using less spoiler just before the flare???

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

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 |