Slip to landing on PPG practical test

Eric,

I've had two cases of not being able to open dive brakes
due to low temperatures. One in a Kestrel 19, where
at 19,000 feet on a cold autumn day in Scotland the
over-centre lock became so stiff I couldn't break it
out, the other in a twin Grob due to water inside the
airbrake box freezing and jamming the mechanism.

Never experienced a problem in a considerable amount
of cloud flying above the freezing level in the UK
- I've never heard of the ice on the wings getting
as far back as the airbrake cut-out. If you needed
to open the brakes in iceing conditions (to prevent
overspeeding) I would expect that after a very short
time it would become impossible to close them.

Chris Rollings

In 5000 hours of soaring, I've had the spoilers freeze
shut once. A
brief shower shortly before towing off for what eventually
turned into a
wave flight did the trick. I discovered them frozen
at 4000' AGL while
descending at the end of the flight, but at 3000 AGL,
they unfroze. I
had a tail chute, so a slip would not have been needed,
even in this case.

Has anyone else had spoilers freeze shut without flying
in clouds, were
it seems like you should be expecting it to happen?


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Eric Greenwell
Washington State
USA

Avoiding the sling shot effect by transferring the elastic recovery of
the rope into a yaw motion of the sailplane rather than an increase in
speed, creating more slack, and introducing another cycle of slack,
boing, slack, boing, slack, boing...

I had mine freeze shut also. It was raining lightly before we took off and
I then went to over 20K in our wave. I was at altitude for quite a long time
and discovered while descending that the spoilers on my Jantar 2A were
completely frozen shut. I tried everything I could to get them open without
success. In the manual it states that the 2A is not approved for slipping.
Our runway is 3000ft long at 600ft msl. Fortunately we usually have quite
a bit of wind here so that helps shorten the landing. I modified my pattern
and had no problems getting it stopped well before the end of the pavement
with the wheel brake.

Gary Boggs

"Eric Greenwell" wrote in message
...
Todd Pattist wrote:
"Bill Daniels" wrote:


Note that I'm not suggesting that slips be removed from the training
syllabus, just that perhaps they should not be taught as a landing aid.
Slips to a landing is just so...20th century.


What would you use the slips for if not altitude control
during landing? I'm amazed at a proposal to do away with
teaching the use of this valuable landing tool.

In 5000 hours of soaring, I've had the spoilers freeze shut once. A
brief shower shortly before towing off for what eventually turned into a
wave flight did the trick. I discovered them frozen at 4000' AGL while
descending at the end of the flight, but at 3000 AGL, they unfroze. I
had a tail chute, so a slip would not have been needed, even in this case.

Has anyone else had spoilers freeze shut without flying in clouds, were
it seems like you should be expecting it to happen?


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Eric Greenwell
Washington State
USA

Why not dive to match speed of the tug while remaining off to the side so
you will still get the dampening of the yawing effect?

When the slack in the rope is very large, the speed of the glider can get
well below the speed of the tug if you're not careful, resulting in a very
hard jerk when it comes tight. I prefer a combination of these two
techniques if the slack is extreme.


"Todd Pattist" wrote in message
...
CV wrote:

You didn't want to have your nose
pointed at the towplane tail when the rope came tight so yaw
cushioned things

Hmmm. I don't follow this.

Here is the situation : you are offset from the towplane and
flying coordinated with your fuselage parallel to the tug -
the tow hook is attached ahead of the glider's CG. When the
rope comes tight, the nose of the glider will quickly yaw to
point towards the tug. This yawing action cushions some of
the shock on the rope and decreases the likelihood of it
breaking. If during the dive to accelerate you end up with
the nose of the glider pointed directly at the tail of the
tug, there will be no yawing action and the maximum force on
the rope will be higher.
Todd Pattist - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)

There is a rumor around that someone left Mt. Mitchell
wave in N.C. and flew back to Chester S.C. and discovered
on arrival that the brakes (ailerons?) had frozen up
and had to fly around awhile to unfreeze. Have no idea
who it was.

At 08:00 02 November 2004, Chris Rollings wrote:
Eric,

I've had two cases of not being able to open dive brakes
due to low temperatures. One in a Kestrel 19, where
at 19,000 feet on a cold autumn day in Scotland the
over-centre lock became so stiff I couldn't break it
out, the other in a twin Grob due to water inside the
airbrake box freezing and jamming the mechanism.

Never experienced a problem in a considerable amount
of cloud flying above the freezing level in the UK
- I've never heard of the ice on the wings getting
as far back as the airbrake cut-out. If you needed
to open the brakes in iceing conditions (to prevent
overspeeding) I would expect that after a very short
time it would become impossible to close them.

Chris Rollings

In 5000 hours of soaring, I've had the spoilers freeze
shut once. A
brief shower shortly before towing off for what eventually
turned into a
wave flight did the trick. I discovered them frozen
at 4000' AGL while
descending at the end of the flight, but at 3000 AGL,
they unfroze. I
had a tail chute, so a slip would not have been needed,
even in this case.

Has anyone else had spoilers freeze shut without flying
in clouds, were
it seems like you should be expecting it to happen?


--
Change 'netto' to 'net' to email me directly

Eric Greenwell
Washington State
USA

Gary Boggs wrote:
I had mine freeze shut also. It was raining lightly before we took off and
I then went to over 20K in our wave. I was at altitude for quite a long time
and discovered while descending that the spoilers on my Jantar 2A were
completely frozen shut. I tried everything I could to get them open without
success. In the manual it states that the 2A is not approved for slipping.
Our runway is 3000ft long at 600ft msl. Fortunately we usually have quite
a bit of wind here so that helps shorten the landing. I modified my pattern
and had no problems getting it stopped well before the end of the pavement
with the wheel brake.

And, your runway slopes uphill - a huge help.


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Eric Greenwell
Washington State
USA

Well, it's only 30 feet in 3000, but it does make a difference. Many pilots
land short the first few times they fly here. It looks flatter than it is.

Gary Boggs


"Eric Greenwell" wrote in message
...
Gary Boggs wrote:
I had mine freeze shut also. It was raining lightly before we took off
and
I then went to over 20K in our wave. I was at altitude for quite a long
time
and discovered while descending that the spoilers on my Jantar 2A were
completely frozen shut. I tried everything I could to get them open
without
success. In the manual it states that the 2A is not approved for
slipping.
Our runway is 3000ft long at 600ft msl. Fortunately we usually have
quite
a bit of wind here so that helps shorten the landing. I modified my
pattern
and had no problems getting it stopped well before the end of the
pavement
with the wheel brake.

And, your runway slopes uphill - a huge help.


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Eric Greenwell
Washington State
USA

Thanks to all who replied and especially for the link to the designee
bulletin clarifying the intent of the task. I'll be talking with the
examiner soon.

As I recall hearing, the L/D was 28/1 with the drogue
deployed.


Considerably less. Probably 15:1 with modified chutes (more area than
stock).

I spent several thousand man-hrs bebuilding/restoring S/N 12012 and
flew it for a couple of hundred hours.

Seems I recall
a concerted effort to remove them from the market in
order to save lives.

To my knowledge, only 1 person got killed - from a spin-in. Not much
to do with the ship as it is docile and very, very honest.

Another pilot slammed in after taking off with elevator disconnected.
Ship was essentially gone from stick forward but pilot only received
moderate damage to ankles / feet. He would have been very dead in a
modern ship.

Afaik by now all 12's have been converted to the 20 flap system with
landing setting.

Sissies. evil grin

Sure. Flaps only go down about 50 deg and made little difference in
flight path or landing skills. The extra drag was more than
compensated for by the lower landing speed and extra float. Every
little bit helped!



Pretty big ego concerning one's flying skills I guess.

Most of the pilots that flew them extensively were very conservative,
highly disciplined, albeit highly confident folks (Scott, Schuemann,
Herold, Greene, Smith, Nelson)

Basic landing technique in glass spoilerless:

1) Downwind abeam touchdown at 4-500 ft agl.

2) Speed 50-55 kts and held very closely, even in extreme slips!
Get fast and eat fence at end!

3) Set max-effort slip meaning that rudder is stalled and pedal is
held to
floor by air pressure. Ship rotates 50 degrees and a small amount
of bank
holds heading. May require using adverse yaw to get into this
condition or
slipping one way and then dynamically going the other way to get
into
stable, rudder-stalled slip.

4) Adjust pattern to arrive as low as one can over threshold, holding
55 kts
attitude

5) Hold slip through flair and continue to bleed speed.

6) Kick out slip and do a tail-low wheel landing.

7) Put flaps negative and brake to halt.

One can also slip hard mostly in the turns by rolling to 90 degrees
bank, feeding in full top rudder and pulling g to load wing. Very
effective way to descend from height.

Flaps can be slowly retracted post-flair to set ship on ground.
However, if too fast, you will not be able to land ( do not ask me how
I know!)

The real way to land short is to deploy #1 chute downwind abeam at
70-80 kts. Adjust pattern and point nose at threshold, holding a
minimum of 75 kts. As threshold is cleared, and you are close to
ground, deploy second (tail chute). Ship quits flying immediately and
will stop in 200-300 feet wth minor braking.

This method was used by Schuemann to safely fly X-C on the Appalachian
ridges for more than 2K hours accident-free. However, it is not for
the faint heart for the sloppy. Actions and timing are crucial. Must
be seen/experienced to be appreciated. The movies of this maneuver
are amazing!

While all of this sounds extreme and dangerous, it is most definitely
not. the techniqus were developed by some of the most experienced
analytical and conservative pilots in the sport. As I said
previously, I have actually tried all of these techniques, first at
altitude and then in many gliders to full stop landings. While it is
considerably more difficult than conventional landings, it is not
superhuman nor dangerous. If this were the case, most of the 12's
would be kindling wood and the pilots dead. Neither is the case!
There is a very large amount of empirical evidence in many different
locations in the wildest weather to support this hypothesis!

Armchair, wannabe R.A.S. theorists not withstanding!

Stalling in severe slips results in the nosefalling through and out of
the slip to a wings level recovery with very little effort or altitude
loss. Dragging a wingtip in glass during a Steady-State slip is
essentially impossible as the wingtip is never lower than the main
wheel. These gliders are severely rudder-limited. If the ship touches
down in a slip, it bounces up and straightens itself out (at least for
the '12. Never had it happen in any other ship!)

While I am high-time in power and glider and was flying more than
full-time (7 days /week for many months for many years) when I was
training for the '12, I do not consider myself a super pilot and
several of my less experienced friends were able to consistently land
their 15m / std glass ships spoilerless in less than 2000 ft.

Best, Mark

Mark Grubb wrote:

Another pilot slammed in after taking off with elevator disconnected.
Ship was essentially gone from stick forward but pilot only received
moderate damage to ankles / feet. He would have been very dead in a
modern ship.

What was it about the ASW 12 that saved him, compared to modern ships
like the ASW 27, Ventus 2, etc?

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Eric Greenwell
Washington State
USA