Fatal crash Arizona

On Wednesday, May 7, 2014 1:20:44 PM UTC+12, Bill D wrote:
I can assure you that the higher a glider's performance, the safer it is. It's the old, low L/D gliders that can run out of altitude before getting lined up with the runway.

It's a mystery to me why some people think you can "get away with" so much more in old gliders than in those great big heavy clumsy glass ones.

Somewhere in this thread I saw a statement that you could safely turn back from 150 ft in an old glider (which I agree with), but you're a dead man if you try it below 300 ft in glass.

The differences that govern such a thing just aren't that big!

Let's look at some numbers for weight and wing area of typical training gliders (from Wikipedia):

ASK13: 290 kg, 17.5 m^2
Blanik L13: 292 kg, 19.15 m^2

PW6: 360 kg, 15.3 m^2
ASK21: 360 kg, 17.95 m^2
Puchacz: 368 kg, 18.16 m^2
Janus: 365 kg, 17.3 m^2

G103: 390 kg, 17.9 m^2
Duo Discus: 410 kg, 16.4 m^2
DG1000: 415 kg, 17.5 m^2

There's not a lot of difference in the wing areas, with individual variations bigger than the generational differences.

Yes, the glass ones weigh a bit more. How much more?

Someone flying solo in an ASK21 is at about the same all up weight as someone in a ASK13 with a smaller than average instructor in the back seat.

Someone flying solo in a DG1000 is at about the same all up weight as someone in a ASK13 with a largish instructor in the back seat.

We expect students to be able to cope with the flying characteristic differences between having an instructor and not having one -- and to cope with that difference on their first time flying alone!

At 02:06 09 May 2014, Bruce Hoult wrote:
On Wednesday, May 7, 2014 1:20:44 PM UTC+12, Bill D wrote:
I can assure you that the higher a glider's performance, the safer it
is.
It's the old, low L/D gliders that can run out of altitude before getting
lined up with the runway.

It's a mystery to me why some people think you can "get away with" so
much
more in old gliders than in those great big heavy clumsy glass ones.

Somewhere in this thread I saw a statement that you could safely turn
back
from 150 ft in an old glider (which I agree with), but you're a dead man
if
you try it below 300 ft in glass.

The differences that govern such a thing just aren't that big!

Let's look at some numbers for weight and wing area of typical training
gliders (from Wikipedia):

ASK13: 290 kg, 17.5 m^2
Blanik L13: 292 kg, 19.15 m^2

PW6: 360 kg, 15.3 m^2
ASK21: 360 kg, 17.95 m^2
Puchacz: 368 kg, 18.16 m^2
Janus: 365 kg, 17.3 m^2

G103: 390 kg, 17.9 m^2
Duo Discus: 410 kg, 16.4 m^2
DG1000: 415 kg, 17.5 m^2

There's not a lot of difference in the wing areas, with individual
variations bigger than the generational differences.

Yes, the glass ones weigh a bit more. How much more?

Someone flying solo in an ASK21 is at about the same all up weight as
someone in a ASK13 with a smaller than average instructor in the back
seat.

Someone flying solo in a DG1000 is at about the same all up weight as
someone in a ASK13 with a largish instructor in the back seat.

We expect students to be able to cope with the flying characteristic
differences between having an instructor and not having one -- and to
cope
with that difference on their first time flying alone!

I think you are missing the point. The difference between the perceived
attitude of a Discus flying at 45kts (too slow) or 55kts (much better) in a
turn is very small, easy to get wrong.
The perceived attitude difference in a T21 Sedburgh between 35kts (slow)
and 45kts(better) is quite large, easy to spot if you got it wrong. Bearing
in mind that a T21 would not stall until you got it back to 22-25kts made
low turns much more unexciting. The T21 and T31 are the gliders I was
referring to.
When it all turns to ratsh1t in a glass glider it happens that much more
quickly than it ever did in wood.

At 00:13 10 May 2014, Don Johnstone wrote:
At 02:06 09 May 2014, Bruce Hoult wrote:
On Wednesday, May 7, 2014 1:20:44 PM UTC+12, Bill D wrote:
I can assure you that the higher a glider's performance, the safer it
is.
It's the old, low L/D gliders that can run out of altitude before
getting
lined up with the runway.

It's a mystery to me why some people think you can "get away with" so
much
more in old gliders than in those great big heavy clumsy glass ones.

Somewhere in this thread I saw a statement that you could safely turn
back
from 150 ft in an old glider (which I agree with), but you're a dead man
if
you try it below 300 ft in glass.

The differences that govern such a thing just aren't that big!

Let's look at some numbers for weight and wing area of typical training
gliders (from Wikipedia):

ASK13: 290 kg, 17.5 m^2
Blanik L13: 292 kg, 19.15 m^2

PW6: 360 kg, 15.3 m^2
ASK21: 360 kg, 17.95 m^2
Puchacz: 368 kg, 18.16 m^2
Janus: 365 kg, 17.3 m^2

G103: 390 kg, 17.9 m^2
Duo Discus: 410 kg, 16.4 m^2
DG1000: 415 kg, 17.5 m^2

There's not a lot of difference in the wing areas, with individual
variations bigger than the generational differences.

Yes, the glass ones weigh a bit more. How much more?

Someone flying solo in an ASK21 is at about the same all up weight as
someone in a ASK13 with a smaller than average instructor in the back
seat.

Someone flying solo in a DG1000 is at about the same all up weight as
someone in a ASK13 with a largish instructor in the back seat.

We expect students to be able to cope with the flying characteristic
differences between having an instructor and not having one -- and to
cope
with that difference on their first time flying alone!

I think you are missing the point. The difference between the perceived
attitude of a Discus flying at 45kts (too slow) or 55kts (much better) in
a
turn is very small, easy to get wrong.
The perceived attitude difference in a T21 Sedburgh between 35kts (slow)
and 45kts(better) is quite large, easy to spot if you got it wrong.
Bearing
in mind that a T21 would not stall until you got it back to 22-25kts made
low turns much more unexciting. The T21 and T31 are the gliders I was
referring to.
When it all turns to ratsh1t in a glass glider it happens that much more
quickly than it ever did in wood.



All completely correct but there is one even bigger problem, most pilots
when making a low level turn off a launch failure or to modify a
circuit/pattern that has got too low, tend to be looking for/at the place
they intend to land with little or no attention to spare for the ASI,
attitude or slip/skid indicator, that's why these events are so productive
of stall/spin accidents. Training needs to emphasise, GLANCE AT THE ASI
EVERY 2 - 3 SECONDS IN THESE CIRCUMSTANCES. Attitude is un unreliable
indicator very near the ground, even the smallest undulations in the
terrain can give a false impression and just being low can make the
attitude look more nose down than it is.

At 07:20 10 May 2014, Chris Rollings wrote:
All completely correct but there is one even bigger problem, most pilots
when making a low level turn off a launch failure or to modify a
circuit/pattern that has got too low, tend to be looking for/at the place
they intend to land with little or no attention to spare for the ASI,
attitude or slip/skid indicator, that's why these events are so
productive
of stall/spin accidents. Training needs to emphasise, GLANCE AT THE ASI
EVERY 2 - 3 SECONDS IN THESE CIRCUMSTANCES. Attitude is un unreliable
indicator very near the ground, even the smallest undulations in the
terrain can give a false impression and just being low can make the
attitude look more nose down than it is.


Surely best practice is simply to keep the speed on until you have got it
all sorted. Certainly in modern slippery gliders. Too much speed is much
safer than too little and costs very little in height through a turn.

Isn't this what you taught us Chris?

On 5/10/2014 7:24 AM, Jim White wrote:
Certainly in modern slippery gliders. Too much speed is much
safer than too little and costs very little in height through a turn.

From the standpoint of preventing stalls, I can only agree. But if
your goal is to actually make it back to the runway, that advice should
be tempered with a bit more information!

Remember that turn radius increases with the SQUARE of airspeed. That
means that a small increase in airspeed will result in a significant
increase in turn radius. As the pilot, your goal in that situation
should be to shoot for the proper airspeed for the situation. Not too
much, but certainly always keeping a margin above stall speed.

By all means don't risk a stall! But remember that too much airspeed
could add to your troubles.

At 11:24 10 May 2014, Jim White wrote:
At 07:20 10 May 2014, Chris Rollings wrote:
All completely correct but there is one even bigger problem, most pilots
when making a low level turn off a launch failure or to modify a
circuit/pattern that has got too low, tend to be looking for/at the
place
they intend to land with little or no attention to spare for the ASI,
attitude or slip/skid indicator, that's why these events are so
productive
of stall/spin accidents. Training needs to emphasise, GLANCE AT THE ASI
EVERY 2 - 3 SECONDS IN THESE CIRCUMSTANCES. Attitude is un unreliable
indicator very near the ground, even the smallest undulations in the
terrain can give a false impression and just being low can make the
attitude look more nose down than it is.


Surely best practice is simply to keep the speed on until you have got it
all sorted. Certainly in modern slippery gliders. Too much speed is much
safer than too little and costs very little in height through a turn.

Isn't this what you taught us Chris?


Certainly a bit faster than optimum costs very little but you still need to
GLANCE AT THE ASI
EVERY 2 - 3 SECONDS IN THESE CIRCUMSTANCES to check what speed you are
doing.

Lots of playing with numbers but I think Chris'
airspeed checking is the most important; a well sealed modern sailplane
gives no clue to the airspeed from the
air noise. Furthermore you may be in turbulence/ wind
shear situation.
Apologies if this was said before.
John F.

At 11:01 11 May 2014, Chris Rollings wrote:
At 11:24 10 May 2014, Jim White wrote:
At 07:20 10 May 2014, Chris Rollings wrote:
All completely correct but there is one even bigger problem, most
pilots
when making a low level turn off a launch failure or to modify a
circuit/pattern that has got too low, tend to be looking for/at th
place
they intend to land with little or no attention to spare for the ASI,
attitude or slip/skid indicator, that's why these events are so
productive
of stall/spin accidents. Training needs to emphasise, GLANCE AT THE
ASI
EVERY 2 - 3 SECONDS IN THESE CIRCUMSTANCES. Attitude is un unreliable
indicator very near the ground, even the smallest undulations in the
terrain can give a false impression and just being low can make the
attitude look more nose down than it is.


Surely best practice is simply to keep the speed on until you have got
it
all sorted. Certainly in modern slippery gliders. Too much speed is much
safer than too little and costs very little in height through a turn.

Isn't this what you taught us Chris?


Certainly a bit faster than optimum costs very little but you still need
t
GLANCE AT THE ASI
EVERY 2 - 3 SECONDS IN THESE CIRCUMSTANCES to check what speed you ar
doing.

On Sunday, May 11, 2014 5:01:08 AM UTC-6, Chris Rollings wrote:
At 11:24 10 May 2014, Jim White wrote:

At 07:20 10 May 2014, Chris Rollings wrote:

All completely correct but there is one even bigger problem, most pilots

when making a low level turn off a launch failure or to modify a

circuit/pattern that has got too low, tend to be looking for/at the

place

they intend to land with little or no attention to spare for the ASI,

attitude or slip/skid indicator, that's why these events are so

productive

of stall/spin accidents. Training needs to emphasise, GLANCE AT THE ASI

EVERY 2 - 3 SECONDS IN THESE CIRCUMSTANCES. Attitude is un unreliable

indicator very near the ground, even the smallest undulations in the

terrain can give a false impression and just being low can make the

attitude look more nose down than it is.





Surely best practice is simply to keep the speed on until you have got it

all sorted. Certainly in modern slippery gliders. Too much speed is much

safer than too little and costs very little in height through a turn.



Isn't this what you taught us Chris?





Certainly a bit faster than optimum costs very little but you still need to

GLANCE AT THE ASI

EVERY 2 - 3 SECONDS IN THESE CIRCUMSTANCES to check what speed you are

doing.

Being constantly aware of one's airspeed is nothing more than basic airmanship. Why and where would this not be the case?

At 15:46 11 May 2014, Bill D wrote:
On Sunday, May 11, 2014 5:01:08 AM UTC-6, Chris Rollings wrote:
At 11:24 10 May 2014, Jim White wrote:

At 07:20 10 May 2014, Chris Rollings wrote:

All completely correct but there is one even bigger problem, most
pilots

when making a low level turn off a launch failure or to modify a

circuit/pattern that has got too low, tend to be looking for/at the

place

they intend to land with little or no attention to spare for the ASI,

attitude or slip/skid indicator, that's why these events are so

productive

of stall/spin accidents. Training needs to emphasise, GLANCE AT THE
ASI

EVERY 2 - 3 SECONDS IN THESE CIRCUMSTANCES. Attitude is un
unreliable

indicator very near the ground, even the smallest undulations in the

terrain can give a false impression and just being low can make the

attitude look more nose down than it is.





Surely best practice is simply to keep the speed on until you have got
it

all sorted. Certainly in modern slippery gliders. Too much speed is
much

safer than too little and costs very little in height through a turn.



Isn't this what you taught us Chris?





Certainly a bit faster than optimum costs very little but you still
need
to

GLANCE AT THE ASI

EVERY 2 - 3 SECONDS IN THESE CIRCUMSTANCES to check what speed you
are

doing.

Being constantly aware of one's airspeed is nothing more than basic
airmanship. Why and where would this not be the case?

Maybe when you are distracted having been surprised by a launch failure.
It happens, it happened on a check ride I did 2 weeks ago with a pilot who
had not flown for a while. That is why a procedure needs to be formulated
for a moderate level of skill and currency. An experience pilot, current
and on top of his game probably does not need a procedure, he is capable of
formulating and executing his own, he knows his own limitations and the
limitations of his aircraft.
Solly made it up as he went along, procedure dictated that he found a
runway.
The key is knowing what you are going to do before the worst happens.