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JShumate

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Everything posted by JShumate

  1. JShumate

    FAA: Exterior Reg. Number

    The Federal Aviation Administration (FAA) has posted a rule in the Federal Register requiring small drone owners to display the FAA-issued registration number on an outside surface of the aircraft. Owners and operators may no longer place or write registration numbers in an interior compartment. The rule is effective on February 25. The markings must be in place for any flight after that date. When the FAA first required registration of small drones in 2015, the agency mandated that the registration marking be readily accessible and maintained in readable condition. The rule granted some flexibility by permitting the marking to be placed in an enclosed compartment, such as a battery case, if it could be accessed without the use of tools. Subsequently, law enforcement officials and the FAA’s interagency security partners have expressed concerns about the risk a concealed explosive device might pose to first responders upon opening a compartment to find a drone’s registration number. The FAA believes this action will enhance safety and security by allowing a person to view the unique identifier directly without handling the drone. This interim final rule does not change the original acceptable m*thods of external marking, nor does it specify a particular external surface on which the registration number must be placed. The requirement is that it can be seen upon visual inspection of the aircraft’s exterior. The FAA has issued this requirement as an Interim Final Rule—a rule that takes effect while also inviting public comment. The FAA issues interim final rules when delaying implementation of the rule would be impractical, unnecessary, or contrary to the public interest. In this case, the agency has determined the importance of mitigating the risk to first responders outweighs the minimal inconvenience this change may impose on small drone owners, and justifies implementation without a prior public comment period. The FAA will consider comments from the public on this Interim Final Rule, and will then review any submissions to determine if the provisions of the ultimate Final Rule should be changed. The 30-day comment period will end on March 15, 2019. To submit comments, go to http://www.regulations.gov and search for “RIN 2120-AL32.” As Transportation Secretary Elaine Chao promised last month, today the FAA also posted proposed new rules to let drones fly routinely at night and over people, and to further integrate them safely into the nation’s airspace. The comment period for these proposals begins tomorrow and will end April 15. The post FAA: Exterior Reg. Number appeared first on Model Airplane News. View the full article
  2. JShumate

    DIY Airplane Tail Ski

    During winter, most of the planes we fly are tail draggers and just have skis on the front. Small skis for the tail of the plane are unavailable. If the snow is soft or crusty, this more or less works: the wheel drags through the soft snow or stays up on top if the snow is crusty. You do run into a problem once in a while where the tail wheel and wire catch in a soft part of the snow or footprint on the runway (left by someone retrieving a plane or coyote). If you’re lucky the snow gives, but after watching the rudder and wheel suddenly depart from the tail of my friend’s E-flite Carbon Cub giant scale foamy during a landing, I decided it was time to make a ski that would just replace the tail wheel on any airplane. My winter airplane is the E-flite Super Cub 25e. This has version 1 ski design. It is a profile of the ski curved shape with two side pieces, made out of 1/8” plywood, to form a keel for the ski. Add some scr*p canopy plastic bent to the curve, plywood, CA, trim to shape and you have a ski. Canopy plastic was used for the ski, trying to keep it light and not affect the CG. This the key photo for success. The front skis have axle attachments, mid ski, which is strong enough to keep the skis from pitching up (causes trim changes to flight controls) or downward (which results in some colorful landings). The rear tailwheel wires are generally pretty thin so the rear ski has to be axle forward. You can see above the axle location is forward (1/3 the length back from the front of ski). Gravity wants to make the rear drop, keeping the tip up for landings. A fail safe is also required in case of rough snow crust. This makes it impossible for the ski to pitch downward and get caught in the snow. Just drill a hole anywhere at the front of the ski and put the plane in takeoff/landing position on a table. Loop some wire through the hole and through some scr*p copper tubing (similar to pull-pull aileron connections). Snug the wire up on the tail wheel leg, crimp and trim. Paint if you want. Above shows the ski painted to match the Cub colors and size of the ski relative to the Du-Bro Snowbird Snow Skis (Part 825 R). This photo shows the ski mounted to the airplane and looks great. You can also see the snow is not always a smooth surface. Take the plane out next weekend with a new tail ski and brag to your friends about how the rudder on your airplane is not going to come off like it does on some airplanes? Well, after a few flights on crusty snow, the plastic had broken from the cold and the tail of the plane was sinking into the snow. I did get razzed a bit about, where was my new ski? Hence version 2. The version 2 ski is shown above with a ruler for scale. Same ski design as version 1, but with 3/32’ plywood formed to shape and glued onto a similar frame and painted. The plywood was cut to the top view profile and size I wanted and the front half, soaked overnight. While it was soaking I took a scr*p of 2×2 and cut the ski side view profile in it with my scroll saw. The ski was placed in the form and clamped until dry (overnight) On the first attempt with the form the plywood cr*cked so I modified the front ski angle. There are a couple of thin wedges at top of photo to help hold ski nose in the revised profile shape. Above shows the dry ski and form. The finished ski is still on the Cub and has sustained several winters of service. The same technique could be used to form the main skis for a smaller aircraft. A wire from the front of the ski connecting close to the fuselage is required to keep it from dropping forward when flying/landing. The wind from flight seems to keep the skis relatively level and in a minimum drag position. I hope this article will get a few more pilots successfully enjoying winter flying. Our field is several miles from a main road across a farmer’s field which isn’t plowed in the winter. Most of us have 4-wheel drive trucks with tow ropes and equipment to pull you out from the back if you get stuck on the way into the field. Text & Photos By Art Irwin The post DIY Airplane Tail Ski appeared first on Model Airplane News. View the full article
  3. JShumate

    CLASSICS OVER GEORGIA

    Wow! Get your WW I aircraft ready! Thus new RC event is intended for models of any size, any power, as long as they are aircraft models of full-size aircraft from between 1903 and 1938! Mark your calendar for May 23-25. AMA sanction #7387. $25.00 Entry Fee. The event will be flying off a 1,500 foot grass runway and the field has 30/50amp RV service with water hook ups. Also on site are air conditioned his/her restrooms with showers. For more information contact CD: Mark Chapman mc2fastnlow@comcast.net 904-705-3178 Site location: Heath/Green Sky Ranch 248 Wells Cemetery Rd. Hinesville, Ga. 31313. GPS 31.84479 – 81.6125 For RV reservations contact Dan Green 912-660-4343. The post CLASSICS OVER GEORGIA appeared first on Model Airplane News. View the full article
  4. JShumate

    Gas m*ffler Silencer

    Interesting, how much of a power loss have you noticed using these?
  5. JShumate

    Covering Wings with Fabric

    I really enjoy the wing covering process as it impresses me just how much the fabric strengthen and stiffens the wing panels. Just like the fuselage, the first step is ... Continue reading ... Join our premium membership! The post Covering Wings with Fabric appeared first on Model Airplane News. View the full article
  6. Covering a wing panel with film covering is fairly simple and easy to do, even for those with little skill; that is, until you get to the wingtip. Of course, all wingtips are different shapes, and not all fall in the category of difficult to cover. Some have a gentle taper to a rounded tip with very few compound curves, making covering a simple process. Others can be more difficult. The wingtip I describe here is one of those that can’t be covered along with the wing. The better way is to cover it separately. Although you will end up with a seam on the final wing rib, you will find it a more reasonable approach to success. I went through this covering process with UltraCote film covering several times and noticed that it makes a difference how the film covering is cut from the roll. I found it best to leave extra material when covering the length of the wing, and then use the piece trimmed off at the end to cover the tip. Using a piece of film cut parallel to the edge of the roll will cause it to sag severely in the shrinking process. The secret for success is to make sure the piece you cut is perpendicular to the roll edge. Oh, yes, this tip will also work with MonoKote. So, heat up your covering iron and trim iron, grab a sharp knife and follow along in the photos my process for covering that pesky wingtip. Tools required for covering and covering the wingtip. (DSC9749) Typical problem wingtip, with the covering problem occurring between the gusset and the leading edge. Cover the wing panel and trim off at the last rib, leaving a generous overlap ironed down against the rib. The rib thickness is not enough surface area to retain the film when shrinking. Note: Black marks indicate the amount of overlap covering fore and aft. On the piece of covering to be applied, develop a contour to fit the rib for an even overlap seam, generally to the shape of the rib contour. The overlap should be approximately 1/4 inch. Using the trim iron, tack the covering at one end to the rib just inside the black mark. Later, you can remove the black mark with alcohol. Grabbing the loose end, pull it across the top of the rib for an even-width seam, and iron in place. You are now ready to tack and iron down the opposite side. Before you start to tack down the covering, place the wing on the workbench with the wingtip extending over the edge. Use a sandbag to hold it down, so you’ll have two hands to work with. Starting near the front, pull the covering straight down and tack it in place. Work along in small increments toward the trailing edge. Now, move to where you started, and do the same thing going forward. Try and get the covering as tight as you can. Lift and retack, if necessary, as you go along. The covering should lay flat and tight without gathering and bunching up. Trim off the excess covering, and seal it in place with the covering iron. Using the trim iron, shrink the covering staying away from the seams on both sides. Gently glide the iron over the surface until the covering is wrinkle-free. You will have to do this four times, on each side of each tip, to complete the wing. What a beautiful wingtip, and not a wrinkle to be seen. A covering job you can be proud of! TEXT & PHOTOS BY JERRY SMITH The post Model Plane Construction: Covering a Wingtip appeared first on Model Airplane News. View the full article
  7. Filmed at the Tokoroa Airfield in New Zealand, this Russian heli has a multitude of scale details, including rockets that explode when they hit the ground! The poster notes that New Zealand’s Civil Aviation Authority had approved the rockets, which are reportedly Bird Bangers, pyrotechnics used to scare away nuisance birds from an area. With or without the armament it’s certainly an impressive aircraft! Our thanks to XJet for taking this great video and posting it on YouTube. The post Seriously Scale Turbine Helicopter appeared first on Model Airplane News. View the full article
  8. One of the apprehensions all pilots experience is knowing our planes are at risk every time they take to the air. Then there is a real sense of accomplishment when the plane makes it safely back to terra firma. As our confidence builds, we start doing maneuvers closer to the ground and thereby increase the chance of meeting up with the earth. Eventually, a wrong move is made, or a servo or radio malfunction occurs, and in one brief terrifying moment, the plane hits the ground. Your pride and joy now sits helplessly wounded. But don’t fear; although the plane may be damaged, in many cases, it is far from dead. The good news is that more than 80 percent of crashed planes can be fixed using simple construction techniques that I share with you here. I admit that I have personally used many of these repair m*thods, and they all work quite well First-aid kit for crash repairs > Clear packing tape > Various glues: quick-drying CA (foam safe, if you fly foamies), epoxy > Glue gun > Fiberglass or cotton material for reinforcement > Balsa scr*ps and/or ice cream sticks > Covering material > Covering iron > X-Acto knife > Needle-nose pliers > Soldering iron > Scissors Clean sweep–don’t leave any part behind The first thing to remember when you get to the crash site is to turn off the power. You may then want to mourn a bit before you begin the salvage operation; this is perfectly fine and accepted in the modeling community. When you’re ready to move on, gather up every piece of the plane you can find; this is a very important part of the repair process. Once back in the shop, begin to put the puzzle pieces back together, and if a piece is missing, I almost guarantee that it will be the hardest one to duplicate. So make sure you pick up all the pieces. Now let’s look at how to repair some common crash/b*mp damage. Landing gear–the first thing to make contact By far the most common airplane mishap has to do with the landing gear either getting pancaked or being pulled right off. After all, this is the first thing that touches the ground and is, therefore, most likely the first thing to be broken off. Many times, new and experienced pilots will stall out the plane on landing, and the plane will hit hard, thus putting a lot of pressure on the landing gear. This constant pounding eventually breaks the plywood that holds on the landing gears. Reconstruction begins by removing the landing gear and piecing all the parts back together. Use thin CA to glue the parts. Reinforce the inside of the landing-gear platform with triangle balsa stock, and use fiberglass or denim material with epoxy to strengthen and bond all the pieces together. On foam planes, use foam-safe CA or epoxy (although this will add some weight) to glue all the pieces back together. Reinforce all the parts with clear packing or reinforced tape. Wingtips–damage at the ends I have seen many competent pilots tip-stall a plane on landing and cause damage to the wingtips. This type of damage is common to many planes, especially low-wing designs. It’s best to prevent rip tears in the covering in the first place by adding a protective wingtip covering. A number of products on the market will prevent wingtip damage, including plastic wingtip guards and adhesive Mylar that sticks to the covering. Both products prevent damage by taking the brunt of the abrasive impact on the ground. But if you’re like me, too late for that; damage done. How do I fix it? The first step is to remove any shreds of torn covering and fill in the damaged balsa or plywood wingtips. You can do this with any wood fillers, but I found spackle or Lite Spackle (available at home centers) the easiest to use. It is easy to apply with a putty knife or an old credit card, and it sands faster than balsa, creating a smooth finish. Cut a piece of color-matched covering that overlaps the existing covering by at least 1/2 to 1 inch all around the damaged area. Use an iron with a higher heat setting, so you can stretch and mold the covering around the complex curves of the wingtip. If you aren’t able to color-match the covering, use a color that works with the color scheme. Cover both tips so that it doesn’t look like a repair when you’ve finished. And once you’ve achieved a great-looking repair, why not try that scuff-resistant Mylar film this time? Covering–easiest to damage The second most common repair is fixing holes in film covering. This damage occurs when you poke your finger through the covering as you pick up the plane, or when a stick pokes through on landing, or broken parts break through the covering, or during transportation to the field. Any of these events can leave your pristine covering damaged and unsightly. These areas need to be repaired as soon as possible because the damage will affect the aerodynamic stability of the plane. The torn covering will get worse as the air pulls up more and more covering on each flight. At the field, you can do a quick repair by using some good-quality packing tape to place over the ripped covering film. Cut the piece of tape so it extends at least 1 inch beyond or around the damaged area. Stick the tape to one side of the tear, and gently pull the tear together before you push down on the entire tape strip. Once at home, you should make a permanent repair. The first step is to purchase the same color covering as in the damaged area. The covering brand and color are often printed at the beginning of the assembly manual. If the damaged area has a complex color pattern, or you just can’t find the right color of covering, you can still repair it by using clear covering. Whether you use a matching color or a clear covering, the steps for repairing the damaged area are the same. Use the low-heat setting on the covering iron, tack down the repair covering on one side of the rip, working from the center out to prevent air bubbles from forming under the film. Pull the repair covering so that the gap in the damaged covering closes, and then tack down the covering again working from the center out. Now, turn up the heat on the iron, and go over the entire repair area to get a nice solid bond that should last the life of the plane. Motor mount–the front is the first to hit Outrunner motors don’t bend or break when the plane encounters a prop strike. The force from the strike is instead transferred to the motor mount, which in many cases is much weaker than the motor. Even a light prop strike may result in some significant damage around the motor mount. Repairs in this area are easily fixable, in most cases. On foam models, glue all of the pieces back together with foam-safe CA or epoxy. When using epoxy, try not to overuse it because cured epoxy adds a fair amount of weight. Fill in any gaps with foam-safe CA and microballoons, and then reinforce the area with some packing tape. Reinstall the motor, and you’re good to go. For balsa models, the fix will require a little more time. Again, glue all the pieces back together with CA. Depending on the construction of the motor area, you can use extra 1/16-inch balsa sheets to reinforce the area, or use light fiberglass with epoxy or CA. I also found that Popsicle sticks work great to beef up an area, especially around the motor mount. Some planes have the motor mounted on a motor box; to reinforce these, you can use balsa triangle stock to strengthen the inside corners. When you’ve finished the repairs, sand everything smooth, and add new covering and/or a new cowl. It’s all good Now you should be able to fly at ease in the knowledge that if an accident with your plane does occur, you can rebuild and, in some cases, make it better than it was. As the saying goes, “If you’re not crashing, you’re not flying”; but now you also know that a crash doesn’t always mean the death of the plane. Enjoy. The post Model Airplane Crash Repair — 5 Quick & Easy Fixes appeared first on Model Airplane News. View the full article
  9. If you love B-25s, then check out this story from Flight Journal’s Editor in Chief Budd Davisson of his adventure getting his B-25 Mitchell rating! I’ll never forget the feeling sitting at the end of the runway, right hand wrapped around two throttles, looking out at 3,600 horses in two big radial engines. The 22,000 pounds of airplane around me agitated gently but noisily in their wake. Now I know how George Plimpton felt facing Green Bay, but at least he could lie down and play dead-I wouldn’t be playing. I was about to fly the big, beautiful B-25 bomber! At that moment I just wasn’t geared toward bombers. Fighters, maybe, or aerobatics, or homebuilts. But big, hulking, roaring bombers-definitely not. Prepared or not, I suddenly found myself in the left seat of N543VT, a North American B-25N, Mitchell. Junior Burchinal, proprietor of Flying Tigers Air Museum, was in the right seat, shouting at me to do this and that. Yes, I’m multi-engine rated, but most of my limited experience has been in a couple of moth-eaten Apaches, and the B-25 bears as much resemblance to an Apache as I do to Raquel Welch. Ninety percent of my flying is done with only stick, throttle, and rudders to worry about-no boost pumps, feathering systems, emergency gear extension, bleed hole icing, Vmc, constant-speed props. Now I had to think about shimmy dampers, exhaust stacks, oil coolers, hydraulic acc*mulators, and brake pressures. In 1971 Burchinal’s B-25, as seen above, was viewed as a really tired looking old airplane because it had never been restored, There were dozens of them around in “still flying but roachy” condition and no one wanted them. Editor’s Note: Thankfully the B-25 that Budd Davisson flew and writes about here, Now Sunday Punch tail number N325N, was restored by Aero Trader, Chino CA, in 2012-2013. Flying a 10-ton aluminum ingot isn’t som*thing you just wander out to your local FBO and do. In any case, I was going through the World War II flight course at the Flying Tiger Air Museum in Paris, Texas. My original intent was to fly the fighters, but the B-25 is also part of the program, intended to broaden your education—and it does, in spades! Heavy in this case means about 17,000 pounds empty, with an allowable emergency overload of nearly 45,000 pounds. That’s more than my hometown weighs! This particular Mitchell probably would be more correctly termed a VB-25N, since it originally was an executive transport for the RCAF. Most B-25s don’t have dual controls, but this one, along with many of the TB-25s still flying, is completely set up for two pilots, as a training ship. Originally, I was to go up with junior and drive the 25 around for an hour or so, just to see how it felt. I began to like the idea of flying the big moose, however, and I soon heard myself saying things about “more time” and the words “type rating” kept popping up. Type rating! That’s the special license it takes to carry passengers in airplanes that weigh more than 12,500 pounds, and the B-25 weighs that much with one wing and both engines removed. It takes a different type rating for each type of airplane. The change in program meant I would have to learn the airplane inside and out, and that’s a lot of territory. Burchinal is a FAA-designated examiner for the B-25, and I knew he would be tough. My first “introductory” flight made me feel like crawling into the bomb bay and going for a walk outside. I thought the Mustang was a departure from the Citabria; the B-25 is in another world entirely. When we got up into the air and over the practice area, Junior signaled for me to take it. I took the wheel, and a slight out-of-trim condition caused the nose to drop. I automatically pulled the nose up—or at least I tried. I was flying with my left hand, my right resting lightly on the throttles. I could hardly pull the wheel back with one hand! I released the throttles and brought the other hand over to help, barely getting the nose up level. I finally had enough sense to wheel in some up trim. The controls couldn’t be that heavy! I made a turn to the left, or at least my hand did, but the control wheel resisted my attempts to move it. Grasping it firmly, determined to do it with one hand, I forced one end down, and the wings responded smartly enough by rolling obediently into a left bank-then the nose started to fall. With the 30-degree bank I was holding, I had to force the wheel to the rear to keep the nose from falling. It had started losing altitude the second I started to roll. I wasn’t prepared for the heavy control pressures. Just to prove to me that the airplane would fly, junior reached up and punched a red b*tton on the console between us that started moving levers. As I was watching him, I saw the right propeller come to a stop, its blades edged into the wind. He diddled with some trim wheels and sat there, hands off, boring along with only one engine going. Satisfied that I had been suitably impressed, he fired up the other engine and headed back to his field. I expected a long approach, nose high, with lots of power, dragging it in over the wires and stomping on the brakes to get stopped. He aimed the nose at the runway and I figured we were going to make a high speed pass. When we were over the middle of the runway at about 200 knots indicated, he pulled up hard to the left in a tight chandelle. While he was doing this, he started scurrying around the c*ckpit, throwing this and yanking that. Suddenly, I realized he was doing a 360-degree overhead approach, fighter style, right off the deck in a B-25. At the top of the chandelle, we were downwind opposite the end of the runway. He brought the throttles back, turned into the field and beautifully completed the 360-degree turn as he plunked us down on the runway. The man certainly knows his airplane. I knew I had my work cut out for me, so I started memorizing systems and going through the preflight checklists. When all the gizmos and gadgets are explained, you find there aren’t that many things that are drastically different from what you’re used to. It’s still an airplane, and you must check the oil and gas, the struts and tires, the controls and so forth. The B-25 does have several particulars that we little-airplane drivers don’t see often and that must be checked. For one, the shimmy damper has a little nubbin, a small rod for all practical purposes, that sticks out of the top. If it doesn’t stick out at least three-eighths of an inch, you don’t fly. On airplanes as big as the 25, if the shimmy damper fails, it can destroy the airplane. Junior told me about a Mitchell he saw that lost the damper on landing roll-out: it sheared rivets and buckled sheets back into the wings, completely wrecking it. He lost one on the B-26 while taxiing into a parking place, and in the time it took to roll 10 feet all the Plexiglas was shaken out of the nose. Just below the shimmy damper is a knurled cap screwed on to a bolt-like affair that goes through the strut. Under the cap is a pin that can be pulled out, allowing the nose strut to turn freely for towing. The cap has to be finger tight. You really have to depend on the half-inch-thick book that makes up the preflight checklist. The view from just behind the top turret position ahead of the bomb bay bulkhead. At the bottom, under the curved frame, is a short ladder that goes to the hatch on the bottom of the airplane. You enter the flight deck through a hinged hatch that contains a ladder, located in the belly of the airplane, about in line with the propellers. When you climb up, you find yourself standing in a small room, about six feet square, going from the top to the bottom of the fuselage. It has a couple of jump seats and a Plexiglas bubble in the top for navigation work. The forward side of this area is only about three feet high, opening into the back of the c*ckpit. Getting up into the pilot’s seat is a major operation. The cabin roof is fairly low and the seats are close together, which means you have to walk on the row of kn*bs and levers that cover the space on the floor between the seats. The instrument panel isn’t nearly as complex as would be expected. It’s actually simpler than in many light twins. Some of the instrument placement is rather odd, and every available inch of side panel is covered with emergency system controls. The throttles, props, and mixtures are where you’d expect them to be, and most of the rest of the switches for starting, fuel management, and feathering are on the trapezoidal-shaped panel just in front of the throttles. The props are feathered by depressing the appropriate large red b*tton on this panel. The Ham-Standards feather in less than 10 seconds and unfeather in about twice that time. Since feathering is by electrically driven pumps, it’s a good idea to check the generator panel on the right side of the c*ckpit to make sure both generators are working, or if one is out, that you don’t feather the engine with the good generator. I must have spent at least eight hours sitting in the airplane running through emergency procedures and making imaginary touch and goes. Since I’m not used to handling any kind of procedure at all, it took some effort even to remember to bring the gear up, or push the props up on final. I spent so much time in there and would get myself so wound up psychologically flying patterns in my mind, that I’d get the adrenaline pumping and one leg would be twitching uncontrollably. Yeah, I was just a little hyped! On my second hop we did stalls and all the other exercises that go into learning an airplane’s bad habits. Satisfied that we had enough altitude and there was no traffic around, I started reducing power and bringing the nose up, feeling for the stall. I thought an airplane this big would flop on the ground, tail first, when you stalled it nose high, but I was pleasantly surprised. We were light, so the stall didn’t show up until we were way down around 70 knots. When it broke, there was no mistaking it, but it wasn’t as violent as in many modern twins. It jumped once, dropping the nose through the horizon, and rolled left slightly. Keeping the nose down and adding power, we had flying speed in less than a thousand feet, losing no more than 1,200 feet, and I had been slow adding power. The only hard part was the physical exertion involved. As the airplane slowed down and the sink rate went past the peg, the controls lost some of their effectiveness, calling for bigger control deflections, which meant more arm muscle. The panel itself is pretty straight forward but the console has a herd of levers, switches and b*ttons that have to be deciphered. The big control yoke is right against your chest during flair and the runway disappears behind the nose. Single-engine drills in the B-25 are really fun (spoken sarcastically). One thing is certain: when an engine shuts down, there is no doubt which is the “idle foot.” My good foot was working so hard that after each hop it took several hours for my knees to stop shaking. During my multi-engine training, I remember seeing an engine feathered just once; that’s all the FAA requires. Burchinal feathered one everywhere except at the gas pump. There are only two things to remember when feathering a B-25; remember what the Vmc is for your weight, and move your f*nny forward in the seat because you have to be seven feet tall for your legs to push the rudder all the way down. I found myself wedging my shoulder against the seat and practically standing on the rudder, lying sideways in the seat, right hand frantically cranking in rudder trim located at the base of the control console. Once the trim is in, the airplane is a pussycat, but if you don’t start cranking trim right off the bat, the pussycat will eat one leg, and maybe your entire lunch. The handbook says the minimum single-engine control speed at 27,000 pounds is an incredible 126 knots (145 mph). We investigated Vmc and found that at our reduced weight of around 22,000 pounds we could fly it right down to 80 knots indicated and still hold the nose straight. Doing single-engine stalls, I got very good at leaping on that power and bringing it back quickly. You forget to reduce power only once in a power-on, stalled, engine-out situation, then the B-25 does all the talking and you do the listening. For my first landing, we flew a wide downwind at 120 knots and I ran through the landing check as fast as I could because the airport was disappearing rapidly. Burchinal played co-pilot. I called for the gear and at the same time pushed the props up to 2200 rpm, where they would stay until we were on the ground. Mixture went to auto-rich and boost pumps went first to low, then high. By this time I was way past the airport, so I brought the power back a little and started a turn on to base. The second I started the turn, I knew what junior had been talking about when he mentioned heavy aircraft and the way they need power and don’t need steep banks. When the wing went down, the airplane started sinking immediately and I had to advance power to catch it. Not even in the Mustang did I have this feeling of being behind the airplane, of being rushed. On base, I found myself using a lot of power just to maintain status quo, cranking in trim every few seconds. I stuck up two fingers, indicating to Burchinal I wanted half fl*ps, adding more power and trim. As I turned final, I stuck up four fingers for full fl*ps and started gently reducing power and struggling with the nose to get 110 over the fence. Then I had 110 knots and Burchinal was yelling to bring the B-25 power back. I thought he was crazy, that we’d never make the runway, but I killed the power anyway, keeping my nose pointed at the numbers, 110 knots on the gauge. The flat top of the console has all the engine control stuff on it including the fuel boost and starter switches. The big kn*bs on the two forward corners are the red “feather” b*ttons for the props. At the bottom of the console on the floor is the landing gear lever. I started bringing the nose up and Burchinal started yelling “Pull, pull!” He grabbed the wheel and helped me. It turned out I was flaring in the right place, but I would have touched down on all three, or just a little nose high, but I would have been too hot. Burchinal kept me pulling and we touched down with the nose in an impossibly steep nose-high attitude, completely hiding the runway. Roll-out was arrow straight and Junior cautioned me to be very, very gentle on the brakes, because they are sensitive. My toes crept up on the top of the rudder pedals and pushed as gently as they could. j*rk! And the nose strut compressed as I nearly locked the brakes. They have double discs and just need a whisper of pressure to stop the wheel. Trying to taxi smoothly was a near impossibility. Once we were on the taxiway, junior started telling me to call for what I wanted, meaning fl*ps up, cowl fl*ps open, and boost pumps off. I proved once and for all how calm and cool I was: In my gruffest, most professional voice, I called out, “Gear up!” It just wasn’t my day. Takeoffs are really, really exciting-possibly even more so than in the Mustang, because you know the tricycle gear will take care of the takeoff roll and you have more time to bask in the glory of flying a bomber. In the Mustang, I was always a little too busy for sight-seeing. After making sure that everything on the quadrant was full forward and the boost pumps were on, I’d call for one-quarter fl*ps and start the throttles forward. As soon as the airplane is moving, the rudders are effective and you only have to touch the brakes just once before the rudders come in. The power must come up slowly to keep the prop governors from surging and you have to monitor manifold pressure to keep it under 44 inches. Considering the amount of airplane around you, the acceleration is fantastic and the noise is even more so. There are different kinds of noise. In the Mustang, it was almost unbearable. In the B-25, it was just as loud, but it didn’t seem to bother me. It was like the difference between a rifle and a shotgun. The Merlin in the Mustang cr*cked and barked, but the R-2600s in the Mitchell roared like a tired lion, and had a softer, less harsh noise. Since I knew Vmc was 80 knots, I picked the nose up at 80 knots and let the airplane run on the mains until it indicated 100 knots, lifting it off and calling for, or grabbing, the gear as soon as possible. On my second takeoff, as soon as we broke ground and I had yanked the gear up, Junior nonchalantly caged the right engine. Aside from a few frantic moments and a foot that was turning purple, the B-25 climbed out as if it didn’t even know half its engines were out. On the type-rating check ride, Junior tossed a single-engine landing and a single-engine go-round into the same hour. Junior has a knack of working you right up to the edge of your talent, forcing you to learn as you go. The single-engine landing was really interesting because we were five miles from the field when he punched it out. This meant I was going to have to drive it in, play with all those levers, fight the airplane, and land it as well. At first, I tried to figure out how much power it was going to take to keep us up with the gear down and half fl*ps, and then I remembered that I didn’t dare put the gear down until I had the runway made. The airplane won’t fly with only one engine and the gear hanging out. Finally, I was on final, keeping it high just in case, waiting until the last second to drop the gear, remembering it would take longer to extend with just one hydraulic pump working. As soon as the gear started out and I reduced power to let the airplane down, it became just another of those pull, pull, pull kind of landings. It took nearly four hours in the B-25 before I got used to pulling so hard and getting the nose so high. B-25s and “Catch 22” When they made the movie of Joseph Heller’s slightly off-center anti-war movie, they unwittingly saved the lives of the majority of B-25’s still flying today. Frank Tallman and company was task with coming up with som*thing like 25 flying B-25’s and, in so doing, resurrected a bunch of derelicts that had only a few years left before becoming beer cans. The movie is worth seeing if nothing else to watch mass takeoffs of Mitchells from the dusty strip they hacked out of the Mexican desert. by Budd Davisson The post Getting a B-25 Type Rating — Budd Davisson gets to know the Mitchell Medium Bomber appeared first on Model Airplane News. View the full article
  10. When working with an internal comb*stion engine, we always have to deal with the heat that is created by this process. In many cases, the opening in the cowl will allow enough air to flow over the engine to maintain a cool temperature. But when performing extended 3D maneuvers, we have only the air produced by our prop to keep the engine cool, and sometimes this may not be enough. That is when we want to direct the air to flow over the main engine component that is creating the most heat-the engine head. Extra airflow over the engine can be accomplished by manufacturing ducting inside the cowl to direct the air where you want it to go. Here are three very important facts about air: Air will always flow in the path of least resistance. Air pressure will form a wall that will prevent any airflow from coming into the cowl if it is allowed to build up. That is why the exit hole is always recommended to be three times larger than the entry hole. By funneling air, it will increase in speed. If we make a ducting system at the opening of our cowl, it leads only to the engine head(s). It will become the path of least resistance that will force the cooling air to travel over cylinder head(s). I used materials common to most model airplane enthusiasts. The cowl ducting can be made from a variety of materials including fiberglass, tin, plywood and balsa wood. Let’s take a look at what we need for the project. 1 The materials I used include (left to right) 3/32 balsa wood for the ducting or baffles, hobby blade, 5-minute epoxy (or 30-minute epoxy), microballoons, pattern transfer gauge, felt-tipped pen and a Dremel tool with drum sander bit. 2 My first step is to increase the airflow coming into the cowl by enlarging this front opening. By increasing the opening size in a downward direction, I also center my cowl entry hole to the engine’s cylinder head. 3 The cowl on this TOC Katana comes in two parts and allows me to work on the lower part while it is still attached to the aircraft. This makes my job of fitting the duct work much easier. I begin by enlarging the entry hole using the sanding drum on my Dremel tool. My Shop-Vac sucks up any dust created from the sanding drum and keeps the area clean. 4 I start by using a pattern duplicating tool to make a rough outline of my engine head. I then transfer this outline to the 3/32 balsa wood. This pattern does not have to be exact and can also be created from cardboard or any other material you want to use. 5 With the outline transferred to my balsa wood, I begin cutting out the major portions with my hobby blade. Then, I trim up the edges and do any final modifications with my Dremel tool. By using balsa wood, this is a quick and relatively easy process. Consider your first piece a pattern piece that may need extra work, or you may need to make an entirely new piece to get it just right. 6 Here is my first piece with some scribe lines that show additional material that needs to be removed. Again, I use the Dremel tool for all the detailed removal. I cut out two pieces, one from the bottom of the opening and the other for the top; in most cases, they will be very close to the same size. 7 I now take both pieces and tack-glue them into place using BSI thick CA glue and placing two to three drops around the edge where the ducting contacts the cowl. Then I hit it with a quick spray of CA accelerator to hold my piece firmly in place. I repeat this process on the upper duct, or baffle, so it is also tacked in securely. 8 I now work on my side baffling. This does not have to be cut with precision; I am only concerned with directing the airflow to the top and bottom of the cylinder head. After cutting my pieces to the correct length and angle, I again tack them in with two drops of thick CA and accelerator. After repeated fittings with my upper cowl and using my Dremel tool with the sanding drum, I finally get a perfect fit. Now, when my upper cowl is attached, there is a 1/16-inch gap between the side baffles and the upper baffle. I want to make sure that everything fits correctly before I final-glue the baffles. To this end, I bolt on the upper and lower cowl, along with the side screws, to ensure I have a proper fit. 9 All that is left to do is to mix up some epoxy and microballoons and apply it to all of the corners of my ducting/baffles. I added some triangle balsa to the bottom of the ducting where it attached to the cowl for added support. Make sure you work with fresh epoxy; if it starts to cure, mix a new batch. Fresh epoxy will flow into the wood fibers and make for a stronger bond. I only mixed up enough epoxy for each corner; I ended up mixing about 12 small portions of epoxy for this side alone. 10 As you can see from this view, I now have a larger opening for air to flow in and help cool the motor. All air that now flows in through the cowl opening has to go over the engine cylinder head on its path through the engine compartment. That makes efficient use of all cooling air, resulting in a much lower overall engine temperature. This is a simple addition to any engine compartment that will always improve your engine’s performance and efficiency. Try it and enjoy! The post Keep it cool: 10 steps to control air flow appeared first on Model Airplane News. View the full article
  11. One of the more unique features found on giant scale RC airplanes, and on warbirds in particular, are the inset hinges that use long, thin pivot wires to secure the control surfaces in plane. For my current project, an 85 inch span Douglas Skyraider, this type of hinging is used with the rudder, here are some pix and tips from my building board. Here you see the full-size rudder from a museum Skyraider. You can see that it has three inset hinge pivot points. On the Bench When it comes to building a control surface with inset or recessed hinging, you have to build very accurately and follow the plans precisely. I am building my Skyraider with laser cut parts from LaserCutUSA.com and they match the Nick Ziroli plans precisely. Here are the rudder ribs, the sub-leading edge and the parts I used for the hinging. They are easy to obtain consisting of a length of 1/6-inch welding rod and the yellow inner section of a Gold-N-Rod pushrod from Sullivan Products. These are cut over size to begin with. Cut the side sheeting to size and glue the sub-leading edge and the ribs to the right side as shown here. Notice I drew extension guide lines on the plans to help guide the placement of the ribs. Precision is the key to all properly build RC warbirds. I use ZAP CA glue for most of my building, but when it comes to gluing on sheeting for the rudder, I also use Titebond yellow carpenter’s glue. Here’s a close up of the lower end of the rudder. As you can see, the first hinge support is about an inch from the bottom and the hinge pin wire is secured to the bottom of the hinge. It travels in a straight line all the way to the top support. Here’s the completed hinge assembly all glued together and sanded smooth. It fits the plans precisely in width and length. Note that I have drawn a centerline on the sub-leading edge. Slide the wire into the yellow Gold-N-Rod and tack glue it over the centerline. Make sure to keep them straight and centered. I drew guide lines on either side of the yellow tube to ensure it is glued in the correct orientation. Next glue 1/8 inch filler strips on either side of the yellow tube and pivot wire, here the left filler piece has been glued in place. Here both filler strips have been glued in place, trimmed and sanded to shape flush with the outside surfaces of the rudder. This shows the three 1/8-inch plywood hinge support tabs that will secure the hinge to the fin and the lower rudder post of the fuselage. Mark the locations for the clearance slots that will be formed between the leading edge blocks that will be added next. The slots should be about 3/16 inch wide. Using the plans as a guide, laminate the wood together to form the blocks. These should be slightly longer and wider than the final pieces so they can be planned and sanded to shape after gluing them in place. Measure the distance between the hinge slots and sand the blocks ends square, cut to length, (slightly over size), and then sand the opposite end square until you have the exact length needed. Here you see the bottom end of the rudder with the leading edge blocks glued in place and rough shaped to size. Here is one of the support tabs and the rudder. The space between the leading edge blocks forms the slot (or recess) for the hinge pivot point. Next simply cut through the yellow guide tube with a Hobby razor saw, (remove the wire pin first), and clean out the pocket to fit the plywood support tab. Cut the slot down through the 1/8 inch filler strips. I use a back-stroke saw from Sears. It is very sharp and cuts through balsa and the plastic tube easily. Here you see the pivot wire reinstalled. All that’s left is to use your hobby knife to recess the slot near the center to clear the plywood support tab. A sharpened length of 3/16 inch brass tubing can be used, and then smooth everything out with some fine sandpaper. This shows the finished installation of the rudder on the fuselage. Since my fuselage is not yet built, this example, (courtesy of Gains Smith), shows the setup. You use the completed rudder assembly and attachment tabs as a guide to glue the tabs in place on the fin and fuselage structure before they are sheeted over with balsa. Stay tuned for more photos to show additional details. The Skyraider will be the subject of a new Build-Along Series. The post Workbench Building Techniques — Inset Wire Hinging for Scale Surfaces appeared first on Model Airplane News. View the full article
  12. JShumate

    Valentines Dinner

    CCRCC will again hold a Valentine's Day dinner at the Ribeye, 1701 S. Neil St., Champaign, IL. The dinner will begin at 7 PM on Tuesday, February 12th. Should be a fun event again this year. Be sure to bring your significant other! Guests welcome! Mike Trautman promises party favors for all in attendance! Mike needs to let the Ribeye know how many of us will attend. Please RSVP to Mike (painless6@comcast.net) or any club officer by Sunday, February 10th.
  13. JShumate

    U of I Armory Flying

    until
    Indoor flying at the armory. Download the PDF for rules and waiver form Spring 2019 Armory Track UAV Rules & Regulations.pdfSpring
  14. JShumate

    U of I Armory Flying

    until
    Indoor flying at the armory. Download the PDF for rules and waiver form Spring 2019 Armory Track UAV Rules & Regulations.pdfSpring
  15. JShumate

    U of I Armory Flying

    until
    Indoor flying at the armory. Download the PDF for rules and waiver form Spring 2019 Armory Track UAV Rules & Regulations.pdfSpring
  16. JShumate

    U of I Armory Flying

    until
    Indoor flying at the armory. Download the PDF for rules and waiver form Spring 2019 Armory Track UAV Rules & Regulations.pdfSpring
  17. JShumate

    U of I Armory Flying

    until
    Indoor flying at the armory. Download the PDF for rules and waiver form Spring 2019 Armory Track UAV Rules & Regulations.pdfSpring
  18. While I was building my giant-scale Top Flite F4U Corsair ARF, I wanted to add just a touch of detail to help break up its overall-blue paint scheme. Regardless of your model’s color, adding some visual surface detail helps your plane gain depth and realism. It’s easy to do with some basic techniques and supplies—here’s how I did it. The technique for applying panel lines with a pen has been around for a long time, but fine felt-tip pens really make the task simple. First, clean the surface of your plane and really degrease it so the ink will last. You also need some flexible, straightedge rulers, and some basic templates. I use plastic drafting templates for making small panels and the other quick details. For larger circles, templates are also available at most office supply stores. Scale color profile drawings from aviation books, online drawings and photos also make handy references for detail placement. Remember, this is not a full-blown detailing treatment. I just wanted to add a hint of detail to add some eye candy to an otherwise smooth, film-covered ARF… MODEL AIRPLANE NEWS PREMIUM members can access this article and many others highlighting amazing techniques, RC airplane builds and projects. When you become a member, you’ll get instant online access to our back-issue archives, the latest Model Airplane News Digital Editions, all of our newsstand-only special issues, and much more. Membership includes exclusive access to our enormous collection of RC information. 7+ years of digital editions of Model Airplane News Flight Journal and Model Airplane News special issue digital editions, previously only available on newsstands Free access to our magazine app through the iTunes Store – get Model Airplane News on your mobile or tablet device Aerobatic flight technique video lessons for plane & helicopter pilots Contests & giveaways only for members 30 years of Model Airplane News archives 10 years of Electric Flight archives 5% off ALL Air Age Store purchases every time you shop http://www.airagestore.com/memberships/planes/one-full-year-of-exclusive-member-access-for-only-24-95.html The post EASY RIVETS & DETAILS — Improving the looks of any ARF Warbird appeared first on Model Airplane News. View the full article
  19. If you’ve seen individual IMAC maneuvers, you’ve probably noticed one factor that ties everything together: straight and level flight. When flying an aerobatic sequence, you must start and finish each of your maneuvers in straight and level flight. Since straight and level flight signifies the end of one maneuver and the beginning of the next (see Figure 1), it’s fitting to discuss this portion of your sequence. You should practice straight and level as much as you do any other maneuver. It is also where new precision-aerobatics pilots should begin. It may seem like the most boring thing to do, but in reality, straight and level flight is one of the most difficult maneuvers to master. Sure, rolling circles, tail slides and multiple snaps each have their own levels of difficulty, but think about what comes before and after each one of these: straight and level flight. One of the most difficult things to do after performing a rolling circle or a snap is to retain the same flight path. The judges look for your ability to regain control and execute the exit of the maneuver. To score well, you must learn what “wings level” looks like at various flight altitudes and box positions. And for this, there is only one solution: practice. Begin by flying your plane parallel to the runway about 100 yards away from yourself. When you reach the end of the aerobatic box (1,800 feet wide maximum), pull the plane vertical. If your plane does not head straight up, you didn’t have your wings level (see Figure 2). Typically, most fliers hold their inboard wing too low during what looks to them like straight and level flight; when the plane is pulled into a vertical climb, it will start to come in toward the pilot. Continue doing this at various altitudes until you can achieve a vertical pullout. As the plane continues upward, other forces such as prop torque will affect your plane, but you need only concentrate on the initial pull up for this exercise. If you find that you have to apply rudder immediately after you “pull” up-elevator, then you are not flying level. High-wing, mid-wing and low-wing planes will all look different in flight with respect to the ground. Your paint scheme can also “throw off” your perception of your plane’s attitude. Learn what wings-level looks like by practicing it over and over. Now let’s take the wings-level exercise one step f*rther: inverted. Yep, throw out your previous sight picture and start again. In an aerobatic sequence, straight and level flight is not limited to upright flight only. In fact, you may spend as much as 30 percent of your flight time inverted while in between maneuvers. You also need to know what inverted wings-level flight looks like. Push down-elevator to enter into a hammerhead at each end of the box, and notice which way the plane immediately leans. Fix the lean angle on the next try with your ailerons immediately before adding the elevator push from straight and level flight. Once the push begins, only rudder should be used. The same thing goes for upright flight. Use the ailerons before the pull, and then use the rudder to correct during and after the pull into the vertical. Wind correction is another factor that will influence straight and level flight and your vertical lines. (Note: “wind correction” means that you must lean the plane’s heading slightly into the wind to keep the plane’s flight path parallel to the runway and perpendicular to the ground during a vertical climb. See Figure 3.) If the plane is crabbed during a vertical entry, it will immediately lean toward the direction of crab. You may need to take some of the crab out of the plane with rudder immediately before the pull. (I emphasized the word “some” to signify that there is no hard-and-fast rule concerning how much to remove.) A certain amount of crab-angle wind correction should be maintained to keep it parallel to the runway. In IMAC competition, you may want to leave in some of this crab since all vertical maneuvers are affected by the wind direction. Each plane will act differently depending on its weight, the length of its tail moment and the amount of crosswind velocity. The only way to find how much crab angle you’ll need to remove is by practicing. It may seem simple, but I can’t over-emphasize how important it is to master straight and level flight—for aspiring aerobatic pilots and seasoned veterans, as well. Think of it as the glue that holds your sequence of maneuvers together. BY DAN WOLANKSI The post Straight and Level Flight — Master the basics. appeared first on Model Airplane News. View the full article
  20. When it comes to RC Golden Age racers, no one does flying models better than the world recognized guru of scale Gee Bees – Henry Haffke. When I teamed up with Henry to build the 1/3-scale version of his Howard DGA-5 “Ike” Golden Age racer, I added several details that a racer this size needed to look right. One of them being a functional c*ckpit hatch. This simple working detail can add life to any airplane so here’s how I did it. Enjoy! Start with small screws and hinge material from Nelson Hobby Specialties http://www.nelsonhobby.com/. Jerry Nelson specializes in all sorts of giant scale hardware. You’ll also need a small screw driver and instead of a small drill but, use a sharpened piece of music wire to pierce the surface of the model. This is quicker and easier than using a drill bit. First you have to build the c*ckpit section and make sure it fits properly in place. I build the hatch in place on the fuselage so I know it will fit and match the model’s outline. Tape the roughed out hatch cover in place. Without taking the tape off, position the hinge as shown centered on the hinge line. Stick the sharpened wire into the screw hole and install the screws, working from one end to the other skipping holes as you go. The fill in the rest of the holes with screws. Here the hatch cover is in place with the hinge screwed in place. Now remove the c*ckpit hatch cover and start working on it to smooth its surface and fill in any seams or other defects. Once it’s sanded smooth, finish it with a layer of fiberglass cloth and Pacer Z-Poxy Finishing resin. Use two coats and sand between each. Sand smooth again and prime with your favorite spray on primer. I like cheap Krylon primer from the hardware store. Go over the primed hatch cover and fill in any imperfections and pin holes with glazing putty. Let dry and sand smooth with fine sandpaper. Repeat the process as much as necessary until you have a perfectly smooth surface. Now spray a coat of white primer on, let dry, lightly sand and then spray on your final paint job, in this case Insignia White. I use F&M Enterprise’s Scale Stits Poly Tone paint applied with a Nelson HVLP spray gun. To keep the hatch in place, I use strong ¼-inch diameter magnest (from Hobby-lobby.com) instead of a complicated latching pin installation. Simply drill a hole in the bottom rail of the hatch cover and the top rail of the fuselage opening and glue the magnets into place. They hold very securely but allow easy access to the c*ckpit interior. The post Functional Scale c*ckpit Hatch RC Airplane Access appeared first on Model Airplane News. View the full article
  21. On January 28, 1986, the NASA shuttle orbiter mission STS-51-L and the tenth flight of Space Shuttle Challenger (OV-99) broke apart 73 seconds into its flight, killing all seven crew members. The crew consisted of five NASA astronauts and two payload specialists. The spacecraft disintegrated over the Atlantic Ocean, just off the coast of Cape Canaveral, FL., at 11:39AM EST. The disintegration of the vehicle began after a joint in its right solid rocket booster (SRB) failed at liftoff. The failure was caused by the failure of O-ring seals used in the joint that were not designed to handle the unusually cold conditions that existed during this launch. The seals’ failure caused a breach in the SRB joint, allowing pressurized burning gas from within the solid rocket motor to reach the outside and impinge upon the adjacent SRB aft field joint attachment hardware and external fuel tank.This led to the separation of the right-hand SRB’s aft field joint attachment and the structural failure of the external tank. Aerodynamic forces broke up the orbiter. STS-51-L crew: (front row) Michael J. Smith, Dick Scobee, Ronald McNair; (back row) Ellison Onizuka, Christa McAuliffe, Gregory Jarvis, Judith Resnik. The crew compartment and many other vehicle fragments were eventually recovered from the ocean floor after a lengthy search and recovery operation. A tragic loss for the entire nation. The post We Mourned as a Nation: Space Shuttle Challenger appeared first on Model Airplane News. View the full article
  22. JShumate

    Aussie Spitfire in 1/4 Scale

    This 1/4-scale Spitfire sports the scheme of a full-size Mk VIII aircraft that’s still flying and based at the Temora Aviation Museum in New South Wales, Australia. Built by Malcom Harle from the Flying Legends kit designed by Mike Booth, the 110-inch-span plane is powered by a Desert Aircraft 85cc gas engine turning a 26×10 prop. Thanks to Pete and Dean Coxon, who videotaped Malcom flying in 15mph winds — with a crosswind! — at the Greenacres meet in Walsall, UK. The post Aussie Spitfire in 1/4 Scale appeared first on Model Airplane News. View the full article
  23. JShumate

    Repairing a Fiberglass Cowl

    The great thing about almost ready to fly airplanes is that for the most part, they come with great looking fiberglass engine cowls that fit beautifully and often are painted at the factory. The general method of attachment to the fuselage is the use of through-the-cowl screws making assembly quick and simple. After time however, as you build up flight time, engine vibration and everyday knocks and dings will take their toll and our once shiny engine cowl will start to show its age. Of course if one is available, you could simply replace your old engine cowl with a new one, but that’s going to cost you at least 20 bucks not including postage and handling. A great way to save that cash and apply it something you really need, like a gallon of fuel or a new servo, is to repair your cowl by yourself. Here’s how I did it for my Hangar 9 Piper Pawnee crop-duster ARF. It is a variation of the full-size repairs we made in the USAF when I worked on fiberglass radomes, flat panels and nose cones. 1. Here’s some of the basic tools and materials you’ll need to fix a cracked and worn-out engine cowl. You’ll need fiberglass cloth, Z-poxy Finishing resin, mixing cups and mixing sticks, masking tape, sandpaper, and a Dremel Moto-Tool with some Robart medium grit Carbide grinding bits. You’ll also need some tack cloths, a bottle of spray cleaner, acetone or MEK solvent, denatured or Rubbing alcohol, and some paper towels. You’ll also need a clean place to work and it helps to place some old newspaper or brown wrapping paper to protect your work surface. 2. Start by carefully removing the old engine cowl from your airplane. If some cracked or broken cowl parts fall away, be sure to save them. Set the rest of the model aside so you don’t get any epoxy resin on your model or the engine. 3. Thoroughly clean the engine cowl using some spray cleaner inside and out. To really degrease the surface of a very old and greasy fiberglass cowl use Acetone or MEK solvent. Use a paper towel and wipe the cowl down, then go over it again with the solvent to really get the oil and grime removed. If you don’t start with a squeaky-clean surface, your repair won’t adhere properly. 4. Inspect the cowl and indentify any cracks and damage you want to fix. The first thing you should do whenever you find a crack is to stop-drill it to stop it from spreading. Cracks are formed by stress and stress in a material always looks for the path of least resistance. Sharp corners and jagged holes and cutouts in cowls are where they pop up. When there is a sharp angle in an edge it causes a stress riser which concentrates the forces until a crack forms. When you drill a hole at the end of a crack, you show down its progression by spreading out the area the stress is acting on. So, whenever you see a crack, repair it as soon as possible so it won’t spread. 5. For some damage that happens from vibration and metal parts rubbing against the fiberglass (such as m ufflers,) the best way to repair and prevent the damage from spreading, is to simply use a grinding bit or cutoff wheel and enlarge the opening by removing the damaged portion. You can see this damage easily with its fractured gel coat and black grease deeply embedded in the edges of the fiberglass. After you degrease the area use a fine tip felt pen and mark the material you’ll remove. 6. Slowly grind away the material up to the pen mark then use some 220 grip sandpaper and smooth the edges of the opening so there are no more sharp edges to encourage further cracking. You can leave the edges as is, or you can lightly spray with a primer and then shoot a coat of matching color paint to seal the edges. This will help minimize future grim and oil from embedding itself into the fiberglass. 7. For holes that have cracked out to an edge, like where there attachment screws hold the cowl, you should use a cutoff wheel and lightly remove the very edges of the crack to expose new, clean material. On the inside surface use a grinding wheel to remove a thin portion of the fiberglass and then go over the area with some 220 grit sandpaper to expose clean material for the repair to stick to. 8. On the outer surface of the cowl, mask off the repair area so you can protect the undamaged finish. Use 220 grit sandpaper and go over the repair area and expose fresh gel coat and fiberglass. Wipe the inside and outside of the repair area and swipe it with a tack cloth to get all the ground fiberglass powder up and away. 9. /P> Take some fiberglass cloth, roll it up and then with a sharp pair of scissors cut it into shreads. Do this over some paper and cut the cloth over and over again until you end up with very fine shards of fiberglass. This will be used as a thickening material and will be mixed into the epoxy resin. 10. Place the fiberglass shards in a mixing cut and slowly add the finishing resin till you have a 50:50 mixture of resin (both parts A & B) and the filler material. Use a mixing stick and really combine the mixture until it is slightly stiff and strings when you lift the stick from the mixture. 11./o:p> To make the repair build up really smooth, make two backer sheets from balsa wrapped with some MonoKote clear backing, or Great Planes Plans Protector sheeting. Use some tape to hold it in place around the balsa sheets. 12. Apply a small glob of resin/filler mixture on the outside of the cowl repair area. Make sure to get the mixture to flow into the hole and crack. keep the amount of filler on the outside surface to a minimum. 13. Turn the cowl over and place it on top of one of the backing strips. Use a weight to hold the cowl down snuggly over the backing strip and apply more filler material over the inner repair area. 14. Place the second backing strip over the repair and press down firmly to spread the mixture out. Place the weight on top of the strip and set aside until the repair mixture has set. (30 minutes to 1 hour depending on your brand or resin.) 15. Here’s what the repair looks like after the backing strips are removed. But you’re not done yet! 16. Cut 3 or 4 patches of medium weight woven cloth into square patches. The should be an inch all around larger than the repair area. Mix up some more resin and apply the patches over the repair. 17. Apply patch material to both the inside and outside of the engine cowl, cover with the release plastic and squeegee out the resin to make a smooth flow of resin. Set aside to set up. 18. When the resin has cured, remove the release sheet and trim the repair material flush with the edge of the cowling. While the repair material is not completely set up it can be easily cut with a sharp hobby knife. Cut the access material away and then let fully cure before you sand the surface and edge smooth with sandpaper. 19. Now to make the repair literally disappear, sand the resin and feather it out to the surrounding surface. Use some model filler to fill any pinholes or defects and sand smooth. 20. Mask off the cowl again and hit with a couple light coat of sandable primer and let dry. Repeat the process until the surface is smooth and flaw-free. Spray the area with a couple light coats of paint to match the engine cowl’s color. Let dry. 21. Reinstall the engine cowl on the model and mark the location for the attachment hole. Remove from the model, drill a pilot hole and then slowly enlarge the hole by using larger and larger drill bits until it is the proper size. Lightly sand the hole to smooth the edges and if you like, add a light clear coat to add an addition layer of protection. Well, that about it. I hope this How To technique helps you enjoy the hobby a little more while saving some coin. And who doesn’t want to do that?! So what are you waiting for? Go out and take your newly repaired airplane out and do some flying… The post Repairing a Fiberglass Cowl appeared first on Model Airplane News. View the full article
  24. Of all 3D maneuvers, it’s possible that none represent 3D flying more than hovering. While learning to hover can be extremely challenging, you can make it easier for yourself by knowing the primary forces involved. Control while hovering is maintained solely by the propeller thrust or “prop-wash” over the tail surfaces and the inboard portions of the ailerons. It typically takes approximately half throttle to maintain a stationary hover but that usually provides only marginal control. Therefore, you need to continually pump the throttle higher while hovering in order to generate more propwash over the surfaces without holding the higher throttle positions long enough to cause the airplane to climb. Next, understand that the “propwash,” generated by the turning propeller, spirals around the fuselage and strikes the left side of the vertical tail, thus producing a strong left yaw tendency during hover. Consequently, you’ll need constant right rudder inputs to keep the fuselage vertical. (Note: Building in a couple degrees of right thrust lessens the effect of the propwash while hovering, but it does not eliminate it.) A great deal of the propwash also strikes the underside of the left stab, causing the plane to pitch forward during hover. Therefore, barring any wind, you can expect to regularly need up-elevator along with right rudder to keep the fuselage vertical while hovering. There is also considerable left rotational torque while hovering, so you’ll need to hold in large amounts of right aileron to keep the wings stationary. If the plane continues to torque to the left despite holding in full right aileron, you may have to increase the right aileron travel. If you can’t keep the plane from torquing even with full aileron, you’ll have to boost the throttle higher each time the plane starts to torque to further increase the effectiveness of the ailerons. CONTROL TECHNIQUE The standard entry into a hover starts by slowing the airplane and then abruptly pulling to vertical, causing the airplane to suddenly stop all forward movement. Be aware that you most likely will need to input some right rudder and aileron to counter the propeller forces while pulling up to vertical. Then immediately start pumping the throttle to maintain the same height as well as control. A hover will quickly unravel if you are late correcting a deviation, so keep your fingers moving at all times, even when the airplane appears momentarily stable. This will make sure that you’re always ready to respond to deviations the instant they occur. As a rule, if the tail swings more than five degrees from vertical while hanging on the prop, it will be very hard to stop the deviation due to the pendulum effect. To minimize over-controlling, you must try to limit your rudder and elevator corrections during hover to small brief bumps or jabs. If a deviation is larger than five degrees and requires a larger correction, any large correction will have to be immediately followed by a quick opposite jab to keep the response from escalating. Try to limit over-controlling by keeping your inputs tiny and brief, and if you must input a larger bump, immediately input an opposite bump to limit the response. ADVANCED HOVER TIPS Since a sustained hover demands immediate corrections, use of too much expo will delay the control response and thus hinder hover success. If you feel that the plane is lagging behind your control inputs, reducing the expo settings will likely improve your ability to hover. CG Considerations It has long been said that an aft CG makes an airplane easier to hover. While a tail-heavy condition helps flat spins and tumbling maneuvers, after years of 3D flying and testing, neither an aft nor forward CG has proven to have much impact on hovering flight. In fact, more and more professional 3D pilots set up their planes these days slightly nose-heavy to make them more predictable and less erratic. All things considered, most pilots are best served to go with a “neutral” CG (near the wing’s thickest point or approximately one third of the wing chord) to achieve the best overall performance. Although it’s rarely possible to achieve a perfectly vertically balanced airplane, i.e., with the tail hanging straight down, getting it as close as possible can make the airplane lock into a much easier hover. If you can, try to position the batteries and other items as high as possible in the fuselage to offset the weight of the landing gear, etc. On the other hand, if over-controlling seems to be a persistent problem, i.e., the corrections you make typically end up causing more deviations. To solve this, in addition to practicing smaller control inputs, try increasing your expo percentages. If your airplane exhibits an especially strong tendency to pitch forward while hovering, putting in additional up-elevator trim will certainly help. But the trick that works best is to aim to hover with the fuselage tilted a couple degrees toward the canopy. Some 3D pilots like to determine the exact power setting that their airplane hovers at and then they flatten the throttle curve a bit around that setting to make the throttle less sensitive. On a similar note, using a lower pitch propeller affords a larger power sweet spot during hover in which the throttle is less sensitive and therefore less prone to over-controlling. CONCLUSION To avoid over-controlling, try to limit your rudder and elevator corrections to small, brief bumps or jabs when working to keep the fuselage vertical during hover. While there will always be pilots who try to impress others by throwing the sticks into the corners until altitude forces them to recover, they don’t come close to knowing the satisfaction that comes from learning to hover. It may be challenging, but you can take confidence from knowing that you’re now armed with the knowledge to learn at a rate much faster than most! Good luck. The post Learn to Hovering — Master this 3D Move appeared first on Model Airplane News. View the full article
  25. Where do we sign up to take a ride in this super-size drone? Here’s the scoop from creator Boeing: Boeing yesterday successfully completed the first test flight of its autonomous passenger air vehicle (PAV) prototype in Manassas, Virginia. Boeing NeXt, which leads the company’s urban air mobility efforts, utilized Boeing subsidiary Aurora Flight Sciences to design and develop the electric vertical takeoff and landing (eVTOL) aircraft and will continue testing to advance the safety and reliability of on-demand autonomous air transportation. The PAV prototype completed a controlled takeoff, hover and landing during the flight, which tested the vehicle’s autonomous functions and ground control systems. Future flights will test forward, wing-borne flight, as well as the transition phase between vertical and forward-flight modes. This transition phase is typically the most significant engineering challenge for any high-speed VTOL aircraft. “In one year, we have progressed from a conceptual design to a flying prototype,” said Boeing Chief Technology Officer Greg Hyslop. “Boeing’s expertise and innovation have been critical in developing aviation as the world’s safest and most efficient form of transportation, and we will continue to lead with a safe, innovative and responsible approach to new mobility solutions.” Powered by an electric propulsion system, the PAV prototype is designed for fully autonomous flight from takeoff to landing, with a range of up to 50 miles (80.47 kilometers). Measuring 30 feet (9.14 meters) long and 28 feet (8.53 meters) wide, its advanced airframe integrates the propulsion and wing systems to achieve efficient hover and forward flight. “This is what revolution looks like, and it’s because of autonomy,” said John Langford, president and chief executive officer of Aurora Flight Sciences. “Certifiable autonomy is going to make quiet, clean and safe urban air mobility possible.” The test flight represents the latest milestone for Boeing NeXt. The division works with regulatory agencies and industry partners to lead the responsible introduction of a new mobility ecosystem and ensure a future where autonomous and piloted air vehicles safely coexist. In addition to the PAV, the Boeing NeXt portfolio includes an unmanned fully electric cargo air vehicle (CAV) designed to transport up to 500 pounds (226.80 kilograms) and other urban, regional and global mobility platforms. The CAV completed its first indoor flight last year and will transition to outdoor flight testing in 2019. “Boeing was there when the aviation industry was born and in our second century, we will unlock the potential of the urban air mobility market,” said Steve Nordlund, vice president and general manager of Boeing NeXt. “From building air vehicles to airspace integration, we will usher in a future of safe, low-stress mobility in cities and regions around the world.” The post Boeing’s Autonomous Drone Takes Flight appeared first on Model Airplane News. View the full article
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