DG505, DG500 Spoiler box does not drain and freezes
karen
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
guy
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
Eric Greenwell
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
Darryl Ramm
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
2G
>
> - Show quoted text -
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
Darryl Ramm
I don't think the wing interior to spoiler box connection (where the
control rods enter the spoiler box) is all that airtight on most
gliders and will see ambient internal wing/fueslage pressure, some of
which will leak out around the spoiler box top, but modern spring
loaded tops seal pretty well. So I am not sure that a small hole in
the bottom would increase that leak rate significantly. But hey, if
done really well you've got yourself a blown turbolator :-)
There are gliders around with holes drilled in the bottoms of the
spoiler box, for attaching wing tie down hardware. Normally I'd tape
those but you'd never measure the difference if not.
Darryl
Andreas Maurer
wrote:
Not a single of the current German gliders built later than 1980 has a
drain hole in the spoiler box.
Bye
Andreas
uncl...@ix.netcom.com
> On Wed, 9 Dec 2009 18:05:15 -0800 (PST), karen <mom2kj...@gmail.com>
Our ASK-21 has drain holes
It isn't a big deal to add a small hole 3/16 diameter or so at the low
point if you are getting water accumulation in the wing.
It's much better to drain if you are getting any significant water in
the wing.
Concern about drag- tape it . I predict you can't measure this drag,
If a hole is put in, it would be wise to seal the foam core with a
little epoxy to keep water out.
UH
JJ Sinclair
drain holes at the inboard end and sealed the holes with epoxy. Also
watch the drain holes the ailerons, we found one plugged (like I
forgot to re-drill it after a repair) and found the scoop forward of
hinge line full, frozen and jammed!
Cheers,
JJ
Bob Kuykendall
> I don't think the wing interior to spoiler box connection (where the
> control rods enter the spoiler box) is all that airtight on most
> gliders and will see ambient internal wing/fueslage pressure...
In my experience, the better racing gliders generally have pretty well-
sealed airbrake boxes. I think that it's a common practice to use a
rubber bellows to seal the push-pull tube entry. I don't use a
bellows, but my airbrake boxes are also sealed off from the wing
interior.
Thanks, Bob K.
Andreas Maurer
wrote:
>Our ASK-21 has drain holes
Ours not. :)
Bye
Andreas
Jim
wrote:
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.
brian whatcott
>
> 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.
>
> 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
brian whatcott
> 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
Eric Greenwell
handling problems - Tom's context. Perhaps you are talking about
something on the tail boom?
bildan
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.)
John Smith
> 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.
bildan
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.
ZZ
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
Bob Kuykendall
> ...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.