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Airbus has similar long-standing issues. On ground / airborne detection logic was broken in 1993 and is still broken in 2019, to a point that it can cause loss

by mopsi 7y ago

Airbus has similar long-standing issues. On ground / airborne detection logic was broken in 1993 and is still broken in 2019, to a point that it can cause loss of flight controls. Boeing, in contrast, uses simple radar altimeter. Whenever altitude reads 10 feet or less, the aircraft is considered to be "on ground" and things like thrust reversers become available. I personally avoid praising or preferring Airbus when bashing Boeing. Who knows what else is under that rock too.

CaptainZapp 7y ago
Airbus has similar long-standing issues. On ground / airborne detection logic was broken in 1993 and is still broken in 2019, to a point that it can cause loss of flight controls. So you're claiming that Airbus knowingly leaves a critical defect in their planes, which may cause the loss of flight controls and which they refreain from fixing for almost 30 years? Either come up with a reliable source for this statement (which is extremely hard to believe) or allow me to call bullshit!
- TremendousJudge 7y ago
  >which may cause the loss of flight controls and which they refreain from fixing for almost 30 years? And, that as far as we know, hasn't caused
- lightedman 7y ago
  NTSB already notes long-standing issues with all aircraft, all you need to do is read. Airbus for example has a flaw in the A300-600 line where the tailfin can get ripped off due to bad rudder manufacture, that's been around and still exists since the turn of the millennia. My pal consistently bitches about having to do constant preventative work on that section of that line of planes (he's an Airbus engineer.)
- mopsi 7y ago
  > So you're claiming that Airbus knowingly leaves a critical defect in their planes, which may cause the loss of flight controls and which they refreain from fixing for almost 30 years? A320's computers monitor gear for uncompression of 1 second or longer. Computers are not in sync. If landing gear decompresses due to bouncing for long enough to be seen for 1 second by one computer, but short enough to get missed by the other, computers will produce different outputs and the system will shut down, freezing important flight control at a dangerous phase of flight and leaving pilots in a situation they have not been trained for. Given the very obviously flawed and incredibly poor design that's easy to understand even for laymen, I would have very hard time believing that no-one at Airbus ever noticed, no-one ever spoke up. I think this would reflect even more poorly on Airbus. Especially so considering that there have been multiple hull-loss accidents with fatalities (LH2904, TAM3054), where air/ground detection has been a contributing factor. Throughout the years, the aircraft has been unable to tell whether it's on the ground or in the air.
  - inferiorhuman 7y ago
    Especially so considering that there have been multiple hull-loss accidents with fatalities (LH2904, TAM3054), where air/ground detection has been a contributing factor. Throughout the years, the aircraft has been unable to tell whether it's on the ground or in the air. With the Lufthansa flight the problem was not the aircraft design but rather that the pilot remained on only one main gear for too long. The Airbus design requires weight on both wheels (this had nothing to do with computers being out of sync) in order to prevent things like the Lauda Air (Boeing 767-300ER) crash where the thrust reversers deployed in flight causing the plane to drop out of the sky, killing everyone. Same deal with the TAM flight. For whatever reason the pilots didn't properly position the thrust lever on one engine. That had nothing to do with computers being out of sync and had absolutely nothing to do with ground detection. Meanwhile with the Boeing 737, a single (unreliable) radar altimeter (RA) is used as part of the ground detection and a single failed RA caused a Westjet 737 to start pulling back on the throttles. http://avherald.com/h?article=41e84cb5 http://avherald.com/h?article=41e84cb5 As far a the Turkish 737 crash: http://avherald.com/h?article=41595ec3 http://avherald.com/h?article=41595ec3 During the accident flight, while executing the approach by means of the instrument landing system with the right autopilot engaged, the left radio altimeter system showed an incorrect height of -8 feet on the left primary flight display. This incorrect value of -8 feet resulted in activation of the ‘retard flare’ mode of the autothrottle, whereby the thrust of both engines was reduced to a minimal value (approach idle) in preparation for the last phase of the landing. ... The problems with radio altimeter systems in the Boeing 737-800 fleet had been affecting several airlines, including Turkish Airlines, for many years and were known to Boeing and the Federal Aviation Administration of the United States of America. ... Despite the fact that Boeing and the Federal Aviation Administration of the United States of America had been aware for many years that the radio altimeter system was causing many problems and was affecting the operation of other systems, this situation was not designated as a safety risk. Reports of problems with the radio altimeter system that could not be resolved by Boeing justified an effort to analyse the radio altimeter system and other related systems. Boeing and the Federal Aviation Administration of the United States of America could have recognised the fact that the problems caused by the radio altimeter system, especially the potential for activating the autothrottle retard flare mode, posed a safety risk. That sounds a lot like the engineering that went into MCAS - using only one input for something safety critical.
inferiorhuman 7y ago
Boeing, in contrast, uses simple radar altimeter. Which is problematic and has killed 134 people. https://www.flightglobal.com/news/articles/easa-cautions-737-operators-of-radio-altimeter-error-326019/ https://www.flightglobal.com/news/articles/easa-cautions-737... things like thrust reversers become available. Boeing rather famously had a problem with in-air thrust reverse deployment (not on the 73 though).
- phantomread 7y ago
  This doesn't change the point you're making, but thankfully it was only 9/134 people according to the article's tagline. The mix of the word "nine" and the number "134" makes it hard to spot
  - inferiorhuman 7y ago
    This doesn't change the point you're making, but thankfully it was only 9/134 people according to the article's tagline. The mix of the word "nine" and the number "134" makes it hard to spot Yeah I'm familiar with the accident in question in passing so I just skimmed the article itself (whoops). RA failure on the 737 isn't unheard of: https://avherald.com/h?article=4924e9ea https://avherald.com/h?article=4924e9ea (2015) https://avherald.com/h?article=48c031e2 https://avherald.com/h?article=48c031e2 (2015) https://avherald.com/h?article=4bc252c2 https://avherald.com/h?article=4bc252c2 (2018) https://avherald.com/h?article=417e726c https://avherald.com/h?article=417e726c (2009) https://avherald.com/h?article=41e84cb5 https://avherald.com/h?article=41e84cb5 (2009) The in-flight thrust reverser deployment killed everyone on the plane, thankfully Niki Lauda took Boeing to task.
- mopsi 7y ago
  > Which is problematic Not at all. Its malfunctions are clear and obvious. If autothrottle starts moving thrust levers in unexpected ways, you turn the autothrottle off and assume manual control. Thrust levers, reversers, braking or any other systems were not blocked or deployed unexpectedly. The aircraft simply reduced thrust too much while in control of speed, which is something one should always look out for, it's an expected failure, a known unknown. The Turkish airplane crashed because the crew was flying an unstable approach and did not pay attention to warnings because their style of flying was expected to trigger warnings. This obscured the malfunction. They came in too fast and too steep, ignored aural warnings, let thrust levers move to idle (which they expected because of high speed), failed to monitor airspeed and didn't notice last minute warnings because they were occupied with checklist that they should've already been through. No-one was actually flying the airplane, despite the fact that there was an extra third safety pilot in the cockpit who was tasked with observing the flight.

by mopsi 7y ago

CaptainZapp 7y ago

Airbus has similar long-standing issues. On ground / airborne detection logic was broken in 1993 and is still broken in 2019, to a point that it can cause loss of flight controls. So you're claiming that Airbus knowingly leaves a critical defect in their planes, which may cause the loss of flight controls and which they refreain from fixing for almost 30 years? Either come up with a reliable source for this statement (which is extremely hard to believe) or allow me to call bullshit!

TremendousJudge 7y ago
>which may cause the loss of flight controls and which they refreain from fixing for almost 30 years? And, that as far as we know, hasn't caused
lightedman 7y ago
NTSB already notes long-standing issues with all aircraft, all you need to do is read. Airbus for example has a flaw in the A300-600 line where the tailfin can get ripped off due to bad rudder manufacture, that's been around and still exists since the turn of the millennia. My pal consistently bitches about having to do constant preventative work on that section of that line of planes (he's an Airbus engineer.)
mopsi 7y ago
> So you're claiming that Airbus knowingly leaves a critical defect in their planes, which may cause the loss of flight controls and which they refreain from fixing for almost 30 years? A320's computers monitor gear for uncompression of 1 second or longer. Computers are not in sync. If landing gear decompresses due to bouncing for long enough to be seen for 1 second by one computer, but short enough to get missed by the other, computers will produce different outputs and the system will shut down, freezing important flight control at a dangerous phase of flight and leaving pilots in a situation they have not been trained for. Given the very obviously flawed and incredibly poor design that's easy to understand even for laymen, I would have very hard time believing that no-one at Airbus ever noticed, no-one ever spoke up. I think this would reflect even more poorly on Airbus. Especially so considering that there have been multiple hull-loss accidents with fatalities (LH2904, TAM3054), where air/ground detection has been a contributing factor. Throughout the years, the aircraft has been unable to tell whether it's on the ground or in the air.
- inferiorhuman 7y ago
  Especially so considering that there have been multiple hull-loss accidents with fatalities (LH2904, TAM3054), where air/ground detection has been a contributing factor. Throughout the years, the aircraft has been unable to tell whether it's on the ground or in the air. With the Lufthansa flight the problem was not the aircraft design but rather that the pilot remained on only one main gear for too long. The Airbus design requires weight on both wheels (this had nothing to do with computers being out of sync) in order to prevent things like the Lauda Air (Boeing 767-300ER) crash where the thrust reversers deployed in flight causing the plane to drop out of the sky, killing everyone. Same deal with the TAM flight. For whatever reason the pilots didn't properly position the thrust lever on one engine. That had nothing to do with computers being out of sync and had absolutely nothing to do with ground detection. Meanwhile with the Boeing 737, a single (unreliable) radar altimeter (RA) is used as part of the ground detection and a single failed RA caused a Westjet 737 to start pulling back on the throttles. http://avherald.com/h?article=41e84cb5 http://avherald.com/h?article=41e84cb5 As far a the Turkish 737 crash: http://avherald.com/h?article=41595ec3 http://avherald.com/h?article=41595ec3 During the accident flight, while executing the approach by means of the instrument landing system with the right autopilot engaged, the left radio altimeter system showed an incorrect height of -8 feet on the left primary flight display. This incorrect value of -8 feet resulted in activation of the ‘retard flare’ mode of the autothrottle, whereby the thrust of both engines was reduced to a minimal value (approach idle) in preparation for the last phase of the landing. ... The problems with radio altimeter systems in the Boeing 737-800 fleet had been affecting several airlines, including Turkish Airlines, for many years and were known to Boeing and the Federal Aviation Administration of the United States of America. ... Despite the fact that Boeing and the Federal Aviation Administration of the United States of America had been aware for many years that the radio altimeter system was causing many problems and was affecting the operation of other systems, this situation was not designated as a safety risk. Reports of problems with the radio altimeter system that could not be resolved by Boeing justified an effort to analyse the radio altimeter system and other related systems. Boeing and the Federal Aviation Administration of the United States of America could have recognised the fact that the problems caused by the radio altimeter system, especially the potential for activating the autothrottle retard flare mode, posed a safety risk. That sounds a lot like the engineering that went into MCAS - using only one input for something safety critical.

inferiorhuman 7y ago

Boeing, in contrast, uses simple radar altimeter. Which is problematic and has killed 134 people. https://www.flightglobal.com/news/articles/easa-cautions-737-operators-of-radio-altimeter-error-326019/ https://www.flightglobal.com/news/articles/easa-cautions-737... things like thrust reversers become available. Boeing rather famously had a problem with in-air thrust reverse deployment (not on the 73 though).

phantomread 7y ago
This doesn't change the point you're making, but thankfully it was only 9/134 people according to the article's tagline. The mix of the word "nine" and the number "134" makes it hard to spot
- inferiorhuman 7y ago
  This doesn't change the point you're making, but thankfully it was only 9/134 people according to the article's tagline. The mix of the word "nine" and the number "134" makes it hard to spot Yeah I'm familiar with the accident in question in passing so I just skimmed the article itself (whoops). RA failure on the 737 isn't unheard of: https://avherald.com/h?article=4924e9ea https://avherald.com/h?article=4924e9ea (2015) https://avherald.com/h?article=48c031e2 https://avherald.com/h?article=48c031e2 (2015) https://avherald.com/h?article=4bc252c2 https://avherald.com/h?article=4bc252c2 (2018) https://avherald.com/h?article=417e726c https://avherald.com/h?article=417e726c (2009) https://avherald.com/h?article=41e84cb5 https://avherald.com/h?article=41e84cb5 (2009) The in-flight thrust reverser deployment killed everyone on the plane, thankfully Niki Lauda took Boeing to task.
mopsi 7y ago
> Which is problematic Not at all. Its malfunctions are clear and obvious. If autothrottle starts moving thrust levers in unexpected ways, you turn the autothrottle off and assume manual control. Thrust levers, reversers, braking or any other systems were not blocked or deployed unexpectedly. The aircraft simply reduced thrust too much while in control of speed, which is something one should always look out for, it's an expected failure, a known unknown. The Turkish airplane crashed because the crew was flying an unstable approach and did not pay attention to warnings because their style of flying was expected to trigger warnings. This obscured the malfunction. They came in too fast and too steep, ignored aural warnings, let thrust levers move to idle (which they expected because of high speed), failed to monitor airspeed and didn't notice last minute warnings because they were occupied with checklist that they should've already been through. No-one was actually flying the airplane, despite the fact that there was an extra third safety pilot in the cockpit who was tasked with observing the flight.