Experimenter is a magazine created by EAA for people who build airplanes. We will report on amateur-built aircraft as well as ultralights and other light aircraft.
Issue link: http://experimenter.epubxp.com/i/418587
EAA Experimenter 9 ROTAX HAS RELEASED a mandatory service bulletin (SB) that may af ect your carbureted Rotax engine. Owners/operators should pay special attention to the requirements of this infor- mation release and in particular the details and requirements as outlined in the actual SB. Compliance to this SB is a manda- tory requirement and af ects serial specifi c engines and carbs as well as any engines or carbs that may have been serviced with new fl oats (Part Number 861 184) from spare parts that were produced from approximately June 1, 2012, onward. (Check SB for details— http://legacy.rotaxowner.com/si_tb_ info/serviceb/sb-912-065.pdf .) The issue stems from a possible manufacturing deviance leading to some fl oats absorbing fuel, which increases their weight af ecting the fl oat level in the carb. Possible ef ects may be a rough running engine especially at low speeds, en- gine stoppage, and/or fuel leakage in the area of the carbure- tor venting. Rotax has developed a quick test method using a special as- sembly of parts. (See SB for the specifi c list of parts required to make up the test tool.) In most cases, the process allows for check- ing the fl oat level while the carbs remain installed on the aircraft. For this test, you must run the engine for two minutes to ensure the fl oat chambers are full, then after shutdown, remove the carb vent line and the choke plate cover (four screws). And using the special test tool, you inject a measured amount of fuel into the carb fl oat chamber until it just starts coming out of the carb overfl ow. At this point, you measure exactly how much fuel you injected into the chamber by which you can determine if it falls into the correct range or not (between 23 milliliters to 40 milliliters). If it fails, then you must remove both fl oats and weigh them together on a precision gram scale (+/- tolerance of 0.1 gram), and if the two fl oats together weigh over 7 grams, then they both need to be replaced. (Floats are supplied in pairs.) Until Rotax comes up with a new fl oat design, all fl oats that have come from replacement parts since June 1, 2012, or which are already installed in carb serial numbers and/or engine serial numbers af ected by this SB, must be checked every 25 hours of run time or every 60 days, whichever comes fi rst. An important point to keep in mind regarding this SB is that even if you replace your floats with a new or the same part number, 861 184, the mandatory 25-hour/60-day checks are still required until such time as Rotax can supply a com- pletely new design of float. Each time the test is performed, a new choke cover gasket, Rotax Part Number 950 030, must be installed. Mandatory Rotax Service Bulletin Requires Carb Checks IMAGINE BEING towed through the air behind an airplane, like a wakeboarder or water-skier being towed by a ski boat. That's the general idea behind the WingBoard, which is being developed by former Young Eagle Aaron Wypyszynski, EAA Lifetime 579057, and president of EAA Chapter 190 in Meridianville, Alabama. Wypyszynski is launching an ef ort to get the product—what he calls "a wakeboard in three dimensions"—of the ground through his company, Wyp Avia- tion. The sport involves a close coordina- tion of the rider, towrope, and composite WingBoard. Its shape has a stable center of gravity while the rider, attached to the board with a binding, stands upright and leans and twists in all directions to maneuver the board. The unique tow- rope design provides stability and also reduces forces on the rider. The phase one prototype is a 1/6-scale model using a remote-controlled airplane that tows the WingBoard with a 3-D-print- ed human model on board. Wypyszyn- ski claims the prototype has proved the aerodynamic stability and control of the design. Next up is work on a phase two prototype, a 40-percent-scale model and fi nal stepping-stone toward the develop- ment of the full-scale prototype. EAAer Launches WingBoard Project