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To Err Is Human: Mistakes and slips in skydiving and other disciplines (blueskiesmag.com)
68 points by fanf2 on Oct 30, 2018 | hide | past | favorite | 56 comments



I skydive and BASE; from my (limited) experience, the disciplines have a risk of 'built in' complacency.

Take skydiving, for example. As a beginner, you're keenly aware that every time you toss yourself out of a plane, you're committing suicide, and every time, the parachute saves your life. Quite quickly, it can be easy to equate "wearing a parachute" to "nothing will go wrong".

A skydive rig is an incredible feat of engineering. Each fold and stitch has a history, a reason and a purpose. It's a thing of beauty. However, in a skydive rig, half the system is a black box: You're not allowed to touch or handle the reserve part. This can foster a complacency, or a shift of responsibility: It doesn't matter if my pack was terrible, I've got my reserve..

Checklists do exist: In theory you'll check your AAD (Automatic Activation Device - it basically fires your reserve if you haven't opened by a certain altitude), your pins (reserve and main), your handles (pilot chute / main handle, cut-away handle, reserve handle), straps (leg straps, chest strap), ring system (RSL and three ring system), and then your own gear (helmet, goggles, alti).

However, expectation of performance (IE, every time you've worn your chute it's worked, leads to complacency), peer pressure (it's totally 'not cool' for experienced jumpers to ask for a gear check) - rushing - and the 'laid back' environment of dropzones erode the seriousness of the task and the importance of stringent checking.


I've only ever jumped in the UK and Spain, but every dropzone I jumped at in the UK required everyone to have a gearcheck from a suitably experienced and qualified skydiver before boarding, and a signature against your name on the manifest confirming it had been done.

I do know that the US had a reputation for being significantly more... trusting of everyone to sort out their own arrangements.

I do know that in fifty-odd jumps, I checked my gear and had someone else do a check for me once I was wearing it, every time. Good habits learned early stick.


So, it's like when you have a second pair of eyes checking your code to make sure there's no bugs. That really helps, in software development, doesn't it?


> it's totally 'not cool' for experienced jumpers to ask for a gear check

Wow. What I'd do after I check my gear, is ask a buddy to check mine and I check his. With a checklist.


You are going to be the only one of 20 people on the plane doing this, for jump after jump, no matter how experienced you become? I wish there was a way to test this. I don't believe you.

In reality, most new jumpers will ask for a gear check for the first few jumps after finishing the training and then stop.

There really isn't a need for a checklist, it isn't hard to remember what to check. The problem is that people are either too lazy, too embarrassed, too complacent, or just too stupid to do the checks (and practice emergency procedures).

Recently, at 10,000 feet up (on the way to 13,000) I asked a 15 jump beginner in a friendly way if she was going to check her handles and practice emergency procedures. She answered that she already did. I sat behind her and watched all the way up, and she had not done these things in the plane which is common safety procedure. I then said, no, I mean in the plane. She ignored me and then went on to jump without checking anything. This is actually pretty common. People don't like to be told what to do.


I had a guy with 50 jumps request to do a 3-way jump this weekend. He was incredibly stressful, jittery and all over the place.

In the plane, no gearcheck - but he did take a stack of selfies. About 10 seconds into the jump, his helmet flew up - it hadn't been attached. Instead of breaking away and pulling, he deathgripped me and tried to reseat his helmet over and over.

We broke off and tracked away from the guy - when he deployed - he'd obviously been unstable - and had about 15 line twists, which he proceeded to slowly undo - while drifting up the jump run, before finally getting a flying canopy well below the hard-deck.

I tried to be as kind as possible to the guy, suggesting less selfies, more gear-checks and revisit some of the basics, but he just shrugged it off.

There were also 2 coaches in the plane that said nothing about the phone on the run up - wtf.


> I don't believe you.

Consider my upbringing. I'm not a pilot, but my father flew combat in WW2 and Korea. He was a stickler for always following the safety procedures to the letter - and flew for 20 years without a scratch. In 1963 he had seatbelts installed in the family car, and we wouldn't move an inch until the belts were on everybody. I'm the same way, and seatbelts have saved both my life and others in my family.

I'm not dying to look cool. And my family sure wasn't cool in the 60's with the seatbelts.

I've also worked on flight critical designs for Boeing. There one learns a lot about arrogance and complacency causing disasters.


HN 101 - overly broad statements will get you in discussions with outliers. Your safety attitude is a function of your families history, own work experience and intellect. You can negate a local culture and use your better judgement. I guess the point is at least 80 out of a 100 jumpers won't and will grow complacent. Then small odds of accidents start compounding. People die.


That's really indicative of a bad culture though. As a pilot, I use checklists and pre-flights religiously, and was appalled at the casualness and lack of safety consciousness eg on a sailboat or when scuba diving.

I've never done sky diving (why jump out of a perfectly fine plane? :-) ), but the culture & attitudes you describe sound scary. Well, at least people have fun and selfies (and, unlike a careless pilot, they (most likely) only endanger themselves). /s


> it isn't hard to remember what to check

My pilot father recounted a story once where he was going through the landing checklist. He was interrupted by the controller on the radio, then continued with the checklist. He'd skipped lowering the landing gear, which is a deadly mistake (he was informed of this by the ground).

Thereafter, whenever he was interrupted while doing the checklist, he started it over.


I recall an "Aviation Disasters" episode where the cause was the pilot was interrupted during his takeoff checklist, and skipped setting the flaps to takeoff position.


There's a PB4Y bomber on the bottom of Lake Washington for the same reason.

https://aviation-safety.net/wikibase/wiki.php?id=82520


> People don't like to be told what to do.

There's a relatively common personality type where telling people to do something is the best, most consistent way to get that person to do the exact opposite thing. The more you try to nag at such people, the more obstinately they resist, even doing counterproductive actions out of spite.


> You are going to be the only one of 20 people on the plane doing this, for jump after jump, no matter how experienced you become? I wish there was a way to test this. I don't believe you.

I'm really really surprised by these comments. Maybe it's a cultural thing but for sure where I live everyone checks at the very least themselves before jumping.

For me it's like saying "sure you won't remember to fasten the seatbelt on your car, ride after ride, once you are an experience driver?". Well, you can be damn sure I will ;)


Which is why I can't see how you're surprised. Seatbelts are the perfect example - in my experience, a lot of experienced drivers don't bother, or at least didn't bother in my country until the fear of getting ticketed for it started to feel real. And I'm convinced that the moment this law would disappear, a significant chunk of drivers would stop bothering with seatbelts.


> Which is why I can't see how you're surprised.

What I am surprised at is the fact that the parent literally says "I don't believe you" regarding something that I experience myself all the time.

It's like they internalized that doing so is not only rare -which it might be in their country- but just not at all possible!!

> Seatbelts are the perfect example - in my experience, a lot of experienced drivers don't bother

See that's quite my point. I don't doubt that people might not use the seatbelt where you live. But if you told me you "don't believe" that the vast majority of people use it here when I see it with my own eyes every day... Then I'd be indeed very surprised.

(As a side note seatbelt usage here in Switzerland is reported to be ~94% by the European transport safety council)


I think this is a cultural thing. In the UK, I would say more people automatically wear a seatbelt than for example Italy. I had an Italian friend who was in a crash where the car flipped but luckily his time in the UK ingrained in him that he should wear a seatbelt, even while riding in the back. On the other hand, he now uses this story to try to change the behaviour of his Italian compatriots who he says very often do not wear seatbelts while in the back of a car.


I am still surprised.

For me, its simple. I want to live. Checking my gear/wearing my seatbelt increases my chances for survival if something goes wrong.

If it takes 5 minutes to make sure you'll live another day, would you not take these 5 minutes?


> For me, it's simple. I want to live.

Some people like risky activities because they don't want to live. It's a cultural thing.


I just checked the stats for seatbelt use in the United States. Interesting, in most states it’s over 90% to 97%, but in New Hampshire it’s only 70%. New Hampshire (I always liked its Live Free or Die motto) has no law requiring seat belt use. See https://crashstats.nhtsa.dot.gov/Api/Public/Publication/8124...


>For me it's like saying "sure you won't remember to fasten the seatbelt on your car, ride after ride, once you are an experience driver?". Well, you can be damn sure I will ;)

I'm not sure about this example. All around the world tons of people don't fasten the seatbelt (and many more wouldn't do it if there weren't fines).


That doesn't mean it can happen at X% probability to everyone. Seatbelts on modern cars, of course, have warning lights and beepers. I never put my belt on before turning the car on, but I never take a trip without it. It's not really a matter of memory, because if I found myself driving without a seatbelt and no memory of how it happened, I'm still conditioned to feel naked.

I wonder if there are really a lot of people who are sensitive to the risk of a fine but not the risk of injury or death.


>Seatbelts on modern cars, of course, have warning lights and beepers. I never put my belt on before turning the car on, but I never take a trip without it

A popular accessory in some countries is a seat-belt "buckle" without the belt. You use it to silence the "seat belt unfastened" beepers.

https://www.ebay.com/bhp/seat-belt-alarm-stopper


> You are going to be the only one of 20 people on the plane doing this, for jump after jump, no matter how experienced you become?

If they want to be safe they will. If they have a death wish, I'm not getting on a plane with them. I'm more than happy I've never encountered this sort of behaviour.


Asking from complete ignorance, is it possible that skydiving occasionally attracts folks who secretly have a death wish?


It's relatively difficult to commit suicide via skydive (at least at the start.. there have been specific cases I have heard of where experienced fliers have killed themselves)

As a student, all your gear is double checked on the ground and just before exit. Even when you're jumping solo - if you don't open your parachute, your reserve will automatically deploy (there's a little computer that will fire the reserve if you're not open by a certain altitude)

Once you're a licenced jumper and have shaken off the 'student' label (meaning noone insists for a gear-check) - you could choose not to enable your AAD (automatic altitude deployer) and kill yourself.

To get to that stage, you've probably invested $3000+ and a lot of time. Not the most efficient way to suicide.


Not unheard of though. German politician Jürgen Möllemann, after running into lots of political difficulties and resigning, died parachuting in 2003. It's unclear whether it was an accident or suicide. (He opened the main chute, cut it off, and did not open the reserve. The AAD was not switched on. EDIT to add: When the other jumpers did a gear check, he went to "get a glas of water".)

https://en.wikipedia.org/wiki/Jürgen_Möllemann


As someone who climbs rocks and wants to eventually get into the sky/base/wingsuit scene, flirting with death is definitely an element that plays a part in the excitement.


I have a close friend who's a psychiatrist who's dealt a lot with suicidal people.

He has described that there is a whole group of people who want to die, but do not want to kill themselves. They often aren't (fully) aware of this nature of themselves.

These people often are very attracted to risky behaviour, and are seen pushing boundaries in extreme sports - skydiving, motorcycling, etc.

But, of course, that doesn't mean that everyone - or even a large number - in these sports are like this.


I agree that the sport is rife with complacency however:

>it's totally 'not cool' for experienced jumpers to ask for a gear check

is not completely accurate. The reason why inside the plane gear checks are not done often anymore except on students is mostly because of the changes in skydiving gear. Typically the only inside the plane things you can't check yourself and need to ask for someone else are the main and reserve parachute pins. These pins keep the container locked, and it's very important that they are not dislodged since they prevent premature parachute openings which can be disastrous. Older rigs had exposed pilot chute bridles, huge pin flaps, and larger canopies/dbags that all made it easier for the pin to wiggle. So it was standard procedure to check the pins 3 times: after packing, before putting on and inside the plane. However jumpers downsize canopies soon as they gain the necessary experience these days, and the modern skydiving container comes free-fly ready with no bridle exposed, pilot chute handle tucked tight, all of which make it harder for the pin to dislodge. This makes most experienced jumpers comfortable checking the pins only in the first 2 steps, packing and before putting the rig on. The risk associated with having someone else mess with the flaps and the pins inside the plane is deemed greater than the risk of pins dislodging between the time they put on the rig and opening the parachute.

Students however do not have the experience to evaluate a properly positioned pin, so having an inside the plane pin/gear check is required.


> it's totally 'not cool' for experienced jumpers to ask for a gear check

I'm not an experienced skydiver (only dove twice) but from what I've seen gear checks are common. Might this be regional?


in my experience with (actual) diving the experienced divers still do a thorough check.


One would assume that divers who don't do a thorough check every time stand less chance of eventually becoming an experienced diver.


As the saying goes in aviation: "There are old pilots, and there are bold pilots, but there are no old bold pilots."


> it's totally 'not cool' for experienced jumpers to ask for a gear check

Yeah, that mentality will get someone killed. Literally one of the first 3 things to do in any dropzone I've been in is a gear check, and I don't jump without it (duh?). I think it's an extremely reckless thing to suggest.


I am not at all condoning a behaviour, simply transmitting an observation.


Yeah, of course. Wish I could say the same for other comments.


>> Take skydiving, for example. As a beginner, you're keenly aware that every time you toss yourself out of a plane, you're committing suicide, and every time, the parachute saves your life.

To be honest, for me, as someone who's neve skydived and never will, it sounds like the mistake is to "toss yourself out of a plane" in the first place.

I can imagine myself preparing to jump and feeling every muscle fibre in my body saying "no, you idiot". Sometimes you should just listen to your base, animal urges- they know what's best. When it comes to knowing what it feels like to hit the ground at anything more than a couple of km/h, your body has a much better imagination than your brain.


Interesting, I am in paragliding and the rule is that the reserve is open, inspected, packed again at least once a year by/with the person flying with the gear. This has also to be done if for any reason the gear went wet or more than superficial dirt.


Skydiving reserves must be inspected and repacked every 6 - 12 months depending on the country. This pack must be done by a licenced rigger.


With nod to Norman’s “The Design of Everyday Things,” including the chapter “Human Error? No, Bad Design.”

For reference, an article he also wrote with that title, discussing design and human error in major transportation accidents:

https://www.jnd.org/dn.mss/human_error_no_bad.html


Having never heard of a "CYPRES fire," just spent 10 minutes googling it and then watching terrifying skydiving videos, like this one (no injuries or deaths, just scary):

https://www.youtube.com/watch?v=DAZXF1UZ1Yg


By far the most 'well known' AAD videos. The human mind is amazing in its ability to adapt to new environments. To a non-skydiver, the most important thing to do when you skydive is to open your parachute.

However it's stupidly easy as a jumper to forget completely about your altitude because you're concentrating on something else. Hard to believe that you're able to easily ignore 'certain death' after a few times - but that's the case.

According to CYPRES documentation, they've had thousands of fires - so in theory - saved thousands of lives - including the ones in this video. Pretty impressive.


Not every CYPRES fire is another life saved: https://www.youtube.com/watch?v=MmOiyrsCRNA

I'm being cynical. The occasional misfire is worth every life saved. I suppose that AAD systems are like airbags. An occasional false positive is better than even a single false negative.


>> However it's stupidly easy as a jumper to forget completely about your altitude because you're concentrating on something else.

When you're falling? What else is there to concentrate on, than how frigging high you are?


Older jumpers at my drop zone used to tell the legend of the South African Three Way. Seems that in the early days of RW, three jumpers were jumping all day long trying to get the first 3-way formation in South Africa. They succeeded, as proven by the position their bodies were in when they found them.


It seems that having a checklist like in aviation (that was also applied to surgery and other areas) could be useful to alleviate some of these slips.

https://news.ycombinator.com/item?id=8862273


One of the changes to surgery was moving from a "did we remove the 5 swabs we put in" type of question to saying how many were removed and writing that down next to how many were put in.

A couple of years ago I changed how our work checked the tyre pressures on company vehicles. It used to be a sheet with the tyre pressure stated at the top then a checklist of if each tyre was OK. I changed it to the checker having to write down each individual pressure.

This had two positive effects. Firstly it helped ensure they actually took the measurement and secondly we could identify slow punctures better.


Point and call

https://www.atlasobscura.com/articles/pointing-and-calling-j...

Someone linked this article in a thread related to worker safety or hazards.

There always seems to be ways to improve safety or reduce failure rate. But the problem is lack of incentive or motivation to make those improvements.

After reading the actual article. The point and call aims to eliminate the "slip" error. By keeping the human awareness focused and engaged in the activity.


I recently went around the USS Midway museum. It struck me that the guy in charge of the catapult would point at each person in turn waiting for an OK, before making a very clear signal to launch. Not quite point and call, mainly because the deck would be too noisy for the call bit, but it worked.


There's a great book by Atul Gawande, The Checklist Manifesto, that talks about this transfer of best practices from aviation to surgery (including checklists and CRM). Informative and entertaining read.

I think it's extremely important, because the case of aviation shows that highly trained professionals make mistakes all the time. Now, bad mistakes in aviation are very visible (hard to ignore a crashed passenger jet). However, bad mistakes in surgery result may result in the death of one person that was sick already. So, it's very easy to "overlook" them.

I feel much more comfortable in a hospital that uses checklists and CRM.


One way to mitigate slips are mnemonics.. in grain them into the students when they are learning, and they will get stuck with them for life. I have one for pretty much everything I do.


Great tip.

I wonder if exaggerated gestures and pointing with the finger, like the Japanese railway operators do would help. I'm going to start doing this myself during my checks (beginner paraglider).


That is exactly how we do them.. you say the word and point to the item with the hand you will be using.

Ex: When landing the plane: GUMPS (gas, undercarriage, mixture,prop,seatbelts ) say them all while pointing to each item.


The theory in this article is based on "Human Error" by James Reason.


I get this mag. Never would I think Id see a link to it here.




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