DFS - 230

[wingsoverk3]

Greetings again gentlemen,
Work on the DFS-230 fuselage continues. I'm building the DFS 230 A-2 version which had dual controls and longer cockpit.













I have a question. In the build plans is what appears to be a trapdoor.
Anyone know what it is?




Best
Vik

[VincentB]

Please Vik, put photos only on the retroplane's server, not on extern hoster like photobucket, and with the right size 600px max, thanks
like explained here http://www.retroplane.net/forum/viewtopic.php?t=3808

it's not a system to release the landing gear?

[Walter L.]

Hi Vik,

you live in one of the most fascinating areas of our planet. I would like to visit your country, if I could....

Concerning your question I can tell you that the DFS 230 had spoilers on the upper side of the wing. In the book of Peter Ocker, who wrote and published a book about Hans Jacobs (who designed the DFS 230), there is a drawing which shows these spoilers. It is a drawing of Vince Cockett, who is a member in this forum....

Tomorrow I will make a picture of it and post it here.

Regards from Germany
Walter

[wingsoverk3]

Hi VincentB,
Gotcha WRT posting photos. My daughter does my IT-work, posting on forums but she'll be off to college in couple of months so I have to learn myself.
Hmmm, I think you're right, it's for the takeoff landing gear.

WalterL, I live in Sikkim which is between Nepal, Bhutan, China. Kanchenjunga is 50km or so west of one of the airfields I fly from. You are more than welcome to visit with one of your birds. I have a small hotel or two, be my guest.
I practice M/L range flying (in non-monsoon months) from Bulbulay Dara N 27° 22' 09.0" E 088° 37' 41.1"
http://www.paraglidingassociationofindia.org/pgfest2012/
http://www.paraglidingassociationofindia.org/pgfest2012/bulbulay-dara-flying-site.html
My own airfield outside bedroom. I replace the CFL with strobe lights during flying season

[Walter L.]

A very nice region...

Here the promised picture. It is from the book: "Hans Jacobs. Pionierleben im Flugzeugbau" (Pioneers life constructing airplanes) from Peter Ocker:





I hope this helps.

Regards
Walter

[wingsoverk3]

Thanks a ton. I was going to install the spoilers anyway but this is the extra validation needed.
Best

[wingsoverk3]

Fuselage is upright first time. RDF900 radio modem (900 MHz) for telemetry will be on top of fuselage aft of wing so the heatsink will be exposed to slipstream.

[wingsoverk3]

Another DFS-230 with no evidence of spoilers.

[wingsoverk3]

Progress on fuselage continues:

[wingsoverk3]

Many thanks to Erik (Ka-6BR), the ventral trapdoor which puzzled me "holds a drogue chute that attaches to the tail skid strut. There is a spring on it, and the latch is operated by a control cable from a servo as near as I can read from the plan."
Thanks Erik for the information. He adds: "the camouflage scheme... is inaccurate in most model kits and aircraft paintings.

"The DFS gliders that assaulted Fort Eben Emael and the three bridges in 1940 were light gray with side insignia painted out with a slightly darker gray.

"The swastika on the V-stab and crosses on the wings were not added until late in the war, as a glider was not considered an aircraft until then. I have found nothing on the squadron code letters & number codes on the fuselage sides.

"The late war 'C' model has the two doors on the fuselage left side and the MG-34 machine gun on the top. I don't know when the machine gun on the cockpit right side was first used. The pilot operated it by pulling a lanyard.

[wingsoverk3]

First avionics suite installed is RFD900 (900 MHz) telemetry radio modem. Since it's a two aircrew plane, might as well have clean uncluttered FPV video feed and let back-seater worry about flight and navigation data.
Glazed cockpit allows for two cameras, forward and rear-facing or a single one with limited pan and tilt. Plus, another camera embedded in wing all controlled via three-way switcher.
Nose will have HobbyKing Glider Nose Tow-Line Release mechanism and airframe will have flight stabilizer, perhaps APM 2.5 or 3.0. In theory, it'll be a lazy man's FPV bird being aero-towed by the three-IC-powered tug for most of the flight.

[wingsoverk3]

Many thanks to Erik (KA-6BR) for providing me with juggernaut of documentation on the original DFS-230.

[wingsoverk3]

The DFS-230 started out as a simple 4-channel analog 72Mhz build to match the Tante Ju mothership but when you put a bunch or retired EEs, well, you know what happens. Now it'll be open 433Mhz UHF openLRS (7-watt Tx) for RC which I've had good experience with. HobbyKing has come out with Orange version which I'm still waiting for. 1.5watt Mondo Extreme 5.8Ghz video downlink for FPV cameras, two in cockpit, one in wing, via 3-way video switcher. Flight stabilization is HK Orange or their APM2.5 clone. Then there's the 900Mhz telemetry for navigation and flight data, including temperature, pressure, airspeed sensors. I'm looking into coding the radio modem to include lost/downed aircraft locator beacon mode activated by magnetic switch. HK navigation strobe lights.
So much electronics: I hope I have enough energy storage onboard as I drew the line on solar panels on wing.
Kanchenjunga is to be our San Grasso/Eben Emael. Longest towline I've used is 150-feet. Will experiment with 100-meters after maiden so I always get higher FPV that tow tug.
It's monsoon here so no flying or even paragliding. Lots of time on my hands.
Only problem I foresee is that I am working off of Klaus Nietzer's plans which has undercambered wings as with the original. The Hawkins plans appear more simple build with flat-bottom (I think Cark Y) airfoils.
Started work on empennage. Both H- and V- stabilators have CF spar caps to avoid chance of flutter due to short tail moment.

[wingsoverk3]

Very good question. My previous 1.55-meter sailplane builds vary between 300 and 450 grams. This one will be heavier. Weights thus far:

The battery is the biggest concern and I'll only know the smallest one I can carry after flight tests. I may just have to forgo live FPV and just record video and rely on telemetry from DFS-230 and FPV live video feed from Ju-52.
The extra servo will be programmed to release take-off wheel dolly and then the towline. I am looking around for a lighter continuous rotation winch servo. The B1226 I have is far too heavy, over 100 grams. I'd like to be able to adjust length of towline inflight. Have used nichrome hot-wire cutter for nylon towline release before. It works.

This build won't be entering any F3B, F3J, F3F, etc., events. It won't even be a conventional glider. Like the original, she'll be towed for the major part of the flight regime. For maiden and testing flights (hi-start or off slope), it'll only be the RC gear with small battery. I'll add the rest of the equipment in stages as I get more used to flying her. Once I get sink/glide rate polars, I'll know best airspeed for distance in the final Kanchenjunga configuration.

If I achieve a fraction of the polars of the original DFS-230, I'll be okay to get released on return leg as winds in October-November are typically west to east by south east so I expect good tailwind. As quoted at fpvlab, "My math says 1:1 glide back home......even a library book could make that glide ratio."

WRT leading edges of the V- and H- stabilators, they're triangle stock sandwiched to 3x3mm square stock. The spars are 3x3mm square stock capped by 3x0.5mm CF. Had to reinforce both for protection against flutter and for mounting GSM patch antenna in H-stab and 900 Mhz VP diversity antenna in V-stab. (The horizontal polarized 900 Mhz antenna goes in port wing). I deviated from Klaus Nietzer's plans for a number of reasons. His design does not have spoilers. I just received Hawkins version which I think is more suited to my 1.64-meter WS.

[wingsoverk3]

[wingsoverk3]

[wingsoverk3]

Bonjour again gentleman. Merci to Jo for the heads up on plans and short kit for 3.11-meter DFS-230. Mine's only half that size, having been sized to match Ju-52 tow tug.
Hope to have a squadron of combat transport gliders. Looking for drawings and documentation on the Hindusthan Aircraft G-1 glider:






The DFS-230 assault glider went into battle with two MG-34s and a MG-15







I was lucky to find separate static and pitot probes for the airspeed sensor to replace my old one.






I hope to hide the sensor probes within the scale MG-34 forward-firing guns.








Work on the vertical and horizontal stabilators has stopped until I get the VP and HP 900MHz patch antennas to install in them.

[wingsoverk3]

Not much progress on the DFS-230. The laser cutting service I use are closed for annual holiday. Work has not even started on the group-build Ju-52 so the DFS-230 will have a lonely maiden. Looking around for a power pod, mind kept coming back to the Mistel (mistletoe) composite configuration of the DFS-230 powered by a Messerschmitt Bf 109. Got the plans off of outerzone.co.uk, scaled it down to match the DFS-230, and off with another monsoon scratch-build.

The Bf 109 "power pod" will have two channels, one for throttle, other for inflight mixture control of the 1.5, 2.5, or 3.2 cc diesel (kerosene, castor oil, ether, amyl nitrate mix) engine. No controls for the flying surfaces, just ground adjustable trim tabs to counter over-prop torque.

Started off on the wings, just 16 ribs to hand-cut.

[wingsoverk3]

Scrounged in my parts bin and came up with a workable solution for the struts connecting the Me-109 and DFS-230. Ball-joints connected via 3-mm all-thread rods. I hope it does the trick. The excess epoxy is to withstand typical vibration of diesel engines:

[wingsoverk3]

Towline hook mechanism finally arrived after six weeks from HobbyKing.
Power pod is beginning to look like one. Still don't know which size engine to use, 1.5, 2.5, or 3.2cc diesel.