Discus Water Tank Leak - Seen This - Fix?
Walter Rogers
Have any of you out there a fix for this problem...
My Discus B #64 (N717V "WX") in the last couple of years has
developed a water tank leak that seems only to occur when dumping
ballast. About one half gallon of water accumulates in the bottom of
the fuselage, draining out several holes and the gear doors (small
amount of water in the forward nose area where my heels are placed).
No leakage is visible before takeoff or during filling.
Conversations with other Discus/Ventus owners all pointed to the
dump valve interior rubber boot. Fortunately, on this serial number, a
threaded insert allows access to the boot. Marty Eiler, who inspected
the boot, claims it was not torn, but did not closely seal against the
interior tube. After packing with grease and testing with a flying
water ballast load, no change was noted. That is, the water still leaks
into the cockpit. In an earlier test with the wings on saw horses and
tanks filled with water, we were unable to detect any leakage through
the dump valve fitting either with the valve open or closed.
I have been unable to install the correct rubber boot yet, since there
are at least two styles of boot. The one I was shipped was the wrong
type.
QUESTION: Does anyone out there have experience with this wing
tank leakage symptoms? Do you really think this is the rubber boot...
or could there be a leak from somewhere else?
Anxious for your comments... U.S. Standard Nationals start in one
week at Minden...
Walter Rogers
Palmdale, CA "WX"
(661) 947-3947
wro...@qnet.com
Lars Peder Hansen
looked OK visually. Tried everything: grease, extra rubber O-rings, threatening with for
sale ads, woodoo, the lot. Nothing helped, until I installed a new set of correctly sized
rubber O-rings. Problem went away..
Happy Soaring, and good luck
Lars Peder
Todd Pattist wrote:
> wro...@cello.qnet.com (Walter Rogers) wrote:
>
> >My Discus B #64 (N717V "WX") in the last couple of years has
> >developed a water tank leak that seems only to occur when dumping
> >ballast.
>
> I can't help, but when you fix it, please let us know the
> solution. I'm surprised you can't reproduce it on the
> ground, that's what I'd be trying to do too.
>
> ---
>
> Todd Pattist Ventus C - WH
> Fly safely, fly often.
> (remove "DONTSPAMME." from my e-mail address to contact me)
> ---
--
_________________________________________________________________________
Lars Peder Hansen
Denmark branch of The Global Village.
mailto:l...@post1.tele.dk
Phone, Work:(+45) 87310700 Home:(+45) 86523988 Mobile:(+45) 40350870
_________________________________________ I'd rather be soaring... __________
The secret of the universe is: @*&!!/?%CONNECTION LOST
Bob Lepp
Would altitude and temperature present leakage conditions which cannot
be duplicated at ground level? Would a lower pressure outside the tanks
and perhaps a bit of built up pressure within force water past 'colder,
harder' seals that work ok on the ground?
Bob
Walter Rogers wrote:
>
> Discus and Ventus owners worldwide:
>
> Have any of you out there a fix for this problem...
>
> My Discus B #64 (N717V "WX") in the last couple of years has
> developed a water tank leak that seems only to occur when dumping
the BAILEYS
w/water ballast........should i tell him/Shouldn't I? THat'll be a first -
Icing in the cotpit!
MilesB
John Wilton <jwi...@globalnet.co.uk> wrote in message
news:7jh681$m0o$1...@gxsn.com...
> I recently heard about an LS4 with similar symptoms that was traced to
> a leaking fin ballast dump valve that was sucking back along the inside
> of the fuselage when flying. If you use fin ballast it might be worth
> investigating this possibility.
>
>
> John Wilton
> ASW20C
>
>
> Walter Rogers wrote in message <7jfn6d$3aa$1...@cello.qnet.com>...
John Wilton
Tim Harrison
These have no contact between the water apparatus and the
fuse, so this is probably not a fix for the original problem
of the Discus. However, others might benefit from this
info.
I was very disappointed to have great difficulty preventing
water leaking from the dump valves. These are slightly
tapered metal plugs which should fit snugly into the skin
recess.
I became very frustrated at the constant dripping, trying to
seal with meticulous cleaning, or big globs of Vaseline or
grease. I only got more grumpy!
The only way I have found is to use the "lipstick" stuff
which is used to protect lips against sunburn, wind-chapping
etc. This is slightly harder, has not frozen and comes in a
handy container. A blob of about 5 mm square on a finger
and just smoothed around the seat before closing has eased
my anger greatly.
**** Posted from RemarQ - http://www.remarq.com - Discussions Start Here (tm) ****
MikeYankee
Thomas Knauff
Walter Rogers wrote:
> My Discus B #64 (N717V "WX") in the last couple of years has
> developed a water tank leak that seems only to occur when dumping
> ballast.
Most likely, the water is coming in through the gap between the wing and
fuselage. This will happen if the wing root tape is loose. You might try
placing an additional row of tape on each side of the tape you use on the
bottom side of the wing and at the trailing edge for a distance of a foot or
so.
--
Thomas Knauff
Schempp-Hirth Sailplanes
Knauff & Grove Soaring Supplies
3523 South Eagle Valley Road
Julian, Pa 16844
Phone (814) 355 2483
Fax (814 355 2633
Email: tkn...@earthlink.net
http://www.glider.com/knauff/
Gary Osoba
Unfortunately, the weather patterns which have afflicted several
contests throughout the US in early May also took a toll at the 4th
Annual Ultralight Soaring Championship which was held last week at
Sunflower Aerodrome, Kansas.
Although some flying did take place, no tasks were called in this short
4-day meet. Big thunderstorms and tornadoes eventually gave way to
overcast skies with very low level cumulus and 30-40 mph winds. Not a
good plan.
Interest and development in very light gliders presently focuses in two
categories: US FAR 103 Ultralights which have empty weights of less than
155 lbs., such as the Carbon Dragon, and FAI D-U Ultralights with AUW's
of less than 220 kg such as the homebuilt Woodstock.
These gliders, particularly the lightest of them, are able to utilize
atmospheric energy and patterns which are not realizable in larger,
heavier ships.
Not better. Not worse. Just different.
The benefits are not confined to reliable soaring in weak conditions and
consistent low saves, but extracting energy from horizontal eddies and
shear components which occur at higher cruising altitudes and which
scale is accomodated at relatively slow flight speeds but is missed at
the higher cruise speeds and heavier wing loadings common to the other
classes of sailplanes. I gave a talk at the Knoxville Convention about
this latter effect utilizing data gathered from GPS tracking during the
contest at Hobbs last summer. There it was shown how effective
interthermal glides of up to 60:1 were being achieved in a little
Woodstock (designer's claimed max L/D 24:1) along orientations which cut
90 degrees *across* the dry-line alignment. Rapid and continuous
variation of heading at relatively low cruising speeds and a light wing
loading made this possible. Of course, along the alignment of the
dry-line convection one could do better with infinite or climbing
glides.
Last year I used similar techniques in a 500km-plus distance to a goal
flight in the little Woodstock from here in Kansas. For the purposes of
comparison with the recent PW-5 record flight from Arizona to New Mexico
(for which congratulations are certainly in order to the pilot and
crew!) this flight was accomplished at a speed some 7 mph faster than
the PW-5 flight. Minimization of circling time through these and other
Microlift flight techniques was the key.
Individuals such as Paul MaCready and Bruce Carmichael (see current
article in Soaring Magazine), seeing the potential to utilize certain
atmoshperic effects, have championed the cause of very light glider
develpment for decades. In recent years, the Sailplane Homebuilders
Association, a division of the SSA, has focused much analysis and design
evergy into this category and is leading the world in this regard. New
and superior designs, both homebuilt and ready to fly are about to be
introduced. An excellent periodical is published which regularly
chronicles the pertinent issues in this regard.
Both at last year's meeting of the august Sailplane Development Panel of
OSTIV and on this year's agenda the very light sailplane is being
analyzed. The US delegate to this panel, Dan Armstrong, is a talented
aerospace engineer and a strong proponent of the very light sailplane's
future as was the late Oran Nicks.
Lest some who post regularly to this newsgroup get the wrong idea about
the nature of this post, I do not think that very light sailplanes can
possibly cover the entire scope of soaring potential. I enjoy flying a
variety of designs, and presently own what is arguably the heaviest
single-place glider in the world, an experimental open class ship which
possesses an AUW wing loading of some 12 psf *without* any ballast. I
think the PW-5 is great, I think the ASW-22 is great, I love soaring.
It is fascinating to watch these developments unfold, and even more
satisfying to experience the flying which is unique to the lightest of
designs. Personally, the most fascinating soaring I have ever
experienced has been in the prototype Carbon Dragon because it comes so
close to the type of flying we see in natural soaring birds.
Those who are intersted in learning more about this area can contact me
directly via private e-mail.
Best Regards to All, Whatever You May Fly,
Gary Osoba
Current Ultralight Soaring Champion (by default)
President, Sailplane Homebuilders Association
Project Coordinator, LightHawk ULS
Sean
soaring...<<
LOL ;-{)
Gary,
I loved this line ! I think you've got yourself covered <g>.
--
se...@direct.ca
Donald Ingraham
> Most likely, the water is coming in through the gap between the wing and
> fuselage. This will happen if the wing root tape is loose. You might try
> placing an additional row of tape on each side of the tape you use on the
> bottom side of the wing and at the trailing edge for a distance of a foot or
> so.
I agree. This happened on my Discus CS a couple times. I'd peel the tape
off the bottom of the wing/fuselage gap after flying ballasted and to my
horror water would drip out. A small amount was in the fuselage too.
I also thought I had an internal leak, but when I mentioned it to a top
Discus pilot he suggested slightly over-lapping the wing-junction tape
with a second piece of tape from the zig-zag to the trailing edge. About
a foot, as Tom suggests. That cured it.
I'd be interested in a procedure to get the rubber dump valves seated
tight/flush if there is one. Vaseline stops mine from leaking, but
they do sit 1/8" or more recessed and trip the laminar flow I'm sure.
_______________________________________________________
Don Ingraham
SGI Friends help you move.
d...@sgi.com Real friends help you move bodies.