A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Spoilers or Airbrakes - Whats in a name?



 
 
Thread Tools Display Modes
  #21  
Old May 18th 08, 12:10 AM posted to rec.aviation.soaring
Nyal Williams[_2_]
external usenet poster
 
Posts: 259
Default Spoilers or Airbrakes - Whats in a name?

Way back when ... there were terminal velocity dive brakes on gliders. (I
believe another term was DFS dive brakes, but am not sure about that).
These brakes would hold the glider below VNe in a vertical dive. At some
point, as air foils became thinner, manufacturers agreed that the air
brakes would be designed to hold the glider below VNe at a 45 deg. descent
angle. I believe this was sanctioned by JAR, IGC, or some such.

Spoilers will place no limit on speed and cannot be used in a steep or
High Parasitic Drag Approach, whereas airbrakes can be.

No one has mentioned an important difference between flaps and airbrakes
(whether spoilers, divebrakes, airbrakes, or your term of choice). This
difference is the effect had on closing them after having established a
stabilized descent under their use.

Retracting the airbrakes causes the stall speed to be lowered and the
glide angle to improve. If you are low and slow, retracting improves
EVERYTHING.

If you are low and slow and retract flaps, stall speed goes UP and you
might find yourself in the woods, creek, fence, or whatever is short of
the touchdown point.


At 13:53 17 May 2008, Tony Verhulst wrote:
>user wrote:
>> I'd continue to use them interchangeably .....
> > If during a positive control check the pilot corrects your call
>> of "spoilers," look under the wing for the extra
control surface.
>
>Yes, I've seen at least 2 books (FAA Glider Flying Handbook and
Russell
>Holtz's Glider Pilot's Handbook of Aeronautical Knowledge)where the

>writer claimed that if the ..um.. "device".. extended top
surface only
>it was a spoiler and if it extended from both survaces it was an air
>brake. Seems dubious to me.
>
>Tony V LS6-b "6N"
>
  #23  
Old May 18th 08, 02:25 AM posted to rec.aviation.soaring
Nyal Williams[_2_]
external usenet poster
 
Posts: 259
Default Spoilers or Airbrakes - Whats in a name?

Poorly stated; corrections inserted.

At 23:10 17 May 2008, Nyal Williams wrote:
>Way back when ... there were terminal velocity dive brakes on gliders.
(I
>believe another term was DFS dive brakes, but am not sure about that).

>These brakes would hold the glider below VNe in a vertical dive. At
some
>point, as air foils became thinner, manufacturers agreed that the air
>brakes would be designed to hold the glider below VNe at a 45 deg.
descent
>angle. I believe this was sanctioned by JAR, IGC, or some such.
>
>Spoilers will place no limit on speed and [will not be effective] in a
steep or

>High Parasitic Drag Approach, whereas airbrakes can be.
>
>No one has mentioned an important difference between flaps and
airbrakes
>(whether spoilers, divebrakes, airbrakes, or your term of choice).
This
>difference is the effect had on closing them after having established
a
>stabilized descent under their use.
>
>Retracting the airbrakes causes the stall speed to be lowered and the
>glide angle to improve. If you are low and slow, retracting improves
>EVERYTHING.
>
>If you are low and slow and retract flaps, stall speed goes UP [the
lift DECREASES]
and you
>might find yourself in the woods, creek, fence, or whatever is short
of
>the touchdown point.
>
>
>At 13:53 17 May 2008, Tony Verhulst wrote:
>>user wrote:
>>> I'd continue to use them interchangeably .....
>> > If during a positive control check the pilot corrects your
call
>>> of "spoilers," look under the wing for the extra
>control surface.
>>
>>Yes, I've seen at least 2 books (FAA Glider Flying Handbook and
>Russell
>>Holtz's Glider Pilot's Handbook of Aeronautical Knowledge)where
the
>
>>writer claimed that if the ..um.. "device".. extended
top
>surface only
>>it was a spoiler and if it extended from both survaces it was an
air
>>brake. Seems dubious to me.
>>
>>Tony V LS6-b "6N"
>>
>
  #24  
Old May 19th 08, 03:39 PM posted to rec.aviation.soaring
Lew Hartswick
external usenet poster
 
Posts: 33
Default Spoilers or Airbrakes - Whats in a name?

Ralph Jones wrote:
Variometer American Heritage Dictionary

A variable inductor used to measure variations in terrestrial
magnetism.

rj

I would say that the "American Heritage Dictionary" has abslutely
no electronic knowledge then. :-)
...lew...
  #25  
Old May 19th 08, 05:10 PM posted to rec.aviation.soaring
Nyal Williams[_2_]
external usenet poster
 
Posts: 259
Default Spoilers or Airbrakes - Whats in a name?

I'll bet that definition and that instrument are both older than ours --
nad more widespread, probably.

At 14:39 19 May 2008, Lew Hartswick wrote:
>Ralph Jones wrote:
>> Variometer American Heritage Dictionary
>>
>> A variable inductor used to measure variations in terrestrial
>> magnetism.
>>
>> rj
>I would say that the "American Heritage Dictionary" has
abslutely
>no electronic knowledge then. :-)
> ...lew...
>
  #26  
Old May 20th 08, 01:25 AM posted to rec.aviation.soaring
Tony Verhulst
external usenet poster
 
Posts: 193
Default Spoilers or Airbrakes - Whats in a name?

Nyal Williams wrote:
I'll bet that definition and that instrument are both older than ours --
nad more widespread, probably.



Ralph's point, IMHO, is that you don't go to a general dictionary to get
specialized information.

Tony V.
http://home.comcast.net/~verhulst/SOARING
  #27  
Old May 20th 08, 03:32 AM posted to rec.aviation.soaring
sisu1a
external usenet poster
 
Posts: 569
Default Spoilers or Airbrakes - Whats in a name?

On May 19, 5:25 pm, Tony Verhulst wrote:
Nyal Williams wrote:
I'll bet that definition and that instrument are both older than ours --
nad more widespread, probably.


Ralph's point, IMHO, is that you don't go to a general dictionary to get
specialized information.

Tony V.http://home.comcast.net/~verhulst/SOARING


Furthermore, you may even want to look elsewhere for general
information. Websters is full of definitions like this:

Hill - "a raised elevation of land, smaller than a mountain"

Mountain - "a raised elevation of land, larger than a hill"

no joke.

Paul Hanson
  #28  
Old May 20th 08, 11:55 AM posted to rec.aviation.soaring
Peter Higgs
external usenet poster
 
Posts: 47
Default Spoilers or Airbrakes - Whats in a name?

Hi All, just to be pedantic... If you only partially deploy any device,
it has a different aerodynamic characteristic.....

The first stage of Flaps gives an increase in Lift.
Second Stage of Flaps gives Lift And Drag.
Final Stage of Flaps gives Huge amounts of Drag, without any more Lift.

A quick look at your 'Barn Doors' will give you a reasonable idea of
what is likely to happen... I cannot imagine that vertical airbrakes
would ever give an increase in lift, even if only just cracked open a
millimeter or so.

Pilot Pete


At 20:14 16 May 2008, Andy wrote:
On May 16, 8:56=A0am, Mike wrote:
According the the original Glasser-Dirks owner's manual for a DG100G,
the sailplane has "spoilers".


I suspect that the original owner's manual is written in German and
that the word "spoilers" is not mentioned. I don't have my
Schleicher manual here but I think they call them Klappen. Not being
picky for the sake of it, but pointing out that "spoiler" was probably
the word chosen by the translator not necessarily by the manufacturer.

Andy


  #29  
Old May 20th 08, 02:55 PM posted to rec.aviation.soaring
Nyal Williams[_2_]
external usenet poster
 
Posts: 259
Default Spoilers or Airbrakes - Whats in a name?

At 02:32 20 May 2008, sisu1a wrote:
On May 19, 5:25 pm, Tony Verhulst wrote:
Nyal Williams wrote:
I'll bet that definition and that instrument are both older than

ours
--
nad more widespread, probably.


Ralph's point, IMHO, is that you don't go to a general dictionary to

get
specialized information.

Tony V.http://home.comcast.net/~verhulst/SOARING


Furthermore, you may even want to look elsewhere for general
information. Websters is full of definitions like this:

Hill - "a raised elevation of land, smaller than a mountain"

Mountain - "a raised elevation of land, larger than a hill"

no joke.

Paul Hanson


It defines gorse as furze and it defines furze as gorse with no further
explanations in either place.

My point was that the definition of a variometer is not the property of
the soaring community. ;-)
  #30  
Old May 20th 08, 05:21 PM posted to rec.aviation.soaring
sisu1a
external usenet poster
 
Posts: 569
Default Spoilers or Airbrakes - Whats in a name?

On May 20, 6:55 am, Nyal Williams wrote:
At 02:32 20 May 2008, sisu1a wrote:



On May 19, 5:25 pm, Tony Verhulst wrote:
Nyal Williams wrote:
I'll bet that definition and that instrument are both older than

ours
--
nad more widespread, probably.


Ralph's point, IMHO, is that you don't go to a general dictionary to

get
specialized information.


Tony V.http://home.comcast.net/~verhulst/SOARING


Furthermore, you may even want to look elsewhere for general
information. Websters is full of definitions like this:


Hill - "a raised elevation of land, smaller than a mountain"


Mountain - "a raised elevation of land, larger than a hill"


no joke.


Paul Hanson


It defines gorse as furze and it defines furze as gorse with no further
explanations in either place.

My point was that the definition of a variometer is not the property of
the soaring community. ;-)


Correct! It was the name of a short wave radio part (variable
inductance coil = variometer since around 1895) long before it was the
name for our sensitive VSI's. http://www.qsl.net/in3otd/variodes.html

Paul
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Spoilers, no spoilers? Amine Piloting 39 February 14th 08 03:37 AM
spoilers vs. ailerons [email protected] Piloting 36 August 8th 05 11:24 AM
Airbrakes Pop Out at 115 kts ContestID67 Soaring 13 May 10th 05 01:50 PM
ASW19b best descent rate on approach (full airbrakes) Robert Sharpe Soaring 1 April 30th 05 11:41 AM
L-13 Spoilers Scott Soaring 2 August 27th 03 06:08 AM


All times are GMT +1. The time now is 09:28 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.