When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I might add that we pilots will sometimes SLOP (Strategic Lateral Offset Procédure) on oceanic tracks- to the right of centerline- to actually reduce the probability of collision because the accuracy is so tight, a pilot error may guarantee a conflict.
Thank you for that SLOP. I will remember this on our next trip to Europe!
News reports said the first crash came a day after the same 737 had a problem diving and climbing. A crash was avoided by a pilot riding in the back, who came forward and told the PIC how to work around the issue.
Here's my question- when they landed the plane, why didn't they report the issue and ground it? Did they just walk away and go home? And then it crashes the next day? WTF?
If this was similar to the Airbus 330 issue, the problem is NOT repeatable. So technicians can't fix it. No condition (heat or cold), electromagnetic interference, vibrations can induce the software error. And the error did not show up when tested on that specific plane, after the incident --- using the same plane, same onboard computer. Only repeating the programming over-&-over, hundred of times --- revealed basic, random, core-level crossover of sensor data. 0's and 1's switched in binary data from altitude sensor data with angle of attack sensor data. And this was not repeatable. Only randomly found. But, the implications were, based on this data misinformation, the computer thought the plane was not in a safe envelope and reacted. Taking the plane out of auto-pilot into a "fail-safe" mode which the pilots initially didn't understand. In the Airbus case, rapid anti-stall dive and increasing speed. Only the actions of the US Navy Vet pilot saved the plane. As it went into and out of this "fail-safe" mode... all the way to the emergency landing.
The "fix" was another warning to the pilots to give them more time to react. What they are supposed to do, was not clear in the program I watched.
The implication is, somewhere deep in the software programming is an issue. Which happens at random. No specific condition causes it to surface.
Last edited by windhund116; 03-20-2019 at 05:12 PM.
If I have read correctly there is one sensor for the input. I would think with something this important there would be redundancy with multiple sensors.
My god we did redundancy on a conveyor line with no lives on the line.
If this was similar to the Airbus 330 issue, the problem is NOT repeatable.
I disagree. It has repeated, at a MINIMUM, three times, and two of those times ended in crashes with all hands lost. I can understand why these aircraft have been grounded. I don't understand why Boeing has taken so long to come out with a software fix, if in fact it fixes the problem.
Morris, I think what he was saying is that the problem is not repeatable ON DEMAND. That is to say, it cannot be reproduced under controlled conditions which would allow for identification of the root cause. That could change, of course as the investigation into the recent crashes continues, or through further testing.
IMHO: It is a case of pilots relying too heavily on computers to fly the aircraft without good old pilot skills. I.E. in March of 2018 I got to fly in the right seat in a friends Phenom 100. His pilot was told that I used to fly general aviation back in the late 70's. The PIC went on to explain the "glass cockpit" and then stated: "You have to realize that you are not really in an air craft, you are in a computer that flies!" The twenty-eight year old pilot then went on to tell me. That he made a point of learning to fly the "old school" way. So that he was not dependent on the computers and could fly the air craft with seat of the pants piloting skills. Which seems to be the problem in the 737-800 Max crashes. The pilots not over riding the MCAS systems to fly the air plane with stick & rudder skills.
Last edited by Matt_in_VA; 03-20-2019 at 08:25 PM.
Morris, I think what he was saying is that the problem is not repeatable ON DEMAND. That is to say, it cannot be reproduced under controlled conditions which would allow for identification of the root cause. That could change, of course as the investigation into the recent crashes continues, or through further testing.
Exactly. You need to be able to find what causes the error, in order to fix it.
The program made me feel that this part of the computer program cannot be turned off. The purpose is to override or correct pilot input errors. Which are the cause of many crashes.
03-18-2019, 02:00 PM
