not sure I'm parsing this question correctly, but it sounds like a contracts question, and I'm not at all privy to the contract between any airline and Boeing, whether they have any contingency for this. The actual risk is complex, an airline with more capacity depending on the new model has more risk as they take on new planes and retire old ones, but does the contract reflect that complexity? I have no idea. For all I know, there's generic terms for handling all certification problems that crop up, including airworthiness directives from the FAA that affect A&P's rather than pilots. It might be the two sides split the cost 50/50 for all I know, or maybe they use binding arbitration to keep the airing of dirty laundry as much out of the public view as possible.

salawat 7y ago

If I may direct your attention to FAR 25.173... And https://www.seattletimes.com/seattle-news/times-watchdog/the-inside-story-of-mcas-how-boeings-737-max-system-gained-power-and-lost-safeguards/ https://www.seattletimes.com/seattle-news/times-watchdog/the... There are more than enough reasons to reasonably decertify the aircraft. When you start doing things that "fly-in-the-face" of industry best practice, and begin requiring the most liberal interpretation possible of regulations as written, it's time to start dialing back what you're willing to let slide. Even with these "minor tweaks" to every fuselage, the airframe can reasonably be assumed to have further problems. As a for instance, what happens if a dual flameout in flight occurs? Does the Ram Air Turbine make enough power to run the Flight Control Computer and all it's dependencies to ensure the MCAS functionality stays intact until the plane can be safely touched down? If not, will there be simulator training so pilots are prepared? There is more than enough publicly available information to be cause for concern.

dunmalg 7y ago
>As a for instance, what happens if a dual flameout in flight occurs? Does the Ram Air Turbine make enough power to run the Flight Control Computer and all it's dependencies to ensure the MCAS functionality stays intact until the plane can be safely touched down? Isn't MCAS a solution to address greater nose pitch-up due to stronger thrust vectoring effects from the new engines? In a dual engine flameout where all thrust is lost, doesn't thrust vectoring cease to be an issue?
- salawat 7y ago
  It's not actually the thrust MCAS counters; that is counterable by elevator alone. MCAS counters extra lift generated by the nacelles shape and position at high Angle of Attack. No thrust is required to reproduce the aerodynamic effects MCAS is intended to counter. That's why this damn kludge of a system is so concerning. It's an active airworthyness hack to counter a passive aerodynamic characteristic of the airframe. So if a double flameout occurs, killing all power, and killing the Flight Control Computer due to unreliable voltage being supplied from the Ram Air Turbine, the pilots are stuck flying a glider that'll try to pitch into a stall on them if they aren't careful. Again, normally wouldn't worry about something like this, but they missed/intentionally left out the single AoA sensor... So...yeah... I have severe concerns about this design, and the effort put into known, unlikely, but highly severe failures.
  - t0mas88 7y ago
    > So if a double flameout occurs, killing all power, and killing the Flight Control Computer due to unreliable voltage being supplied from the Ram Air Turbine, the pilots are stuck flying a glider that'll try to pitch into a stall on them if they aren't careful. Maybe you shouldn't post such strong statements about a technology you know very little about. First: The 737 does not actually have a RAT. Second: On types that have a RAT (e.g. the A320) it isn't electrical, it provides hydraulic power to operate the flight controls. If you need emergency electrical power from a RAT equipped aircraft it will be from an haudraulically driven AC generator through a constant speed drive. It will not have voltage fluctuations, only risk is frequency being off and aircraft systems are designed to deal with that.