Private pilot dropout hours - US
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sdb...
I agree with your reasoning that if you die at 100 hours you can't kill yourself at 300 hours. However, only about 2% of GA pilots will die in flying accidents, whereas a much higher (and currently unknown to us) proportion will give up early in their flying careers.
The question is, I guess, simply whether a high proportion of the deaths were 'accidents waiting to happen', and what proportion happened to generally competent, appropriately cautious people who just got unlucky.
If the former is predominantly true, then I guess it may be important to take the effect into account. If the latter is predominantly true, then I doubt it will have much influence on the statistics.
I'm still not convinced it's exactly analogous to the monty hall problem though.
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I agree with your reasoning that if you die at 100 hours you can't kill yourself at 300 hours. However, only about 2% of GA pilots will die in flying accidents, whereas a much higher (and currently unknown to us) proportion will give up early in their flying careers.
The question is, I guess, simply whether a high proportion of the deaths were 'accidents waiting to happen', and what proportion happened to generally competent, appropriately cautious people who just got unlucky.
If the former is predominantly true, then I guess it may be important to take the effect into account. If the latter is predominantly true, then I doubt it will have much influence on the statistics.
I'm still not convinced it's exactly analogous to the monty hall problem though.
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Last edited by abgd; 31st Dec 2011 at 11:23.
In 1995 the CAA published CAP 667 -Review of General Aviation Fatal Accidents 1985-1994. This appeared to be a very authoritative document so based upon my own observations, I asked them what proportion of owner operators were involved in in these accidents. They had no idea. I believe on further investigation it was shown to be a substantial proportion indicating that they had omitted to consider a major factor in their analysis.
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I wonder whether 'freedom of information' requests would be a good way of getting at some of the data - alas currently too busy to really formulate questions and mow through vast amounts of data.
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I asked them what proportion of owner operators were involved in in these accidents. They had no idea. I believe on further investigation it was shown to be a substantial proportion indicating that they had omitted to consider a major factor in their analysis.
Probably just the fairly self evident fact that nearly every pilot who has clocked up more than a few hundred hours is an aircraft owner.
It gets awfully expensive to do a lot of hours when renting.
So while one would expect owner pilots to have the most prangs because they are the highest hour group, one would also expect them to have the highest currency
So what does this tell us? It could be that currency doesn't matter much because low currency owners simply avoid nontrivial flights. I think that is probably true because most low hour pilots I know (owners or renters) don't go anywhere past the local burger run on a nice day.But all this could have been surveyed, by a body which gets access to the CAA database and which can anonymise the data so the CAA cannot see individual identities.
So what does this tell us?
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Well, you have to have 1 hour every 2 years with an instructor, in the UK. Whether that's sufficient to make a difference is another matter.
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Probably just the fairly self evident fact that nearly every pilot who has clocked up more than a few hundred hours is an aircraft owner.
abgd,
Sorry, you're absolutely right. I didn't mean that the killing zone is an exact parallel to the game show thing (I didn't realise it way Monte Hall, thank you), merely that it was an example of how stats are altered by each changing event. I think we're agreeing!
SDB73, There has been a fundamental change to the odds as you know with certainty that one empty box has been removed. Where is the flaw in my logic?
Box 57 and 100 (or more generically the box you chose originally and the final alternative) will have carried 50% probability from the start.
At the start, each box has a 1% chance of being selected by you. Which means that you have 1% chance of selecting box 57. Agreed?
If so, then no matter what happens after that, there is still only a 1% chance that the box you selected is a winning box. Because nothing can change the past. In the past you selected a box, and there is only a 1% chance that the box you selected was a winner. Agreed?
If so, when 98 empty boxes are then remove, there is STILL a 1% chance that the box you originally selected is a winner. If you disagree at this point, go back to the previous paragraph.
So, if you know for sure that there is only a 1% chance that the box you are currently selecting is a winner, and that there is only one other box remaining, AND (critically) that one of the two boxes is a winner, it is a concrete mathmatical / statistical fact that there is a 99% chance that the other box is a winner.
I hope this is clear now. and trust me, I sound clever now, but I argued 50/50 originally also, until it clicked.
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Well, you have to have 1 hour every 2 years with an instructor, in the UK. Whether that's sufficient to make a difference is another matter.
It is a big missed opportunity.
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I think we're agreeing!
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Despite the shortcomings in the data used for The Killing Zone, I think most people would be inclined to agree that inexperienced pilots by hours on type are more likely to be involved in an incident than not.
Insurance companies employ actuaries to compute premiums. The best is to get yourself a few insurance quotes and play around with the different parameters to see how it affects that quote.
Insurance companies employ actuaries to compute premiums. The best is to get yourself a few insurance quotes and play around with the different parameters to see how it affects that quote.
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Way off topic, but I had to post this. I watched a repeat of QI yesterday where Stephen Fry gave the following good example of extremely simple statistics which can be very easily completely misinterpreted.
It is true that Iceland has more Nobel Prize winners per capita than any other place on earth.
It is also true that Iceland has only one Nobel Prize winner!
It is true that Iceland has more Nobel Prize winners per capita than any other place on earth.
It is also true that Iceland has only one Nobel Prize winner!
In 1995 the CAA published CAP 667 -Review of General Aviation Fatal Accidents 1985-1994. This appeared to be a very authoritative document so based upon my own observations, I asked them what proportion of owner operators were involved in in these accidents. They had no idea. I believe on further investigation it was shown to be a substantial proportion indicating that they had omitted to consider a major factor in their analysis.
I *think* that the most recent was the 2008 CAP 780, downloadable here and covering 1998-2007.
You probably could analyse UK statistics to see if the alleged Killing Zone exists or not, but I doubt any other country provides a well enough documented population to find out. It would be interesting and worthwhile to do so, but would take a while - although all you'd actually need to do is look up all the individual accident reports from the AAIB website and note the captain's hours. Easy enough.
G
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Insurance companies employ actuaries to compute premiums. The best is to get yourself a few insurance quotes and play around with the different parameters to see how it affects that quote.
Car insurance? Under 21? Male? That'll be £3500 please sir.
A pension Madam? I'm afraid you'll have get much less than your brother - you're just likely to live longer, and get used to the idea of a little poverty. That's the fact of it, I'm afraid.
But when I applied for life insurance recently, I had a chat with the broker about the exact question, and he was quite dismissive of the models insurance companies used to calculate premiums for aviation. Specifically, he felt that they were poor at taking into account different mission types, and different aircraft types, which every pilot knows have very different risk profiles.
It was a source of a lot of contention between hang glider pilots and paragliders back in the day - travel insurance costs rocketed after paragliders were invented, because their pilots were considerably more likely to have accidents. Yet insurance companies at least initially lumped them into the same category.
Before paragliders were invented, hang-gliding travel insurance was cheaper than insurance for skiing. The thought occurred to me that this might not be because they were 'safer' but because it cost less to repatriate a dead body than a person with tetraplegia.
Last edited by abgd; 1st Jan 2012 at 12:42.
Thread Starter
You probably could analyse UK statistics to see if the alleged Killing Zone exists or not, but I doubt any other country provides a well enough documented population to find out.
If that doesn't do the job, and you have a genuine safety research purpose, then I'd suggest contacting the CAA and asking nicely. They will certainly have this information because it's in everybody's periodic medical forms.
G
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However we are back to square one, because nobody has the data on flying patterns.
Sure one could analyse the AAIB reports and plot them according to commander TT, but let's say there is a peak at 500hrs. It tells us nothing unless we know the distribution of flying hours etc.
One would need to do a fair size survey to get that.
The FAA (and possibly the CAA also) have annual hours data, from the medical applications where you state your current TT. But that TT is not broken down according to aircraft type...
I think the info FTN publish is just what the CAA have on their stats website.
Sure one could analyse the AAIB reports and plot them according to commander TT, but let's say there is a peak at 500hrs. It tells us nothing unless we know the distribution of flying hours etc.
One would need to do a fair size survey to get that.
The FAA (and possibly the CAA also) have annual hours data, from the medical applications where you state your current TT. But that TT is not broken down according to aircraft type...
I think the info FTN publish is just what the CAA have on their stats website.
At risk of repeating myself - every medical revalidation I have to fill in a box stating my total hours. That goes to the CAA.
So, with the exception of the DVLA/NPPL medical, that information should all exist on a central database at Gatwick. I agree that it's not on the CAA stats website, or at-least I can't find it. I've certainly found in the past that Gatwick are pretty helpful to safety researchers who ask questions with a clear objective.
G
So, with the exception of the DVLA/NPPL medical, that information should all exist on a central database at Gatwick. I agree that it's not on the CAA stats website, or at-least I can't find it. I've certainly found in the past that Gatwick are pretty helpful to safety researchers who ask questions with a clear objective.
G
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Well, you have to have 1 hour every 2 years with an instructor
I'd be interested to see some stats on deceased/serious injury commander's admin issues.
I seem to read about more people with expired licence/medical/permit type of issues than seems reasonable. Some folk will say that having an expired medical or licence is not a contributing factor, but it may be symptomatic of an unsafe approach to aviation.
Thread Starter
Sure one could analyse the AAIB reports and plot them according to commander TT, but let's say there is a peak at 500hrs. It tells us nothing unless we know the distribution of flying hours etc.
Perhaps it also reflects your situation, which is that you fly interesting and demanding x-countries in sometimes challenging conditions in a complex aircraft (yes, I spent an interesting few hours on your website). I'm interested in low airtime pilots in simple aircraft because that's me, and I'd be delighted if I could analyse only such pilots, as I agree it would make the analysis more valid. But both areas are interesting.
I would expect, though, that you wouldn't find any sharp peaks amongst private pilots. Without the tyranny of a schedule, some people will get complex or aerobatic training right away, whilst others may take much longer. In my view you'd be more likely to see gradual trends, perhaps with an initial peak +- a dip. You might find an exception to this at around 200 hours, due to the 'dropout' as modular students converted their ppls to cpls.
What you might still be able to do usefully, would be to exclude the concept of a substantial 'killing zone', or at least put an upper limit on how large the effect is. And you could potentially draw on other sources to support your interpretations.
I appreciated Big Piston's point that, at the end of the day, the important thing is to know what the most common types of accidents are, and avoid the accident du jour.
Last edited by abgd; 2nd Jan 2012 at 05:43.
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As Genghis says, the CAA do have TT data (at least TT between medicals) but they don't have data on the type of flying people do.
Pilot A could do 50hrs/year flying between Goodwood and Beachy Head on sunny Sundays (as indeed great many do). Pilot B could do 50hrs on business-type trips, doing DIY approaches into Welshpool
Whether A or B is more likely to get killed depends on
- how careful they are (B is IMHO likely to be more careful, perhaps?)
- how well maintained (A is likely to be a renter and thus flying a less well maintained plane, but since others fly that plane most of its hours, they are more likely to have an engine failure)
- weather (B will be more at risk)
- equipment (B is likely to have better kit, e.g. GPWS)
Yes I do long trips and 100-150hrs/year so I should be more likely to get killed (especially with this kind of stuff, although to be fair my time actually crossing the Alps is only 1-2% of my TT) but I am quite picky about avoiding hazardous high altitude weather, and I fly IFR so don't scud run; also maintenance is money-no-object.
So one would need to do a pretty detailed flying pattern survey to make sense of what really makes people crash.
Pilot A could do 50hrs/year flying between Goodwood and Beachy Head on sunny Sundays (as indeed great many do). Pilot B could do 50hrs on business-type trips, doing DIY approaches into Welshpool
Whether A or B is more likely to get killed depends on
- how careful they are (B is IMHO likely to be more careful, perhaps?)
- how well maintained (A is likely to be a renter and thus flying a less well maintained plane, but since others fly that plane most of its hours, they are more likely to have an engine failure)
- weather (B will be more at risk)
- equipment (B is likely to have better kit, e.g. GPWS)
Yes I do long trips and 100-150hrs/year so I should be more likely to get killed (especially with this kind of stuff, although to be fair my time actually crossing the Alps is only 1-2% of my TT) but I am quite picky about avoiding hazardous high altitude weather, and I fly IFR so don't scud run; also maintenance is money-no-object.
So one would need to do a pretty detailed flying pattern survey to make sense of what really makes people crash.
Last edited by peterh337; 2nd Jan 2012 at 08:19.