• Gear Warning (in progress) - The Cambridge 302 has an integrated gear warning system. This will alarm when the airbrakes are opened and the gear is not down and locked. In addition the Cambridge 302 will alarm if the airbrakes are opened during take off roll when above 25 kts. I am using magnetic reed switches rather than the more typical mechanical micro switches as these magnetic switches are non-contact. I run the wiring and created brackets to hold the magnetic switches. An electrical wiring diagram, including the gear warning, for this ship is available here.
• Seal push rods at wing root - The real problem mentioned in the spring repair above has to do with the pressurization of the cockpit at high speeds from vents. The only exit point for the air is out the wing roots and then the airbrake caps. Sealing the push rods openings should help this and increase performance a bit.
• Cockpit Air Extractor - Another solution to the above problem is to give an easy exit point for the air coming into the cockpit from the vents. This is generally along the top of the turtledeck. This has the advantage of allow more air into the cockpit which can be useful in desert regions. The DG-101 has a removable hatch on the turtledeck to access the aileron and airbrake hookups which could be fairly easily replaced to facilitate this modification. [need links to RAS articles].

Documentation Links

• A Flight Evaluation of the DG-101G, Richard H. Johnson, Soaring, May 1985
  (scanned from the original article)
  High Resolution (20mb)    Low Resolution (2mb)
• Glaser Dirks (DG) - Main Web Site
  • Glaser Dirks (DG) - Technical Notes
• Wikipedia DG-100/DG-101 Web Site
• Sailplane Directory DG-100/DG-101
• Miscellaneous DG-100/101 Documentation

Video - a DG-101G following a DG-300 for a Landing

The N101RP Trailer

As you can see in the pictures below, the trailer is home built. However, it is about the best looking and functional home built wooden trailer that I have seen. A good friend commented, "It's like looking inside a piano!".

It is made of wood (mostly plywood) covered in fiberglass cloth and then painted in 2006 with Benjamin Moore Polyamide epoxy paint (M37 84). Whomever manufactured the steel and aluminum fittings, they are first class. It is quite weather tight and I have never had an insect or rodent issue. While the trailer is heavier and less aerodynamic than a fiberglass trailer (i.e. Cobra), I have found that it is easier to rig as there is a simpler ramp system and faster fuselage dolley raiser with its over-center lever approach (no cranking/pumping - see images below). More details above in the Upgrades and Changes section.

Interior Details;

• The fuselage is held onto the fuselage cradle by a nylon strap. A single motion with the fuselage dolly raising arm and the fuselage is at the exact height for assembly. When the fuselage/cradle is rolled into the trailer, the cradle mates with a 1/4" steel receiver (new) to hold it down during travel. The rear wheel settles into a fitted floor recess. The tail boom can be strapped down to floor rings using supplied padded automotive seat belt webbing and buckle.
• The wings are held in place onto their rolling dollies by placing the spar pin hole over a nylon male fitting and then secured with large easy to handle custom-made wing knurled bolts. When stowed the wing dollies are held in place (root) under a 1/4" steel plate (new) and is then can be pinned in place for travel. Each wing tip is held in place (aft) by really nice custom-made fittings which also captures the ailerons. Slick!
• The elevator is held in place with a custom-made hinged interior roof rack with a securing pin.

• Anti-Sway Bar - The trailer did sway especially when being overtaken by a semi. Adding forward weight helped. Then I added one of these devices which really helped.
• Electrical
• Wiring - Rewired the trailer lighting end to end using ring lugs and added terminal blocks fore and aft.
• Lighting - Replaced the existing small two incandescent brake/turn lights with LED. I also added amber and red clearance LED lights along each side and fender mounted brake and turn signal LED lights.
• Ramp - I extensively modified the tail ramp configuration. Originally there was no ramp off the end of the rear door. I added the hinged diamond plate ramp to aid rolling the fuselage dolly onto the ground.
• Wing Dolley Track - I extended the wing dolly U-channel track onto the rear ramp (previously it stopped inside the trailer) which makes it much easier to grasp the wing spar. The original track was also only 1/2" tall so was replaced with 1" tall track. This prevents the dolly from possibly jumping the track and more securely holds the dollies in place during transport.
• Hatches - The front hatch is now held open by a marine grade chrome latch and has a stainless steel hinge with rubber weather guard. The rear hatch is locked with marine grade chrome 1/4 They never leak.
• Tie Downs - There were no trailer tie downs so I added BOAT CLEATS. You might find boat cleats are a bit odd to find on a glider trailer but they are simpler to use than the typical trailer tie down rings, doesn't rattle around during road trips and, as I like to say, "If it's good enough for the Queen Mary, it's good enough for my glider!".
• Front Storage (Interior) - I added this storage box between the wings to hold the tire jack, etc. I have two heavy plastic, folding top, storage boxes that sit on top of this box.
• Front Storage (Exterior)- I use it to store tie downs, jockey wheel, chocks, etc. At first I added a heavy duty plastic "tub" which did not last very long. Then I added this baked enamel steel box with hydraulic lift which came from Harbor Freight. To connect it to the coupler tube there are four 1/4" thick "Unistrut" steel L brackets, an internal 2x12 wood floor, and 1/2" galvanized bolts. A diamond plate version would be nicer but more expensive.
• Spare tire - there wasn't one. Now there is. Braced inside and out with 1/4" steel. 'Nuff said.
• Boom Tie Down - The tie down was a steel shaft going through the hollow middle of the tail wheel axle. This didn't seem safe nor good for the tail with twisting loads. I changed it to a (sheepskin covered) seat belt similar to what you might find in Cobra trailers.
• Outriggers - During rigging the trailer aft would rest on a 8"x8" wood block which I had to lug around (and forget). I added screw type outriggers at the rear of the trailer which are found on some commercial glider trailers. These lower to stabilize the trailer and can be raised into the trailer bed for travel.
• Rear Wheels - I added under floor "skid" wheels at the rear of the trailer.
• Reflectors - Important when parked and unlit. I added;
  • "European" triangular reflectors at the rear.
  • 3M reflective tape on the rear and sides.
  • Round reflectors on the fenders.
• Fuselage Cradle Over-center Lock - The fuselage is raised for wing rigging via an ingenious cradle using an over-center lever arm. The arm was loosely captured by a block of wood against the cradle itself. Not very secure and the arm could slip backward against the wing's leading edge. I manufactured this plate which locks the arm in place and yet allows easy access. The swirled pattern is called "engine turning" and helps to hide surface marring (and looks cool too). This is easily done with a small cup type wire brush held in a drill press.
• Cradle Capture Bracket - This locks the cradle to the trailer floor for transport. It was wood and is now 1/4" steel.
• Jockey Wheel - To raise and lower the trailer onto the tow ball, there was a standard US screw jack. I replaced it with a "European" removable jockey wheel and bracket which I find superior but which are not easy to find in the US. Fits nicely into the external storage box.
• Locks - Changed out the front and rear door locks with heavily chromed units from Lee Valley.
• Glider Boom Tie Down - The tie down was a steel shaft going through the hollow middle of the tail wheel axle. This didn't seem safe nor good for the tail with twisting loads. I changed it to a (sheepskin covered) seat belt similar to what you find in Cobra trailers.
• Vertical Stabilizer Lock - The fuselage can rotate slightly in its cradle. This could allow the vertical stabilizer to touch the side of the trailer. I added padded blocks in the "dog house" to limit side to side travel and protect the vertical stabilizer.