DG-101 - increase performance/sealing/winglets(?)

I've been flying my DG-101 for a year now and really love it. However, there are some gaps which haven't been sealed and I'd like to give tuning a shot.

Does anyone have experience using aileron fences? Would it be worth using to increase handling?

My rudder has no gap sealing to transition from tail to rudder. Is this advised to still have that sealed?

Is turbulator tape something interesting? I have seen some articles on this for a Standard Cirrus but can't seem to find a definitive answer.

Last but not least, winglets. I know there are no factory upgrade winglets available for a DG-100/101, but could it be possible to add the DG-300 winglets?

Every % of performance is welcome, feel free to add your options

On Thursday, 11 July 2019 11:44:55 UTC+3, Senna Van den Bosch wrote:
I've been flying my DG-101 for a year now and really love it. However, there are some gaps which haven't been sealed and I'd like to give tuning a shot.

Does anyone have experience using aileron fences? Would it be worth using to increase handling?

My rudder has no gap sealing to transition from tail to rudder. Is this advised to still have that sealed?

Is turbulator tape something interesting? I have seen some articles on this for a Standard Cirrus but can't seem to find a definitive answer.

Last but not least, winglets. I know there are no factory upgrade winglets available for a DG-100/101, but could it be possible to add the DG-300 winglets?

Every % of performance is welcome, feel free to add your options

Fences: not worth it

Aileron+rudder sealing: teflon + mylar everywhere

Turbulator: probably not worth it with that profile

Winglets: prepare for long and expensive paper work

Best aerodynamic performance improvement is almost always good electric bugwipers unless you fly over desert.

Make sure your vario system doesn't leak then spend anything else on
aerotows

PF

At 10:52 11 July 2019, krasw wrote:
On Thursday, 11 July 2019 11:44:55 UTC+3, Senna Van den Bosch wrote:
I've been flying my DG-101 for a year now and really love it. However,
there are some gaps which haven't been sealed and I'd like to give tuning
a
shot.

Does anyone have experience using aileron fences? Would it be worth
using
to increase handling?

My rudder has no gap sealing to transition from tail to rudder. Is this
advised to still have that sealed?

Is turbulator tape something interesting? I have seen some articles on
this for a Standard Cirrus but can't seem to find a definitive answer.

Last but not least, winglets. I know there are no factory upgrade
winglets available for a DG-100/101, but could it be possible to add the
DG-300 winglets?

Every % of performance is welcome, feel free to add your options

Fences: not worth it

Aileron+rudder sealing: teflon + mylar everywhere

Turbulator: probably not worth it with that profile

Winglets: prepare for long and expensive paper work

Best aerodynamic performance improvement is almost always good electric
bugwipers unless you fly over desert.

Rudder, aileron and elevator (or trim tab if all-flying tail) are easy to do and should help. I've heard it said by people who know what they're talking about that with these old profiles it maybe useful to put turbulators on the top surface of the wing - but then it's a pain to clean & the potential difference is negligible anyway.

I've never seen a DG100/101 with winglets - perhaps DG may produce a NEO kit one day?

Something i've always wondered about with mine, there is clearly an extreme amount of washout at the wingtips - at anything above about 80 knots the tips begin to bend downward a large amount. Perhaps winglets might relieve some of the drag caused by the washout at high speed, while still retaining it's good manners?

Nick.

On Thursday, July 11, 2019 at 9:40:39 PM UTC+1, Nick Gilbert wrote:
Rudder, aileron and elevator (or trim tab if all-flying tail) are easy to do and should help. I've heard it said by people who know what they're talking about that with these old profiles it maybe useful to put turbulators on the top surface of the wing - but then it's a pain to clean & the potential difference is negligible anyway.

I've never seen a DG100/101 with winglets - perhaps DG may produce a NEO kit one day?

Something i've always wondered about with mine, there is clearly an extreme amount of washout at the wingtips - at anything above about 80 knots the tips begin to bend downward a large amount. Perhaps winglets might relieve some of the drag caused by the washout at high speed, while still retaining it's good manners?

Nick.

It is pointless installing turbulator tape or winglets on any glider wing unless you have clear experimental aerodynamic evidence for your glider type that the exact turbulator position and/or the design and installation of the winglets actually does more good than harm - the latter is quite possible in both cases otherwise.

On Thursday, July 11, 2019 at 4:40:39 PM UTC-4, Nick Gilbert wrote:
Rudder, aileron and elevator (or trim tab if all-flying tail) are easy to do and should help. I've heard it said by people who know what they're talking about that with these old profiles it maybe useful to put turbulators on the top surface of the wing - but then it's a pain to clean & the potential difference is negligible anyway.

I've never seen a DG100/101 with winglets - perhaps DG may produce a NEO kit one day?

Something i've always wondered about with mine, there is clearly an extreme amount of washout at the wingtips - at anything above about 80 knots the tips begin to bend downward a large amount. Perhaps winglets might relieve some of the drag caused by the washout at high speed, while still retaining it's good manners?

Nick.

Sealing will give the best bang for the time and money, after getting the instruments working well and getting the CG in a good place.
Most of the airfoils of that vintage will benefit from turbulators on the bottom to slightly help the high speed portion of the polar.
The key from my experience with unflapped ships is to discipline yourself to not fly too fast and use the better glide angle that results to do less time climbing.
Nothing to do about the twist. Just enjoy the docile handling.
Many of the older ships can't get winglets due to bending issues, and more importantly stiffness in twist.
I say seal it up and enjoy a very nice glider. I had one for a short time.
FWIW
UH

On Thu, 11 Jul 2019 14:27:23 -0700, unclhank wrote:

Most of the airfoils of that vintage will benefit from turbulators on
the bottom to slightly help the high speed portion of the polar.
The key from my experience with unflapped ships is to discipline
yourself to not fly too fast and use the better glide angle that results
to do less time climbing.

Agreed, and I have them fitted on my H.201 Libelle to improve fast
cruise. Other gliders with the same wing section may also benefit -
Glasfaser knows exactly where to put the undersurface turbs on the
Wortmann FX66-17A2-182 section.


--
Martin | martin at
Gregorie | gregorie dot org

Op donderdag 11 juli 2019 23:27:24 UTC+2 schreef :
On Thursday, July 11, 2019 at 4:40:39 PM UTC-4, Nick Gilbert wrote:
Rudder, aileron and elevator (or trim tab if all-flying tail) are easy to do and should help. I've heard it said by people who know what they're talking about that with these old profiles it maybe useful to put turbulators on the top surface of the wing - but then it's a pain to clean & the potential difference is negligible anyway.

I've never seen a DG100/101 with winglets - perhaps DG may produce a NEO kit one day?

Something i've always wondered about with mine, there is clearly an extreme amount of washout at the wingtips - at anything above about 80 knots the tips begin to bend downward a large amount. Perhaps winglets might relieve some of the drag caused by the washout at high speed, while still retaining it's good manners?

Nick.

Sealing will give the best bang for the time and money, after getting the instruments working well and getting the CG in a good place.
Most of the airfoils of that vintage will benefit from turbulators on the bottom to slightly help the high speed portion of the polar.
The key from my experience with unflapped ships is to discipline yourself to not fly too fast and use the better glide angle that results to do less time climbing.
Nothing to do about the twist. Just enjoy the docile handling.
Many of the older ships can't get winglets due to bending issues, and more importantly stiffness in twist.
I say seal it up and enjoy a very nice glider. I had one for a short time..
FWIW
UH

Thanks! I will be contacting DG and SCT Terlet (where I bring my glider for ARC) for advice. I have seen some DG-100 with different wingtips than mine, wingtips more like the LS-4, with a very slight curve and narrowing to the end of the tip, where my DG's wingtips have some sort of block (about 1 inch) with a metal skid. Maybe it would be possible to replace these?

On Fri, 12 Jul 2019 02:44:30 -0700, Senna Van den Bosch wrote:

Thanks! I will be contacting DG and SCT Terlet (where I bring my glider
for ARC) for advice. I have seen some DG-100 with different wingtips
than mine, wingtips more like the LS-4, with a very slight curve and
narrowing to the end of the tip, where my DG's wingtips have some sort
of block (about 1 inch) with a metal skid. Maybe it would be possible to
replace these?

About the tip skids: yes, it may be possible to replace them under EASA
rules - I replaced the tip skids on my Libelle without any arguments from
my inspector and Glasfaser, who hold the type certificate, certainly
didn't object. They supplied the new skids.

My original skids were certainly non-standard. They were rectangular
rubber blocks about 15mm thick, 20mm wide and 200mm long. The new ones
are bigger: 50% longer, nearly twice as wide, 50mm deep and a nice
aerodynamic shape. I haven't noticed any handling differences since
fitting them.

But, why do you want to replace yours? IMO ugliness is not a good enough
reason for a job that may be harder than it looks.

I had a good reason for replacing the old skids, which were on the glider
when I bought it. They were far too shallow because they let the aileron
touch the ground at full deflection and, as there was slight abrasion on
the aileron undersurface at the TE, I thought that fitting taller skids
was a good idea. This is why I fitted 50mm skids instead of 30mm.

That solved the aileron abrasion problem, but there are other possible
problems that you need to be aware of. These were my issues:

- the old skids served to keep the tip dollies, needed to guide the wings
into my box trailer, on the wing. These slip over the LE, wrap round the
tip and have a chord-wise extension that passes inside the tip skids and
clips over the TE to hold the dolly in place.

I was careful to position the new skids so that the tip dollies still
fitted correctly.

- my tow-out wing dolly is designed to be put on by sliding it in along
the wing after slipping it over the tip. It is a single airfoil-shaped
loop of fibreglass with carpet inside it and the wheel attached on forks
to the underside.

I completely forgot that it had to pass over the tip skids, and ended up
cutting it's top surface 50mm in front of the TE and fitting over-centre
latches to let it be opened and put round the wing from the front, rather
than passing it over the skid. That now works OK, but I had a fair amount
of fiddling to make the latches work correctly without distorting the
shape of the 'loop' and hurting the wing while still closing firmly
enough to stay in place while the glider is being towed round the
airfield. This involved two visits to the airfield for trial fitting and
adjustment with workshop time after each visit - I live an hour's drive
away from the airfield.


--
Martin | martin at
Gregorie | gregorie dot org

On 12/07/2019 10:44, Senna Van den Bosch wrote:

Thanks! I will be contacting DG and SCT Terlet (where I bring my glider for ARC) for advice. I have seen some DG-100 with different wingtips than mine, wingtips more like the LS-4, with a very slight curve and narrowing to the end of the tip, where my DG's wingtips have some sort of block (about 1 inch) with a metal skid. Maybe it would be possible to replace these?


The different wingtip profile is an official DG mod covered by DG100 TN
301-20. See the DG website for info.

https://www.dg-flugzeugbau.de/en/mai...echnical-notes

--

Nick Hill