Bill has volunteered to be our first out of house tester for the Sync Master throttle system for the Rotax 912 engine. This blog will be updated with information every time that he comes in to the shop. We installed the Sync Master throttle system on his Just Air Super Stol which has a Rotax 912ULS 100hp engine installed.
You can see the slack in the cable at the carburetor after 49 hrs of operation. Originally there was only a small amount of slack. It is possible this was simply caused by the new cables stretching a little. He still had a full stroke from idle to full throttle so this slack was of no significance to the Sync Master's operation.
Brian John Carpenter of Corning, California has been named the 2017 National Aviation Technician of the Year. Very simply, Brian has become the go-to guy when it comes to the construction and maintenance of—and education about—Light Sport Aircraft. Anytime he’s not teaching a Light Sport Repairman Workshop, you’ll probably find Brian in his hangar at the Corning Municipal Airport working on his Electric Motor Glider or creating an aviation educational YouTube video.
Brian has had a passion for aviation since he was a child, building and flying RC aircraft. In junior high, he progressed to building a self-launching glider out of homemade materials and started jumping off a small hill trying to fly. In 1979 he earned his pilot’s certificate while in the Navy. After graduating from Helena Vocational Training Institute (Montana) with his A&P mechanic certification, Brian worked as a lead mechanic for Aero Union, a large aircraft operation and maintenance company (now defunct) based in Chico, California. By 1985, he was the Chief Inspector, and was promoted to the Director of Maintenance by 1990.
In 1991 Brian opened his own aviation company, Rainbow Aviation Services, a full service FBO in Corning, CA, providing a variety of aviation services including: inspections, maintenance, flight instruction, test flights, and aircraft certification. The principal focus of Rainbow Aviation Services is Light Sport Aircraft. Rainbow's Light Sport Repairman Courses have been taught throughout the United States and Australia. The company is a source of LIght Sport expertise for aviation enthusiasts, flight instructors, mechanics and even FAA inspectors. Brian has mentored over 3,000 repairmen since the light sport rule was implemented in 2004, and is the only active provider of FAA-approved training for the Light Sport Repairman rating.
Brian has built 36 aircraft so far, and has become an innovative aircraft designer. His current project—the EMG-6, an electric motor glider—is a perfect example. Brian is developing a low cost, electric aircraft to meet the needs of the average person, making the aircraft affordable, and creating complete video instruction for the build. Another example of his innovative approach is that Brian has designed over one hundred 3D-printed parts for use on the EMG-6, and has written at length about optimal methods of 3D printing aircraft components.
Over the years Brian has given back to the aviation in community in myriad ways. He serves as an EAA Technical Counselor, presents workshops, forums and seminars for various aviation events, authors aviation educational articles and videos (including a monthly column in EAA Sport Aviation magazine), and serves as a volunteer technical expert for EAA’s Homebuilder’s Tips video series, just to name a few. Together with his wife Carol, Brian co-authored two books, one about ultralights and another for sport pilots.
Brian holds Commercial Pilot, CFI, Remote Pilot (drone), and A&P mechanic certificates, and a current Inspection Authorization. He is an FAA Designated Airworthiness Representative (DAR) and Designated Sport Pilot Examiner, holds a Light Sport Repairman Maintenance rating, and is a Rotax Authorized Factory Instructor. In 2006, Brian received the John Moody Award, the most prestigious award in Light Sport Aviation. firstname.lastname@example.org
This article will focus on the Bing 64 CV (Constant Velocity) carburetor. The basic principal of operation utilizes a vacuum operated slide that varies the venturi size which, in turn, maintains a constant velocity of air passing through the carburetor at all engine power settings. The advantage of the CV carburetor is that it supplies the engine only as much fuel/air mixture as the engine demands. For an aircraft applications, where we have large excursions in altitude, this is exactly what the doctor ordered. The Bing 64 carburetor (Figure: 1) has become, hands-down, the most popular carburetor used in the light sport industry. It is used on both the Rotax 912 as well as the 914. It is also used on the HKS 700 E, the Stratus, the Rotec Radial, and the Jabiru engines. This carburetor has a long history of great reliability, on a plethora of aircraft.
Figure 1 The Bing 64 CV (constant velocity) Carburetor
"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.
January 30, 2017
For the last 16 days straight we have been engaged in a light sport
repairman maintenance class. This is one of the smallest classes that
we've ever had. Four of the students that signed up for this class had
to pull out for various reasons just before the start of class. The
wintertime classes are always limited to a maximum of 12 to accommodate
the facilities during the cold winter months. As it turned out the best
day, weather wise, of the entire class was the last day. All of the
students graduated with flying colors and will now move on to utilize
their FAA light sport repairman maintenance certificate in different
ways. Although this was a small size class of only 8 students, they came
from pretty much every corner of the United States. And unlike a normal
class, we had no foreign students this time. The next class will be in
May and is already starting to fill. This is the 1st class that we have
taken the class photo with a drone.
Low cost hydroforming on the Rainbow Aviation Video channel with your
host Brian Carpenter. In this episode were going to be taking a look at a
low cost way to manufacture your own aluminum hydro-formed parts. This is a companion video for technically speaking article published in the May 2016 sport aviation magazine
Before looking at batteries - consider the voltage current demand. Let’s compare voltage to gasoline. One gallon of gas contains 33.7kWh energy
according to EPA or 33,700Wh. How big of battery would that be? An NCM
Lithium-Ion pack would be 33.7kWh, 172 cells, 635v, 107Ah and weigh 927
pounds. If you factor in the fact that the average car only gets 23% of
that energy - the battery pack would still weigh: 213 pounds. So adding a
big current demand is not good. Nor is it a good idea to equate the
battery pack weight to 5 gallons of fuel in ultralights. ("apples to apples”)
For Sea-Kite.com the number one incentive was to build a highly efficient motor and use less energy.
It has been easy for some motor designers to make high kW demanding
motors. The problem - airplanes just couldn’t carry enough batteries.
Big motors also disqualify themselves to be used with solar and other
power supplies like fuel cells.
What is the
best battery and what on the “drawing board?” As for the future - higher
energy batteries can be made, but they are only good for 3 or 4 charges
and need to be scraped. The batteries that Tesla has been using,
sourced from Panasonic, for its Model S electric cars are mostly likely a
lithium-ion battery with a cathode that is a combination of a lithium, nickel, cobalt, aluminum oxide. The battery industry calls this an "NCA battery" and they've been around - and made by Panasonic, LG and Samsung - for many years.
lithium-ion NCA batteries use a combination of 80% nickel, 15% cobalt
and 5% aluminum. (The anodes in these traditional lithium-ion batteries
is usually a graphite combination, which acts as a host for the lithium
ions.) The addition of the aluminum to the NCA battery makes it more stable.
a home battery grid - Musk said that Tesla will use a lithium-ion
battery with a nickel, manganese, cobalt oxide cathode called an NMC (or
NCM) battery. Many traditional NMC batteries use one-third equal parts nickel, manganese, and cobalt.
do we stand among all the choices? NCM still reigns as king for safety
and it works great for cars that handle the slight increase in weight.
We have found a new source for the NCA which offers the weight
savings needed in aviation. As soon as we have all the numbers - they
will be posted on our website. Our new motor has an advantage because
with a slower charge time, lower discharge demand and our new Active BMS
- the safety went way up.
“There’s an app for that.” This overused cliché becomes more and more apropos every day. Even for the aircraft builder, we now have a virtual toolbox in our pocket that has become indispensable. We have reached the point in technology where it is now the norm for an aircraft manufacturer to publish maintenance manuals, parts manuals, and all other documentation, for that matter, in a digital format. If you’ve grown up on paper, the transition to digital can sometimes be difficult, but the rewards are well worth the effort.
#1 The PDF Reader App:(Figure: 1) The Rotax manuals, for example, consists of literally thousands of pages spanning more than a dozen different manuals. The ability to use a search function on a 500-page manual can really speed up the process of locating the information that you’re looking for. In our shop, we have a library of aircraft maintenance manuals accumulated over the last 40 years.
The classic 4130 chromoly steel welded structure has always been one of the most common building mediums to work with on experimental aircraft. This type of construction lends itself to a multitude of different types of applications and renders one of the highest strength to weight ratio manufacturing techniques, especially when it comes to fuselage assemblies. The welding of steel tube assemblies is a process that can be readily learned by just about anyone. And with current welding technologies like the TIG (tungsten inert gas) welder now coming down in price and becoming readily available to the average builder, precision welded aircraft subassemblies are no longer relegated to the professionals. (Figure: 1) Although this article is not a treatise on welding techniques, it is the primary answer to “How do I become a good welder?”
Becoming a good welder requires that you learn the principles of welding. Our recommendation, especially if you’re brand new to welding, is that you simply engage in a training program. Often a community college class is your most cost-effective method of learning the skills you need. And then, of course, practice is the key to becoming proficient. As you begin the process of welding, one of the first things that you will identify is that it becomes very easy to make beautiful looking welds if everything is set up properly. Good equipment, good environment, clean materials, and, equally as important, a proper fit of the pieces of material which you’re welding together. This has always been one of the most frustrating parts of making a 4130 chromoly steel fuselage assembly. Typically, when we are working off of a set of plans, we are taking a piece of 4130 tubing, cut it to length, and then grinding each end to precisely interface with the adjacent tube. We refer to this as “coping”. This process is usually a lengthy process of trial and error. We place the tube in position, then mark it, and then grind the end of the tube, refit the tube in place, check it, market and duplicate the process all over again until we have a proper fit. The process can be tedious, but if you have patience and a good eye for spatial orientation, with a little bit of practice, you can become pretty good at the process. All this being said, I’ve never met anyone who has welded a steel fuselage frame who has not come across the issue of fitting the tube and ending up with a fairly large gap on accident. If you’ve ever tried to close up that 1/4-inch gap by welding, you know that the end result isn’t going to be all that pretty. Those really pretty welds, that we all admire, are primarily a result of having two pieces of metal properly prepped and with a very nice clean consistent fit against each other. The welding bead flows very seamlessly and consistently because of this close contact. Producing a beautiful weld with these conditions is a no-brainer.
"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.
November 12, 2016
We have just finished up a marathon of 120 hr. Light Sport Repairman maintenance classes. October and November have been totally consumed by teaching. This class was the second half of a split class that that started three months ago and returned in late October to finish up the second half. The split class is normally smaller than the full class. This is held normally once a year to accommodate students that can't take 3 weeks off at a time.
An oleo strut is a pneumatic air–oil hydraulic shock absorber. The primary purpose of the oleo strut, as you are probably already aware, is to absorb the landing loads on an aircraft. The force, which the aircraft structure is subject to, can be expressed in Newton’s 2nd law of physics F = M A or Force = Mass X Acceleration. Acceleration is simply the change in velocity over time. If we can double the time interval for deceleration of the aircraft through the landing gear by lengthening the shock strut, you can see that we can reduce the total force exerted on the structure by half. This is the basis for incorporating the long struts on STOL (Short Takeoff and Landing) aircraft like the Just Aircraft SuperSTOL and the Fieseler Storch. Watching these aircraft performing short field operations, you can see what appears to be near vertical approaches, culminating in a very impressive squat of the aircraft as the long stroke landing gear struts absorb the landing loads.
Although there’s been many variations upon the oleo strut, there is some particular genius in its design. The basic physics incorporated in the operation of the oleo strut is what has made it so popular in so many different designs from the smallest aircraft to the largest. This basic design concept (Figure: 1) is so efficient that even the most modern of aircraft use the same basic principles that adorned aircraft landing gear designed and built as far back as the 1930s.
Let’s look at the basic operation of the oleo strut. (Figure: 2) Inside the strut we likely have a combination of Mill-H-5606 hydraulic fluid and dry air or nitrogen. The primary job of the air located in the upper chamber of the strut is to act as a spring. And the primary job of the hydraulic fluid, which is located in the lower chamber of the strut, is to regulate and transfer the loads from the lower half to the upper half of the strut and subsequently into the airframe. Located in between the upper and lower sections, but attached to the upper portion of the strut, is an orifice (Shown in Green). This orifice restricts the flow of hydraulic fluid from the lower half to the upper half of the strut. This basically lengthens the time interval during the compression stroke created by the landing gears impact with the ground. Many early strut designs simply stopped at this point using a fixed orifice to control the fluid transfer from the lower to the upper half of the strut. Later designs improved upon this concept by incorporating one more component called the metering pin (Shown in Pink) which takes the design to an entirely new level. This metering pin is attached to the lower portion of the strut and is tapered starting at the top getting wider as it approaches the bottom section of the strut. This metering pin is co-located within the center of the orifice essentially creating a variable sized orifice. When the strut is fully extended, the gap between the orifice and the metering pin is relatively large allowing fluid to flow rapidly. According to Newton’s 2nd law the greatest amount of force imposed onto the landing gear structure will be at the point where we have the highest amount of deceleration (initial impact). As the rate of strut compression decreases, so does the force. This design allows the restriction between the orifice and metering pin to progressively get smaller and smaller essentially maintaining a constant force onto the structure while exponentially decreasing the rate of strut collapse. (Figure: 3) This allows the entire length of the lower section of strut to progressively collapse absorbing the landing loads over the longest time interval possible. It’s really quite a brilliant concept. A properly serviced strut is virtually impossible to bottom out because of this increasing restriction. Landing forces that could cause the strut to bottom out would likely result in ripping the strut from the aircraft structure. Recognize that it is the fluid and only the fluid that is responsible for the struts’ amazing ability to absorb these landing loads. A strut that has lost its fluid is virtually useless. A strut without fluid is the equivalent of welding the bottom half of the strut to the upper portion strut in the collapsed position. The time interval for deceleration, in this case, drop off dramatically. This, in turn, increases the loads imposed into the structure to also increase proportionally. We often wonder how many of the accidents, where we see a collapsed nose strut, are a direct result of improper servicing or simply loss of fluid.
Tim sent the Webinar report from yesterday. We want to thank everyone for giving us such a high rating. And even though we only had 173 attendees we feel pretty good about the total attendance. Especially considering we were up against the 3rd presidential debate. Maybe that's why we did have such good attendance. Everyone looking for an escape. We will post the link to the webinar When it becomes available.
We are getting ready for doing our new VLOG (Video blog). It will be called the "Hangar 7 Video blog" We will be doing a weekly Video update with everything that is happening not only on the EMG-6 but with the going's on at Rainbow Aviation as well.
Register now and block your calendar to be able to attend the EMG-6 Electric Motor Glider webinar hosted by EAA. The webinar will be on Wednesday, October 19, 2016 at 7 PM to 8:30 PM central daylight time.
Our moderator for the webinar will be Tim Bogenhagen from EAA.