DG505, DG500 Spoiler box does not drain and freezes

On Thu, 10 Dec 2009 06:05:48 -0800 (PST),
wrote:

Our ASK-21 has drain holes

Ours not.



Bye
Andreas

On Wed, 9 Dec 2009 18:05:15 -0800 (PST), karen
wrote:

No moisture drain hole in the spoiler enclosures. Searched for any
blog or discussion group on this subject. No joy.

Waiting to hear back from the factory for a mod or some solution
besides a hangar or wing covers.

Doesn't water get in also flying through storms and perhaps freeze as
you go high enough?

Are all 500 and 505' the same?

Thanks.

Karen

Karen

I thought the drain hole in the 505 is the hole the mid-wing tie-down
lug screws into on the lower surface of the wing.

Darryl Ramm wrote:

The boxes are sealed but the lower floor of the box usually is or
touches the bottom wing skin so if you really wanted to you could
drill a hole right there through the lower skin. Your A&P may have a
different idea.

But why? /snip/

Darryl

Drains are fitted to powered airframes because it takes relatively
little trapped water to give a very nasty aft pitching (or rolling)
moment...

Brian W

2G wrote:

Boy, I thought you guys were glider pilots! There is no "drain"
because that would be a path for high pressure air from the bottom of
the wing to escape to low pressure air on top, creating drag.

Tom

Good one Tom. Draggy or CofG in limits. Which would you prefer?

Brian W

brian whatcott wrote:
2G wrote:

Boy, I thought you guys were glider pilots! There is no "drain"
because that would be a path for high pressure air from the bottom of
the wing to escape to low pressure air on top, creating drag.

Tom

Good one Tom. Draggy or CofG in limits. Which would you prefer?

Brian W
It would take far more water than a spoiler box can hold to cause
handling problems - Tom's context. Perhaps you are talking about
something on the tail boom?

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

On Dec 9, 7:05*pm, karen wrote:
No moisture drain hole in the spoiler enclosures. Searched for any
blog or discussion group on this subject. No joy.

Waiting to hear back from the factory for a mod or some solution
besides a hangar or wing covers.

Doesn't water get in also flying through storms and perhaps freeze as
you go high enough?

Are all 500 and 505' the same?

Thanks.

Karen

Karen

If spoiler boxes don't have drain holes, you have to keep water out of
them. Closed spoilers alone definitely won't keep water out.
Recently, I spent an agonizing hour fishing baguette sized chunks of
ice out of ASK-21 spoiler boxes after a snowstorm.

Control rods and their fittings will eventually corrode even though
they have some anti-corrosion protection. There's also the possibility
of ice whose expansion can damage both the box structure and control
fittings. Standing water inside airframes is really bad news,
particularly in freeze thaw weather, no matter what material they are
made from.

If the glider is tied outside, taping some plastic sheet over the
spoilers will keep water out. I'd also probably just drill some 3mm
drain holes too but that could be questionable from a legal point of
view. (BTW, Plexiglas drills make really neat holes in composites.)

bildan wrote:
If the glider is tied outside, taping some plastic sheet over the
spoilers will keep water out.

Eight short pieces of duct tape (one for each joint) seal them pretty
well and are a matter of a few seconds. At least that's what I do when
for whatever reason I have to leave a glider outside overnight. Every
glider pilot should have a roll of duct tapy handy, anyway.

That said, I consider it pretty cruel to tie a plasic glider outside.

On Dec 11, 10:15*am, John Smith wrote:
bildan wrote:
If the glider is tied outside, taping some plastic sheet over the
spoilers will keep water out.

Eight short pieces of duct tape (one for each joint) seal them pretty
well and are a matter of a few seconds. At least that's what I do when
for whatever reason I have to leave a glider outside overnight. Every
glider pilot should have a roll of duct tapy handy, anyway.

That said, I consider it pretty cruel to tie a plasic glider outside.

It's pretty cruel to leave any glider outside no matter what it's made
of. Freeze-thaw cycles will even work rivets in an aluminum aircraft
loose.

Then there's the experience of having a bucket of ice water dumped
down your collar from where it collected inside the wings of a 2-33 as
your student grinds the glider to a stop on the skid.

I remember flying a Pratt-Reed on a ridge in a driving rainstorm.
(Yeah, I know.) My passenger called my attention to an alarming
amount of water collecting in the bottom of the cockpit pod. I used a
pencil to punch some drain holes through the fabric so we didn't have
to land.

Darryl:

I agree. I have limited experience with spoiler freezing in flight but
both times, the spoiler caps froze to the little ledges that they mate
with. The amount of water required to have this happen is very small and
therefore the preflight inspection should include a careful look at the
caps and ledges. If you encounter rain in flight and then climb above
the freezing level, cycling them often should help keep them functioning.

Paul
ZZ



Darryl Ramm wrote:
On Dec 9, 7:22 pm, Eric Greenwell wrote:
guy wrote:
Oh...Karen. Why fret.
Just return the plane to the factory and they will add those drain
holes they forgot to place as a free warranty repair.
Great customer service!
Guy
"No drain holes" may be the standard. My ASH 26 E does not have drain
holes in the spoiler boxes, and does not need them as long as the
spoilers are closed when it rains on the ground. If rain gets into the
boxes when flying, I've never heard of it happening; personally, I've
never looked in the boxes after flying through rain, but none ever
poured out when I derigged, either. If they are open when it rains, the
boxes will fill with water. The boxes are sealed, so it doesn't run into
the wing.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

The boxes are sealed but the lower floor of the box usually is or
touches the bottom wing skin so if you really wanted to you could
drill a hole right there through the lower skin. Your A&P may have a
different idea.

But why? I suspect the largest issue with spoiler freezing is by rain
wicking around the spoiler door and freezing or by direct icing
action. Having enough water inside the spoiler box and having that
freeze seems a remote case. And you need to have enough for that to
freeze and lock onto something important to stop the blades extending.
I suspect that would take quite a lot of water.

Although my ASH-26E usually lives in a trailer sometimes it is left
out overnight and in the the morning even after light rain I normally
see no water in the spoiler boxes. After washing with a hose I'll see
a bit of water inside the spoiler box. Same on a club DG-1000S. Just
to be nice I usually mop any water out with a dry rag more because I
don't want moisture in there encouraging rust etc. not from concern
about freezing.

If the glider is permanently kept outside then a set of good wing
covers are probably an answer to lots of questions.


Darryl

On Dec 12, 7:53*pm, ZZ wrote:

...both times, the spoiler caps froze to the little ledges that they mate
with...

That sounds to me like a good argument for keeping the airbrake cap
mating surfaces waxed. if epoxy won't stick to wax, I can't imagine
that ice would.

Thanks, Bob K.