Gimli Glider
en.wikipedia.org
en.wikipedia.org
Talk about a uniquely Canadian story - running out of fuel because of a mistake in Imperial to Metric unit conversion. This from someone who was in high school in 1978, The Year Dope Dealers Got an 'A' in Math.
And if you don't get that joke, you're not a Canadian who grew up in the transition from Imperial to Metric.
[0] https://en.m.wikipedia.org/wiki/Gimli_Glider
[edit: duh, added the reference. I get it, after having it being explained to me. Thanks folks. ]
Scientists recently proved the existence of a soul inside of all life forms [0].
They can also be dangerous[1]: gaze into the void, and the void gazes back. Cast into void, and you might get a null pointer exception.
it simply is not a priority, it could be slowly slipped into prominence by emphasizing the measurements on everyday items instead of making those in small print
Every science class I had in high school used metric. We also spent a fair amount of time going through it in elementary and middle school math classes.
My younger sister (by 20 years) spent a good deal of time on the metric system in her math classes.
I've done experiments switching to metric. It's not a good idea to rely on my GPS for speed limit information. My home thermostat apparently doesn't have a Celsius setting (and would confuse my wife if it did). It's difficult, but mostly possible to switch here...but what's the point? It's a lot of work for comparatively little benefit.
Britain has all of this in metric; the beer, road signs and casual (non-medical) body measurements are the only exceptions.
If you didn't know this was 16" on center, and 2x2 framing, you'd think some mad drunk person had come up with these numbers. I also like to imagine building inspectors walking into a building and saying "Oh, these studs are 407mm apart. Tear the building down."
[1] : https://en.wikipedia.org/wiki/Metrication_in_the_United_Stat...
Metric conversion in the UK isn't complete: on road signs, distances are in miles and speeds are in miles per hour. Pints are used to serve draught or keg beer.
In aviation, height/altitude is measured in feet or flight levels (hundreds of feet), horizontal distance is measured in nautical miles, and speed is measured in knots.
Even in France, we use pints to serve beer...
In the UK and US they still have ye olde measures - 568.3mL and 473.2mL respectively.
Milk was the same for a while and you still see it occasional though we've gone to liters mostly.
Most things are metric now though.
Feet for altitudes are not ideal, but it's become a convention (in China they use meters) (Now if they were to mix feet and miles in the altitude that would have been bad)
Construction on the other hand is still mainly in imperial/US units, which makes sense given that the use the same material providers as the US.
The risk of confusion was too high, and there was at least one case of a severe overdose when a weight was accidentally given in pounds rather than kilogrammes.
If an American child was hurt outside the USA, and the parent overheard the nurse saying their weight was 55kg, would they know whether that's accurate? That's why it's important that the same units are used at home and in science.
Imperial is only really used in consumer facing situations. If we forced everything over to metric, would it make that much of a difference? Would the US economy suddenly surge due to a more efficient system? Unlikely.
And hey, if it's good enough for NASA, it's good enough for the rest of the states. ;)
Worst hit, would probable be the automobile industry. But I'd say there'd be advantages to metrification there too.
They use metric.
Why? The French system has exactly two benefits: it's popular, and it's easier to perform abstract conversions (i.e., conversions between units on paper). OTOH, it is worse at performing concrete manipulations (i.e., dividing one physical quantity into another): accurately cutting or dividing quantities into tenths without the aid of a guide of some sort (e.g. a ruler or measuring cup) is so difficult as to be basically impossible, while cutting or dividing into halves is so easy that a child can do it, and thirds are not much harder at all.
Yes, it happens that it's easier to 'do science' currently using French units, but that is because all of the standard constants happen to be based in those terms: there's no fundamental reason one couldn't use Rankine instead of Kelvin and so forth.
I won't claim that the standard system of units is perfect (the partial decimalisation the Brits attempted in the 19th century was misguided): indeed, it could get a lot better: nautical miles are probably better than statue miles; a reset in the length of the yard so that there are 1,728 yards in a mile would probably be a decent idea; a cup ought to be 16 cubic inches; and so forth.
But throwing away 12 (with its divisors of 6, 4, 2 & 3) for 10 (with half as many: 5 & 2) was a foolish, foolish decision by the French.
If they'd really wanted to be revolutionary, they'd have adopted base-12 numbering instead of trying to fit the world to base 10.
(I will grant the the French system of paper sizes is elegant, and I wouldn't mind us adopting a similar system based, of course, on the yard)
The paper sizes are German, and adopted by the ISO.
Dealing with French units is a pain.
(as an aside, the reason I call them 'French units' is because the name 'metric' privileges them: our standard units are no less a system of measures than are they; this too is my problem with 'SI,' since our system is (or was) likewise international)
I guess, but for what it's worth, I've never heard that before. It's a poor way to communicate, if communication is your goal.
No farmer or brewer deals in units that are easier to half in American rather than metric units. They use tonnes, hundreds or thousands of litres, and large areas. Outside America, they don't need to convert between units of the same type: no acre-feet, bushels, pounds, tons, or all that crap.
Calling them "French units" sounds like xenophobia. The American system was never international, and the British system didn't extend that much further than the French, at the time of the empire.
In America, anyone who would deal solely in tonnes can deal solely in tons; anyone who would deal solely in hectolitres can deal solely in barrels (traditionally, 128 quarts); anyone who would deal solely in kilolitres can deal solely in tuns (traditionally, 1,024 quarts). No-one in America has to say '7 tuns, 2 hogsheads, 3 gallons, six quarts and a fluid oz' any more than he'd say '7.2850546 kilolitres.'
> Calling them "French units" sounds like xenophobia.
Oh, I'm not xenophobic! I just don't think they deserve a privileged position.
> The American system was never international, and the British system didn't extend that much further than the French, at the time of the empire.
The American system was used in Liberia; prior to the Russian Revolution the majority of the peoples of the world used systems of measurement substantially similar to the Anglo-American system, and could (should have, IMHO) rationalised and standardised that, rather than adopting the objectively inferior decimal principal.
Then your argument that these quantities are easily divided is irrelevant.
> 7.2850546 kilolitres
My house's water meter measures up to 99,999.999m³, or in litres up to 99,999,999 litres.
Europe other than Britain and Ireland didn't use the British system, and neither did their colonies, China, Japan, etc. All the British colonies except the USA chose the metric system after independence.
The SI system is the only one that's truly international, set up by international treaty between many countries.
A0 is 1 m^2, by area, with sides in a ratio of 1:sqrt(2).
When you fold it in half, you get the same ratio, but now A1:
A1 is 1/2 m^2.
A2 is 1/4 m^2.
A3 is 1/8 m^2.
A4 is 1/16 m^2.
etc.
So, if you buy paper, it will be, say, 80 g/m^2. Now, one page of A4 thus is 5 g.
By your count, the "standard" system (how is it standard if it's used almost nowhere?) has 1 point: A foot being 12 inches means it has more divisors than 100 cm to a metre.
So, therefore the final score based on your appraisal is Metric 3, Freedom Units 1.
A clear win for the metric system.
Top marks!
Historically, it seems baffling. Their real name, "imperial units", are a clue that they're all but rooted in freedom. They're inherited from the country that the US broke free from…
Plus, the Metric system stems from the French Revolution, making it a better contender for the term "freedom units".
Finally, wasn't there a whole PC phase in 2003 where expressions with "French" in it, like "French Fries", were renamed "Freedom Fries"? It all makes things rather confusing.
Yes, easy halving and quartering was important back when the population was not used to decimals. But surely, most people these day can tell that half of 100 cm is 50 cm, a quarter is 25 cm, and a third 33.33 cm.
So, the Gimli glider had a glide ratio of 12:1. We're 10 km high, how far can we glide? Well, 120 km.
That's how we'd compute it in a metric world. In the real world, the Gimli glider was 32,000 feet high. How many nautical miles can it glide? Quick?
In the real world, the Gimli glider was 9,753.6 m high. How many km can it glide? Quick?
Of course, in real life one would cheat: a nautical mile is about 6,000 feet, so 32,000 feet works out to about 5 nautical miles, which means that it can glide about 60 nautical miles. One can always grab a calculator (or slide rule — they're actually quicker at this than calculators) to be certain (12:1 at 32,000 feet gives 63 nm/110 km).
117,043.2 m. In about 5 seconds in my head. By doing value × 10 + value × 2. Because multiplying by 10 is so easy, because arabic numerals are in base 10.
And by cheating, which obviously we would do as a first approximation, it is also much more trivial in SI units: 9,753.6m is about 10km, × 12 → 120km. At most 1 second to find. Faster again.
But my fundamental point: we already have the mnemonics ready for base 10, and we won't switch away from arabic numerals any time soon, so we might as well benefit from it.
It isn't a competition. After all, the metric system is screwed up: having 60 seconds in a minute is a pain (but wow, so many divisors! — really though, just an inheritance of an ancient culture that did not use base 10 numerals; using higher bases isn't an indication of modernity) and the fundamental definition of the second doesn't map to any physical reality in an intuitive way anymore.
It is simply less screwed up.
No, in duodecimal. It's generally better: https://en.wikipedia.org/wiki/Duodecimal
And you can count by twelves on the knuckles of your fingers, so anyone who still needs to count on his fingers can still do it (I'm not certain why this is such a selling point for decimals: surely we're all intelligent enough to use higher bases?).
Like, sure, Pearson had glider experience... but he applied that experience flawlessly in an aircraft with a brick-like glide ratio, landing with no slats or flaps, all the while losing control authority as the airspeed dropped and made the RAT less and less effective, with 69 human lives at stake. Holy shit.
For anyone who's interested, Wikipedia is full of these stories of disasters and near-disasters, and they make for interesting reading.
I doubt they practice it much in 767s, though, despite the fact that they actually glide better. :)
What you of course do are power-off landings – on airfields, for example from the downwind, and simulated, i.e., you make a go-around just before landing, outside an airfield. Sometimes, it works, sometimes, it doesn't, there are many factors … that's why you actually fly with power idle and not with power off. There're still a few incidents, i.e., somehow the practice becomes tool real!
All in all, power-off landings and other emergency training are an important part of becoming a pilot but you don't spend that much time for them. Other things are much more time-consuming in a typical 45-hour syllabus.
Slipping to lose altitude fast is a regularly trained maneuver for glider pilot.
Still an amazing feat to pull that landing.
You're thinking of https://en.wikipedia.org/wiki/United_Airlines_Flight_232
where so much of the plane broke that they had to invent a new way to fly it.
I can't turn up a reference right now, but like you say, in the next few years that failure was repeatedly simulated, and all the simulated planes crashed.
(IIRC, Haynes declined to try his hand at any of the simulations, explaining that the one time when it really mattered was enough for him.)
Flight 232 is another very interesting story, for sure.
Aren't flaps used to lower stall speed?
I have flown gliders at a beginner level (so no flap) and the reason we did side/straight ahead slips was because we came in too high (emergency procedure or bad estimation) and would have ended up touching down too far with not enough space left to land safely.
I assumed they came in a bit too high as an insurance (you can burn height but can invent it), but just ended up with a lot more than they expected just because if their lack if familiarisation with the situation in that plane, so much that the dive break alone weren't sufficient to burn it.
Then, you put in flaps to have a less efficient wing profile and descent more steeply (without gaining excessive speed).
However, here they did not have enough power to do that, so the Captain put it into a slip: flying uncoordinated, with (say) left rudder, but right aileron, flying somewhat diagonally (or rather, flying straight ahead still towards the runway, but presenting not only the nose, but a bit of the aircraft body to the wind).
That gets you down quite well.
Those are really the techniques when you're too high on the approach: 1. Flaps 2. Slip 3. S-Turns
You want to be going as slow as possible when you land (aircraft make poor racecars), and most aircraft call for some level of flaps on landing. Increasing lift lowers the stall speed, which is good, and increasing drag allows you to lose altitude without gaining speed. Without flaps they would have to land too fast.
Advertisement: https://www.av8n.com/
Not that the pilot was the only one responsible off course, but he had his share of blame in the whole thing.
Th RAT comes to the rescue in such situations. Its a Ram Air Turbine which pops out of the body when called upon. The turbine spins and generates just enough electricity to power the crucial instruments and controls.
I was touring a Hamilton Sundstrand factory a long time ago that manufactured these RATs. They had a tally board up that listed situations where the RAT was deployed and the number of people that survived the incident.
Talk about being motivated to do a good job!
I don't know exactly which systems it powers, but have been told that in the case of engine failure, the plane cannot fly without it. You may be correct about the specifics.
There are some components that are considered like that GPS that have small enough power requirements and are critical enough that they can have significant battery and others that are powered by the RAT, and yet others that just don't work with a main engine failure.
Highly suggest watching some of the Mayday episodes about the power failure incidents like Gimli, its very educational.
Isn't "backup batteries" a loose description of an APU? https://en.wikipedia.org/wiki/Auxiliary_power_unit
The startup procedure for that aircraft relies on either a tether from the ground to provide external electricity, or on the battery to provide electrical power to the instruments/HUD before the APU is spun up.
If we look at the case of Cactus 1549 [1], though, we see Capt. Sullenberger turned on the APU immediately after both engines failed. This has been hailed [1,2] as a good decision -- no doubt because the A320 relies so heavily on electronics for control and it could have helped them restart the failed engines.
Commercial jets certainly do also carry traditional batteries for various uses. Take the Boeing 787 as an example; its onboard batteries originally presented a fire hazard [3].
[1] https://en.wikipedia.org/wiki/US_Airways_Flight_15494
[2][PDF] http://www.ntsb.gov/investigations/AccidentReports/Reports/A...
[3] https://en.wikipedia.org/wiki/Boeing_787_Dreamliner_battery_...
Of course, they don't power much - typically a few backup instruments and the APU starter - so the RAT[1] is used to power certain hydraulics/instruments so that the pilots can maintain control.
[0]Why is the battery $11,000? Well, it has to undergo a lot of testing and contain thermal runaway. See the problems with the 787's new Lithium Ion battery https://en.wikipedia.org/wiki/Boeing_787_Dreamliner_battery_...
[1]For fun, here's a test flight that shows the 787 RAT deployed: https://i.stack.imgur.com/xYQPP.jpg
"Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them going again. I trust you are not in too much distress"
1) Per my first flight instructor, this is the reason students now learn how to forward slip. Up until then it was just viewed as a glider move. Thankfully the captain was an experienced glider pilot. It's required to demonstrate this maneuver for your private license (not sure about sport license).
2) This ultimately led to overhaul and standardizations for fuel / weight calculations.
3) Because the engines powered the electrical systems via the alternator, the plane lost a number of electrical systems until the ram air turbine kicked in (amazing little invention and kinda saved the day). Afterwards, many subsequent aviation systems were designed to be operated independently from requiring the alternator to be running.
Good documentary/recreation on the incident: https://www.youtube.com/watch?v=Bct1mWUp8to. Miraculous that everyone survived, the captain deserves an accolade for quick thinking.
Edit: I'm dead wrong. :)
[1][PDF] https://www.faa.gov/training_testing/testing/test_standards/...
https://www.faa.gov/documentLibrary/media/Advisory_Circular/...
A forward slip is absolutely required for a PPL checkride and has been for decades (if you'd like a source, see page 45 of the definitive FAA ACS: https://www.faa.gov/training_testing/testing/acs/media/priva...).
However, transport category aircraft (among other issues) have swept wings, which are far less stable in a slip - so slips are neither taught nor recommended for jets.
You have no idea how hard it is to get Americans to use 100% metric everything, even in the year 2016 in a highly technical field. It's incredibly frustrating. I'm amazed at the number of people under age 30 who have clearly not been taught even the basics of the metric system in middle school and high school, or intentionally disregarded/forgot it.
Working in the US domestic economy is unavoidable to do many things in US customary units when construction/physical engineering of things is involved. For example if building mission critical telecommunications towers to EIA/TIA 222G standards, everything is going to be in US customary units (the tower structure itself, the fasteners, the guy cables, the anchors, the foundation/concrete job, the dimensions of the equipment shelter, the electrical conduit, etc).
American in a highly technical field here. I have no issues with using SI units when appropriate. But there is a tremendous lock-in, at least in some areas. Aerospace is a nasty mishmash, resulting in things like aircraft that "think" about altitude in feet, fuel in pounds, gear displacement in inches, but electric field strengths in W/m^2 and geopositioning in meters. All of those choices were made long ago, I'm stuck with them. My only defenses are to keep meticulous track of units and convert where necessary (while paying attention to things like numerical error).
We only get down to proper metric units when dealing with the fiber itself, but even that is lashed to aerial pole-to-pole strands, where the steel strand is in US units, all of the hardware is US.
The battery backup shelves for large AGM lead acid batteries: All US units. The batteries themselves are specified in inches and pounds. Once again it can all be converted, but that's the default unit from the manufacturer. Floor loading calculations? Pounds per square foot.
https://en.wikipedia.org/wiki/Mars_Climate_Orbiter
>However, on September 23, 1999, communication with the spacecraft was lost as the spacecraft went into orbital insertion, due to ground-based computer software which produced output in non-SI units of pound (force)-seconds (lbf·s) instead of the SI units of newton-seconds (N·s) specified in the contract between NASA and Lockheed.
I have a feeling that with the decline of American manufacturing, they'll feel more pressure to convert to metric because it's a bit cheaper on imported things and there's less locally made stuff that needs to convert.
Non-construction materials are already readily available in metric units. I can buy grade 8 bolts in any size, metric or US customary. I can't buy 400 x 800 plywood, and why the hell would I want to? Everything here is built on 24 or 18 inch centers. You'd have to be insane to build a house using metric dimensions.
US customary units are nowhere as difficult to use as people make them out to be, especially at the scales being used for construction. I find metric and US customary equally easy to use, and I think that metric is much easier to use when it comes to electricity, but I find US customary much easier to use for everything else.
For instance, the meter is widely held to be better than the traditional US customary units. I think this is true for science, but when it comes to everyday uses I find the US system easier to perform math with purely because it's base 2 rather than base 10, and most of the time I'm dividing things in half several times.
Need to find the center of a 1-7/8" board? It's 15/16ths, which is really easy to calculate if you understand fractions. That's basically like figuring out the center of a 50mm board -- 25mm, obviously. However if you divide each board again, you get 15/32nds, or 12.5mm. If you divide again, into eighths, you get 15/64ths, or 6.25mm.
Maybe 15/64ths seems a bit clunky, but my tools usually have markings down to 64ths, and I have bits available all the way down to 64ths. The example I picked was deliberately bad for US imperial, and it still was pretty easy to calculate.
I think US customary units are really confusing to metric types because they don't really have a reason to use fractions in daily life. Math with fractions is really easy to do in your head though, and most tradesman are doing the math in their head.
I wouldn't be surprised if we saw a bigger push towards metric as education shifts away from pencil and paper. Metric makes way more sense than US customary does when you are doing math on a computer.
I'm equally frustrated by how hard it is to get others to use standard units instead of the French ones. There's no particular reason why 'technical fields' should mandate use of French units: one can fly an æroplane, run power to a lightbulb and get a man to the moon all in standard units — indeed, that's how those things were initially done.
Sure, you can fly your plane with bolts measured in inches and fuel measured in pounds, but good link getting replacement parts or accurate refueling next time you're in a stopover in Japan or Italy or Egypt. And have a good time trying to sell machine parts into an international market, or trying to buy from that same market.
Not quite. At least as far as the flight guidance and navigational systems, NASA used metric internally for the moon missions and had the computer display the converted equivalent in US customary units to the crew.
In reality, you have the accepted world standard and the US one, with a small smattering of UK units thrown in. To argue the entire world should switch back to the US standard instead of the other way around is ridiculously obtuse.
The entire world switched to one country's system once. All of Europe used substantially the same system, and switched from it to one country's radically different system.
There's no reason it couldn't be done again. If it made so much sense to do one thing (of course, I don't actually think it did make that much sense: it was in the main driven through by governments seeking to radically break with the past) then surely if it makes sense to do something else, we all ought to?
- prefixes based on powers of 10 are better aligned with how we calculate today, namely with base 10 numerals, and decimal fractions (unless we switch to base 12 or base 8 numerals).
- a single unit per physical quantity, together with prefixes, is better than the proliferation of units in those customary systems (often with different units of the same physical quantity in different contexts, for example length vs area vs liquid volume vs non-liquid volume, or mechanical energy vs heat energy).
- the system is coherent and somewhat minimal.
- the units are derived from the world, not from the length of some king's feet or arms or what have you. Of course, that's a somewhat subjective benefit.
At any rate: the original metre was 1/10,000,000 the distance from equator to pole (that's why 90*60=5400 nautical miles = 10,000 km, approximately). The original kilogram ("grave") was the mass of 1 dm^3 of water.
Of course, one can fly an aeroplane or get a man to the moon without SI units. One can also do it without GPS and without computers and without internet and without antibiotics and without all the other achievements of civilisation. But why would one?
[1] https://en.wikipedia.org/wiki/International_System_of_Units#...
FabHK, no, French units are inferior to the standard units:
- 2 and 5 are poor factors; 2, 3, 6 & 8 are superior. We ought to switch to base 12: among other things, ⅓ is not a non-terminating duodecimal.
- It is better to have multiple units for multiple purposes: anyone measuring interstellar distances in inches or metres rather than in parsecs or lightyears is, simply, wrong. One always has the freedom (and indeed, the professional obligation) to use only one unit where it matters (e.g. anyone measuring bread pans in fractions of a mile or metre is, again, simply wrong.
- The system is scaled to human beings, and eschews superficial minimality (BTW: steres and hectares). There are many useful units at human scale, with a few units where needed outside that scale (there's not really much need for a lot outside of human scale).
The units are derived from the world: the nautical mile is equal to one minute of latitude (that's 1/60th of 1/360th); a pint is a pound of water.
- The units are useful for manipulating concrete quantities. Half a volume of liquid is itself a useful measure, as is double (it goes mouthful → jigger → jack → gill → cup → pint → quart → pottle → gallon and so on, doubling all the way up until a tun). As a computer guy, it's pretty awesome to see 64, 128 & 1,024 in my unit quantities.
As I note elsewhere, I'm in support of rationalisation of the system: history has not been kind (c.f. rulers who kept the tax per unit the same, but decreased the size of the unit). I think that there's definitely improvement to be made.
But throwing it all out and adopting a decimal system goes in exactly the wrong direction.
If we lived in a base 8 or base 12 world, a radically rationalised version of the customary royal measures based on doubling or factors 8 or 12 might be preferable. But we are not.
> It is better to have multiple units for multiple purposes.
Why?
Differences in scale are easily accounted for with the prefixes:
mili, micro, nano, pico, femto, atto takes you down to 10^-18; with zepto and yocto you get to 10^-24.
kilo, mega, giga, tera, peta, exa takes you up to 10^18; with zetta and yotta you get to get to 10^24.
countries which have officially adopted the metric system vs those which have not: https://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/Me...
But we learnt about the Gimli Glider in my university computer risks course. It was a masterful piece of flying (and you'll note that most people who've tried to reproduce it in simulators fail).
Sobering reading:
https://en.wikipedia.org/wiki/List_of_airline_flights_that_r...
There's a lot of flights there with casualties (including one in 2005 where a pressurisation failure caused the crew to pass out; the autopilot flew the plane to Greece where it entered a holding pattern until it ran out of fuel; interceptors spotted a flight attendant trying to land the plane with portable air equipment, but he didn't make it. No survivors). Airliners don't really glide well.
The Helios flight in 2005 was unfortunate. The flight attendant trying to control it had some pilot training, but not enough to handle an out-of-fuel airliner at relatively low altitude.
It's a fascinating case study in failure recovery in the worst possible scenerios, and how systems fail to begin with.
...Come to think of it, those are all subjects Cantrill likes to talk about. If you like playing Bryan Cantrill Bingo, I think this might make its way onto your scorecard soon...
That's great, but I wonder how big of a coincidence this is - how many aircraft did Air Canada have, especially running on presumably the same leg that Pearson and Quintal would have been running?
MAYDAY Air Crash Investigation S05E02 Gimli Glider Air Canada Flight 143
One of the passengers mentioned that during the last-minute sideslip manoeuvre, he could almost tell what clubs the golfers on the course below them were using. :)
Yes, that is where I had first read about it too. Don't remember exactly, but probably under the section called Drama in Real Life.
What seems initially just like pilot error may also be due also to workplace conditions, bad training, a lack of communication, or fatigue — a chain of events and circumstances that culminates in the accident. It's fascinating.
I credit this show and MythBusters for pushing me into Science and Tech.
Mythbusters is fun and entertaining, Mayday is educational and entertaining.
The earliest episodes were more scientific and educational. They spent quite a bit of time explaining how they were going to construct something and then showing how they actually built it. It became pure entertainment--devoted especially to blowing things up--once the show achieved success.
Another example of a show descending to the lowest common denominator: The first years of "Biography" on the A&E Network had stories about explorers, scientists, and world leaders--Michelangelo, Henry Ford, Julius Caesar, Marconi, Marco Polo--but now it's nothing but celebrities.
I've never actually seen any of the biography series (I just associate it with shallow celebrity profiles) I'll have to dig up the earlier episodes, thanks!
[I get it, no criticism of Myth Busters allowed]
A more recent mini-show that gives you a similar discovery experience (albeit at a smaller scale) is the MrGear channel at YouTube: https://www.youtube.com/channel/UCo6DJdltbIub80bLiyJRv3w
The most fascinating ones to me are the ones where there is a completely survivable mechanical failure, combined with human failures that lead to crashes. The one that comes to mind there is the plane where the engine was leaking fuel, so the tanks were not equal so the pilots engaged the cross-feed valve, causing BOTH tanks to drain leading to an out-of-fuel situation. If they hadn't done that, they could have easily made it to their ETOPS airport with minimal issues.
Also, that show makes me sound smarter than I am. I've had conversations with pilots, who will ask if I'm a pilot. Its great fun for parties when you run into pilots (GA and commercial).
In this case the pilots followed standard procedure for a fuel imbalance, which is the alert they got.
They could also have looked at the rate of fuel consumption across both tanks to determine that the fuel consumption on the right tank was way higher than the engine could consume, but that was not SOP at the time (it is now, and the A330 [and probably other planes] now compute that information and alarm on it).
Its all layers, planes, with minimal exception, really don't crash from a single failure.
There is the wonderfully named "Swiss Cheese model of accident causation" [1] elaborating on that. An accident happens when all the holes in the cheese line up...
But Air France 447 is a recent example where it's really tempting to say that sheer pilot incompetence was the biggest factor: https://en.wikipedia.org/wiki/Air_France_Flight_447
A stall horn is hard to overhear.
>appropriate action is the opposite in normal and alternate law
I'm not sure what you are referring to here, but the fact that the appropriate action was to push forward to bring the nose down was the same regardless of alternate law/normal law. The bad UI was that the stall alarm shut off when the stall became so severe, which is why the pilots pulled up to stop the stall alarm (making the stall worse).
>Even worse, the second pilot can't "feel" on the stick what the first pilot does.
The system warns on dual input when it conflicts like that. Again, recognizing this condition is a very basic requirement of understanding the airbus control system. Regardless of that, the pilots did not communicate what they thought the problem was and what they were doing to solve it. Competent pilots don't end up in a situation where one is silently doing the opposite of the other and they don't realize it.
Nevertheless, I wonder whether that particular accident would have happened with the physical link between yokes, rather than the side sticks; and whether there are lessons to be learned from that regarding UI/human-system-interface.
But then, how idiot-proof should planes be...
I am convinced that much of human error is due to bad user interface, especially in technical settings. I think it is an important lesson that both pilots failed to recognize (in a stressful situation):
1. the plane was in alternate law 2. either actions contradicted each others
One anecdote of a serious aircraft problem due to a programming shortcut I remember from a conference roughly and very simplified translates to this pseudo code for something related to landing/takeoff:
if wheels_rolling()==false: in_air=true
The problem was of course...plane with wheels on the ground but not rolling due to ice (more like sliding and there was some sensor mishap that also). And well relying on the rotation of the wheels as a height indicator and many other things...
[1] There is another famous canadian "glider" story involving a jet over the atlantic. All i remember is that the pilot was a former bush pilot who ignored his instuments, refusing to believe he had a fuel leak.
> Pearson consulted the master minimum equipment list (MMEL), which indicated that the aircraft was not legal to fly with blank fuel gauges but due to a misunderstanding, Pearson believed that it was safe to fly if the amount of fuel was confirmed with measuring sticks.[14]
> The 767 was still a very new aircraft, having flown its maiden flight in September 1981. C-GAUN was the 47th Boeing 767 off the production line, and had been delivered to Air Canada less than four months previously.[15] In that time period there had been 55 changes to the MEL, and some pages were blank pending development of procedures.
> Because of this unreliability, it had become practice for flights to be authorized by maintenance personnel. To add to his own misconceptions about the condition the aircraft had been flying in since the previous day, reinforced by what he saw in the cockpit, Pearson now had a signed-off maintenance log that it had become custom to prefer over the MEL. [0]
The flight crew was assigned partial responsibility for the incident as they did not follow a procedural checklist. The originating problem was the installation of an incorrect fuel system component which allowed fuel lines to chafe and subsequently leak.
Piché was discovered to have smuggling experience which took some of the luster off his public image in the days after the incident.
One heck of a landing nonetheless.
[0] https://en.m.wikipedia.org/wiki/Air_Transat_Flight_236
[edit: realised the referenced article does mention smuggling and fixed an autocorrect error]