planes vs cycles

Just because a
vehicle carries more passengers, that doesn't mean it's unfair to take that
into account when comparing safety.


Depends how you are measuring "safety", what you are comparing it to, and to
what end.

If there's only two airliner flights in a year, each carrying 300 passengers,
one crashes, and they all die.... and there's only two motorcycle trips in that
same year, and one crashes, killing the rider, is the plane really 302 times
more dangerous than the motorcycle?

Are you 302 times more likely to die in a plane crash than by riding a
motorcycle?

Jose

--
(for Email, make the obvious changes in my address)

"Teacherjh" wrote in message
...
Depends how you are measuring "safety", what you are comparing it to, and
to
what end.

If there's only two airliner flights in a year, each carrying 300
passengers,
one crashes, and they all die.... and there's only two motorcycle trips in
that
same year, and one crashes, killing the rider, is the plane really 302
times
more dangerous than the motorcycle?

I never said anything about making relative comparisons. I'm just pointing
out that you can't say it's "not fair" to compare the two. Depending on
what information you're interested in, it might be completely fair.

As for your sample comparison, if you're looking for passenger-flight safety
numbers then yes, the airliner is 600 times "more dangerous" than the
motorcycle when measured in fatalities per trip (I don't know where you came
up with 302, since you failed to specify your units). Whether that's an
interesting comparison to someone is up to them to decide.

Are you 302 times more likely to die in a plane crash than by riding a
motorcycle?

Measured how? You haven't specified the units you're using, but assuming
you did the math right, then statistically speaking (using your obviously
statistically insignificant sample) the answer would be "yes". In your
example, the statistical difference would be explained as much by the
greater likelihood of actually riding in an airplane versus in a motorcycle,
and the units change once you make the assumption that the passenger is on
each, but with the parameters you've specified so far, airliners are
statistically more likely to kill a given person.

Pete

As for your sample comparison, if you're looking for passenger-flight safety
numbers then yes, the airliner is 600 times "more dangerous" than the
motorcycle when measured in fatalities per trip (I don't know where you came
up with 302, since you failed to specify your units).


There are two crew members on a jetliner. At least the hypothetical one I was
using. One jet crashes, killing all aboard (300 pax, 2 crew). This represents
half of all jet activity. One motorcycle crashes, killing all aboard (one
person). This represents half of all motorcycle activity (in my hypthetical
Oz).

So, if we "count" the fatalities, a jet is 302 times more dangerous. But if we
just count the fatals, they are equally dangerous.

If these statistics hold up for the next year (two flights, two motorcycle
rides), and I decide to fly rather than take the motorcycle, how much more
likely am I to die? Not 302 times more likely.

I never said anything about making relative comparisons.

That's what the thread's about.

As for "more likely to kill a given person" that depends on whether the person
is given before making the choice (to fly or ride), or after.

Jose

--
(for Email, make the obvious changes in my address)

"Ash Wyllie" wrote in message
...
Tom Sixkiller opined

"Greg" wrote in message
...
"PaulH" wrote in message
om...
Thank you for the link. The report shows for GA overall 1.33 fatal
accidents per 100,000 hours in 2002. If we use an average speed of
125 mph, we have 1.33 fatal accidents for 12.5 million miles.

Anybody have motorcycle data?

Is the 125mph a pirooma number? Is that a fair estimate of GA aircraft
average speed?

Good point. Does that include corporate aviation?

GA would be Cubs at 75MPH up to turboprops (ignoring the corporate big
iron)
at 300MPH.

GA also includes helicopters. Break them out, and GA would look a lot
better.
The real question, to my mind, is what is the figure for SE piston
aircraft?


-ash
Cthulhu for President!
Why vote for a lesser evil?


Exactly, GA accident statistics cover such a broad range of flight
activities the numbers mean absolutely nothing regarding the type of flying
I do.

"Teacherjh" wrote in message
...
There are two crew members on a jetliner. At least the hypothetical one I
was
using. One jet crashes, killing all aboard (300 pax, 2 crew).

I see...I misread your post, and thought you had both airplanes crashing,
not just one. Not getting enough sleep these days I guess.


If these statistics hold up for the next year (two flights, two motorcycle
rides), and I decide to fly rather than take the motorcycle, how much more
likely am I to die? Not 302 times more likely.

No. But then, that's not the calculation you'd use for making that
comparison. You seem to intentionally be mixing your units in order to
prove some point. What point you're trying to make is lost on me, but you
need to stop mixing your units. You have to use the units that address the
comparison you want to make.

If you want to compare overall transportation safety, then a measure that
accounts for the number of passengers is useful. If you want to compare
individual passenger risk, then a per-trip analysis would be more useful.

As an example of someone that might care about the former more than the
latter, consider an insurance underwriter writing policies that cover
passenger losses.

I never said anything about making relative comparisons.

That's what the thread's about.

By "relative comparison", I mean "a quantified ratio of risk". The thread
started out asking simply whether one activity was more risky than another.
The question of HOW MUCH riskier one is than the other wasn't asked, nor
should anything I wrote be construed as addressing that question.

Pete

General Aviation 0.036 / million passenger-miles
Motorcycles 0.309 / million passenger-miles

Making GA about 9 times safer than motorcycles to get from one place to
another.

Another shibboleth ruined!

What do the same statistics say about GA and automobiles?

Of course, as posted earlier, it really should be *driver*-miles, not
passenger-miles, since automobiles likely carry more people on average
than GA aircraft.

And where does GA stop? Does it include biz jets? I think what most of
us would like to know is the hazard of *lightplanes" perhaps defined
as single-engine recips. I don't suppose there are enough P-51s around
to skew the numbers.

all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

"James Robinson" wrote in message
...
PaulH wrote:

Thank you for the link. The report shows for GA overall 1.33 fatal
accidents per 100,000 hours in 2002. If we use an average speed of
125 mph, we have 1.33 fatal accidents for 12.5 million miles.

Anybody have motorcycle data?

Much information is available in this report:


I'm not sure how anyone came to making this comparison, but I've been riding
for 35 years and I can tell you that i doesn't take nuch cockpit time to
determine that flying exposes you to less danger than riding. Now, if 30,000
other people started flying 10 feet away while phoning, eating, reading,
sleeping, etc. things would clearly change. But for the basic premise, you
don't even need the stats.

You seem to intentionally be mixing your units in order to
prove some point. [...]

If you want to compare overall transportation safety, then a measure that
accounts for the number of passengers is useful. If you want to compare
individual passenger risk, then a per-trip analysis would be more useful.

As an example of someone that might care about [overall transportation safety
instead as opposed
to individual passenger risk] consider an insurance underwriter writing
policies that cover
passenger losses.


My point is really the same as yours - that comparing apples to hand grenades
is tricky. As for an insurance underwriter, depending on the policy, there
will be more people paying for policies in airplanes than in motorcycles, so
the costs is spread out too. However, having the state spend money to address
road safety vs airway improvements would be an example of where the raw numbers
rather than the "relative risk" is more important.

Jose


--
(for Email, make the obvious changes in my address)

"Teacherjh" wrote in message
...
[...] As for an insurance underwriter, depending on the policy, there
will be more people paying for policies in airplanes than in motorcycles,
so
the costs is spread out too.

How do you figure that? Generally speaking, an insurance policy goes with
an airplane or motorcycle, not specifically the driver of that vehicle.
That is, you don't wind up with more policies for airplanes just because
there are more people riding in an airplane.

However, having the state spend money to address
road safety vs airway improvements would be an example of where the raw
numbers
rather than the "relative risk" is more important.

Yes, that would be another example.

Pete

"Cub Driver" wrote in message
...
What do the same statistics say about GA and automobiles?



This keeps popping up but in the end, any transportation system is only as
safe as it's operators make it. You can make aviation very safe or very
dangerous and the same goes for driving and cycling. However, on the roads
your safety is more dependant on others than in aviation.

A few days ago I was rear ended while driving my Accord at 35 on a local
main road. The lady who hit me was driving a large SUV at around 55 and
said she wasn't looking when she hit me. They are going over my car now but
it may very well be totalled (I was extremely lucky and was not injured).
In my experience driving seems obvoiusly more dangerous than aviation
especially when you figure in the experience and competence of the other
operators.