airbrake position while tied outside

[CK]

I have recieved conflicting answers about the airbrake position while
my Cirrus is tied down outside. Can the experts of RAS clarify this
for me? Thanks ahead of time!

[Vorsanger1]

Good morning

When the plane is parked, with the expectation that I will fly it soon, I keep
it with the spoilers extended in their full "out" position. When I am done for
the day and put the plane away the spoilers are down and locked.

That's the way I learned to do it, and it works for me.

Cheers, Charles
CFI-G

[Shawn Curry]

CK wrote:

> I have recieved conflicting answers about the airbrake position while
> my Cirrus is tied down outside. Can the experts of RAS clarify this
> for me? Thanks ahead of time!
>
Unless your POH says something besides closed and locked, why would you
do anything else? Think bugs birds and weather getting into the spoiler
boxes. If you're leaving them opened to kill lift, you need stronger
tiedowns!

Shawn

[CK]

Thanks for the quick response. I was curious since this past summer,
I noticed a lot of planes tied out overnight with divebrakes out.
Would the tiedowns need to be stronger with the airbrakes out? That
was my logic, which could be flawed since I am not an aerodynamic
engineer. ;o)

[Nolaminar]

Get the tail up a couple of feet if you have wind concerns.
And if there is that much concern, put it in the box and in some area that is
protected.
GA

[Eric Greenwell]

CK wrote:
> Thanks for the quick response. I was curious since this past summer,
> I noticed a lot of planes tied out overnight with divebrakes out.
> Would the tiedowns need to be stronger with the airbrakes out?

No, the airbrakes reduce the lift on the wings when it's coming from the
front of the plane. This reduces the stress on the tiedowns, and I
believe it reduces the chance the tiedowns will loosen in gusty winds.
Raising the tail as Bob suggests is even more effective.

Some people use the wheel brake as a parking brake, so the spoilers are
open to apply the brakes (if the brake is on the spoiler handle). Some,
like myself, prefer to tie down to the spoiler pivots instead of the
wing tips, and the tiedown strap keeps the spoilers from closing.


--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Walter Kronester]

Do not forget to look into the manual of your ship.
For many planes it is stringently recommended to UNLOCK
the airbrakes whenever the plane is parked for longer times!!
I think it is a good idea for all of our plastic birds!
--
Best regards Walter

[Sevenbravo]

My glider has some nice hard points, to attach tie downs to, in the
spoiler boxes. These, plus the wingtips, gives me four tie down
points plus the extended spoilers lock my wheel brake. I use them for
overnight parking only though.


Doug Turner 7B

[Chris OCallaghan]

Ah, what would life be without a controversy? Here's some conflicting
information to digest.

Open spoilers are rain catchers. Closed spoilers are not completely
sealed. If it rains, water will dribble in. If it rains hard and long,
the spolier box will slowly fill and at some point begin to spill
through the control rod access hole into the wing.

Solution, leave the spoilers closed and tape the seams. Or better yet,
get a set of wing covers.

BTW, I'm not sure putting the spoilers up wins you any net advantage.
It reduces the lift the wing is producing a little, but at the cost of
more surface area presented to the wind. The only real advantage I see
is that it accuates the wheel brake on many models. The key to
securing an aircraft for weather is no slack in the ropes. I suspect
deploying the spoilers is part placebo, a convenient "extra" for those
who are content to stick a pair of stands under the wings for the
night and call the glider secure.

Those contributors mentioning birds, beasts, and bugs also have a good
point. Taken in whole, I'd vote to leave 'em closed.

[Vaughn]

"Chris OCallaghan" > wrote in message
om...
> Ah, what would life be without a controversy? Here's some conflicting
> information to digest.
>
> Open spoilers are rain catchers. Closed spoilers are not completely
> sealed. If it rains, water will dribble in. If it rains hard and long,
> the spolier box will slowly fill and at some point begin to spill
> through the control rod access hole into the wing.
>
> Solution, leave the spoilers closed and tape the seams. Or better yet,
> get a set of wing covers.

It is possible to have it both ways. If you really want to spoil the
lift of your wing while parked, you can make your own strap on spoilers of
padded wood or aluminum. Here in Florida, we get afternoon thunderbumpers
with winds that can briefly reach hurricane force. Over the years, I have
seen more than one glider get unnecessarily trashed. In addition to good
tiedowns, I like to see a moderately raised tail, and an extra tiedown
anchor for the tow hook.

Another issue that nobody has yet mentioned is the possible lack of UV
protection inside the spoiler box, this might be a good reason to keep
spoilers closed while tied down outside.

Vaughn

[CK]

Thanks for the posts - and the patience! Two last questions on straps
to tie down. It seems logical the press to release type strap could
possibly come loose, but it is a bad idea to use rachet straps? I
have nice eyebolts that screw into the bottom of the wings for tiedown
(I think that is what they are for...) and would accomidate the hook
quite well. I was looking in a local supply store, and they have a
variety of rope breaking / working strength - if rachet straps are a
bad idea, what breaking / working strength would work?

Thanks again!
CK

[Vaughn]

"CK" <hv2flyG@yahooDOTcom> wrote in message
...
> - if rachet straps are a
> bad idea, what breaking / working strength would work?

I like ratchet straps (tightened judiciously) with two caveats: 1) The
cheaper straps weaken very quickly when exposed to weather and sunlight, and
2) Those wide open hooks could fall free from an eye if your tie ever got
loose enough, leaving you with a glider that is not tied down. You may be
able to prevent this somewhat by "customizing" the hook, squeezing it almost
closed in a vise.

Vaughn

[Mark James Boyd]

> I think rain is likely, I use some 2" foam pipe insulation that is
>split lengthwise, place it over the spoilers, then use a bungey on the
>spoiler handle to pull the spoilers down against the foam. The foam
>seals the gap.

Someone mentioned boards with insulation or aluminum to spoil the
lift. I'm a bit worried about damage to the surfaces. I
was thinking that some foam "hollow column shape" wrapping,
cut in half and put along the leading edge, might work for
this. Has anyone tried any of these three (boards, aluminum,
leading edge)?

[Eric Greenwell]

Vaughn wrote:
> "CK" <hv2flyG@yahooDOTcom> wrote in message
> ...
>
>> - if rachet straps are a
>>bad idea, what breaking / working strength would work?
>
>
> I like ratchet straps (tightened judiciously) with two caveats: 1) The
> cheaper straps weaken very quickly when exposed to weather and sunlight, and
> 2) Those wide open hooks could fall free from an eye if your tie ever got
> loose enough, leaving you with a glider that is not tied down. You may be
> able to prevent this somewhat by "customizing" the hook, squeezing it almost
> closed in a vise.

Even better is to use hooks with a spring-loaded lever that prevents the
hook from coming off the tie-down, no matter how loose it gets. I've
seen many of the strap type tie-downs that had loosened, so I wouldn't
trust a plain hook.

--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Eric Greenwell]

Chris OCallaghan wrote:

> Ah, what would life be without a controversy? Here's some conflicting
> information to digest.
>
> Open spoilers are rain catchers. Closed spoilers are not completely
> sealed. If it rains, water will dribble in. If it rains hard and long,
> the spolier box will slowly fill and at some point begin to spill
> through the control rod access hole into the wing.
>
> Solution, leave the spoilers closed and tape the seams. Or better yet,
> get a set of wing covers.

Rain is the major disadvantage of tying down with the spoilers open. If
I think rain is likely, I use some 2" foam pipe insulation that is
split lengthwise, place it over the spoilers, then use a bungey on the
spoiler handle to pull the spoilers down against the foam. The foam
seals the gap.

--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Mark Navarre]

This thread has pretty much run out, but I thought I would state that, if you
must tie down outside and expect high winds, four tiedown points on the wings
(in addition to tow hook and tail) are better than two, and if the only inboard
location on the wing happens to be inside the spoiler box, use what you got. I
use this location on my ship when tying down overnight on wave days (it's
easier to tie down than derig in 20+kts wind!), but know that I must vacuum the
sand and gravel out of the bottom of the spoiler box in the morning. It's
amazing how large of a grit size the wind will make fly two or more feet off
the ground, especially considering it comes from beyond the edge of our paved
ramp 300 feet away where the dirt ends. The spoilers are only held open less
than 1/4 inch with my setup, which consists of a large metal hook that goes
around the chordwise pivot in the spoiler box, then a 2" wide strap to get over
the LE of the wing, then rope attached to the strap for ease of knot tying.
The spoiler cap closes on the strap and traps the hook in place even if the
rope becomes loose.
As an aside, if there is an insurance claim for wind related ground damage, the
insurance company will only want to know if the aircraft was "tied down" and
what it was tied down to, they are not likely to deny the claim if you used
three ropes where five was needed. But you might be unpopular with the owners
of the other aircraft that yours flipped over on top of!
Ropes with non-slip knots, tied up tight against the rings or cables at both
ends, beat ratchet or cam-lock straps for simplicity and durability, and if
they do loosen in the wind, there is no hardware to flap around and trash your
gelcoat or paint.
-
Mark Navarre
ASW-20 OD
California, USA
-

[bumper]

You may be aware, but screw in eyebolts lose a substantial amount of their
rated strength if the load angle in increased beyond about 30 degrees. Also,
if the tie down comes off the eyebolt at an angle, and unless the eyebolt
has a relatively large shoulder, you will end up with bent screws and/or
damage to the surrounding composite in high winds.

My Stemme was shipped with eyebolts with felt washers to "protect" the
surface. This is exactly *not* what you want! The felt will compress and the
bolt will bend. Better is a large mylar, nylon or similar washer to protect
the surface. Make sure the eyebolt is good and snug and keep the tie down as
perpindicular to the wing as possible.

all the best,

bumper

"CK" <hv2flyG@yahooDOTcom> wrote in message
...
> Thanks for the posts - and the patience! Two last questions on straps
> to tie down. It seems logical the press to release type strap could
> possibly come loose, but it is a bad idea to use rachet straps? I
> have nice eyebolts that screw into the bottom of the wings for tiedown
> (I think that is what they are for...) and would accomidate the hook
> quite well. I was looking in a local supply store, and they have a
> variety of rope breaking / working strength - if rachet straps are a
> bad idea, what breaking / working strength would work?
>
> Thanks again!
> CK

[Kevin Neave]

>> Ah, what would life be without a controversy? Here's
>>some conflicting
>> information to digest.
>>
>

Seems a shame to spend all that money on a trailer,
then not use it !

:-)

Kevin

[CK]

Wouldn't want to get the trailer dirty? ;o}

CK