from Hacker News

Boeing Passenger Jet Nearly Crashes Because of Known Software Bug

by xrayarx on 6/8/24, 6:52 AM with 65 comments

• by HL33tibCe7 on 6/8/24, 10:38 AM

  https://avherald.com/h?article=5194536c

  and https://www.gov.uk/aaib-reports/aaib-special-bulletin-s1-sla... is the AAIB report

  Summary:

  > The aircraft took off from Runway 09 with a thrust setting significantly below that required to achieve the correct takeoff performance. Rotation for the takeoff occurred only 260 m before the end of the runway and the aircraft passed over the end at a height of approximately 10 ft. The N1 required to achieve the required takeoff performance was 92.8% but, following an A/T disconnect when the crew selected TOGA, 84.5% was manually set instead. Despite an SOP requirement to check the thrust setting on takeoff, the crew did not realise that the thrust was not set correctly until after the takeoff although they had noted how close to the end of the runway they were. The A/T had disconnected when the TOGA switch was pressed due to a fault with the ASM associated with the thrust lever for engine 1. This disconnect was a known issue with the older type ASMs fitted to the aircraft type. The manufacturer has issued a Fleet Team Digest for operators detailing the issue and the SB for replacing the ASMs with a newer model.

• by kashunstva on 6/8/24, 8:53 AM

  The title here and the text of TFA reduce the incident to a single point of failure. There are conditions in which the TO/GA mode when engaged will fail to set the calculated and the crew is required to manually set the takeoff thrust. Confirmation of takeoff thrust set should be called out. Was that done? Boeing is under justifiably intense scrutiny for many of its manufacturing and engineering practices but the press needs to apply intellectual honesty in reporting incidents like this. It seems that the crew may have known that the thrust was not properly set when TO/GA was engaged and then manually set an incorrect thrust. Like many incidents, this is likely to have layered causes. Why not report that upfront?

• by ggm on 6/8/24, 7:36 AM

  Being operator-conditioning-trained to click through warning signs is a huge problem for everyone.

  The car drivers with dashcams on that stretch of motorway they cleared at 30m must have some fantastic vision. I hope it's been uploaded to the Web (like sint maarten but not beach: trucks)

• by ThinkBeat on 6/8/24, 11:29 AM

  The pilots turned off the autopilot for takeoff due to a known bug.

  Flying manually the pilots made an error when setting the required thrust that nearly caused the plane to run off the runway without getting off the ground?

  Is that correct? In which case it seems like pilot error.

• by ojosilva on 6/8/24, 1:31 PM

  I'm not comfortable with a future where Boeing becomes niche or "commercially deprecated", with current planes aging and no good maintenence path forward. It will become a safety liability that we passengers will have to bear.

  Boeing's demise would create an amazing opportunity for Chinese aviation to make its move. It takes decades to really enter the market but it could, slowly, happen. Embraer otoh is not in a position (huge investment) or just not interested (too risky) to enter those 737/MAX and long haul markets.

• by ChrisMarshallNY on 6/8/24, 10:48 AM

  > Pilots manually set the thrust level following a software glitch that Beoing [sic] was aware of before take-off.

  Oooh... that's gonna leave a mark.

• by IG_Semmelweiss on 6/8/24, 12:14 PM

  It is really disheartening to see a cutting-edge engineering company making news for failures of design or engineering, vs in the news for innovation engineering, new designs, and new trials.

  Its as if the soul of the company has been taken away forever.

  Contrast Boeing with Nvidia, Tesla, etc

• by K0balt on 6/8/24, 12:22 PM

  I suspect the most interesting part of this is why, precisely:

  If this is a known bug, incorrect setting of the throttle and subsequent disconnect of the auto throttle system, why is the aircraft still deemed airworthy while using the auto throttle during takeoff?

  How was using defective equipment critical to flight safety if engaged not specifically prohibited in an addendum to the POH?

  Because that would require additional training and be a bad look, that’s why, I suspect.

  If a FAR23 (light) aircraft had a defective throttle cable that sometimes failed to effect the commanded throttle setting under certain conditions, it would be grounded immediately pending remedial service or, if impossible, at least placarding of the prohibited configuration and modification to the POH to specified prohibit that configuration, as well as implicating changes into training materials if the aircraft fell into the high performance category.

  That Boeing is operating at a lower standard of flight safety than is typically required of SLA regulations is an indication of a deeply broken relationship with regulators.

• by mrbluecoat on 6/8/24, 1:41 PM

  > The CVR fitted to G-FDZS was not removed from the aircraft as it continually overwrites itself, retaining only the last two hours of audio. As such, the recording of the takeoff would have been overwritten during the flight to Las Palmas

  In 2017, the date that aircraft began production, we had terabyte thumb drives and 24kbps Ogg Vorbis, why a two hour limit?

• by DemocracyFTW2 on 6/8/24, 6:21 PM

  > The 737-800 plane cleared runway nine with just 260 metres (853ft) of tarmac > to spare at a height of 10ft.

  > It then flew over the nearby A38 road at a height of just 30 metres (100ft) > travelling at the speed of around 150kts (about 173mph).

  This got my head spinning, what a jumble of units

• by southernplaces7 on 6/8/24, 11:17 AM

  By this point, with all the news of Boeing disasters, I almost assume that if you wanted to commit suicide by skydiving without a parachute, a flight to the right height in a Boeing would be more likely to kill you than the jump.

• by germandiago on 6/8/24, 11:07 AM

  What's with Boeing lately? In the last years I see a lot of news related to crashes and problems with those.

  Is it me? I did not take a deep look into the topic.

  How does it compare to Airbus security-wise, with the real data from fatal crashes at hand?

• by Havoc on 6/8/24, 10:50 AM

  Is this the one that was spewing flames yesterday or different incident?

• by mrjin on 6/8/24, 9:36 AM

  Wow, Boeing again.

• by iLoveOncall on 6/8/24, 10:44 AM

  It's amazing that Boeing planes are still allowed in the air at all at this point.

• by userbinator on 6/8/24, 10:13 AM

  Ultimately an unintended consequence of trying to reduce costs. Otherwise they'd just use full throttle.