fabian wrote:
think part of it all is that we as humans are just very bad at estimating risk when it comes to low probability events. For example (far) more people have died in car accidents because they were afraid of flying commercially, or wanted to avoid the hassle of increased security measures, after the 911 attacks than in the attacks itself. [1,2]So I ended up asking myself this question: How dangerous is GA flying? Well there is a measure for that which is kinda useful. A micromort: Its just a 1 in 1 million probability of dying, or 1 death in 1 million people.
A very good post – thank you! I agree completely with your comment in the first paragraph above. It really quite horrible to see the expenses, both in terms of resources and limitations to our freedom and dignity, that have been imposed on us to achieve an increase in safety which is – at best – totally marginal. The US alone has ten “9/11” every year in road traffic accidents
That it does. But if you have been inactive for several months or much less years then it is a sad mistake that your previous 500 hrs will kick in as soon as you fly again. Some serious refresher training will be needed or even required.
fabian wrote:
The take away from that is that flying is safer than taking your motorbike but the bad news is that driving would be associated with about a factor 10 less risk
I’ve once undertaken a similar calculation (albeit without the concept of micromorts) based on German data. The data was obviously incomplete and I had to make some assumptions, but I came to the same conclusion that GA flying is about 10x more dangerous (in terms of track made good) than driving. GA flying and riding your motorbike seemed to be on par.
Patrick wrote:
…I came to the same conclusion that GA flying is about 10x more dangerous (in terms of track made good) than driving. GA flying and riding your motorbike seemed to be on par.
In the 90’s I believe, I read a study that came to the same conclusion. So this seems to be a reasonable approximation that could be used when discussing GA risk with non-flyers.
Yet, this risk comparison is factually completely off, because highly individual. In case of the motorbike, I can be the best and most careful driver in the world, yet I have a higher risk of being killed on the road because many more risks lie in the hands of other people who make mistakes or drive very reckless.
In aviation, the risk of being involved in an accident might be the same as in motorcycling, but it is much more controllable by the pilot. The aircraft is much more unforgiving than any landbased vehicle and thus you own risk is much more dependent of your own actions when involved with aviation. This means your personal risk may be much lower compared with motorcycling, it might, however, very well be much higher.
Maybe, but my feeling tells me that if I had made ~500.000km (2.500 hours x ~200 km/h) in a motorcycle over the last 15 years, I would be dead five times now…
Also, if you walk you may end up gaining fitness and living longer, despite your chances of being squished by a car.
I guess you overestimate the risk of fatal accidents riding a motorcycle.
http://www-nrd.nhtsa.dot.gov/Pubs/812035.pdf
What is true is that in GA the probability of a non fatal accident is about 5 times higher than a fatal accident.
In case of motorbikes its 18 times more likely to be injured than killed. Which means you would have been quite more likely to have been involved in a motorcycle accident but surviving it.
What is true is that in GA the probability of a non fatal accident is about 5 times higher than a fatal accident. In case of motorbikes its 18 times more likely to be injured than killed. Which means you would have been quite more likely to have been involved in a motorcycle accident but surviving it.
I’m not big on counting but I’ve certainly ridden 600K or more kilometers on motorcycles worldwide and have never required medical treatment as a result. I have however fallen off many times in solo accidents (I’ve never tangled with a car). The reason for motorcycle having a statistically high ratio of fatal accidents, regardless of how that statistic might compare to aircraft, is because those are the motorcycle accidents that invariably get reported. Most of the others do not get reported. Conversely, aircraft accidents are almost always reported regardless of severity.
I agree based on my own observations that aircraft accidents are much more likely to be fatal than motorcycle accidents. I think the statistics underreport that situation: given the number of unreported motorcycle accidents instead of the ratio of 18/5 it would not surprise me if in reality it is 100/5 or twenty times more likely to die in any given aircraft accident versus any given motorcycle accident. Light aircraft accidents are not hugely frequent but I think when they occur they do tend to be fatal.
From the end of here
Because the discussion about experience always comes up around these topics I want to add my bag of cents, hopefully not too off topic ;-)
Lets look at the best and statistically most thorough paper on this subject, which I know of:
Knecht, R. (2015) “Predicting Accident Rates From General Aviation Pilot Total Flight Hours” [ 1 ]
Available on the FAAs website:
https://www.faa.gov/data_research/research/med_humanfacs/oamtechreports/2010s/media/201503.pdf
There are many findings in there which most people, myself included, probably don’t want to hear. You can also still argue about the findings based on the noisiness of the data, as well as the resulting not too great fit of the postulated models. By the way, if you have read “The killing zone” best to forget about it again: as addressed by Knecht in the book only accident distributions based on Total Flight Hours (TFH) were considered but not rates, which essentially makes the assumption that the pilot population is evenly distributed, so that there are just as many 10 000 hour pilots as there are 5000 hour pilots as there are 100 hour pilots. Which is obviously very wrong, and quite frankly a rookie mistake.
I’ve plotted the two models shown in figures 8 and 9 on top of each other, making the differences between IR and non IR pilots more obvious
What we can see is that there is quite arguably a correlation (R2_nonir=.654, R2_ir=.775) between TFH and accident rates. Especially for the low TFH this model should be quite accurate since there is sufficent data for a good fit there, with increasing TFHs the model will diverge more. You can also see this quite well when you look at the original figures with the histogram data superimposed.
There is a peak accident rate for non IR pilots at around 500 flight hours. Which means that until this point risk keeps increasing, and many pilots never actually pass over this peak within their flying career. One can also see that non instrument rated pilots with 150 TFH have the same accident rate as 2000 TFH pilots, about 0.004 fatal or serious accidents per 100 hours.
Obtaining an instrument rating makes flying initially slightly safer but leads to a higher peak accident rate. This only levels out again after 3000 TFH, eventually resulting in lower baseline. If we look at the total accident rate over a pilots flying life (integral of the model), we see that in total an instrument rating only leads to a lower accident rate if the pilot flies more than 7200 hours. Which very few private pilots will actually reach.
Next we can speculate why this is actually the case, for me a good explanation is that there is a lot of risk compensation going on for low hour pilots and that confidence increases faster than skill. Leading to increased risk taking.
What should also be noted is that according to the Nall Report (2013) [ 2 ] accident rates are quite lower for commercial fixed wing operations than for non commercial fixed wing ops by a factor of about 2-3. While ATPs und CPLs seem to be over represented in non commercial fixed wing accidents, but this is hard to say since for these neither rates nor baseline hours are provided, I would still not expect that there are equally many ATPs + CPLs as PPLs flying non commercially, but maybe they fly far more hours, etc. Hard to say.
Of course these commercial ops are also biased more towards higher performance aircraft.
1 https://www.faa.gov/data_research/research/med_humanfacs/oamtechreports/2010s/media/201503.pdf
2 https://www.aopa.org/-/media/files/aopa/home/training-and-safety/nall-report/25thnallreport.pdf
