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How strange that they both had issues at around 6000-8500 feet, briefly recovering, then nose diving. Even more interesting is the recent 767 Amazon cargo flig

How strange that they both had issues at around 6000-8500 feet, briefly recovering, then nose diving. Even more interesting is the recent 767 Amazon cargo flight crash in Texas also did a node dive at around 8000 feet which somehow has escaped the news with this new crash [1]. The pilots decided on a path around weather, were at 11-12000 feet, descended 3000+ feet and then the plane essentially did a similar nose dive. Is this a data problem? > As the plane passed through 12,000 feet at a ground speed of 290 knots (340 mph), the pilots indicated they preferred the westerly route option ATC had given them around the rain; air traffic control told them they would need to descend quickly to 3,000 feet to do so, and radar data reveals the Boeing turned to a heading of 270º as requested and descended through 8,500 feet. One minute later, the controller told the crew they would be past the bad weather in about 18 miles, and to expect a turn to the north. The crew responded "Sounds good" and "Okay," according to the NTSB, and the plane leveled out at 6,200 feet before rising 100 feet more. > That, apparently, is when things went haywire. The aircraft began what the NTSB report described as "small vertical accelerations consistent with the airplane entering turbulence," according to the flight data recorders recovered from the accident scene. Seconds later, with the plane holding steading at 230 knots (265 mph), the engines went to full power, and the nose of the plane rose four degrees...then the aircraft pitched nose-down for the next 18 seconds, reaching a maximum pitch of –49º in response to the plane's elevator inputs. The Ethiopia 737 Max has almost the same issue [2] > ADS-B data recorded for ET302 by FlightRadar24 shows that the aircraft, after reaching an altitude of 8,025 feet above sea level, suddenly dipped, plunging 400 feet before recovering briefly. But the aircraft's vertical speed remained unstable, and a few minutes later it dove into the ground. For reference, the airport the flight took off from is at 7,631 feet above sea level—so the aircraft never reached more than 500 feet above the ground, not leaving much room for correction. All of these planes had issues in the 6000-8500 feet range and then both suffered the same plunging fate after briefly recovering from a dip / nose stabilization issue. Hopefully the ADS system is secure and not susceptible to infiltration/hacks causing the plane to react to incorrect data at a range that is not recoverable. [1] http://www.thedrive.com/news/26933/amazon-boeing-767-cargo-plane-was-going-almost-500-mph-in-texas-crash-ntsb-says http://www.thedrive.com/news/26933/amazon-boeing-767-cargo-p... [2] https://arstechnica.com/information-technology/2019/03/faa-acting-chief-says-satellite-data-provided-link-between-boeing-crashes/ https://arstechnica.com/information-technology/2019/03/faa-a...

ravedave5 8y ago
I was going to suggest this is likely a common cruizing height, but no, it doesn't seem to be. That's an interesting correlation.
xmly 8y ago
I guess the correlation here is the stalling problem often happens during this height range. Both 737 were in the ascending process, while the 767 is during normal flying. For me, the 767 hit with some kind of strange turbulence then the engines went to max and caused a typical stall crash. You could google about the stall crash, such as : https://www.dw.com/en/why-do-airplanes-stall-and-why-is-it-so-dangerous/a-47869837 https://www.dw.com/en/why-do-airplanes-stall-and-why-is-it-s... For both 737 max, their MCAS system thought they had a stall potential and triggered on nose dive while the airplanes were actually in the perfectly normal situation. For 767, they do not have this autonomous system and the stall warning was not even triggered. So it was a purely manual operation. If they have a perfectly functioned MCAS like the 737 max has, they may have survived. So a working MCAS could save plane from crash like 767 had. Just the MCAS on 737 max was not working correctly and MAY potentially have caused the tragedy.
- drawkbox 8y ago
  > Both 737 were in the ascending process, while the 767 is during normal flying. It might not have anything to do with ascent/descent but the range / altitude and how systems react at that altitude. Maybe the systems are designed to be more reactive at this height because there is less chance to recover than if you are cruising at 30k feet. What is most interesting to me is how the Amazon cargo plane 767 crash made almost zero news and has quickly been replaced in the news with the 737 Max 8/9 issues. Though all situations are very similar, straight nose dives that were sudden at the 6000-8500 feet range. There has to be something to that. 767 crashes and emergencies are EXTREMELY rare [1]. Most are related to human intervention such as terrorism, pilot error, fuel error and only a very small amount are mechanical errors. Of the 12 problems, only 5 were mechanical error. [1] https://en.wikipedia.org/wiki/Category:Accidents_and_incidents_involving_the_Boeing_767 https://en.wikipedia.org/wiki/Category:Accidents_and_inciden...

ravedave5 8y ago

I was going to suggest this is likely a common cruizing height, but no, it doesn't seem to be. That's an interesting correlation.

xmly 8y ago

I guess the correlation here is the stalling problem often happens during this height range. Both 737 were in the ascending process, while the 767 is during normal flying. For me, the 767 hit with some kind of strange turbulence then the engines went to max and caused a typical stall crash. You could google about the stall crash, such as : https://www.dw.com/en/why-do-airplanes-stall-and-why-is-it-so-dangerous/a-47869837 https://www.dw.com/en/why-do-airplanes-stall-and-why-is-it-s... For both 737 max, their MCAS system thought they had a stall potential and triggered on nose dive while the airplanes were actually in the perfectly normal situation. For 767, they do not have this autonomous system and the stall warning was not even triggered. So it was a purely manual operation. If they have a perfectly functioned MCAS like the 737 max has, they may have survived. So a working MCAS could save plane from crash like 767 had. Just the MCAS on 737 max was not working correctly and MAY potentially have caused the tragedy.

drawkbox 8y ago
> Both 737 were in the ascending process, while the 767 is during normal flying. It might not have anything to do with ascent/descent but the range / altitude and how systems react at that altitude. Maybe the systems are designed to be more reactive at this height because there is less chance to recover than if you are cruising at 30k feet. What is most interesting to me is how the Amazon cargo plane 767 crash made almost zero news and has quickly been replaced in the news with the 737 Max 8/9 issues. Though all situations are very similar, straight nose dives that were sudden at the 6000-8500 feet range. There has to be something to that. 767 crashes and emergencies are EXTREMELY rare [1]. Most are related to human intervention such as terrorism, pilot error, fuel error and only a very small amount are mechanical errors. Of the 12 problems, only 5 were mechanical error. [1] https://en.wikipedia.org/wiki/Category:Accidents_and_incidents_involving_the_Boeing_767 https://en.wikipedia.org/wiki/Category:Accidents_and_inciden...