Question160: "Hey Jack, I was hoping to have you explain the proper way to fly with coordinating rudder. I have had people show me to turn first using the Ailerons, and then apply opposite rudder. I have also had people say to turn first with the rudder and add opposite Ailerons second. Also apply both in the same direction. Please help! Thanks, Chuck"
Jack: Hi Chuck, Thanks for writing. Some of what you described here for effective use of the rudder to fly a plane is a recipe for disaster. With the opposite deflection of rudder and aileron your plane will more than likely enter a spin and not make a smooth clear turn. The rudder used in the same direction will keep a turn clean and make the tail of the airplane actually cause the turn to occur. Warbirds have always tended to drop the tail in a turn with aileron only input and most beginning pilots learn to bank the plane with the ailerons and then force the turn with an up elevator input. There is no argument that that will turn the plane but it is not the proper coordination of the flight surfaces to keep a clean line throughout the turn. You need to practice with the rudder and really experience how it effects the turning ability of your plane and I assure you, you will see much cleaner and smoother flight once you start to coordinate rudder input when you fly. You can turn your plane in wing level flight by just inputting enough rudder deflection. The plane will turn flat but that is not an efficient turn either. With the addition of rudder input in the direction you are going to turn coupled with your aileron input again in the same direction you are going to turn, will make the plane track smoothly and turn very well. Tail dragger aircraft are especially responsive to rudder input and aid takeoff and landing immensely. Warbirds are usually over powered and if you don't use the rudder on takeoff and landing there is no way you will master the flight envelope until you start to include the rudder input. Some fighter type aircraft require a lot of right rudder on takeoff and you will not get the plane to track straight down the runway without it. Cross winds are also pretty easy to deal with when the rudder is used because you can then use the ailerons to control the roll axis and the rudder to maintain the flight direction or better word here is course.
In dealing with this situation opposite deflection is correct. The plane will yaw left or right depending on the control input and the wind direction but the actual direction of flight in reference to the direction of the runway can be maintained.
The best way to learn this Chris is to take you plane up high and start to move that rudder stick and carefully watch the airplane. Turn without the rudder and then in the same flight direction start to ease in the rudder with the ailerons and watch the plane. You will see a difference. Practice the turns until you are comfortable with the amount of rudder input you need. Your whole flight envelope will improve and you will find that the airplane will go exactly where you want it to and that you can maintain a course setting with an opposing wind quite easily. You just have to interrupt your comfort zone and try it. Go slow and watch the rudder effects. You will catch on pretty quickly and get the turns down before you start to try flying more complex flight maneuvers. I keep going back to full scale flight. You will have many hours of flight time under your belt before a good instructor will ever let you try the more complex maneuvers.
Have you ever done a big loop but had difficulty keeping the flight direction you wanted. You enter the loop lined up with the runway and by the time you come through the bottom you have a major flight direction change. You can stop that with coordinated rudder input. Again try it at a safe altitude and you will discover some really cool things about flying.
Master the basic stuff and the transition to the complex maneuvers is really quite smooth. This is a good discussion that has come up here before.
Start slowly and it will all come together. Good luck Chuck. Jack Devine"
Back To List
Question161: "Hi Jack, Thank you for your response. Glad I asked! Currently I am flying a Holman 190d-9. It fly's nicely. I have been flying for over 5 years and have worked myself up to this caliber of planes. Using rudder on takeoff and landing are now natural, just figuring out the use of it in "in the air" was my problem.
Too many people had sooo many different answers. I'll give it a shot next time I go flying. I'll try to lead in to the turn with both aileron and slight rudder, and hold the rudder al the way through the turn (sound right) and then in future turns gradually build up the amount of rudder I use until it feels right. But in general I want to use the aileron input to start the turn and at the same time enter rudder in the same direction and hold the rudder input through the entirety of the turn, correct? Thanks again for your help. Sincerely, Chuck"
Jack: "Hello again Chuck, I thought a lot about your questions and I'm happy to hear that you are understanding what I was trying to tell you. Adding to what I put in my last answer to your question I think you need to focus on three basic rules that apply to every airplane model or full scale. You operate within three axis' of control. Pitch which is controlled by the Elevator, Roll which is controlled by the ailerons and Yaw which is controlled by the Rudder. In level flight the yaw axis is affected and changed by rudder input which changes the heading of the airplane. The roll axis is controlled by the ailerons and input from the ailerons changes the roll attitude of the plane and it does so by increasing the lift on one side of the wing and partially creating a stall on the opposite side of the wing.The up moving aileron interrupts that airflow across the wing and disturbs the lift capability of the wing on that side of the wing. The down moving aileron on the opposite wing actually generates more lift and that is what causes the plane to start a roll when aileron input is given to the ailerons. The problem is the roll axis does not generate a good stable directional change without additional support from the other flight surfaces. When airspeed is slow you can quickly get into big trouble when you over bank a plane with too much aileron input and I know you have seen models especially getting ready to enter a turn to final just fall out of the sky and crash. They did so because the wing could not create enough lift to keep the aircraft flying with the low wing in full stall caused by the aileron deflection that spoiled the lift on the low wing. The top wing is still flying with the down deflection aileron and the pilot sees the roll starting and he immediately inputs full opposite aileron which deepens the stall on the low wing and disaster is a second or two away. It's an unrecoverable condition. Now, consider the same situation in flight but when the stall is noticed you input opposite rudder to yaw the plane back into a more favorable flight attitude. Get off the ailerons so the wing
generates maximum lift and you will quickly return to level flight while avoiding that fatal stall. I think this is what you were describing in your first question and under the conditions I just described the opposite rudder is the right input.
Remember the rudder is there to turn the plane so use it as the primary turning input and then coordinate the aileron input to achieve the angle of bank that you are looking for. Opposite rudder will increase the airspeed of the stalling wing and make it produce lift again sooner. As the rudder forces the nose to move in the direction of the deflection the low wing will have a higher airspeed than the wing that is high and the added lift it generates will right the airplane and help it get back to level flight. I told you in my last response that you need to see that your plane will turn without the aileron with just the use of the rudder and once you see this response in the air I think it will help you really start to begin your coordinated flight control inputs. Rudder with a little aileron should have you turning smoothly but like in full scale it takes practice. Any instructor pilot will tell you the rudder is every bit as important as the other two axis controls and coordinated input will make all of your flight time much more pleasurable and gaining an understanding of how they work together is the key to becoming a good pilot. The key Chuck is practice, practice, practice. Best of luck with your FW 190! Jack Devine"
Back To List
Question162: "Hello, Jack! I have a bunch of warbirds! all are hand crafted; me-109,Corsair, helldiver, ta 152 H-1, P-51 precious metal.
They are huge and as scale as possible.. I have put hand crafted engines and my own technologies in them..including variable pitch prop and cowl flaps.
Now let's get to the question. I have a lot of expirience and am a great pilot, and the planes fly awesome.
The bf-109G's gear (hand-crafted by me) is really hard to use; the landings are rough
and dangerous and I broke my scale prop on the last landing.. It is extremely hard to land, even with my expert skills (note i have flown those babies for almost 15 years now and i'm 20) so maybe you could help me with that?"
Jack: "Hi Rado, Sounds like you have a hanger full of very nice warbirds! The 109 has never been an easy plane to land and the set up has to be spot on so you maintain good flight control to touch down. I have see several of the large scale 109s meet their demise on landing and each time I saw it the airplane quit flying, dropped the left wing and hit the ground hard always doing considerable damage to the model. From my point of view you really need to understand the stall point of your model and all of them give you little hints that you are crossing into dangerous territory. I’d suggest taking the model up high and drop the power way back and let the plane stall in the attitude you use to land it. The idea here is to make sure you are ahead of the airplane and when the control inputs start getting a little mushy and the wings start wobbling you are ready with corrective action and can get the plane back into a flying status. Power changes on the approach to landing need to be slow and consistent. You are using the throttle stick as your primary approach speed control and you need to absolutely know how your model responds to changes in power. The flaps on the 109 work very well but they create a lot of drag. That said you have to respond with the addition of power when the stall occurs. Ad power slowly and consistently. Rapid changes on the throttle can create huge prop torque input to the airframes and without the solid penetration of the air the plane can roll to the left and place it into an unrecoverable attitude. The whole idea is understanding the airplane and being ready for the unexpected.
Landing gear on the 109 are usually pretty weak so solid approaches to touchdown are really important. Too fast or too slow the gear will show you the damage that can occur. That said lets talk about the approach. First make sure you study the wind conditions and realize how wind will effect the landing. Watch the pitch and Yaw axis’s of flight for any signs of danger all through your turn to final and final approach.
Flaps are your friend and you need the proper application of the flaps. Once I turn final the flaps are already in position and I control the decent with application or removal of power. Steer the plane with the rudder and control your approach angle/ track with rudder and subtle changes on the throttle. As the model nears contact with the ground and enters ground effect you should be able to let it set in on the mains. As your speed deteriorates let the tail come down on it’s own. Bleed the airspeed of with the model planted on the main gear with the tail surfaces still flying. After a short run on the main gear with the throttle brought back to idle your plane should settle down and not bounce back into the air. You definitely need to practice with the 109. I hope this helps and wish you the best of luck. Jack Devine"
Back To List
Question163: "Hi Jack I have the privilege to test setup and test fly a friends 2.6meter wing span Corsair. The trouble is it is a very old kit and he has never flown the plane. I need to know how to find the CG of the corsair. We have a 80cc Zenoah twin up front and it is painted in Night fighter colours. Please help me. I don’t know what the kit is either but that size might be a Ziroli."
Jack: "Hello Tony, For a CG point on your Corsair I would start at 25% of the root chord of the wing and that should be a safe starting point. TO arrive at the mark simply measure the distance from the leading edge of the wing to the trailing edge of the wing and 25% of that dimension is a good place to start. It’s easy on a calculator. Multiply the measurement number by .25 and the answer is the distance measured from the root cord leading edge back toward the trailing edge of the wing. I run a fine line masking tape line out to the wingtips at the balance point making sure you have a good straight line perpendicular to the root chord. Fly the plane and if you feel it sluggish start moving forward slowly until the model starts to respond. I think you will be just fine at the 25% dimension. Good luck! Jack Devine"
Back To List
Question164: "Hi Jack, great site!!I have a question that I hope that you can advise/help with. I'm building a somewhat modified small scale replica (26"wngspan) of the "1871 Planophere" by Alphonse Penaud without the prop (glider style) launched from about 250' up to test his theory on aerodynamic glide principles. I'm just not sure what to use as a covering: Tissue, Jap paper, thin muslin, or mylar flim. I want it fairly sturdy, but also somewhat simplistic in design. What do you think? Joe Fmr.USAF Lt. Flyer"
Jack: "Hello Joe, Thanks for writing. This is a very different question on a subject that few people even know about. It sounds very interesting. My primary concern in building this type of air craft would be making sure it was as light as possible while maintaining some structural soundness because a glider often makes some really unplanned hard landings. I would think with an early aviation design like this that would be a primary concern. That being said I think that tissue is the lightest of the material choices you mentioned and it has served modelers very well for a long, long time. Shrunk properly it produces a good tight surface and I think it would work well in this application. Silk span would be another choice that I think would work well, I hope this helps and please keep us in the loop with this project. Good Luck Joe! Jack Devine"
Back To List
Question165: "Jack, I have a Top Flite T-34 with cockpit kit, robart retracts..
I just cant have the engine coming out the side of the cowl.. the RCV engines would be the answer. I have access to a RCV 90SP. Can this engine fly her scale? What do you think? As before, I desire scale flight. Nick e.l. Palanza" http://www.top-flite.com/airplanes/topa0160.html
Jack: "Hi Nick, I have recently gained some experience with the RCV 90 motor and I was very impressed at how smooth it ran and it produced very high power for a .90 size motor. You need to keep some extra oil in the fuel for these motors and I use an ounce of Castor oil in a gallon of 15% glow fuel. The castor oil will keep everything well lubricated and keep that motor nice and happy as it hauls your airplane around the sky. I'm sure it would have plenty of power to fly the Top Flight T-34. Let me know how this turns out.
It sounds like a great combination and should give you a very nice flying plane. Jack Devine"
Back To List
Question166: "Hi Jack, my ultimate goal getting into rc airplanes 3 years ago was to fly giant scale warbirds. I have progressed through several different planes; trainer, Sig 40 Star, GP Ultimate Biplane, Nitro Planes 55” Ultimate Biplane, along with simulator experience. For my next plane I plan on getting a warbird. I would prefer a larger plane because of how they fly and how they handle on a bumpy, grass runway. I have been looking at the 76” CMP Corsair, because of its low wing load and nice scale lines, and the Top Flite Giant Scale P-47, because of the P-47’s inherently stable design. In your opinion, do you feel that starting with a larger warbird is a successful formula given my experience or should I consider starting with a .60 size warbird? Thanks in advance. Ryan"
Jack: "Hello Ryan, The first thing I will say to you is that the larger warbirds are definitely easier to fly. The P-47 is the better choice here for a first plane. It is a much more stable aircraft and it has no bad flying tendencies. Fact is I think it is one of the easiest fighters to fly that is currently available and the Top Flite Kit is a good one. A G-62 is perfect power and will let you advance your flying capabilities with a very reliable engine that will perform very well on this plane flight after flight. You can really scale this kit out and the detail you add is totally up to you. The Corsair is my favorite airplane but it is more difficult to fly than the P-47 is. I think after you have mastered a big P-47 the transition into the F4U Corsair would be fairly easy. Build the P-47 and fly the heck out of it and you will develop enough Heavy Metal skill to give you hours of fun becoming a Corsair Driver. Good Luck Ryan and keep us posted!! Jack Devine"
Back To List
Question167: "HELLO, i WAS JUST WONDERING IF THERE IS A WAY TO CALCULATE OR A FORMULAR TO SETTING THE FLAP AND ELEVATOR MIX FOR LANDING. I HAVE A 1/5 SCALE MUSTANG AN I WANTED TO KNOW IF ITS TRIAL AND ERROR OR WHAT. ANY INFOMATION ON THIS SUBJECT WOULD BE HELPFUL. THANK YOU EUGENE"
Jack: "Hello Eugene, Nice to hear from you. I can’t say that I know of a formula for the proper mix of elevator and flap settings but I have three Mustang warbirds and 3 degrees of down elevator with 25 degrees of flap works well for landing in light wind and 6 degrees with full 50 degree flap extension for calm days should keep the plane from needing any trim change. Just keep in mind that those big flaps are also big brakes and you will have to manage your power setting as the airspeed starts to drop off. Keep you approaches fairly steep and let the flaps do their job. Keep power on until you make the runway and then about two feet off the ground start a gentle flair and bring the motor to idle. It should settle into ground effect and set down nicely on the main gear. As the airspeed bleeds off the tail will settle in and your tail wheel will provide very good steering. The rudder will remain effective all the way until tail wheel contact so your landings should be looking good with a little practice. I always use a two position switch for the flaps and then just mix in the rudder. I think you will be really pleased with the result. Good luck with your Mustang! Jack Devine"
Back To List
Question168:
Jack:
Back To List
Question169:
Jack:
Back To List
Question170:
Jack:
Back To List
Question171:
Jack:
Back To List
Question172:
Jack:
Back To List
Question173:
Jack:
Back To List
Question174:
Jack:
Back To List
Question175:
Jack:
Back To List
Question176:
Jack:
Back To List
Question177:
Jack:
Back To List
Question178:
Jack:
Back To List
Question179:
Jack:
Back To List
|
