5 ms·

For context, the 737 NG is previous iteration of the 737 (before the MAX) and among the most popular aircraft ever built, with over 7000 in service. Grounding

For context, the 737 NG is previous iteration of the 737 (before the MAX) and among the most popular aircraft ever built, with over 7000 in service. Grounding this would absolutely cripple the airline industry. However, the NG also has an excellent safety record, and 35000 cycles is equivalent to 5 flights (takeoff & landing) every day for 10 years. So while this may lead to extra checks on older aircraft, it's highly unlikely to cause a MAX-style global grounding.

samstave 7y ago
What is the actual safety record of the B-52, which i subjectively consider to be the safest machine in history. How would the B-52 match up against modern commercial airliners? (Does anyone, other than boeing, even track this stat?) The calc would be something along the lines of; Date-of-design -> completion, testing, commissioning, hours in flight - accidents, crashes,pilot error, time in service, fuselage age, etc... I am subjectively of the opinion that the B-52 is the greatest aircraft ever made.
- ethagknight 7y ago
  Tell me more of this b-53 safety record
- ceejayoz 7y ago
  http://www.airsafe.com/events/models/rate_mod.htm http://www.airsafe.com/events/models/rate_mod.htm indicates 79 fatal 737 incidents with about a quarter billion flights under their belt. https://www.globalsecurity.org/wmd/systems/b-52-safety.htm https://www.globalsecurity.org/wmd/systems/b-52-safety.htm indicates 76 B-52s destroyed in accidents across 7.5 million flight hours. They're not perfectly comparable sets of numbers, but the B-52s look substantially riskier on a per-hour basis.
  - samstave 7y ago
    Thank you for this! 76 machines destroyed, carrying (obstensibly) nukes.. from 7.5mm flight miles == .00001% risk of failure. Did I do the math correctly? With ZERO nuke detonations... And a flight carcass of nearly 70 years old now???
    - ceejayoz 7y ago
      All aviation is pretty damned safe. > With ZERO nuke detonations... Chalk this up to the design of the weapons themselves, not the B-52s. It's actually quite difficult to have an accidental nuclear detonation. > And a flight carcass of nearly 70 years old now??? Today's B-52s are largely Ships of Theseus. Not much in them is going to be original any more.
    - my_first_acct 7y ago
      A handy website [1] notes at least a couple of B-52 nuclear incidents. In 1961, a B-52 carrying nuclear weapons broke up in mid-air over North Carolina; the bombs did not detonate [2]. In 1966, a B-52 crashed due to a mid-air collision with a refueling tanker over Spain. In this case, the non-nuclear explosives in two of the nuclear weapons detonated, scattering radioactive material [3]. So I would not say "zero nuke detonations". And your .00001% failure rate (I didn't check your math) is not meaningful unless compared to the failure rate of other aircraft. The B-52 is impressive, but not flawless. [1] http://www.atomicarchive.com/Almanac/Brokenarrows_static.shtml http://www.atomicarchive.com/Almanac/Brokenarrows_static.sht... [2] https://en.wikipedia.org/wiki/1961_Goldsboro_B-52_crash https://en.wikipedia.org/wiki/1961_Goldsboro_B-52_crash [3] https://en.wikipedia.org/wiki/1966_Palomares_B-52_crash https://en.wikipedia.org/wiki/1966_Palomares_B-52_crash
      - greedo 7y ago
        Most people would not refer to the incident at Palomares as a "nuke detonation," since there was no nuclear detonation. No fissile reaction etc, just conventional explosives that are part of the weapons trigger. To call it a "nuke detonation" is disingenuous.
    - dralley 7y ago
      B52s were used for conventional bombing plenty often during their service lifetime. And they came damn close to accidentally detonating on American soil on occasion. https://en.m.wikipedia.org/wiki/1961_Goldsboro_B-52_crash#Later_analysis_of_weapons_recovery https://en.m.wikipedia.org/wiki/1961_Goldsboro_B-52_crash#La...
    - 7y ago
- brians 7y ago
  That’s not subjective; you just made it up. For one thing, B-52s seem to have substantial safety externalities for nearby cities.
  - burnte 7y ago
    >That’s not subjective; you just made it up. That's the definition of subjective. You're thinking objective.
    - samstave 7y ago
      Thank you. This is going to come across a subjectively offensive to people on HN, aside from the old timers, as I am such, stop trying to prove how smart you are. Listen more. Engage rather than flex your ego. Discuss rather than downvote. I almost never vote on anything, @dang may likely be able to look at my click record. I don’t click on votes too often, I engage in discussion as often as possible. (Constantly hit with “you’re posting too fast”) So don’t downvote me. Talk to me please. EDIT; cowards
      - kelnos 7y ago
        Ok, I'll bite: your original comment wasn't useful at all, and didn't push the conversation forward. Making a baseless suggestion that the B-52 is the "safest machine in history" is not useful. You presented no evidence for this claim, and used "subjective" as a weasel word to avoid responsibility for what you were saying. And then, incredibly, you make a -- reasonable -- assertion as to how you would determine a plane's safety and reliability, but then don't actually bother to try to apply that to the B-52. And then someone downthread uses something similar to your methodology (while presenting hard numbers and sources) to prove you wrong that the B-52 is the safest plane ever. So my subjective opinion is that you've provided nothing of value to this conversation, and that is why you've been downvoted. Oh, and calling people "cowards" when you don't like what they're saying or doing? If you want to invoke "old timers" on HN, you might as well at least pay attention to the site guidelines. As someone who has had an account here for 10 years (funny coincidence that you and I created our accounts within a week of each other), you should be well aware of them.
Pfhreak 7y ago
The part was found damaged at 35,000 cycles. That means it took less than or equal to 35,000 cycles. It's not clear whether it cracked earlier, how many such failures would be needed to down the plane, etc.
- mieseratte 7y ago
  Assuming a proper maintenance schedule, we can reasonably reduce that time window.
  - djsumdog 7y ago
    How often are these particular frame components inspected for cracks or wear?
    - alexis_fr 7y ago
      I don’t know for these. C-checks for 737NG are performed every 730 days and include corrosion/wear checks for the most stressed parts, but not all parts (which are checked at D checks): https://en.wikipedia.org/wiki/Aircraft_maintenance_checks https://en.wikipedia.org/wiki/Aircraft_maintenance_checks
  - hn_throwaway_99 7y ago
    The article indicated the crack was found not during a regular inspection, but during modifications: "Boeing notified the agency of the matter after it discovered the cracks while conducting modifications on a heavily used aircraft." And they only found the cracks in other aircraft after specifically looking for it after they noticed the crack in the first aircraft, so it doesn't sound like something checked as part of routine maintenance.

samstave 7y ago

What is the actual safety record of the B-52, which i subjectively consider to be the safest machine in history. How would the B-52 match up against modern commercial airliners? (Does anyone, other than boeing, even track this stat?) The calc would be something along the lines of; Date-of-design -> completion, testing, commissioning, hours in flight - accidents, crashes,pilot error, time in service, fuselage age, etc... I am subjectively of the opinion that the B-52 is the greatest aircraft ever made.

ethagknight 7y ago
Tell me more of this b-53 safety record
ceejayoz 7y ago
http://www.airsafe.com/events/models/rate_mod.htm http://www.airsafe.com/events/models/rate_mod.htm indicates 79 fatal 737 incidents with about a quarter billion flights under their belt. https://www.globalsecurity.org/wmd/systems/b-52-safety.htm https://www.globalsecurity.org/wmd/systems/b-52-safety.htm indicates 76 B-52s destroyed in accidents across 7.5 million flight hours. They're not perfectly comparable sets of numbers, but the B-52s look substantially riskier on a per-hour basis.
- samstave 7y ago
  Thank you for this! 76 machines destroyed, carrying (obstensibly) nukes.. from 7.5mm flight miles == .00001% risk of failure. Did I do the math correctly? With ZERO nuke detonations... And a flight carcass of nearly 70 years old now???
  - ceejayoz 7y ago
    All aviation is pretty damned safe. > With ZERO nuke detonations... Chalk this up to the design of the weapons themselves, not the B-52s. It's actually quite difficult to have an accidental nuclear detonation. > And a flight carcass of nearly 70 years old now??? Today's B-52s are largely Ships of Theseus. Not much in them is going to be original any more.
  - my_first_acct 7y ago
    A handy website [1] notes at least a couple of B-52 nuclear incidents. In 1961, a B-52 carrying nuclear weapons broke up in mid-air over North Carolina; the bombs did not detonate [2]. In 1966, a B-52 crashed due to a mid-air collision with a refueling tanker over Spain. In this case, the non-nuclear explosives in two of the nuclear weapons detonated, scattering radioactive material [3]. So I would not say "zero nuke detonations". And your .00001% failure rate (I didn't check your math) is not meaningful unless compared to the failure rate of other aircraft. The B-52 is impressive, but not flawless. [1] http://www.atomicarchive.com/Almanac/Brokenarrows_static.shtml http://www.atomicarchive.com/Almanac/Brokenarrows_static.sht... [2] https://en.wikipedia.org/wiki/1961_Goldsboro_B-52_crash https://en.wikipedia.org/wiki/1961_Goldsboro_B-52_crash [3] https://en.wikipedia.org/wiki/1966_Palomares_B-52_crash https://en.wikipedia.org/wiki/1966_Palomares_B-52_crash
    - greedo 7y ago
      Most people would not refer to the incident at Palomares as a "nuke detonation," since there was no nuclear detonation. No fissile reaction etc, just conventional explosives that are part of the weapons trigger. To call it a "nuke detonation" is disingenuous.
  - dralley 7y ago
    B52s were used for conventional bombing plenty often during their service lifetime. And they came damn close to accidentally detonating on American soil on occasion. https://en.m.wikipedia.org/wiki/1961_Goldsboro_B-52_crash#Later_analysis_of_weapons_recovery https://en.m.wikipedia.org/wiki/1961_Goldsboro_B-52_crash#La...
  - 7y ago
brians 7y ago
That’s not subjective; you just made it up. For one thing, B-52s seem to have substantial safety externalities for nearby cities.
- burnte 7y ago
  >That’s not subjective; you just made it up. That's the definition of subjective. You're thinking objective.
  - samstave 7y ago
    Thank you. This is going to come across a subjectively offensive to people on HN, aside from the old timers, as I am such, stop trying to prove how smart you are. Listen more. Engage rather than flex your ego. Discuss rather than downvote. I almost never vote on anything, @dang may likely be able to look at my click record. I don’t click on votes too often, I engage in discussion as often as possible. (Constantly hit with “you’re posting too fast”) So don’t downvote me. Talk to me please. EDIT; cowards
    - kelnos 7y ago
      Ok, I'll bite: your original comment wasn't useful at all, and didn't push the conversation forward. Making a baseless suggestion that the B-52 is the "safest machine in history" is not useful. You presented no evidence for this claim, and used "subjective" as a weasel word to avoid responsibility for what you were saying. And then, incredibly, you make a -- reasonable -- assertion as to how you would determine a plane's safety and reliability, but then don't actually bother to try to apply that to the B-52. And then someone downthread uses something similar to your methodology (while presenting hard numbers and sources) to prove you wrong that the B-52 is the safest plane ever. So my subjective opinion is that you've provided nothing of value to this conversation, and that is why you've been downvoted. Oh, and calling people "cowards" when you don't like what they're saying or doing? If you want to invoke "old timers" on HN, you might as well at least pay attention to the site guidelines. As someone who has had an account here for 10 years (funny coincidence that you and I created our accounts within a week of each other), you should be well aware of them.

Pfhreak 7y ago

The part was found damaged at 35,000 cycles. That means it took less than or equal to 35,000 cycles. It's not clear whether it cracked earlier, how many such failures would be needed to down the plane, etc.

mieseratte 7y ago
Assuming a proper maintenance schedule, we can reasonably reduce that time window.
- djsumdog 7y ago
  How often are these particular frame components inspected for cracks or wear?
  - alexis_fr 7y ago
    I don’t know for these. C-checks for 737NG are performed every 730 days and include corrosion/wear checks for the most stressed parts, but not all parts (which are checked at D checks): https://en.wikipedia.org/wiki/Aircraft_maintenance_checks https://en.wikipedia.org/wiki/Aircraft_maintenance_checks
- hn_throwaway_99 7y ago
  The article indicated the crack was found not during a regular inspection, but during modifications: "Boeing notified the agency of the matter after it discovered the cracks while conducting modifications on a heavily used aircraft." And they only found the cracks in other aircraft after specifically looking for it after they noticed the crack in the first aircraft, so it doesn't sound like something checked as part of routine maintenance.