A bit breezy today...

On 2/4/2014 11:18 AM, kirk.stant wrote:
On Monday, February 3, 2014 6:23:50 PM UTC-6, son_of_flubber wrote:


So Kirk, you're saying that you don't check the automated weather
broadcast wind numbers before you launch? (We don't have WX broadcast at
my home airport.) I also like to check the weather radar before launch
because lots of times the forecast thunderstorms are tracking well to the
north or south.

That's right, I don't check it. I look at the windsock on our hangar, and
take a moment to see what the wind is doing at our field (which also
doesn't have a WX broadcast). If I'm planning an XC flight I'll look at
the XCSkies wind forecasts for the times of the flight, and of course keep
an eye on large scale changes (approaching storms, etc). But at takeoff?
I look out the window to see if there is a lull or gust or thermal, and
plan accordingly.

But I don't obsess about a few knots, and am happy taking off or landing a
bit downwind if it makes the operations smoother or safer (common to land
the towplanes downwind to save turnaround time).

It's more the quality (gusty or variable) vs the quantity (raw velocity) of
the wind that I care about. For example, I know with a westerly crosswind
there will be turbulence once we get out of the wind shadow of the hangar.
That is not going to be in any automated report ;^).

But hey - nothing wrong with using every tool at your disposal. My cockpit
is testament to that (lots of gizmos)!

And I must admit that I fly mostly from either desert or flatland sites,
which may not have the conditions you have to cope with. So please don't
take my comments as being derogatory! Just having a little fun on
RAS...waiting for the snow to start falling again...

Cheers!

Kirk 66


With the personal exception of the last paragraph and a half, "What kirk said."

For years I flew without any electrical system, eventually upgrading to a
rubber duckie handheld, and, ~96+% of my soaring time launched from
intermountain western U.S. airstrips (as in, affected Very Much by upwind
mountainous terrain, airfield-based upwind obstructions, "the usual" western
gusts, etc.).

Other than keeping a beady eye on temperature trends in summer, and my usual
"concerned like a shepherd in winter" eye on weather in general, I can't
recall ever actually checking a forecast *for soaring go/no-go
decisions*...since experience had led me to conclude "personal eyeball" was
more soaring-worthy accurate than anything from the NWS. That's not a knock on
the NWS, rather a nod to trusting one's own assessment of reality, which by
its very nature has a finer resolution/granularity - and, out here, in my
experience, accuracy - than anything ever obtainable from the NWS.

Point being, never let personal anality (of which some have accused me)
overrule common sense, personal assessment and judgment.

Bob W.

P.S. Tomorrow's predicted high here is 4F (and decreasing); I didn't need that
NWS tidbit to've long ago concluded no thermals, no wave and no soaring in
these parts tomorrow!

On Monday, February 3, 2014 10:35:26 PM UTC-5, Dan Marotta wrote:
Couldn't you could hold the wind-o-meter out the window in the pattern to

gauge the winds?

Ha. I'd rather use a deliberate stall to find the most important number on my ASI.

On Wednesday, February 5, 2014 8:43:36 AM UTC-6, son_of_flubber wrote:

Ha. I'd rather use a deliberate stall to find the most important number on my ASI.

Of course, you realize that the ASI indication of stall speed is pretty much useless.

Quick, you are in the pattern, heavy passenger in the back seat, you overshoot the turn to final so crank it over to 50 degrees of bank and pull it around (with your spoilers still out a bit) - what's your indicated stall speed!

If we had a nice little AOA indicator, it would be trivial - but we usually don't, so relying on airspeed is at best a poor approximation of how close to a stall you are. Better be up on all those other indications of a stall that Tom Knauff is always harping about!

There are times the airspeed indicator is pretty useless as a control instrument. While thermalling, for example; or while landing (in the flare, not the pattern). Do you know what speed you touchdown at? I have no idea what it is for any of the planes or gliders I fly - who looks at the airspeed indicator in the flare? What we really need is a groundspeed indicator so we can get a feel for how far it will take to stop!

Come on spring!

Kirk
66

What they all said. I looked out the window and, since it's snowing and I
can't see the mountains to the west, north, or east, decided that it's
probably snowing at the airport as well. But, since I'm the tow pilot du
jour, I called just to be sure. Yup. We're cancelled.

C'mon spring!

Getting worked up for a soaring camp in Salida in June. Gonna try to fly up
while the wives bring the trailers.

"Bob Whelan" wrote in message
...
On 2/4/2014 11:18 AM, kirk.stant wrote:
On Monday, February 3, 2014 6:23:50 PM UTC-6, son_of_flubber wrote:


So Kirk, you're saying that you don't check the automated weather
broadcast wind numbers before you launch? (We don't have WX broadcast
at
my home airport.) I also like to check the weather radar before launch
because lots of times the forecast thunderstorms are tracking well to
the
north or south.

That's right, I don't check it. I look at the windsock on our hangar,
and
take a moment to see what the wind is doing at our field (which also
doesn't have a WX broadcast). If I'm planning an XC flight I'll look at
the XCSkies wind forecasts for the times of the flight, and of course
keep
an eye on large scale changes (approaching storms, etc). But at takeoff?
I look out the window to see if there is a lull or gust or thermal, and
plan accordingly.

But I don't obsess about a few knots, and am happy taking off or landing
a
bit downwind if it makes the operations smoother or safer (common to land
the towplanes downwind to save turnaround time).

It's more the quality (gusty or variable) vs the quantity (raw velocity)
of
the wind that I care about. For example, I know with a westerly crosswind
there will be turbulence once we get out of the wind shadow of the
hangar.
That is not going to be in any automated report ;^).

But hey - nothing wrong with using every tool at your disposal. My
cockpit
is testament to that (lots of gizmos)!

And I must admit that I fly mostly from either desert or flatland sites,
which may not have the conditions you have to cope with. So please don't
take my comments as being derogatory! Just having a little fun on
RAS...waiting for the snow to start falling again...

Cheers!

Kirk 66


With the personal exception of the last paragraph and a half, "What kirk
said."

For years I flew without any electrical system, eventually upgrading to a
rubber duckie handheld, and, ~96+% of my soaring time launched from
intermountain western U.S. airstrips (as in, affected Very Much by upwind
mountainous terrain, airfield-based upwind obstructions, "the usual"
western gusts, etc.).

Other than keeping a beady eye on temperature trends in summer, and my
usual "concerned like a shepherd in winter" eye on weather in general, I
can't recall ever actually checking a forecast *for soaring go/no-go
decisions*...since experience had led me to conclude "personal eyeball"
was more soaring-worthy accurate than anything from the NWS. That's not a
knock on the NWS, rather a nod to trusting one's own assessment of
reality, which by its very nature has a finer resolution/granularity -
and, out here, in my experience, accuracy - than anything ever obtainable
from the NWS.

Point being, never let personal anality (of which some have accused me)
overrule common sense, personal assessment and judgment.

Bob W.

P.S. Tomorrow's predicted high here is 4F (and decreasing); I didn't need
that NWS tidbit to've long ago concluded no thermals, no wave and no
soaring in these parts tomorrow!

Damn hard to stall most gliders in a 50° bank... I think my 2-32 will do it tho, but I haven't tried it in a while. Sounds a little like practicing bleeding?

Boggs

On Wednesday, February 5, 2014 12:15:06 PM UTC-5, kirk.stant wrote:

Of course, you realize that the ASI indication of stall speed is pretty much useless.

The observed ASI indication of a deliberate and gradually entered forward stall in calm air factors in ASI instrument error and CG effects. I take that number and add a safety factor based on AGL, wind, and level/banked flight to set my minimum acceptable AS.

The observed ASI at deliberate stall is going to be more useful/accurate than what the POH says. It is also a sanity check on CG calculations.

Quick, you are in the pattern, heavy passenger in the back seat, you overshoot the turn to final so crank it over to 50 degrees of bank and pull it around (with your spoilers still out a bit) - what's your indicated stall speed!


Heavy passenger moves CG forward and increases stall speed.
Spoilers open increases stall speed.
50 degree bank increases stall speed 25-30%. (50% is rather steep for turn to final.)

So I agree that indicated stall speed is useless in the pattern, but setting pattern speed based on observed stall speed is smart. Let's say observed stall speed is 40 knots X 1.3 = 52 knots, so 60 knots would be prudent when entering turn to final. I would shed 5 knots of that on final before entering ground effect.



If we had a nice little AOA indicator, it would be trivial - but we usually don't, so relying on airspeed is at best a poor approximation of how close to a stall you are. Better be up on all those other indications of a stall that Tom Knauff is always harping about!


Yes of course. It is also useful to be able to recognize adverse yaw without a yaw string. IMO CFIGs should take the front yaw string off the glider for at least one lesson (but keep the rear seat yaw string).


There are times the airspeed indicator is pretty useless as a control instrument. While thermalling, for example;

Please elaborate. I check my IAS before steepening a bank, for example.

Do you know what speed you touchdown at?

In most cases, I actually touch down at stall speed. I guess that would be a bit slower than the stall speed observed at altitude because of the lower draw in ground effect?

On Wednesday, February 5, 2014 2:30:22 PM UTC-5, Waveguru wrote:
Damn hard to stall most gliders in a 50° bank... I think my 2-32 will do it tho, but I haven't tried it in a while. Sounds a little like practicing bleeding?


There is not enough back stick/elevator to stall my glider in a steep bank (POH says so and I've tried it), but spiral dives are a real possibility.

On Wednesday, February 5, 2014 2:35:21 PM UTC-5, son_of_flubber wrote:
On Wednesday, February 5, 2014 2:30:22 PM UTC-5, Waveguru wrote:

Damn hard to stall most gliders in a 50° bank... I think my 2-32 will do it tho, but I haven't tried it in a while. Sounds a little like practicing bleeding?


There is not enough back stick/elevator to stall my glider in a steep bank (POH says so and I've tried it), but spiral dives are a real possibility.

It might actually be possible to stall my glider if I entered a steep bank from a close-to-stall speed. I've not tried that and I always check my speed before a hard bank.