{"id":9549,"date":"2014-12-23T20:07:19","date_gmt":"2014-12-24T03:07:19","guid":{"rendered":"http:\/\/cafe.foundation\/blog\/?p=9549"},"modified":"2014-12-23T20:07:19","modified_gmt":"2014-12-24T03:07:19","slug":"two-motor-electric-german-ultralight-made-usa","status":"publish","type":"post","link":"http:\/\/cafe.foundation\/blog\/two-motor-electric-german-ultralight-made-usa\/","title":{"rendered":"A Two-motor Electric German Ultralight \u2013 Made in the USA"},"content":{"rendered":"

If you are young enough and in good physical condition, dragging a 100-pound ultralight airplane to the top of a hill and hopping off allows an incredibly low operating cost for a very green aviation experience.\u00a0 As one gets older, this kind of flight is still attractive, but some form of landing gear or training wheels, and quite often, some form of motive power, become necessary.<\/span><\/p>\n

\"ULF-1<\/a>

ULF-1 being bungee-cord launched. Pilot can also lower his or her gear to foot launch into a stiff breeze<\/p><\/div>\n

The German ULF-1 <\/a>has been around for several years, prompting several builders to put their own distinct look on the vintage-looking sailplane.\u00a0 \u00a0In fact, over 40 of the microlift-capable craft have been built from plans supplied by designer Dieter Reich.\u00a0 ULF-1 is a highly capable vehicle, with the longest flight so far lasting six hours and the furthest distance flown around 140 kilometers (87 miles).\u00a0 The original was constructed by Heiner Neumann, and each example built since has incorporated the usual homebuilder\u2019s touches to each new version.<\/p>\n

\"Homebuilder<\/a>

Homebuilder showing results of patient work, high parts count necessary to achieve low weight<\/p><\/div>\n

This Russian link <\/a>gives a view of an EAA member building the basic wooden frame.\u00a0 Note all the \u201cfiddly bits\u201d required to keep weight down.\u00a0 Much of this could be done with bargain bags of spruce<\/a> from Aircraft Spruce and a lot of uninterrupted time.<\/p>\n

\"ULF-1E<\/a>

ULF-1E with twin pusher motors, steerable nose wheel, and other refinements<\/p><\/div>\n

Klaus Burkhard, who oversees a splendid web site on ultralight sailplanes, advises that a very different variant is going together in Charlotte, North Carolina.\u00a0 He calls it \u201ca very exciting \/ revolutionary E-Project<\/a>, and notes that \u201cHolliday Obrecht and his crew,\u201d are crafting \u201csome remarkable alterations, the most exciting one\u2026 a 2-motor electric drive for enabling the ULF-1 to be self-launched.\u00a0 Please see my new blog describing the project<\/a>, which might be of interest for you.\u201d<\/p>\n

\"Holliday<\/a>

Holliday Obrecht (wearing glasses and to right of vertical tail) with merry band of North Carolina helpers<\/p><\/div>\n

Burkhard thinks the \u201ctechnical amendments \u2018Made in [the] USA\u2019\u201d are an \u201cabsolute quantum leap from the original design, comparable to the differences between the original Zeppelins\u2019 construction to the high-technology versions floating over Friedrichshafen today. \u00a0\u00a0Burkhard acknowledges the \u201cE\u201d suffix represents the electrical, self-launching hopes for the craft, but the construction marks a \u201cNew Technology\u201d that calls for a \u201cmore appropriate model-designation\u00a0“ULF-1 NT,”<\/i> rather than just calling it the \u201cObrecht ULF-1E.<\/em>\u201d<\/p>\n

The two electric motors will drive four-bladed folding pusher propellers.\u00a0 To compensate for that added weight to the rear of the craft, the nose has been extended 200 millimeters (7-7\/8 inches).<\/p>\n

Burhard\u2019s entry highlights the other, often high-tech ways the builders are maintaining the 115 kilogram (254 pound) empty weight that will allow flight under FAR Part 103 ultralight rules in America.<\/p>\n

\"Despite<\/a>

Despite substitution of chunks of Styrofoam for thin strips of wood, much careful fitting is still required<\/p><\/div>\n

The complex wooden construction has been simplified with CNC-cut Styrofoam\u2122\u00a0ribs, although the pictures show a still-involved wooden structure that requires (and seems to be getting) attention to meticulous joinery.\u00a0 Burkhard points out that the team is not interested in doing a \u201cquick and dirty job,\u201d but wants to \u201cmaster the art of wooden-glider craftsmanship.\u201d\u00a0 This may add a few years to the schedule, but the team will have a machine that can self-launch at local airports \u201cin the flat-lands.\u201d<\/p>\n

Holliday Obrecht and his enthusiastic friends are making an aircraft that trades sweat and time for big bucks, and that may be a signal to others that the essential elements of \u201cold-time\u201d aircraft construction have merit in this new age of electric transport.\u00a0 We\u2019ll be following their progress avidly.<\/p>\n