Greetings,

This may get many comments, but I'm curious as to the consensus.

On a recent training flight (wasn't me...) the student was advised to go
to about 2/3 spoiler just before the flare.

Normal approach, field was made, on target for a nice touchdown.

When I was getting instruction, I was always encouraged to progress
toward full spoiler in the pattern and to ideally get to a full spoiler
and stabilized approach once the target touchdown point was "in range".
Advice given was that full spoilers minimized the potential for
ballooning and provided maximum drag and minimized lift. i.e. get on
the ground and stay there and make a positive effect to get the glider
stopped. Additionally, I've always been of the mind set that unless
there was an unusual circumstance, that spoiler changes near the ground
were usually best avoided.

Any other thinking as to a benefit in reducing spoiler just before the
flare?

Just pondering...

Gary

Gary Emerson wrote:
> Any other thinking as to a benefit in reducing spoiler just before the
> flare?

a) Some gliders (not the Duo 8^) cause sufficient sink rate at full
extension to make for a rather firm arrival if not reduced.

b) Some gliders actuate the wheel brakes at full extension, and some
instructors are known to get overly concerned about generating a screech
and a nice puff of smoke.

Marc

"Gary Emerson" > wrote in message
. net...
> When I was getting instruction, I was always encouraged to progress toward
> full spoiler in the pattern and to ideally get to a full spoiler and
> stabilized approach once the target touchdown point was "in range".


I was not taught (nor did I teach) any such thing. First of all, spoiler use
is type-specific. If you have a glider with very effective spoilers, you are
less likely to need them full on. If you are flying something with wimpy
spoilers, you might routinely fly your whole final to touchdown with them full
on.

I was taught that the theoretical "ideal", perfectly-planned and executed
pattern would have about 50% spoilers throughout the full pattern. If you are
at 50%, then you have maximum authority to either increase or decrease your
glide angle as conditions warrant.

Vaughn

Vaughn Simon wrote:
> I was taught that the theoretical "ideal", perfectly-planned and
executed
> pattern would have about 50% spoilers throughout the full pattern.

I've heard this before, and wondered about why it's "ideal" to have
spoilers open during the downwind and base leg. What was the reason your
instructors gave you?

I've always flown - and taught - the downwind and base legs with the
gear down, spoilers closed. This way, my turns to base and final are as
high as possible, and the final is longer, giving me more time to
stabilize it, to make corrections (especially big ones), and inspect the
landing area.

> If you are
> at 50%, then you have maximum authority to either increase or decrease your
> glide angle as conditions warrant.

I agree with this technique, and it is what I strive for on final. I do
use somewhat less spoiler if the glider has a strong landing flaps (ASW
20, e.g.), or responds significantly to just cracking the spoilers.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

On Oct 25, 7:12 pm, Gary Emerson > wrote:
> Greetings,
>
> This may get many comments, but I'm curious as to the consensus.
>
> On a recent training flight (wasn't me...) the student was advised to go
> to about 2/3 spoiler just before the flare.
>
> Normal approach, field was made, on target for a nice touchdown.
>
> When I was getting instruction, I was always encouraged to progress
> toward full spoiler in the pattern and to ideally get to a full spoiler
> and stabilized approach once the target touchdown point was "in range".
> Advice given was that full spoilers minimized the potential for
> ballooning and provided maximum drag and minimized lift. i.e. get on
> the ground and stay there and make a positive effect to get the glider
> stopped. Additionally, I've always been of the mind set that unless
> there was an unusual circumstance, that spoiler changes near the ground
> were usually best avoided.
>
> Any other thinking as to a benefit in reducing spoiler just before the
> flare?
>
> Just pondering...
>
> Gary


One principle not commonly taught, but worth understanding, is that
spoilers
do somewhat different things in parts of the pattern.
I teach the use of approximately 1/2 spoiler from a point abeam the
touchdown.
This uses "safety altitude up at a rate proportional to distance left
to touchdown
thus providing a fairly constant rate of descent and pretty much
constant height
margin.
This assumes steady airspeed selected for conditions.
Adjust spoilers moderately for changes in angles to the touch down
point.
On final, the effect of spoilers changes.
In the early part of final , they are rate(and angle at constant
speed) of descent
control.
As we transition into the flare and touchdown phase the spoilers
become rate of
deceleration control thus determining when the glider no longer has
enough speed to fly.
Teaching this principle of leaving the spoilers alone(unless sink or
other factor dictate) allows a smooth transition into the flare
without losing the drag needed to land at the target.
This method leads to pilots who can land at low energy with minimal
extra float.
It also means that only the pitch control hand needs to do something
which is much easier
for students to master.
Some try to "improve on what we teach" thinking less spoiler near the
ground will give slower sink
and smoother landings. After bouncing around in ground affect and
landing poorly and
long, they come back to what they are taught
>From the start, I teach that last part of final, if possible, is with
full spoilers to get pilots used
to steep final like is needed landing in a field . This way they will
revert to habits that work well
during their first "stressful" outlanding.
Hope this was not too "windy".
UH

wrote:

> I teach the use of approximately 1/2 spoiler from a point abeam the
> touchdown. This uses "safety altitude up at a rate proportional to distance left
> to touchdown thus providing a fairly constant rate of descent and pretty much
> constant height margin. This assumes steady airspeed selected for conditions.
> Adjust spoilers moderately for changes in angles to the touch down
> point.
> On final, the effect of spoilers changes. In the early part of final
> , they are rate(and angle at constant
> speed) of descent control. As we transition into the flare and touchdown phase the spoilers
> become rate of deceleration control thus determining when the glider no longer has
> enough speed to fly.

How do you use the landing flaps on something like an ASW 20 or 27? Use
them only on final? Save them for situations where spoilers aren't enough?

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Probably a better idea to teach that they are used
as required, rather than automatically opening them
at a fixed positon irrespective of height. Doing this
could end in tears.


At 14:12 26 October 2007, Eric Greenwell wrote:
wrote:
>
>> I teach the use of approximately 1/2 spoiler from
>>a point abeam the
>> touchdown. This uses 'safety altitude up at a rate
>>proportional to distance left
>> to touchdown thus providing a fairly constant rate
>>of descent and pretty much
>> constant height margin. This assumes steady airspeed
>>selected for conditions.
>> Adjust spoilers moderately for changes in angles to
>>the touch down
>> point.
>> On final, the effect of spoilers changes. In the early
>>part of final
> > , they are rate(and angle at constant
>> speed) of descent control. As we transition into the
>>flare and touchdown phase the spoilers
>> become rate of deceleration control thus determining
>>when the glider no longer has
>> enough speed to fly.
>
>How do you use the landing flaps on something like
>an ASW 20 or 27? Use
>them only on final? Save them for situations where
>spoilers aren't enough?
>
>--
>Eric Greenwell - Washington State, USA
>* Change 'netto' to 'net' to email me directly
>* 'Transponders in Sailplanes' http://tinyurl.com/y739x4
>* 'A Guide to Self-launching Sailplane Operation' at
>www.motorglider.org
>

Whilst I have enjoyed reading this thread there is one thing bugging me.
you all keep referring to spoilers, when in actuality I believe you are
referring to airbrakes.
Spoilers, as those of you that have and do fly gliders / motor gliders
which utilise spoilers will know how different
their behaviour is to that of airbrakes.
sits back and awaits #flames#


Mark Dickson wrote:
> Probably a better idea to teach that they are used
> as required, rather than automatically opening them
> at a fixed positon irrespective of height. Doing this
> could end in tears.
>
>
> At 14:12 26 October 2007, Eric Greenwell wrote:
>> wrote:
>>
>>> I teach the use of approximately 1/2 spoiler from
>>> a point abeam the
>>> touchdown. This uses 'safety altitude up at a rate
>>> proportional to distance left
>>> to touchdown thus providing a fairly constant rate
>>> of descent and pretty much
>>> constant height margin. This assumes steady airspeed
>>> selected for conditions.
>>> Adjust spoilers moderately for changes in angles to
>>> the touch down
>>> point.
>>> On final, the effect of spoilers changes. In the early
>>> part of final
>>> , they are rate(and angle at constant
>>> speed) of descent control. As we transition into the
>>> flare and touchdown phase the spoilers
>>> become rate of deceleration control thus determining
>>> when the glider no longer has
>>> enough speed to fly.
>> How do you use the landing flaps on something like
>> an ASW 20 or 27? Use
>> them only on final? Save them for situations where
>> spoilers aren't enough?
>>
>> --
>> Eric Greenwell - Washington State, USA
>> * Change 'netto' to 'net' to email me directly
>> * 'Transponders in Sailplanes' http://tinyurl.com/y739x4
>> * 'A Guide to Self-launching Sailplane Operation' at
>> www.motorglider.org
>>
>
>
>

On Fri, 26 Oct 2007 06:12:29 -0700, wrote:


>
>One principle not commonly taught, but worth understanding, is that
>spoilers
>do somewhat different things in parts of the pattern.
>I teach the use of approximately 1/2 spoiler from a point abeam the
>touchdown.

Very interesting - I guess you are flying a very tight apporach
pattern, starting very high on downwind, right?

I'm just wonderung, because if we'd do this with the ASK-21 in the
traffic pattern at my home airfield (height at downwind about 650 ft
above ground), we wouldn't even reach the airfield.


Bye
Andreas

Phil Collin wrote:
> Whilst I have enjoyed reading this thread there is one thing bugging me.
> you all keep referring to spoilers, when in actuality I believe you are
> referring to airbrakes.
> Spoilers, as those of you that have and do fly gliders / motor gliders
> which utilise spoilers will know how different
> their behaviour is to that of airbrakes.
> sits back and awaits #flames#
>
I've noticed that Americans tend to refer to airbrakes as spoilers. I
wonder if this is because most (all?) Schweitzer iron is fitted with
spoilers rather than Schlemp-Hirth air brakes. Most Americans seem to
have learnt in the SGS 2/33.

Personally, the only spoiler-equipped gliders I've flown are our
Slingsby T-21b and an SGS 2/33. The spoilers on both are memorably
ineffective.


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

You are quite right on all counts, particularly if
you include the 2-22 and the TG-3.

But we know the difference, and we also know that originally
the DFS divebrakes were speed limiting vertically before
the standards were changed.

You'll probably have to get used to it. Language changes;
we must all choose our particular upsets over this
fact.

At 19:06 27 October 2007, Martin Gregorie wrote:
>Phil Collin wrote:
>> Whilst I have enjoyed reading this thread there is
>>one thing bugging me.
>> you all keep referring to spoilers, when in actuality
>>I believe you are
>> referring to airbrakes.
>> Spoilers, as those of you that have and do fly gliders
>>/ motor gliders
>> which utilise spoilers will know how different
>> their behaviour is to that of airbrakes.
>> sits back and awaits #flames#
>>
>I've noticed that Americans tend to refer to airbrakes
>as spoilers. I
>wonder if this is because most (all?) Schweitzer iron
>is fitted with
>spoilers rather than Schlemp-Hirth air brakes. Most
>Americans seem to
>have learnt in the SGS 2/33.
>
>Personally, the only spoiler-equipped gliders I've
>flown are our
>Slingsby T-21b and an SGS 2/33. The spoilers on both
>are memorably
>ineffective.
>
>
>--
>martin@ | Martin Gregorie
>gregorie. | Essex, UK
>org |
>

Martin Gregorie wrote:
> Phil Collin wrote:
>> Whilst I have enjoyed reading this thread there is one thing bugging me.
>> you all keep referring to spoilers, when in actuality I believe you
>> are referring to airbrakes.
>> Spoilers, as those of you that have and do fly gliders / motor gliders
>> which utilise spoilers will know how different
>> their behaviour is to that of airbrakes.
>> sits back and awaits #flames#
>>
> I've noticed that Americans tend to refer to airbrakes as spoilers. I
> wonder if this is because most (all?) Schweitzer iron is fitted with
> spoilers rather than Schlemp-Hirth air brakes. Most Americans seem to
> have learnt in the SGS 2/33.

Hmm, I was taught:
Schemmp-Hirth style glide path control devices are spoilers (kill the
lift, make drag by sticking into the wind and requiring greater induced
drag through higher aoa). Spoilers increase stall speed.
The trailing edge thingees on my old Ventus and Mosquito are dive
brakes. They don't affect lift or stall speed much.
The things on 2-33s remind the student it's time to begin a slip ;-)


Shawn

shawn wrote:
>
> The things on 2-33s remind the student it's time to begin a slip ;-)
>
Very well put!

And to be fair to that bird, it does slip remarkably effectively and
controllably.


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

Nyal Williams wrote:
> You are quite right on all counts, particularly if
> you include the 2-22 and the TG-3.
>
I've just reviewed the descriptions of the 2-22 and TG-3 in Martin
Simon's books in case I'd missed anything. Annoyingly, the text doesn't
mention the brake/spoiler arrangement and the photos don't show it
either. The drawing of the 2-22 shows a broad top surface-only device:
did he get it wrong or does the brake have a really wide sealing strip?
The TG-3 is drawn with a much narrower chord device above and below the
wing and looks much more like an S-H brake.

Thanks for the confirmation about the other Schweitzer gliders.
That was rather a blind guess on my part.

> You'll probably have to get used to it. Language changes;
> we must all choose our particular upsets over this
> fact.
>
Sure. I wasn't meaning to get at anybody though it may have looked like
it. I've tripped up in the past over different meanings of a word and
I'll probably trip again. This is only terminology and we all know what
the other means. Other words have *radically* different meanings on
either side of the pond, something I'm not about to illustrate!


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

"Martin Gregorie" > wrote in message
...
> Nyal Williams wrote:
>> You are quite right on all counts, particularly if
>> you include the 2-22 and the TG-3.
>>
> I've just reviewed the descriptions of the 2-22 and TG-3 in Martin Simon's
> books in case I'd missed anything. Annoyingly, the text doesn't mention
> the brake/spoiler arrangement and the photos don't show it either. The
> drawing of the 2-22 shows a broad top surface-only device: did he get it
> wrong or does the brake have a really wide sealing strip? The TG-3 is
> drawn with a much narrower chord device above and below the wing and looks
> much more like an S-H brake.
>
> Thanks for the confirmation about the other Schweitzer gliders.
> That was rather a blind guess on my part.
>
>> You'll probably have to get used to it. Language changes;
>> we must all choose our particular upsets over this
>> fact.
>>
> Sure. I wasn't meaning to get at anybody though it may have looked like
> it. I've tripped up in the past over different meanings of a word and I'll
> probably trip again. This is only terminology and we all know what the
> other means. Other words have *radically* different meanings on either
> side of the pond, something I'm not about to illustrate!
>
>
> --
> martin@ | Martin Gregorie
> gregorie. | Essex, UK
> org |

Actually, the TG-3 and the 2-22 had top only spoilers hinged at the front
and closed with a spring. You had to overcome aerodynamic and spring force
to hold them open. I have several hundred hours in a TG-3. You can see
there were no lower surface spoilers on this picture.

http://commons.wikimedia.org/wiki/Image:Schweizer_TG-3A_USAF.jpg

Although the 2-22 was a dog, the TG-3 was a reasonably good soaring machine
at about 26:1. The best feature of the TG-3, for the instructor, was the
sliding rear canopy. The worst was the extremely heavy ailerons - most
pilots flew it with both hands on the stick.

There were serious proposals that the 2-22 replacement should have been an
updated TG-3 with lighter metal wings and tail surfaces instead of the
original wood. It would have needed lighter ailerons too. If such a
machine had been produced, it would have been much better than the 2-33.
Note that the TG-3 predates the 2-33 by more than 20 years.

AFIK, the only US made 2-seat glider of this era to have S-H type dive
brakes was the Pratt-Read.
http://www.sailplanedirectory.com/PlaneDetails.cfm?PlaneID=264

Bill Daniels

There is one TG-3 left flying, N60434, S/N 88. It
belongs to a fellow in Tennessee, I believe, Ron Naylor.
This glider never saw military duty and was bought
still in the crate by some folks at Harris Hill, who
sold it to the Tar Heel Soaring Club in Burlington,
NC back around 1960. It is the glider I learned on
after soloing SG-38s with the Belgians, and the glider
I did my Silver badge in, and did some instruction
in -- back when there was no CFI-G and commercial glider
pilots could instruct. (I got grandfathered and people
still ask why.)

At 01:12 28 October 2007, Bill Daniels wrote:
>
>
>
>'Martin Gregorie' wrote in message
...
>> Nyal Williams wrote:
>>> You are quite right on all counts, particularly if
>>> you include the 2-22 and the TG-3.
>>>
>> I've just reviewed the descriptions of the 2-22 and
>>TG-3 in Martin Simon's
>> books in case I'd missed anything. Annoyingly, the
>>text doesn't mention
>> the brake/spoiler arrangement and the photos don't
>>show it either. The
>> drawing of the 2-22 shows a broad top surface-only
>>device: did he get it
>> wrong or does the brake have a really wide sealing
>>strip? The TG-3 is
>> drawn with a much narrower chord device above and
>>below the wing and looks
>> much more like an S-H brake.
>>
>> Thanks for the confirmation about the other Schweitzer
>>gliders.
>> That was rather a blind guess on my part.
>>
>>> You'll probably have to get used to it. Language
>>>changes;
>>> we must all choose our particular upsets over this
>>> fact.
>>>
>> Sure. I wasn't meaning to get at anybody though it
>>may have looked like
>> it. I've tripped up in the past over different meanings
>>of a word and I'll
>> probably trip again. This is only terminology and
>>we all know what the
>> other means. Other words have *radically* different
>>meanings on either
>> side of the pond, something I'm not about to illustrate!
>>
>>
>> --
>> martin@ | Martin Gregorie
>> gregorie. | Essex, UK
>> org |
>
>Actually, the TG-3 and the 2-22 had top only spoilers
>hinged at the front
>and closed with a spring. You had to overcome aerodynamic
>and spring force
>to hold them open. I have several hundred hours in
>a TG-3. You can see
>there were no lower surface spoilers on this picture.
>
>http://commons.wikimedia.org/wiki/Image:Schweizer_TG-3A_USAF.jpg
>
>Although the 2-22 was a dog, the TG-3 was a reasonably
>good soaring machine
>at about 26:1. The best feature of the TG-3, for the
>instructor, was the
>sliding rear canopy. The worst was the extremely heavy
>ailerons - most
>pilots flew it with both hands on the stick.
>
>There were serious proposals that the 2-22 replacement
>should have been an
>updated TG-3 with lighter metal wings and tail surfaces
>instead of the
>original wood. It would have needed lighter ailerons
>too. If such a
>machine had been produced, it would have been much
>better than the 2-33.
>Note that the TG-3 predates the 2-33 by more than 20
>years.
>
>AFIK, the only US made 2-seat glider of this era to
>have S-H type dive
>brakes was the Pratt-Read.
>http://www.sailplanedirectory.com/PlaneDetails.cfm?PlaneID=264
>
>Bill Daniels
>
>
>

On Oct 26, 8:41 pm, Andreas Maurer > wrote:
> On Fri, 26 Oct 2007 06:12:29 -0700, wrote:
>
> >One principle not commonly taught, but worth understanding, is that
> >spoilers
> >do somewhat different things in parts of the pattern.
> >I teach the use of approximately 1/2 spoiler from a point abeam the
> >touchdown.
>
> Very interesting - I guess you are flying a very tight apporach
> pattern, starting very high on downwind, right?
>
> I'm just wonderung, because if we'd do this with the ASK-21 in the
> traffic pattern at my home airfield (height at downwind about 650 ft
> above ground), we wouldn't even reach the airfield.
>
> Bye
> Andreas

LIkely we are teaching a steeper approach profile than you are.
This is because we want pilots used to a fairly step approch on final
to allow shortest landing in a field. It is also easier to judge a
steeper angle.
Pls take the 1/2 spoilers(airbrakes whatever) with a bit of a grain of
salt.
The point is to establish a rate of descent on the order of about
500ft/min
and adjust from there.
UH