6 ms·

This is a fantastic story, and very well recounted. > presumably because a simultaneous engine failure had been too ridiculous for Boeing engineers to contempl

This is a fantastic story, and very well recounted. > presumably because a simultaneous engine failure had been too ridiculous for Boeing engineers to contemplate This is hard to grasp, esp. given the presence of a RAT. You're giving engineering time to add a device specifically made to handle loss of all engines, but don't spend the time to write the corresponding procedure? > ...had determined the fuel weight by multiplying the the number of dripsticked liters by 1.77, as indicated by the documentation. However, unbeknownst to the pilots and the fuel crew, this multiplier provided the weight in imperial pounds; the new, all-metric 767 was based on kilograms, and required a multiplier of 0.8 Darn, how many of these incidents will we require until we finally get rid of the metric system once and for all! > The internal investigation into the incident laid the blame partially upon Captain Bob Pearson and First Officer Maurice Quintal, who should have observed the Minimum Equipment List (MEL) and grounded the aircraft since it lacked functioning fuel gauges This is an interesting take - and as the pilot of the plan it certainly should rest on you that you're responsible for all to be in working conditions before you leave. However combining that it was apparently a frequent failure, with the corporate culture that's outlined, it's a good cautionary tail about resisting the pressure when something's wrong but "everybody's doing it anyways".

dorfsmay 3y ago
> Darn, how many of these incidents will we require until we finally get rid of the metric system once and for all! Are you serious? There are 3 countries in the world not using the metric system. The non-metric system is difficult to use because it's using 12 based units with a 10 based numbering system. Sure switching over is going to be painful but that's true either way, and there are quite a few examples of people switching to the metric system but none, as far as I know, the other way around.
- amanj41 3y ago
  Original commenter was joking
- rootusrootus 3y ago
  > There are 3 countries in the world not using the metric system. The US uses metric for many, many things. Frequently side-by-side with imperial equivalents. AFAIK it's also the official position of the USG that metric is prefered. > The non-metric system is difficult to use because it's using 12 based units with a 10 based numbering system. OTOH, 12 divides evenly by both 4 and 3, which are common divisions.
  - wlonkly 3y ago
    It's mildly worse than that, because the US uses metric side-by-side with US customary units, which at least for volume use the same unit names as Imperial but are smaller. (Does the US use Imperial as well? My most common experience with US vs imperial measure is in pints of beer, although Canada has caught on to the 16 oz pint, and don't even start me on 12 oz "pints".)
    - vba616 3y ago
      The US does not use Imperial measurements that I know of, which can be confusing to Americans if UK mpgs are interpreted as equivalent to US values. But there's more than one kind of ounce in the US. Fluid ounces are volume whereas dry ounces are weight/mass. From memory - and I memorized this from cooking - 8 fluid ounces (one cup or a half pint) is 8.337 dry ounces (assuming the approximate density of water). Then there's metric horsepower vs. other types. It's clearly so much more natural for a horsepower to have a German name (pferdestärke!) and mean 735.5 watts instead of 745.7 watts (numbers copied and pasted, not checked).
      - dmurray 3y ago
        > From memory - and I memorized this from cooking - 8 fluid ounces (one cup or a half pint) is 8.337 dry ounces (assuming the approximate density of water). Why memorise this to such precision if you're already approximating away the density? The job is already done for you, 8 dry ounces is approximately 8 fluid ounces, whether its water, milk, oil, or orange juice. If you need to measure liquid mercury, you're not working in the kitchen; if you need greater precision, you need to measure mass or volume directly as appropriate.
- charles_f 3y ago
  </joke>
  - dorfsmay 3y ago
    Ah! Wasn't clear, should have added a /s.
    - TulliusCicero 3y ago
      No. Death to the sarcasm mark.
      - javajosh 3y ago
        Are you serious? If not you forgot /s
      - registeredcorn 3y ago
        But how else would these freckled ninnies know when sarcasm is implied, if not spelled out explicitly for them in the form of some putrid postscript marking?
    - vxNsr 3y ago
      Sometimes just assuming others aren’t being antagonistic is best. You’ll live a better life.
    - Tepix 3y ago
      Explain how it wasn't clear as a statute gallon of 277.274 cubic inches of water.
  - hluska 3y ago
    That was neither clear (nor funny).
    - AdamN 3y ago
      It was pretty funny ... and pretty clear.
- BoxOfRain 3y ago
  I think the GP might be yanking our chains a little bit. Also you kind of have to include the UK in the list of countries that use imperial measures. We're mostly metric but the roads are in miles/yards and if you tried to take pints (which are larger than American pints at 568ml) out of British pubs in favour of the smaller half-litre it would make the party that did it instantly unelectable. People are nearly always measured in feet and sometimes weighed in stone (14 lb) too. I'm a little surprised we don't measure fuel efficiency in miles to the litre because that would be pretty typical of the British approach to measuring things. I actually don't think it's a bad thing, a bit of mental maths never hurt anyone and it underlines the fact that units of measurement aren't handed down on a stone tablet as a fact of nature.
  - Tade0 3y ago
    > if you tried to take pints (which are larger than American pints at 568ml) out of British pubs in favour of the smaller half-litre it would make the party that did it instantly unelectable. Definitely something only a government with the ability to essentially erase history would able to pull off.
  - _ZeD_ 3y ago
    >>> if you tried to take pints (which are larger than American pints at 568ml) out of British pubs in favour of the smaller half-litre FYI here in metric-land (well, Italy) we normally have glass of beer in the size of regular (600ml) and small (400ml), and half litre is usually used only for weissbier
  - KptMarchewa 3y ago
    What's the problem with just selling 568ml bottles? Why does it have to be named somehow?
    - automatic6131 3y ago
      Most bottles are 660ml and cans are varied, but many are 500ml. However, in pubs and restaurants, the standard glasses are 568ml and half of that, for a half-pint.
- charles_f 3y ago
  Statement of retraction and apologies On jul-25 at 11am pdt, charles_f was standing out to comment on an interesting aviation story. Seeing in passing a reference to issues regarding imperial and metric systems confusion, and given the popularity of this kind of debates on the internet, they decided to set course on a "joke". The joke was thusly constructed: the metric system is commonly used across the world and much more sensical than outdated imperial system, and people commonly announce their discontent for the latter and ask to discontinue its use. Therefore commenting using the opposite point of view as if it were an evidence, and in a serious tone, had a chance to trigger surprise and interrogation in the reader's mind, quickly resolved by the idea that the author wasn't being serious and making fun of this debate, and triggering a chuckle. This type of jokes is commonly referenced as "sarcasm" in the professional jokers world. But before the joke took flight, the joke funniness sensor wasn't working, as well as the joke and sarcasm announcement systems. The author sent Robert, their left moustachioed fat finger, to dip in the joky tank, and check if it was fun. Robert answered "yo bro yain't starting to finish all your jokes by 'just kidding' like a brainless soccer dad". Based on this manual reading the author was reinforced in their certainty that the joke would work and maybe make someone else's life a little brighter for a half second (500 time thaus, for those using imperial), and decided to take off. We all know the result. The joke worked, as some people understood it, but not all detected that it was one. The author would like to apologize for, and retract the "<joke/>" that they added as a comment to their original comment, since adding a revelation that a joke is, indeed, a joke, undercuts the element of doubt and surprise necessary to maximize its effect and duration. The same goes for lengthy, rational discussions about said joke and should be avoided. (It turns out that this particular type of joke can be delivered in their lengthier form, which get ruined if its actual, underlying agenda is revealed in plain text). As such the author would like to also immediately retract this statement and apologize for it.
  - MostlyStable 3y ago
    This is the single best response I have ever seen to someone not understanding a joke on the internet. And I can not agree more completely with >adding a revelation that a joke is, indeed, a joke, undercuts the element of doubt and surprise necessary to maximize its effect and duration. /s is a plague on internet humor.
- thefifthsetpin 3y ago
  I've heard that some countries half converted and it's been a disaster for them. They're using grams and meters but are still clinging to on the old base-12 time-keeping system. I hope the US doesn't stumble down the same path.
toast0 3y ago
> This is hard to grasp, esp. given the presence of a RAT. You're giving engineering time to add a device specifically made to handle loss of all engines, but don't spend the time to write the corresponding procedure? I imagine the RAT's primary purpose is to provide the power needed to restart an engine if all engines had stopped.
- chinathrow 3y ago
  No, it provides power to power flight control systems, linked hydraulics and e.g. some flight instruments. You can't generate the power needed to re-start an engine from a RAT. https://en.wikipedia.org/wiki/Ram_air_turbine https://en.wikipedia.org/wiki/Ram_air_turbine
  - picadores 3y ago
    You can restart by sacrificing height for speed and "propelling" the engines up to speed.
    - delta_p_delta_x 3y ago
      At some point, this isn't sufficient, and pilots need to start the auxiliary power unit (APU) and go through the full restart procedure as though on the ground. But this is a moot point, given there was no fuel left...
      - picadores 3y ago
        Makes one wonder. Fuel is measurable, not only via fuel sensors, but as inertia expected vs inertia actual by laser gyro (https://en.wikipedia.org/wiki/Ring_laser_gyroscope https://en.wikipedia.org/wiki/Ring_laser_gyroscope). There must have been some pretty deviant values on that screen. Unless the system just "calibrated" those deviances away..
nelox 3y ago
Try sending a probe to Mars making the same assumption
- charles_f 3y ago
  What assumption?
  - stickfigure 3y ago
    https://en.wikipedia.org/wiki/Mars_Climate_Orbiter https://en.wikipedia.org/wiki/Mars_Climate_Orbiter
picadores 3y ago
There are procedures, but they are to general and to emergency-manifold to help. Its basically aviate, communicate, crew-resource management applies kind of rules. In this case, discover how the plane flies, glide it towards a landable location, while communicating your intentions and location. Do not get panicy, do not get burdened with to many things (the pilot monitoring not telling about people on the runway counts as such). It makes no sense to capture all the permutations of that. Just get it down somewhat safe.
ezoe 3y ago
> How many of these incidents will we require until we finally get rid of the metric system once and for all! I love you think not other way around.
- cmurf 3y ago
  It seems nice but it’s difficult in practice. Converting to metric for fuel seems reasonable but measuring fuel in weight (mass) and volume would still lead to errors using only meteric. Distance and speeds use a mix of feet, statute miles, nautical miles, meters and kilometers depending on the context and country. Eliminating the difference would mean new approved flight manuals for each airplane, and quite expensive changes to flight instruments as well. There’s a really good fit with feet for altitude in the U.S. that just works well. 1000’ of separation for opposite direction traffic, and 500’ separation between flight rules in the same direction. Directly converting to meters breaks all the simple math involved. Whereas if we keep the math simple, it alters airspace density and capacity. Anyway, there’s no significant desire or effort to drop any of these units.
  - Doxin 3y ago
    going for 150m increments instead of 500 feet increments is only an error of ~8 feet. that doesn't seem so bad. On the topic of switching over: obviously you'd not do it all at once, but phasing in metric on new planes would at least fix the issue eventually.
- charles_f 3y ago
  I love you read not whole comments. https://news.ycombinator.com/item?id=36863874 https://news.ycombinator.com/item?id=36863874

dorfsmay 3y ago

> Darn, how many of these incidents will we require until we finally get rid of the metric system once and for all! Are you serious? There are 3 countries in the world not using the metric system. The non-metric system is difficult to use because it's using 12 based units with a 10 based numbering system. Sure switching over is going to be painful but that's true either way, and there are quite a few examples of people switching to the metric system but none, as far as I know, the other way around.

amanj41 3y ago
Original commenter was joking
rootusrootus 3y ago
> There are 3 countries in the world not using the metric system. The US uses metric for many, many things. Frequently side-by-side with imperial equivalents. AFAIK it's also the official position of the USG that metric is prefered. > The non-metric system is difficult to use because it's using 12 based units with a 10 based numbering system. OTOH, 12 divides evenly by both 4 and 3, which are common divisions.
- wlonkly 3y ago
  It's mildly worse than that, because the US uses metric side-by-side with US customary units, which at least for volume use the same unit names as Imperial but are smaller. (Does the US use Imperial as well? My most common experience with US vs imperial measure is in pints of beer, although Canada has caught on to the 16 oz pint, and don't even start me on 12 oz "pints".)
  - vba616 3y ago
    The US does not use Imperial measurements that I know of, which can be confusing to Americans if UK mpgs are interpreted as equivalent to US values. But there's more than one kind of ounce in the US. Fluid ounces are volume whereas dry ounces are weight/mass. From memory - and I memorized this from cooking - 8 fluid ounces (one cup or a half pint) is 8.337 dry ounces (assuming the approximate density of water). Then there's metric horsepower vs. other types. It's clearly so much more natural for a horsepower to have a German name (pferdestärke!) and mean 735.5 watts instead of 745.7 watts (numbers copied and pasted, not checked).
    - dmurray 3y ago
      > From memory - and I memorized this from cooking - 8 fluid ounces (one cup or a half pint) is 8.337 dry ounces (assuming the approximate density of water). Why memorise this to such precision if you're already approximating away the density? The job is already done for you, 8 dry ounces is approximately 8 fluid ounces, whether its water, milk, oil, or orange juice. If you need to measure liquid mercury, you're not working in the kitchen; if you need greater precision, you need to measure mass or volume directly as appropriate.
charles_f 3y ago
</joke>
- dorfsmay 3y ago
  Ah! Wasn't clear, should have added a /s.
  - TulliusCicero 3y ago
    No. Death to the sarcasm mark.
    - javajosh 3y ago
      Are you serious? If not you forgot /s
    - registeredcorn 3y ago
      But how else would these freckled ninnies know when sarcasm is implied, if not spelled out explicitly for them in the form of some putrid postscript marking?
  - vxNsr 3y ago
    Sometimes just assuming others aren’t being antagonistic is best. You’ll live a better life.
  - Tepix 3y ago
    Explain how it wasn't clear as a statute gallon of 277.274 cubic inches of water.
- hluska 3y ago
  That was neither clear (nor funny).
  - AdamN 3y ago
    It was pretty funny ... and pretty clear.
BoxOfRain 3y ago
I think the GP might be yanking our chains a little bit. Also you kind of have to include the UK in the list of countries that use imperial measures. We're mostly metric but the roads are in miles/yards and if you tried to take pints (which are larger than American pints at 568ml) out of British pubs in favour of the smaller half-litre it would make the party that did it instantly unelectable. People are nearly always measured in feet and sometimes weighed in stone (14 lb) too. I'm a little surprised we don't measure fuel efficiency in miles to the litre because that would be pretty typical of the British approach to measuring things. I actually don't think it's a bad thing, a bit of mental maths never hurt anyone and it underlines the fact that units of measurement aren't handed down on a stone tablet as a fact of nature.
- Tade0 3y ago
  > if you tried to take pints (which are larger than American pints at 568ml) out of British pubs in favour of the smaller half-litre it would make the party that did it instantly unelectable. Definitely something only a government with the ability to essentially erase history would able to pull off.
- _ZeD_ 3y ago
  >>> if you tried to take pints (which are larger than American pints at 568ml) out of British pubs in favour of the smaller half-litre FYI here in metric-land (well, Italy) we normally have glass of beer in the size of regular (600ml) and small (400ml), and half litre is usually used only for weissbier
- KptMarchewa 3y ago
  What's the problem with just selling 568ml bottles? Why does it have to be named somehow?
  - automatic6131 3y ago
    Most bottles are 660ml and cans are varied, but many are 500ml. However, in pubs and restaurants, the standard glasses are 568ml and half of that, for a half-pint.
charles_f 3y ago
Statement of retraction and apologies On jul-25 at 11am pdt, charles_f was standing out to comment on an interesting aviation story. Seeing in passing a reference to issues regarding imperial and metric systems confusion, and given the popularity of this kind of debates on the internet, they decided to set course on a "joke". The joke was thusly constructed: the metric system is commonly used across the world and much more sensical than outdated imperial system, and people commonly announce their discontent for the latter and ask to discontinue its use. Therefore commenting using the opposite point of view as if it were an evidence, and in a serious tone, had a chance to trigger surprise and interrogation in the reader's mind, quickly resolved by the idea that the author wasn't being serious and making fun of this debate, and triggering a chuckle. This type of jokes is commonly referenced as "sarcasm" in the professional jokers world. But before the joke took flight, the joke funniness sensor wasn't working, as well as the joke and sarcasm announcement systems. The author sent Robert, their left moustachioed fat finger, to dip in the joky tank, and check if it was fun. Robert answered "yo bro yain't starting to finish all your jokes by 'just kidding' like a brainless soccer dad". Based on this manual reading the author was reinforced in their certainty that the joke would work and maybe make someone else's life a little brighter for a half second (500 time thaus, for those using imperial), and decided to take off. We all know the result. The joke worked, as some people understood it, but not all detected that it was one. The author would like to apologize for, and retract the "<joke/>" that they added as a comment to their original comment, since adding a revelation that a joke is, indeed, a joke, undercuts the element of doubt and surprise necessary to maximize its effect and duration. The same goes for lengthy, rational discussions about said joke and should be avoided. (It turns out that this particular type of joke can be delivered in their lengthier form, which get ruined if its actual, underlying agenda is revealed in plain text). As such the author would like to also immediately retract this statement and apologize for it.
- MostlyStable 3y ago
  This is the single best response I have ever seen to someone not understanding a joke on the internet. And I can not agree more completely with >adding a revelation that a joke is, indeed, a joke, undercuts the element of doubt and surprise necessary to maximize its effect and duration. /s is a plague on internet humor.
thefifthsetpin 3y ago
I've heard that some countries half converted and it's been a disaster for them. They're using grams and meters but are still clinging to on the old base-12 time-keeping system. I hope the US doesn't stumble down the same path.

toast0 3y ago

> This is hard to grasp, esp. given the presence of a RAT. You're giving engineering time to add a device specifically made to handle loss of all engines, but don't spend the time to write the corresponding procedure? I imagine the RAT's primary purpose is to provide the power needed to restart an engine if all engines had stopped.

chinathrow 3y ago
No, it provides power to power flight control systems, linked hydraulics and e.g. some flight instruments. You can't generate the power needed to re-start an engine from a RAT. https://en.wikipedia.org/wiki/Ram_air_turbine https://en.wikipedia.org/wiki/Ram_air_turbine
- picadores 3y ago
  You can restart by sacrificing height for speed and "propelling" the engines up to speed.
  - delta_p_delta_x 3y ago
    At some point, this isn't sufficient, and pilots need to start the auxiliary power unit (APU) and go through the full restart procedure as though on the ground. But this is a moot point, given there was no fuel left...
    - picadores 3y ago
      Makes one wonder. Fuel is measurable, not only via fuel sensors, but as inertia expected vs inertia actual by laser gyro (https://en.wikipedia.org/wiki/Ring_laser_gyroscope https://en.wikipedia.org/wiki/Ring_laser_gyroscope). There must have been some pretty deviant values on that screen. Unless the system just "calibrated" those deviances away..

nelox 3y ago

Try sending a probe to Mars making the same assumption

charles_f 3y ago
What assumption?
- stickfigure 3y ago
  https://en.wikipedia.org/wiki/Mars_Climate_Orbiter https://en.wikipedia.org/wiki/Mars_Climate_Orbiter

picadores 3y ago

There are procedures, but they are to general and to emergency-manifold to help. Its basically aviate, communicate, crew-resource management applies kind of rules. In this case, discover how the plane flies, glide it towards a landable location, while communicating your intentions and location. Do not get panicy, do not get burdened with to many things (the pilot monitoring not telling about people on the runway counts as such). It makes no sense to capture all the permutations of that. Just get it down somewhat safe.

ezoe 3y ago

> How many of these incidents will we require until we finally get rid of the metric system once and for all! I love you think not other way around.

cmurf 3y ago
It seems nice but it’s difficult in practice. Converting to metric for fuel seems reasonable but measuring fuel in weight (mass) and volume would still lead to errors using only meteric. Distance and speeds use a mix of feet, statute miles, nautical miles, meters and kilometers depending on the context and country. Eliminating the difference would mean new approved flight manuals for each airplane, and quite expensive changes to flight instruments as well. There’s a really good fit with feet for altitude in the U.S. that just works well. 1000’ of separation for opposite direction traffic, and 500’ separation between flight rules in the same direction. Directly converting to meters breaks all the simple math involved. Whereas if we keep the math simple, it alters airspace density and capacity. Anyway, there’s no significant desire or effort to drop any of these units.
- Doxin 3y ago
  going for 150m increments instead of 500 feet increments is only an error of ~8 feet. that doesn't seem so bad. On the topic of switching over: obviously you'd not do it all at once, but phasing in metric on new planes would at least fix the issue eventually.
charles_f 3y ago
I love you read not whole comments. https://news.ycombinator.com/item?id=36863874 https://news.ycombinator.com/item?id=36863874