# Tag Info

32

The objective is very important. You don't build an airplane because you want one faster or cheaper. Neither is the case. The kit won't be cheaper, and it'll take 1 to 2 thousand manhours, minimum, of your time (take the building time claim of any kit and double or triple it to get reality). You build one for the experience of building one. A lot of ...

14

The big disadvantages of a kit: it will take you years to have an airplane ready to fly, and you'll be flying an airplane built by a novice builder. The main advantage of a kit: you (often) don't need all the money up front. Buy the fuselage kit, build it. Then buy the wing kit, and build that. Not all kit planes are sold this way, but several are. No ...

12

The other answers are good, there's a couple of aspects that haven't been covered that I'll touch on in my answer. Safety: Kitplanes have a higher rate of accidents overall than certified airplanes. There's a good article from kitplanes magazine that breaks down causes, it's not authoritative but it's extremely useful in showing the differences in accidents ...

10

No. The strength to weight ratio of PVC is poor compared to aluminum and you would end up with a very heavy, albeit cheap, machine, and will be even worse when compared to carbon fibre tubing, which would be the optimal choice performance-wise. Extruded aluminum tubing would likely be the best choice cost wise. Forget about building a plumb-O-copter.

10

A simplified analysis of column buckling shows that the axial load required for buckling is directly proportional to the second moment of area of the column's cross section: $F=\pi^2EI/(KL)^2$, where F is the buckling load, E is the elastic modulus of the material, I is the second moment of area, and KL is an effective column length based on the geometric ...

6

Well, I would solve with transparent Monokote if it was a model. No accounting for people's taste. Although some very early aircraft featured that look, designers soon realized that covered "slab" sides not only reduced drag, but also improved directional stability. Note that covered area aft of CG acts as an extension of the empennage, allowing for a ...

6

You will need a fixed landing gear and a braced wing to keep your mass at your target of 40 kg. Expect a maximum L/D of not more than 10, maybe even 8. You say that the flight mass will be 100 kg. The weight will be 980 N. 1/10 of that is 98 N. To arrive at a power from that will need a few more heroic assumptions. Your wing loading is probably 12 to 15 kg/...

5

This has been done, but here are some things you'll need to consider. Air-cooled motorcycle engines are designed to produce short bursts of peak power, and to be as light as possible. Lightness is an advantage for any airplane engine, but having an engine designed for brief bursts of high power is not. An aircraft engine has to operate for long periods at ...

5

Yes, of course you can. However, it's probably not a very good idea. PVC pipes are pretty strong and light; circular-section PVC pipes have an excellent strength-to-weight ratio. Being strong and light isn't enough though. Construction materials need to have the appropriate properties (like being strong and light) in the right conditions. In the case ...

5

I fly part 103, specifically a Hy-Tek Hurricane. I also have a G meter on board. It is a Dynon D2, which features an artificial horizon (attitude indicator) and also a G meter. The average G's on takeoff is pretty small, usually around 1.1 to 1.2 Gs. I can also tell you it is impossible to pull anything over 2 G's during takeoff. I actually performed this ...

5

It's a 100cc engine, and it's in the Radio Control section of that web site. It's an engine for model aircraft. I suppose, technically, that's a home-built aircraft, but you're not going to sit in it!

5

That is a complicated process. You need: A positive mold (mandrel) for the canopy. A negative mold for the canopy frame. For a single prototype you can also use the unfinished fuselage itself. A fuselage mold with a molded window sill. First the fuselage positive mold core is built. From that the negative mold is taken, but also a negative mold only for ...

4

A simple explanation of buckling failure is a kinking of the tube wall. Force on the tube deforms it out of round. A flat side is weaker than a curved side just as a flat piece of paper bends more easily than a paper tube. With enough force the flat side folds. Filling the tube with any material that prevents the initial deformation (keeps the tube round) ...

4

I would agree with @TomMcW that joining EAA would probably be a good idea. You could also join the Homebuilt Airplanes Forum. I assume you already know the basics of choosing materials. They are a balance of strength, weight, and cost. I assume your choice of PVC is low cost. So, the big question would be whether it has the rest of the required properties. ...

4

Please read the answer to this question first and try to answer the questions listed there. You need to provide more information! Next, the best place to look is among glider airfoils. The Wortmann FX 63-167 is now 55 years old but still a good start. It was designed for the low speed of a human powered aircraft and has been used on gliders and motor ...

4

The answer depends on how quickly was this 2 m/s velocity reached. Could be 2 g if it happened within 0,2 s (9,81m/s² + 2m/s / 0,2s) Could be 1.1 g if we were accelerating for 2 seconds to get to 2 m/s (9,81m/s² + 2m/s / 2s) Example accelerometer recordings taken during the Cessna 152 takeoff (not exactly ultralight, but also a small plane). The first ...

3

I assume that this is for a Private Pilot - Helicopter license. I also assume you mean something like larger kit aircraft, not ultra-light helicopters like the Mosquito. You can do this, but there are other conditions that must be met: The aircraft must have completed it's flight test phase (this is usually the first 25-40 hours of operation) The CFI must ...

3

You can prevent engine vibrations from being transmitted to the airframe by motion cancellation techniques. Similar in principle to Active Noise Reduction headsets that generate an inverse pressure wave to cancel sound, motion cancellation generates an inverse displacement of a mass to cancel vibrations. Sensors determine the vector(s) required, and ...

3

The controls of any aircraft should move easily under the pilot's control. Large aircraft have hydraulic servos to assist the pilot, or even complete fly-by-wire systems, while smaller aircraft often have aerodynamic trim tabs which act as a simple assistance mechanism. On the ground, with no aerodynamic loads, the controls should move easily without such ...

3

First of all, lets start with a short introduction on buckling. There are two types of buckling, global (or column) buckling, and local buckling. Global buckling is what happens to long slender (thin) structures, with a compressive load. Say you take a piece of plastic pipe with a diameter of 3/4 inch (2 cm +/-) and a length of 8 feet (2.5 m +/-). You ...

3

Yes, the centre of gravity can coincide with the aerodynamic centre of the main wing, particularly because that point is rather unremarkable. For stability, the centre of gravity needs to be ahead of the neutral point, but that is the overall aerodynamic centre if both main wing and horizontal stabilizer are flying at the same coefficient of lift, which ...

3

For longitudinal stability in a conventional wing-and-tail layout, the CG needs to be ahead of the wing's AC. This causes a nose-down moment that is countered by downward lift at the stabilizer, so that the stabilizer will raise the nose as speed builds up. Thus, if the aircraft is disturbed into a dive, the nose will automatically rise as speed builds; ...

2

Strictly speaking, yes. That is not to say the airframe is dangerously unstable in yaw or prone to spinning, only that the tail boom does contribute slightly to tail volume, so, disregarding any weight and balance effects form the fairing and assuming everything else stays the same, the "naked" version will have less lateral stability. The vertical tail ...

2

Assuming that the same wing chord is used for both, one technical difference between the Pietenpol and the Riblett is the depth of the airfoil. The Riblett that has been used on the Air Camper is the 612 (or sometimes the 613.5), which makes it 12% (or 13.5%) deep. With a 60" chord, that's a depth of 7 to 8". The deepest section of the stock Pietenpol ...

2

As you've noted, engine mounts are used to isolate the vibration of the engine from the airframe. Another technique is Dynamic Prop Balancing - adding weights or washers to specific places on the propeller or spinner to eliminate the vibrations. It's the same idea as is used to balance car tires.

2

For a non-working prototype it doesn't look too bad - you have a bell crank connected to a control arm that's attached to the aileron. However, the devil is in the details and messing up a detail can kill you. You will want to use acceptable materials and construction techniques (See AC 43.13). You need to ensure the bell crank is the right size so the ...

2

FLÜGEL World Directory Of Light Aviation 2019/2020 - English PDF could be a good starting point. On pages 278 - 281, a total of 71 lines of electric motors from 42 manufacturers are featured. Disclaimer 1: some data fields are incomplete for many of the entries. There are German, English French and Chinese versions in paper and pdf, starting at €8. Here's ...

2

I'm not a pilot, though I am an aviation enthusiast, and here are some of the pros/cons that have not been mentioned yet. Kit plane pros: Kit planes have experimental classification, which means you can add non-certified parts to the aircraft. This can be especially beneficial for things like exterior lights since non-aircraft LED headlights are cheaper and ...

1

In my experience using PVC to build scale models, PVC doesn't make a good construction material: it's too flexible. PVC pipe will bend under its own weight. the glue typically used to join PVC is pretty weak, impact loads will break the bond.

1

PVC is no where near stiff enough for a given weight. And its strength to weight ratio is poor. The structural efficiency of air machines is absolutely critical otherwise you are building a machine that may not fly at all. Plus, do a search for helicopter ground resonance, especially watch some youtube videos of helicopters destroying themselves.

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