All Articles by Kevin Allard

16 Articles

All Articles by Kevin Allard

16 Articles

Building a balsa kit.

 

Devin Ryan, a member of LOWAM, has spent the 2016/ 2017 winter constructing a Sig.  “4 Star- 60” model airplane.  This plane falls under the “sport / trainer” classification and is highly recommended as a starter aircraft after the basic trainer.

This kit was seen at Cellar Dweller as late as Jan. 20, 2017

He is photographing and documenting the steps he followed and it is all viewable if you follow the link below.

Well done Ryan.

http://dwcryan.com/blog/tag/building-4-star-60/?order=asc

 

Rays Rants silenced

Picture 6

Sad to report that this is the unfinished end of Rays Rants.

Ray passed away in January, 2016

He will be missed.

The Rants were intended by Ray to encourage young fliers to be builders as well as fliers, to experience the pride and satisfaction which comes with the successful flight of a hand crafted model.

Give it a try – Ray will be watching.

THE   END

Rays Rant #9 – Tail Feathers

Ray’s Rant # 9                                        November 1, 2015

THE TAIL OF A MODEL AIRPLANE

The Tail Feather’s, they are more than around for the ride.

In the early years of building model’s, I would build the fuselage first, then the wings, and lastly the tail feather’s. Most kits today have you build the tail feather’s first, then the wing, and then the fuse. And they have their reasons for that, I suppose. I find it hard to change habits I have had for years, so still usually follow my path for building a model.

In looking at the Wright Flyer that introduced heavier than air flying, we find that the elevator was on the front, and the rudders on the back. In looking at the setup, it may have had to do with the balance of the airplane. Even the pilot lay down to fly using his feet to operate the rudders. The engine was centred, and the props were run by a series of chains. Eventually the aircraft took on the form we are more familiar with today. The tractor engine was at the front, with propeller attached, and the Centre of gravity was about 25-30 % of the wing cord.

The tail feathers were grouped at the back of the fuselage. The tail feathers are a very important part of the total airplane. What we refer to as the fin and rudder are really called the vertical stabilizer, and what we usually call the stab is correctly called the horizontal stabilizer. They perform important functions in flight. The vertical stabilizer keeps the plane on a steady course straight ahead, and the horizontal stabilizer keeps the plane on a level flight course.

 

Because of the position of the tail feathers so far back on the fuselage, care must be taken during construction not to build them too heavy. They have to be strong enough to take all the vibration and forces on them, yet light enough so that little compensation is needed during balancing. Every ounce added at the tail, would need four ounces added to the front. If you are building a kit, follow the instructions carefully, and don’t use heavy wood.

The vertical stabilizer can have many shapes to divide up the fin area. Some planes like a Beech 18 have two small fin and rudders, one behind each engine.

The advantage of two small fins over one big one, is less drag as the area of two small ones is less than the area of one big one. Some planes have a large central fin, and a couple smaller ones on the outside, like the Lockheed Constellation. The DH Otter has quite a large fin and rudder, compared to the Beaver, and so does the CL 215/415, this is needed for stability while picking up water. Even some float planes required sub-fins to offset the side area of the floats.

Away back, you could tell the make of many airplanes by the shape of the fin. The De Havilland series of Moth biplanes are easily identified by the shape of their vertical stabilizers .The Norseman and the Stinson’s were easy to identify, and so was the Mooney’s.

This comes to an end of the series on building wooden models. During my years of building models, starting with rubber powered ones, I built mostly scale models, rubber powered, but in the early years not many of them would fly like my imagination thought they should. In fact, it was only a few years ago that I built a rubber powered model that did fly, I think it stayed up about 45 seconds and made many circles before the rubber motor ran down, and she landed. Maybe the fact that it wasn’t a scale model had a lot to do with it. I had a lot of pleasure out of that model over the last few years, without much building. I like working with wood, as I have become familiar with it, and how to build with it, and at my age am unlikely to change to something else.

There is nothing wrong with the new materials of themselves, it’s just that us oldsters find it hard to change from what we get our pleasure and enjoyment from. Hopefully, kits will soon return, along with the desire to build a certain favourite we may have. There are plenty of plans around from many of the old timers up to the modern age, and by learning how to make them will bring a lot of satisfaction in your following of this hobby. Building season is upon us, and soon the shops and basements will get busy, making a new model for the coming season.

I want to do a series on the theory of flight next, to bring up some of the basics we should know, to improve our skills.

Ray

Rays Rant #8 – The challenges

Ray’s Rant #8                                                                        October 2015

I am going to pause on the subject of building wooden airplanes, and take you the steps you would need to go through if you decided to build a certain model.94 resized

The present state of the ARF model world gives quite a wide choice of aircraft, but doesn’t always include an airplane you really like and would like to model.  Down through the years, the model magazines always had a project or two of models, with the appropriate plans to build that airplane.  These plans seem to have disappeared from the usual places you would have found them, but I am sure they are around someplace, and will show up again when modelers once again turn to building.  Right now, the market is very limited for plans, but if you were like me, you bought the plans of models you might like to build down the road.

Sometimes we even bought the kits, and stored them in our basements and workshops until the right time came to build them.  The following story is of one such project.

In the summer of 2011, Ron Pettigrew and Peter Schaffer approached me, and asked if I would join them in a project they had in mind.  Ron had the plans for a Curtiss C-46 Commando, which was a twin engine transport plane used in the second world war.  This was not only quite a project in itself, but it was a larger model than I had ever built up to this time.  It had a wingspan of 8’, and was a model of the largest twin engine airplane used on the allied side during the conflict.  Ron also had the laser cut kit for it, and that would make the project a bit easier, as all the formers, and wing ribs, and other parts were already cut and ready to use.  Before I could decide to join in the project, I would need to look at the plans, and see what I was getting myself in to.  The project seemed doable, so I said I would join in on one condition, and that was that the finished model was their’s, and that my part would be to help teach them how to construct the model.  One of the necessary decisions in deciding to build a certain model, is that you liked the plane, and wanted to model it.  The amount of work needed to get the model up to flying status is huge, and only the desire to see the model fly will keep you going.

The plans for the C-46 are quite large, and are made up for four large sheets.  They are quite complete for those of us who are accustomed to building from plans, and required a bit of time just to digest them.  We needed to find out many things that would make up the project.  What engines to use; how to mount them.  The fuel tanks and system used; how scale were we going to do it; retract wheels or not; real windows, or paint them on.

The first decision we made had to do with the engines.  Ron had an OS90FS he was not using, and I had one as well.  So we decide to use them, instead of two 60 size two cycle like the plan showed.  We felt the 4 cycle engines have a more reliable idle, and on twin you need both engines to run reliably.  In this regard  we then decided to install them sidewinder and not inverted.  Next, we looked at the way the designer installed the fuel tanks.  They were side by side on top of the centre section, and that gave us a possible problem with the fuel siphoning down to the carbs and flooding the engines while not running.  So we moved the gas tanks into the space behind the firewalls, where they would just fit.  That gave us the problem of repositioning the throttle servo’s, which the designer had put in the space behind the firewall’s.  We relocated them to the space where the flap servo’s were, and used a cable to run the throttle.  The only other thing we looked at was the outer wings themselves.  They looked rather thin both in width, and thickness.  So the question we asked was, “had anyone built the model and tried to fly it?”  If we knew that answer, it would have helped in our decision.  However we went with the plan, and the log book showed we had put in 279.5 Hours to complete the model.  We know there were things we did that were not recorded, esp. when we got to putting the finish on, so figure 300 hours closer to what it took to construct the model, and do the engine runs, and taxi tests.IMG_0754-w

We had taken the model to Gimili that year(2012), even though it was not ready for flight.  A group from the US had brought up to the flyin a DC-3 dome up in Buffalo colours as well.  My memory is fuzzy, but I don’t think they tried flying their plane either.  It may not have been ready to go, the same as ours.

We had done the taxi tests and engine run ups in the fall, so the plane was taken to the 2013 flying, and test flown by Mark Sharpe.  Someone used their phone to video the flight.  The take off was great, and the plane flew around and was a good flyer.  During the landing as the plane slowed down, and rounded out for the landing, it dropped its right wing, in a tip stall.  We were glad that we had the video to see what happened, as it happened so quickly.  The damage was slight, and a bit of five minute epoxy would have had it repaired and ready to go, but the tip stall was not a flying error, but a wing problem, and needed to be looked at.

Flaps were not used on the landing, which might have helped, but I really doubt they would have helped.  We brought the plane home, and knew that we had to redesign the outer wing panels to eliminate the tip stall problem.  We did that by widening the tip almost two inches, and thickening the tip as well.

old and new wing

95 resized

We did this by using rib #9 as the tip rib, and having 94 resizeda new set of ribs made on a computer programme.  The new outer wings were constructed during the winter, and in Aug of 2014 at Gimili, we tried again.  When we redesigned the outer wing, we also put in separate servo’s for each flap section, as the joiner the designer had didn’t allow the flaps coming down equally.  This time the plane flew and landed o.k.

During this first flight, the port engine quit, and the plane flew on as if nothing had happened.  In fact the pilot was not aware of the engine out, as the plane flew around just as well, and landed without incident.  On the second flight, everything ran as it should, and the plane landed using the flaps for the first time.

It handled just like it should, but another problem showed up, and that had to do with the tail wheel.  It kept coming loose, so we couldn’t taxi the plane in.  So during this next winter we installed a Robart tail wheel, which handles well in taxi tests, but high winds in Aug. 2015 kept our bird grounded.  We look forward to next year, and hope to get a lot more flying on the model.

Some modelers have said that flying is everything, but that is not our experience.  Seeing your project fly and perform in the air, is a much more rewarding experience, and you won’t agree with this until you have built and flown a successful project, like we did with the C-46.

At this point, I want to say that feedback, and different opinions are welcome.  It is only as we share our experiences with each other as modelers, that we can have greater success in our flying of our projects.

I am adding pictures to this blog, to show the differences in the outer wings, and how only an expert measuring the model to the real airplane would know we had made any changes.

Ray

Rays Rant #7

RAY’S RANT #7

Building Wings

The next subject we have to consider, are the wings of the project. Those interested in flying looked to the birds, and tried to imitate them with the first try at airplanes. I was the Wright Brothers who did the technical work to bring about the first flight of an airplane. This is a big subject, and includes the theory of flight, which I will tackle at a later time. For those that are new to the hobby, and are interested in building, we need to look at some features that are vital to having a good flying model. Thankfully, when we build from a kit, or plans, we know that the resulting model should fly, providing a plane was built from the plans and flown. The advent of ARF’s means we have to look at all the aspects of the model. We usually advise beginners to buy an ARF trainer, so they can get started learning to fly right away. Right now, I think the Sig LT40 trainer is one of the best. It has a larger wing than many trainers, as well as a longer fuse which helps with stability, and slower flight, which makes learning easier.

Wings come in many shapes, and one of terms we use to describe them is Aspect Ratio. This tells us the relation between the wingspan and width (chord) of the wing. The wing of a glider would be called a high aspect ratio wing, because it is long and thin, and designed for high lift and slow speed. On the other end of the scale, we would have a low aspect ratio wing, and these would be found on racing planes, and those designed for speed.

Our models are usually in the middle of these two extremes, because in a trainer we want a wing that will give good lift, a slower speed, so we can learn to react to the input needed to fly the plane. So a good trainer needs to have a relatively high aspect ratio, a flat bottom airfoil (Clark Y) and a constant chord wing. As we gain experience flying, we would then go to a model with a different airfoil, a semi- symmetrical airfoil. This would give us more speed and aerobatic capability than the trainer wing, and require a higher level of flying experience. We would still retain the constant chord with the wing. The next level we would go to is called a double taper wing, where the wing narrows toward the wing tip in chord and thickness. This type of wing would be used on high level aerobatic monoplanes that we see being used in the air shows today.

In picking a particular airplane to build, we would need to look at the wing layout, its airfoil, and aspect ratio. Suppose we wanted to build a model of the Stinson SR-9, and a quick look at the plan form of the wing are extremely narrow wingtips. This should raise a red flag for you, as it raises the problem of wing tip stall. Other planes in this category are the DC3, the DH Mosquito, and many others with a similar wing shape. In the early days, those who built SR9 models, would raise both ailerons to try and defeat the wing tip stall problem. This helped somewhat, but was not the answer.

When coming in to land, the wing needs to stall at the root of the wing and progress outward. In a double tapered wing, this is hard to accomplish. The new technology we use now, we twist the tip with a couple of degrees of washout.   This makes the end of the wing fly at a lesser angle of attack than the root part, so the tip remains flying while the root stalls, allowing the plane to settle in a wing level mode. Sometimes we have to thicken the wingtip’s airfoil so that it will help combat the wing tip stall.

The wing construction on most models is built up from using strong wing spars, and ribs. When we do what was a fabric covered wing, we usually sheet the leading edge back to the main spar, top and bottom. This makes a strong D spar setup. If we are doing a metal covered wing, we sheet the whole wing, which makes a strong wing. In a one piece wing, we have to put in plywood doublers, to stop the wing from folding upwards so the wing tips meet. The load on wings is quite high, and so the centre section needs to be strengthened with strong spar doublers. Some of us have learned this the hard way, when wings have failed in flight. Also, in low winged planes with the wheels in the wing, the doublers help to strengthen the wing for those firm arrivals.

I have built some wings with Styrofoam cores, and sheeting them with 1/16th balsa. The two halves are glued together, with a plywood doubler, then a 4” fiberglass strip is epoxyied around the joint. This makes a very nice wing that is strong, but is heavier than the built up wing. On a pattern ship designed to do aerobatics, the heavier weight is not a problem usually, as the fuselage is lighter than a scale models.

A well designed wing will make a nice flying model.

Also, a straight wing, without warps will make a nice flying model as well.

Most kits today would have tabs on the wing ribs, so that the wing can be assembled on a flat surface, and keep it straight.

There are also a number of wing jigs around homemade or commercially made that will help in assembling the wing so there are no warps.

I use a piece of ¼” plate glass to build wings on, it is absolutely flat with no twists.

On top of that I use a ceiling tile so that I can use pins in the assembly process.

Whatever you use to build the on, it has to be flat with no twists or warps.

Be sure to follow the instructions when building if they are available.

On one model I had the instruction to assemble the wing upside down. Well, I have always built the wing with the top side up, so I went ahead and did it my way. In the end I had to build a new wing, as the washout was in the wing, and so it came out as washin, and didn’t fly very well that way.

So it pays to follow the instruction, and be careful of any changes you make.

In the next blog I want to share our experience with the C-46 project, and changes we had to make. Every time we construct a model, we learn things and lessons, so we won’t make mistakes the next time.

Ray

Transport Canada & MAAC

Transport Canada

and MAAC safety rules

Committee (Standing) – Safety

MAAC recently posted news regarding Transport Canada Regulations to the website but in case you haven’t seen it, you can find the information attached along with a link to the information our website. You might find the statement concerning MAAC members a little ambiguous, but it is accurate. Although it is clear that MAAC members will receive an exemption, all flyers will likely be subject to a basic set of legislated safety rules. As it is currently, there will still be legal consequences for anyone, MAAC member or not, that endangers manned aviation.

Please have a read.

RE: Published Draft of Regulations Amending the Canadian Aviation Regulations (Unmanned Aircraft Systems)

On July 15, 2017 Transport Canada published the expected first draft of proposed changes to the Canadian Aviation Regulations (CARs) related to all Unmanned Aircraft under 25kgs and operated within “Visual Line of Sight” (VLOS) of the pilot. (link below)

http://www.gazette.gc.ca/rp-pr/p1/2017/2017-07-15/html/reg2-eng.php

As noted in previous news and information releases, these legislative changes will have a direct impact on recreational model aviation in Canada. MAAC has been working closely with Transport Canada to ensure our members and their clubs are not adversely impacted by these changes.

To that end, the Board of Directors is very pleased to report that within the published text, Transport Canada recognizes our association’s history, structure and safety culture and clearly states their intention to provide MAAC and its members with an exemption from this legislation. As you will note in the published excerpt below, it is also clear that MAAC will be continuing our work with Transport Canada as criteria for new emerging associations is developed from our association’s template.

“MAAC has a long history of a safety culture, provides continued mentoring and guidance and has insurance for its members. It is Transport Canada’s intent to develop criteria for new emerging model associations that can provide to their members the same mentoring as MAAC does. The proposed Regulations would apply to MAAC members until such time as these criteria are developed and further amendments are introduced to carve out those associations. Until the Regulations can be modified to address new and emerging aero-modelling associations, Transport Canada would issue an exemption to MAAC members to the proposed requirements, so as to not negatively impact this sector of the industry.”

As required by the federal legislative process, after this initial publication, there is a 90 day “comment period” where formal comments/concerns are solicited by Transport Canada. Comments will then be reviewed, considered and appropriate changes made to the original draft before being published a second time in the Canada Gazette and enacted into law.

The MAAC Transport Canada committee along with the board of Directors and their subject matter experts will review the pending legislation in depth in the coming weeks and determine is formal comment from MAAC is necessary. Our members will be kept up to date on these matters as required.

Until this process is completed and enacted into law, the Interim Order relating to model aircraft initially issued by the Minister of Transport on March 20th, since updated on June 16th, remains in effect for all recreational modellers. MAAC members flying at sanctioned fields and events are exempt from the restrictions of that interim order. (link below)

https://www.tc.gc.ca/eng/mediaroom/interim-order-respecting-use-model-aircraft.html

The MAAC Board of Directors applauds our member’s safety record and wish to emphasise that your diligence has never been more important. Please fly safe and smart this season while continuing to mentor and promote fun and safety in this tremendous hobby. Thank you all.

Rays Rant #5 – Learning to build

Ray’s Rant #5                                                                           August 9, 2015

Some modelers are more builders than fliers, and are challenged to create history in model form. With the war on, and the Battle of Britain taking place that summer, many of us boys turned our eyes toward the sky, and longed to reproduce the airplanes we saw, in model form.

It was about the summer of 1940 that I discovered the world of rubber powered models. In a store window on main street were displayed a number of finished models, probably a contest and these were the ones modelers put in. It opened my eyes to the possibilities of not only making models, but ones that would fly.

I was introduced to a lot of new things; LePages model airplane cement, model plans, and how to read them; razor blades that were sharper than pocket knives; dope; and tissue paper, to name a few. It took awhile for us to learn to read plans, so we could reproduce the model we liked. I am attaching an insert placed in a model kit of the early 1940’s. Just about all you needed to know to build the model is on this instruction sheet. Besides this sheet, there were a set of plans to build the actual model from, plus the wood, prop, rubber, tissue, wheels and parts needed to complete the project. This was the beginning of a long learning curve, and this training proved its value years later when I took my airframe course in the Air Force, as many of the airplanes up to the mid-thirties were built this way, steel tubing taking the place of the balsa wood. This type of construction comes out light, strong, and flyable, and lent itself to modeling many airplanes of similar construction. We had to build two sides for the fuselage, one on top of the other, with wax paper in between them. You learned quickly that the wax paper was very necessary. Once this was done, we would pin the two sides to the top view of the plan, and put in the cross pieces, starting and the centre, where three or four would be the same length. Once the glue dried, we would bring the tail end together, then insert the rest of the cross pieces to the tail. Then we had to bring the nose section together, keeping it square, and put in the front formers, and bottom cross pieces. At this point we learned another valuable lesson. That lesson showed us the necessity of making sure the four longerons (the longitudinal member of an airplanes fuselage)were all of the same hardness and flexibility. If they weren’t, you ended up with a fuselage that looked like a banana, because even if you pinned them straight on the plans, once removed, the stronger longeron would go back to its straightness, as the softer one on the other side would bend easier. It is important to pick four pieces, usually 1/16th square for the small rubber powered models (1/4 square on larger models) that are very much the same to prevent this from happening. The sticks you pick also have to be straight, use the others for the short pieces. In using this type of construction in a RC model, it is equally important to pick out similar wood strips, so the fuse will come out straight. The weak points in this type of construction are the number of butt joints, because of the small gluing area. Also, we need to introduce triangulation to keep the fuse square, and not a parallelogram. By adding another piece to cut the square into two triangles, (drawing on the attachment) you significantly strength the structure. To overcome the weakness of the butt joint, we can add a triangle piece on each side of the joint, top & bottom (see attached drawing).

On larger radio controlled models, we can use 1/32 plywood caps, as illustrated, to strengthen the fuselage. These details are usually on the plan, to show you where they are needed. On some models I have, such as the Flybaby, and my Fox Moth, the sides of the box, and the bottom of the fuselage are sheeted with 1/16th balsa, which comes out light and strong, and the joints are strengthened in this way.

I like building models that are practical scale models of the planes I like, using this style of building. By substituting balsa for the planes style of construction, you can easily come up with a wood model, that resembles the full scale one you want to replicate. It may be a bit more work than other styles, but the result is a light, strong model that is a good flyer.

Easybuild model

We will look at a different style of constructing, that will duplicate the metal structures of the planes that came along during the later part of the 1930’s and into the war years in the next blog.