How dangerous is soaring?

On 1 Nov, 10:20, Tom Gardner wrote:

EEK! Which (ex) club, if you don't mind me asking.
And I thought I was quite close enough to B1s maybe 5 miles away,
or C130s at my altitude and where I could count the individual
cockpit window panes.

Borders GC. Lovely club, excellent site beside the Cheviot Hills - and
that was the problem. Normally the fast military stuff stays at 500'
or less, so it isn't a problem for gliders. However both they and we
could be at 500' AGL in the hills, and there were too many close calls
for me to be happy.

It wasn't the military pilots' fault: I am quite sure they don't want
half a ton of fibreglass in their cockpits. However there did seem to
be some serious deficiencies in the Civil Air Notification Procedure,
with information about midweek gliding (hint to Mr Putin: invade over
the weekend) simply not getting through to the pilots.

Is there room in a B1/B52/C130/Tornado for a FLARM? :}

We did have a visit from a military ATC chap, and he said that a Good
Big Radar Reflector would help enormously. I was thinking about
installing an 18" aluminium cube reflector, made for yachts, in the
fuselage above the wheel.

Incidentally, this is probably ten years ago, and I think it very
likely that with the growth of BGC and increase in midweek flying
things should be much smoother and more effective now. Please, folks,
don't let this put you off flying there!

Ian

Ian wrote:
On 31 Oct, 23:08, jeplane wrote:
On Oct 31, 2:11 pm, Marc Ramsey wrote:

How many cars are on the roads you use to get to the gliderport?
How many gliders fly at at the gliderport?
So you are telling me driving is safer than flying? Not sure if I
would drive or fly with you!...:-)

There are about 30,000,000 licensed drivers in the UK. About 3,000
people get killed on the roads every year. That's 1 fatality per
10,000 drivers.

From memory, there are about 5,000 members of UK gliding clubs. About
2 - 3 people get killed gliding per year, on average. That's 1
fatality per 2,500 pilots.

The everage driver does 10,000 miles per annum, which is 200 hours at
50mph. The average gliding club member does something like 10 hours
per annum.

So that's 1 fatality per 2,000,000 driver-hours against 1 fatality per
25,000 pilot-hours.

I'd welcome correction on the figures - I'm doing this from memory of
stuff I looked up ~10 years ago, but I'd be very surprised if driving
risk came within an order of magnitude of soaring risk.

10 hours/year sounds low to me. I'd have guessed 20-30 hours at least.
In support of that figure I did what seemed like very little flying this
year, but found to my surprise that I'd managed 35 hours. I'd guess that
I'd do 50-70 hours in a year with more normal weather.

I thought I'd read that the UK had around 8000 active glider pilots but
I won't argue with you over a change that has relatively little impact
on your argument.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Nov 1, 12:23 pm, Ian wrote:
We did have a visit from a military ATC chap, and he said that a Good
Big Radar Reflector would help enormously. I was thinking about
installing an 18" aluminium cube reflector, made for yachts, in the
fuselage above the wheel.

I've idly wondered about that, but I'd want to know that slow targets
aren't simply removed from the screen before the radar operator even
sees them. Even several decades ago "ground clutter" was routinely
removed by simply ignoring any reflection with a doppler shift of
less than 70mph.

Clearly it has to be more sophisticated than that for airborne
radars,
but I'm sure it is possible.

Not sure I agree with this quote.

How many times have you seen a traffic accident on your way to the
gliderport?

How mnay times have you seen a glider accident at that airport in the
same time frame?

Richard
Phoenix, AZ

On Oct 30, 5:50 pm, Ramy wrote:
" No matter how safe you think you are, the risk is still
significantly higher than most normal activities (such as driving). "

The calculation which yields the 80/1 is only true for the single
instance; my odds of being here next year are another thing entirely.
For that you need to do mortality computations.

Ray

results.

To stay alive for a week, you have to toss "heads" 7 times in a row,
and the probability of that is 0.5 ^ 7 = 0.078125 = 1 in 128

It's not binary, it's multifactorial.

Ray

On Nov 1, 2:11 pm, 1LK wrote:
The calculation which yields the 80/1 is only true for the single
instance;

Single instance of what? If it is the "single instance of a day",
then the calculations are correct.

my odds of being here next year are another thing entirely.
For that you need to do mortality computations.

To stay alive for a week, you have to toss "heads" 7 times in a row,
and the probability of that is 0.5 ^ 7 = 0.078125 = 1 in 128

It's not binary, it's multifactorial.

I don't understand: what do you mean by "it" and "multifactorial"?
Binary? Well yes, flipping a coin is binary; that's why I
subsequently
used your figures (that you didn't bother to include).

It might help if you could explain the reasons (based on an
equivalent
example, if you prefer) why you believe that the calculations are
wrong.
Examples I can think of are
- it is not a 1.25% chance of dying on every day, only on some days
- each day shouldn't be treated as independent from the preceding
days (but that doesn't fit with your original statement)

Anyway, I am glad that your mortality isn't as imminent as it
at first appeared.

On 1 Nov, 14:07, 1LK wrote:
The calculation which yields the 80/1 is only true for the single
instance; my odds of being here next year are another thing entirely.
For that you need to do mortality computations.

I'm having real difficulty understanding this. Are you saying that ...

1) There is a 1/80 chance you'll be dead by this time tomorrow and
that

2) There is a 1/80 chance you'll be dead by this time the day after?

Ian

On Nov 1, 1:20 pm, Martin Gregorie wrote:
Ian wrote:
On 31 Oct, 23:08, jeplane wrote:
On Oct 31, 2:11 pm, Marc Ramsey wrote:

How many cars are on the roads you use to get to the gliderport?
How many gliders fly at at the gliderport?
So you are telling me driving is safer than flying? Not sure if I
would drive or fly with you!...:-)

There are about 30,000,000 licensed drivers in the UK. About 3,000
people get killed on the roads every year. That's 1 fatality per
10,000 drivers.

From memory, there are about 5,000 members of UK gliding clubs. About
2 - 3 people get killed gliding per year, on average. That's 1
fatality per 2,500 pilots.

The everage driver does 10,000 miles per annum, which is 200 hours at
50mph. The average gliding club member does something like 10 hours
per annum.

So that's 1 fatality per 2,000,000 driver-hours against 1 fatality per
25,000 pilot-hours.

I'd welcome correction on the figures - I'm doing this from memory of
stuff I looked up ~10 years ago, but I'd be very surprised if driving
risk came within an order of magnitude of soaring risk.

10 hours/year sounds low to me. I'd have guessed 20-30 hours at least.
In support of that figure I did what seemed like very little flying this
year, but found to my surprise that I'd managed 35 hours. I'd guess that
I'd do 50-70 hours in a year with more normal weather.

I thought I'd read that the UK had around 8000 active glider pilots but
I won't argue with you over a change that has relatively little impact
on your argument.

Ian is basically on the money. The BGA has just under 8,000 members
but that's not the same as active pilots - 5,000 is probably as good a
number as any other. The number of vehicle occupants killed annually
is about 1,700 (another 1,500 die by being hit *by* vehicles). I have
no idea what the average hours-of-flight-per-year is - must vary
enormously.

Of course, in the UK, to get *killed* in a glider is pretty rare -
going back through the AAIB reports for the last ten years or so
there's certainly no pattern in cause, experience, site etc.

Off the top of my head:
Two lost wings (structural failure and at high loads, probably outside
placard, though the wings were understrength)
Two collided with other gliders (three if you count a tug pilot who
hit a Cirrus)
One flew into a parachute DZ and was hit by a skydiver (who also died)
Two? had heart failure (a tug pilot died this way too)
Two died in winch launches, one however was inexplicable (maybe
medical, see above)

A couple of those were in two-seaters where both occupants died.

Two more people were on the ground and were struck and killed by
gliders. One of those gliders was later destroyed in a seperate crash,
though the occupants survived with serious injuries.

Injury accidents are probably frequent enough that statiscally valid
conclusions can be drawn. Early this year the BGA published an
excellent supplement looking at this data, I can't find my copy but
iirc, winch launching (up until the very successful Safe Winch
Launching campaign), low-level stall/spin (though some winch accidents
are really stall/spin, so this probably should be higher), and bad
field landings (selection too late/badly executed) were top of the
list.


Dan

On Nov 1, 3:35 pm, Dan G wrote:
Off the top of my head:
Two lost wings (structural failure and at high loads, probably outside
placard, though the wings were understrength)
Two collided with other gliders (three if you count a tug pilot who
hit a Cirrus)
One flew into a parachute DZ and was hit by a skydiver (who also died)
Two? had heart failure (a tug pilot died this way too)
Two died in winch launches, one however was inexplicable (maybe
medical, see above)

Should add that the guy who flew into the DZ didn't have a parachute
(he didn't get one when using the glider after someone too big to fit
with a chute) and might have had a chance of using it (collision was
at 2,500'), and one of the pilots killed in a mid-air possibly
couldn't jettison his canopy as he'd zip-tied his PDA cables to it -
the other pilot bailed out successfully.


Dan