Hacker News new | ask | show | jobs
by ceejayoz 2309 days ago
Bullshit.

https://nymag.com/intelligencer/2019/04/what-passengers-expe...

8:39:55 a.m.: In a clear sign that something is amiss, the autopilot turns itself off.

8:40:00 a.m.: The MCAS activates.

8:43:04 a.m.: For minutes now, the captain has been using brute physical force to pull the control yoke back in order to keep the plane’s nose from sinking.

8:43:20 a.m.: The demon awakened by the restoration of electric trim reappears. MCAS kicks back in, pushing nose steeply down.

8:43:45 a.m.: Ethiopian Airlines Flight 302 impacts a farm field at nearly 700 miles per hour

That's more than three minutes during which properly disabling MCAS would've been successful and saved the aircraft.
1 comments
blackflame7000 2309 days ago
No, the incident happened at 8:40 and by 8:43 they couldn't pull the nose up because of the horizontal trim being pushed down. That is a very short amount of time to diagnose something completely unexpected. No matter what they did after 8:43 it was too late. You are aware what trim is right? You can't just fix that by pulling on the elevators if the entire rear airfoil is directed downward.
link
ceejayoz 2309 days ago
When’s the last time a car accident involved three minutes of advance warning of that nature?

The nature of the MCAS issue is it kept firing every 5 seconds, making things progressively harder to counteract. It takes a while to get to the “can’t counteract” point.

link
blackflame7000 2309 days ago
It fires every 20 seconds and it takes 2 iterations before it's basically unrecoverable. However, you aren't taking into the account in the "I think I fixed it factor" after the first couple iterations. It's not like they had all 3 minutes to figure it out and fix it. A good amount of time was wasted to see if the fixes had an effect. This answer does a good job of explaining all the things that the pilot has to do in those 3 minutes.

https://www.quora.com/Why-did-the-pilots-on-the-Lion-Air-and...

link
ceejayoz 2309 days ago
That they were able to override the MCAS for several minutes is clear indication it was a recoverable issue with the right training. In fact, a different crew in the same plane the day before did just that.

To return back to the original point for a moment:

40 seconds is a shitload more time to react than the 1-2 seconds you've got when oncoming car traffic veers into your lane unexpectedly. Things in cars happen faster than in planes. A couple seconds of inattention in a plane won't kill you in the same way they will in a car.

link