Earlier quoted context omitted.
Is there a summarized list somewhere of fundamental airworthiness requirements such as the one you listed?
It's 14 CFR 25.173 and 14 CFR 25.175.
Thanks
Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards
21–30 of 43 posts
Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards
#22Earlier quoted context omitted.
So scary. It's like driving a car, trying to slow down, slamming on the brake, but it just keeps accelerating. Cant imagine everyone's feelings on those flights.
The good thing with cars is that the time to avert a crash is generally very low (<1 second - <10 seconds), so while you're bending the supports of your seat pushing down on the brake pedal in panic, that state is not going to last very long.
Well also with a car, you can jut put it in Neutral and let the engine rev and throw a piston while you coast off to the side
Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards
#23Earlier quoted context omitted.
Please post the whole rule. You neglected this bit: > It's ok to post stories from sites with paywalls that have workarounds. Where's the workaround? I don't find workarounds for WSJ. WSJ is locked out. Please post the workaround, or kindly stop badgering people as it is not productive. If there is no workaround that allows us to view WSJ articles, then WSJ article are NOT allowed here, per the rules you yourself sel…
If you don’t know how to workaround WSJ paywalls then ask someone - the rules allow for that. They didn't ask - they just complained. Or pay up and subscribe to the WSJ!
"Moderators: please add [paywalled] or [$] to paywalled content"
That is asking.
Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards
#24Remember the 2010 Ducommun 737 NG (-600 to -900) scandal? Boeing subcontracted key structural components to them to be CNC machined, instead they were crudely hand-fabricobbled and out-of-spec, but Boeing management ordered them installed anyhow. Furthermore, when a Boeing blue-ribbon panel reported its findings, they were ignored. As a result, several aircraft fuselages have broken up on hard landings and runway overruns, killing several passengers. In the past, aircraft fuselages remained intact in similar situations. There are an unknown number of substandard airframes flying around that have the potential to spontaneously break up in heavy turbulence, accelerated fatigue damage, hard landings, and runway overruns. If the flying public and professional pilots were smart, they would avoid aircraft designed, manufactured, or overhauled within the past 20 or so years because of the pervasive, systematic deficiencies introduced by regulatory capture. Older aircraft, if maintained properly, are demonstrably safer until regulators get back on the ball to insist on depth and breadth of safe, proper engineering and manufacturing.
Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards
#25Earlier quoted context omitted.
If you don’t know how to workaround WSJ paywalls then ask someone - the rules allow for that. They didn't ask - they just complained. Or pay up and subscribe to the WSJ!
"Moderators: please add [paywalled] or [$] to paywalled content" That is asking.
No, ask them for the workaround we mean.
Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards
#26Moderators: please add [paywalled] or [$] to paywalled content so I can ignore instead of wasting time. Thanks.
Clear your cookies. For wsj.com.
There is no responsibility to maintain cookies for someone else's benefit.
Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards
#27Earlier quoted context omitted.
I don't agree. I think the lift from the nacelles results in decreasing stick backpressure while the nose is being raised in some circumstances, which is both a handling issue and an airworthiness violation. It's an airworthiness violation because it exacerbates rather than discourages stalls. If the pilot continues pulling back on the stick with reduced backpressure the plane would stall, therefore MCAS is (indirect…
I think it's odd that you describe a failing of 14 CFR 25.173-- the stability airworthiness requirement-- as not being "fundamentally aerodynamically unstable". The stick force inversions you describe are just a symptom of divergent longitudinal stability. If you are trimmed stick-neutral for climb, deceleration doesn't cause sufficient nose drop, which in turn causes further deceleration and the aircraft does not re…
My understanding is that the stick force did not actually invert, but merely failed to increase sufficiently. It’s possible the first derivative of stick force inverted, but an airplane can have positive longitude stability and still fail the stick force curve certification requirements.
Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards
#28Remember the 2010 Ducommun 737 NG (-600 to -900) scandal? Boeing subcontracted key structural components to them to be CNC machined, instead they were crudely hand-fabricobbled and out-of-spec, but Boeing management ordered them installed anyhow. Furthermore, when a Boeing blue-ribbon panel reported its findings, they were ignored. As a result, several aircraft fuselages have broken up on hard landings and runway ove…
Actual accident rates don't appear to back that up; accident rates (per million flights) are drastically higher for both the original 737 and 737 Classic versus the 737 NG: http://www.airsafe.com/events/models/rate_mod.htm
Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards
#29But presumably the pilots of both downed MAXs were pulling back as hard as possible.
So scary. It's like driving a car, trying to slow down, slamming on the brake, but it just keeps accelerating. Cant imagine everyone's feelings on those flights.
Though no doubt terrifying, the crew of ETH302 failed to reduce thrust; doing so may have allowed them to save the airplane.
Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards
#30Earlier quoted context omitted.
I don't agree. I think the lift from the nacelles results in decreasing stick backpressure while the nose is being raised in some circumstances, which is both a handling issue and an airworthiness violation. It's an airworthiness violation because it exacerbates rather than discourages stalls. If the pilot continues pulling back on the stick with reduced backpressure the plane would stall, therefore MCAS is (indirect…
I think it's odd that you describe a failing of 14 CFR 25.173-- the stability airworthiness requirement-- as not being "fundamentally aerodynamically unstable". The stick force inversions you describe are just a symptom of divergent longitudinal stability. If you are trimmed stick-neutral for climb, deceleration doesn't cause sufficient nose drop, which in turn causes further deceleration and the aircraft does not re…
My understanding is that a plane can have non-monotonically increasing backpressure without being aerodynamically unstable, and the difference between the two is all about what the plane does when the stick is released. I don't believe the MAX will ever "stall itself" even with MCAS disabled, as previous planes with aerodynamic instability would if you disable that correction. It requires the pilot to fly into the stall, which is easier than it ought to be due to the placement of the engines relative to the center of gravity.