Educational : Size Comparison of some largest Aircrafts

A size comparison of some of the largest aircraft in the world. The Airbus A380-800 (largest airliner), the Boeing 747-8, the Antonov An-225 (aircraft with the greatest payload) and the Hughes H-4 "Spruce Goose" (aircraft with greatest wingspan).

C-130j.hercules.model

Model aerodynamics

Model aerodynamics

The flight behavior of an aircraft depends on the scale to which it is built. The Reynolds number depends on scale and speed. Drag is generally greater in proportion at low Reynolds number so flying scale models usually require larger than scale propellers.

Mach number depends on speed. Compressibility of the air is important only at speeds close to or over the speed of sound, so the effect of the difference in Mach number between a slow piloted aircraft and a small model is negligible, but models of jets are generally not efficient flyers. In particular, swept wings and pointed noses are used at high Mach number to reduce compressibility drag and tend to increase drag at small Mach number.

Angular momentum also depends on scale. Since torque is proportional to lever arm length while angular inertia is proportional to the square of the lever arm, the smaller the scale the more quickly an aircraft or other vehicle will turn in response to control or other forces. While it may be possible for a pilot to fly an unstable aircraft (such as a Wright Flyer), a radio control scale model of the same aircraft would only be flyable with the center of gravity moved forward. Static stability, resisting sudden changes in pitch and yaw, is generally required for all models and is usually considered a requirement for piloted aircraft. Dynamic stability is required of all but tactical piloted aircraft.

A contest winning paper glider.

Free flight models need to have both static and dynamic stability. Static stability is the resistance to sudden changes in pitch and yaw and is typically provided by the horizontal and vertical tail surfaces, respectively, and by a forward center of gravity. The three dynamic stability modes are phugoid, spiral and Dutch roll. An aircraft with too large horizontal tail may have a plugoid with increasing climbs and dives. Insufficient dihedral and sweep back will generally lead to increasing spiral turn. Too much dihedral generally causes Dutch roll. However, these all depend on the scale, as well as details of the shape and weight distribution. For example the paper glider shown here is a contest winner when made of a small sheet of paper but will go from side to side in Dutch roll when scaled up even slightly.

Electric power Aircrafts

Electric power Aircrafts

Parkzone F-27 Stryker

In electric-powered models, the powerplant is a battery-powered electric motor. Throttle control is achieved through an electronic speed control (ESC), which regulates the motor's output. The first electric models were equipped with DC-brushed motors and rechargeable packs of nickel cadmium (NiCad), giving modest flight times of 5-10 minutes. (A fully-fueled glow-engine system of similar weight and power would likely provide double the flight-time.) Later electric systems used more-efficient brushless DC motors and higher-capacity nickel metal hydride (NiMh) batteries, yielding considerably improved flight times. The recent development of lithium polymer batteries (LiPoly or LiPo) now permits electric flight-times to approach, and in many case surpass that of glow-engines. There is also solar powered flight, which is becoming practical for R/C hobbyists. In June 2005 a new record of 48 hours and 16 minutes was established in California for this class.

Electric-flight was tested on model aircraft in the 1970s, but high-cost prevented widespread adoption within the industry until the early 1990s, where falling costs of motors, control systems and, crucially, more practical battery technologies came on the market. Electric-power has made substantial inroads into the park-flyer and 3D-flyer markets. Both markets are characterized by small and lightweight models, where electric-power offers several key advantages over IC: greater efficiency, higher reliability, less maintenance, much less messy and quieter flight. The 3D-flyer especially benefits from the near-instantaneous response of an electric-motor. As the size of a model aircraft increases, the cost of electric-flight increases much more rapidly than traditional glow-engine flight. As of 2005, an electric-flight conversion for mid-large scale-models (above 0.60in³ glow-engine) is prohibitively expensive (>$400 USD.) Most such models remain powered by the venerable glow-engine, as their pilots prefer the sound and smell of a genuine 2 or 4-stroke IC-engine.

Aircrafts with Jet and rocket

Jet and rocket

Miniature jet turbine

A recent development is the use of small jet turbine engines in hobbyist models, both surface and air. Model-scale turbines resemble simplified versions of turbojet engines found on commercial aircraft, but are in fact new designs (not based upon scaled-down pre-existing commercial jet engines.) The first hobbyist-developed turbine was developed and flown in the 1980s by Gerald Jackman in England, but only recently has commercial production made turbines readily-available for purchase. Turbines require specialized design and precision-manufacturing techniques (some designs for model aircraft have been built from recycled turbocharger units from car engines), and consume a mixture of A1 jet fuel and synthetic motorcycle-engine oil. These qualities, and the turbine's high-thrust output, makes owning and operating a turbine-powered aircraft prohibitively expensive for most hobbyists. Jet-powered models attract large crowds at organized events; their authentic sound and high-speed make for excellent crowd pleasers.

Pulse jet engines, operating on the same principle as the WW II V-1 flying bomb have also been used. The extremely-noisy pulsejet offers more thrust in a smaller package than a traditional glow-engine, but is not widely used. A popular model was the "Dynajet".

Rocket engines are sometimes used to boost gliders and sailplanes. In the 1950s, a type of model rocket motor called the Jetex engine was quite popular. Today, flyers mount readily-available model rocket engines to provide a single, short (<10second) burst of power. However, government regulations and restrictions have rendered rocket-propulsion unpopular even for gliders.

Aircraft with Internal combustion Engine

Aircraft with Internal combustion Engine

An internal combustion powered model aircraft.

For larger and heavier models, the most popular powerplant is the glow-engine, a form of internal combustion engine . Glow-engines appear similar to small gasoline motorcycle-engines, but glow-engines are considerably simpler in operation. The simplest (and cheapest) glow-engines use a two-stroke cycle engine, glow plug to burn fuel, and an external ignition system (a dry cell or other low voltage source.) The fuel is a mixture of slow burning methanol, nitromethane, and oil lubricant (castor oil or synthetic oil.) The reciprocating action of the cylinders applies torque to a crankshaft, which is the power-output of the engine. Vendors of model engines rate size in terms of engine displacement. Common sizes range from as small as 0.01 cubic inch (in³) to over 1.0 in³ (0.16 cc - 16 cc). As Richard Feynman mentioned in his famous There's Plenty of Room at the Bottom lecture, the speed an engine can rotate without breaking tends to go as the inverse of the linear dimension (inverse cube root of the displacement). However, the intake air flow improves less quickly than that with small scale, due to decreasing Reynolds number and, eventually, to viscous flow.

Not all simple internal combustion model aircraft engines use glow plugs. There are also "diesels", that are popular in Europe and the world over. These also are carbureted, not fuel injected. They have an adjustable compression ratio and burn a more easily ignited mixture of ether and kerosene (with lubricating oil). These are preferred for endurance competition, because of the higher energy content of the fuel.

Internal combustion (IC) engines are also made in upscale (and up-price) configurations. Variations include four-strokes, multi-cylinder engines, and even spark ignition gasoline powered units. All IC engines generate substantial noise (and engine exhaust) and require routine maintenance. In the 'scale-R/C' community, glow-engines have long been the mainstay until recently.

Construction

Constructing A Model Flying Aircraft

The construction of flying models is very different from most static models. Flying models borrow construction techniques from vintage full-sized aircraft (although models rarely use metal structures.) These might consist of forming the frame of the model using thin strips of light wood such as balsa, then covering it with fabric and subsequently doping the fabric to form a light and sturdy frame which is also airtight. For very light models, very thin paper can be substituted for fabric. Or, heat-curing plastic films ("heat shrink covering" or "solarfilm") can be ironed on - a hand-held iron causes the film to shrink and adhere to the frame. A hair dryer can also be used.

Home-grown model-construction techniques consist of using formers and longerons for the fuselage, and spars and ribs for the wings and tail surfaces. More robust designs often use solid sheets of wood to form these instead, or might employ a composite wing consisting of an expanded polystyrene core laminated with a surface veneer of wood, often obechi, which protects the core and provides strength. Such designs tend to be heavier than an equivalent sized model built using the traditional method, and would be much more likely to be found in a power model than a glider.

The lightest models are suitable for indoor flight, in a windless environment. Some of these are made by bringing frames of balsa wood and carbon fiber up through water to pick up thin plastic films, similar to rainbow colored oil films. The advent of "foamies," or craft injection-molded from lightweight foam and sometimes reinforced with carbon fiber, have made indoor flight more readily accessible to hobbyists. Many come ready-to-fly, requiring little more than attachment of the wing and landing gear. See: ParkZone Slo-V.

Flying models can be built from scratch using published plans, or assembled from kits. Plans are intended for the more experienced modeller, since all parts must be sourced separately. The kit contains most of the raw material for an unassembled plane, a set of (sometimes elaborate) assembly instructions, and a few spare parts to allow for builder error. Assembling a model from plans or a kit can be very labour-intensive. In order to complete the construction of a model, the builder typically spends many hours assembling the frame, covering it, and polishing/refining the control surfaces for correct alignment. Furthermore, the kit does not include necessary tools, and these have to purchased separately. Finally, a single overlooked error during assembly could compromise the model's airworthiness, leading to disaster.

ParkZone P-51D Mustang

To address these concerns, and increase the hobby's accessibility to the inexperienced and less interested alike, vendors of model aircraft introduced Almost Ready to Fly (ARF) designs. Compared to a traditional kit design, an ARF design reduces the amount of time, skill, and tooling required to assemble the model. The average ARF aircraft can be built with less than 4 hours of labor, versus 10-20+ for a traditional kit aircraft. More recently, Ready To Fly (RTF) radio control aircraft have all but eliminated assembly time (at the expense of the model's configuration options.) Among traditional hobbyist builders, RTF models are a point of controversy, as many consider model assembly as integral to the hobby. Brands associated with these types of aircraft include Great Planes, Hobbico, Carl Goldberg Products, Lanier RC, E-Flite , Hangar 9, GWS, HobbyZone and ParkZone.

Flying model aircraft

Flying model aircraft

Flying models are usually what is meant by the term aeromodelling. Most flying model aircraft can be placed in one of three groups:

• Free flight (F/F) model aircraft are designed and built in a manner that allows the craft to fly without any attachment to the ground.
  This type of model pre-dates the efforts of the Wright Brothers. [1]
• Control line (C/L) model aircraft are designed and built to be flown using cables (usually two) leading from the wing to the pilot. A variation of this system is the Round-the-pole flying (RTP) model.
• Radio-controlled aircraft have a transmitter operated by the pilot on the ground, sending signals to a receiver in the craft.

Some flying models resemble scaled down versions of piloted aircraft almost as much as static models do, while others are built with no intention of looking like piloted aircraft. There are also models of birds and flying dinosaurs. One company, Flying ThingZ of Stroudsburg, Pennsylvania, makes a line of rather whimsical models in addition to a lineup of conventional aircraft. Their more unusual offerings, produced from laser-cut corrugated plastic include a witch on a broomstick, a flying M1A2 Abrams tank, a flying race car and even a 2/3-scale flying lawnmower.

--
Andy

Blimp Zeplin

Teach your kids they will love this one and you can obviously try it in your office too hahaha :)
Andy





This is a paper "airship", "zeppelin" or as we say "blimp". Cut a long strip of writing paper as shown and notch each end as indicated below:

______________________________________________________________ 

 <--Notch                                                                                               

    ___________________________________________________________  

Bend it over and slip each noch together. You will end up with a shape similar to a fish when looking through the opening: Be careful not to fold it at the front, it should be a curve.

That is all there is to assembly. Now place a small pebble (you could also use blue tac or soft silly putty) where indicated and squeeze the stone with your thumb and forefinger. Throw the stone and paper belt straight up. If you do it right the stone will lift the paper to an altitude until the stone begins to fall back to earth. The stone falls out of the loop and the airship begins to spin over the axis and gently returns to earth. When it spins it blurs together and looks just like and airship.

Try it and if you break any windows, please don't blame me. Also this could be a very dangerous toy, you could hit yourself your parents or your friends so only make it and throw it where it is safe to do so.

Blimp/Zeppelin Flying Lesson

Simply dropping the blimp off a balcony, stairwell or out of a high window is the safest way to fly it. It works best out doors where it can fly a long distance. You should drop the blimp parallel to the ground (not nose first or tail first) for the best results. Throwing the blimp with a stone in its nose is your second option you could also use blue tac or soft silly putty. This takes practise and requires you to be very careful you don't hit anyone. Throw the blimp with the stone grasped between finger and thumb vertically upwards and you can get it very high indeed. It will glide a long way floating like a blimp on the air currents. The first people I showed it to called it the flying fish. I like this name a lot!

Napkin Paper Plane

1. Take a square of paper and fold it in half along the diagonal line shown in DIG. 1

   DIG. 1

2. Now fold the long edge over 0.5cm (1/5") and repeat 4 times creasing hard as shown by dotted lines inDIG. 2

   DIG. 2

3. Now tuck the ends of the folded edge inside each other to form a ring. Crease the thick folded ring repeatedly to make perfectly round. The fold should be on the inside as shown in DIG. 3

   DIG. 3

4. It is now a fully functional plane but can be improved by rolling the tip of the triangle of paper around a pencil then unravelling it and making a cut to about 1/3 the length of the triangular area right down the middle of the plane. As marked in DIG. 4.

   DIG. 4

This design is unconventional Stealth but works

1. Start with a plane sheet of A4 paper DIG. 1 .
   
   DIG. 1
   
   
2. Fold along solid line in DIG. 2 to give you DIG. 3 . Make sure the fold is straight and well creased.
   
   DIG. 2
   
   
3. Fold flap shown in DIG. 3 over again.
   
   DIG. 3
   
   
4. Fold down a flap at the top left hand corner to give you DIG. 4 .
   
   DIG. 4
   
   
5. Fold down a flap at the top right corner to give you DIG. 5 .
   
   DIG. 5
   
   
6. Attach sticky tape at the points shown in DIG. 6.
   
   DIG. 6
   
   
7. Now cut along the two dotted lines in DIG. 7 and fold along the solid lines to give the plane at the top of the page. Try stapling at the front to give more weight or taping the two wings together in the middle to make it fly better. I find that experimenting with this plane can make it fly really well.
   
   DIG. 7

This is my favourite model paper plane. (Try out it works)

1. tail out (see label on DIG. 1) and fold along the diagonal line creasing well.
2. DIG. 1
3. Now fold along the diagonal line on DIG. 2 creasing well.

   DIG. 2

4. Now it should look like DIG. 3.

   DIG. 3

5. Fold along the horizontal line on DIG. 4.

   DIG. 4

6. Now push this form together to make the shape in DIG. 5.

   DIG. 5

7. Fold the flaps over to form DIG. 6.

   DIG. 6

8. Now fold along the dark grey lines in DIG. 7.

   DIG. 7

9. Now fold it together as in DIG. 8. Place the tail so that the angle at the end is pressed right up into the nose.

   DIG. 8

10. Now fold where the dotted line is in DIG. 9 under the wing trapping the tail in place.

    DIG. 9

11. Now turn the plane over to give you the plane as shown at the top of the page.

Paper Planes (Just Give it a try)

The rapier I love this plane (I did design it but I can brag can't I?) it flies like a glider but has the elegant shape and great precision of a dart. This plane is the best of both worlds and is so easy to make it must be the best plane on the site!

Paper Helicopter OK! So it isn't a plane but it is a good model and when simply dropped it will stay aloft for ages and spiral down excellently.

Paper Rocket You're right this is not a paper airplane either but is supremely simple to make and has some very interesting science behind it. This was shown to me by a Cambridge (UK) Physics lecturer so must be a great paper airplane (kinda).

Flying Fish One difficult fold inthe whole of this plane. It is a unique design (I think) a bit weird but really flies well in a straight line as a glider. It will stomach a bit of poor folding too so a good one to try if some of the other designs don't fly well for you.

Paper Frisbee This is great fun and best made out of small squares of paper maybe 15cm by 15cm (6" by 6") and thrown like a normal frisbee it will fly quite well especially indoors.

Nicks' Paper airplane This paper airplane is a superb glider it is very well balanced indeed even when made by the most inexperienced child. It can be quickly made from a sheet of A4 paper and I really like it. I drew this page up and placed it on the internet within a day of learning to make this paper airplane.

Origami Paper Airplane 3 This is a really easy to make paper airplane that you will love flying again and again. The blunt nose makes it really easy to reuse as it does not easily get damaged. It is another classic design that has been around for many years and I really like it.

Blimp/Zeppelin This isn't really a plane but is a great little paper airship it looks good and it works great!

Worst ever paper airplane This plane is truly terrible. Nothing can be done to overcome the fact that is about as adept at flying as the Titanic if a little more attractively plane shaped. I do not like this plane but you might want to try it out for yourself once I have shown you how to make it.

Second origami plane To my knowledge this plane is Japanese in origin and it is a fantastic flier you will love it. Play around with it add stabilisers and flaps, it can be a good stunt plane too.

The classic dart This paper airplane is designed for bored people in offices, lectures and classrooms the world over. 7 folds and throw, there isn't a difficult part in making this plane. I must dedicate it to Peter Batey who received my email for a few weeks and sent me this design.

Dmitri's Paper Airplane A simple paper airplane design and indeed a real classic. This plane is slightly more complex than the classic dart above but flies further and is more accurate. This design was sent to me by Dmitri through email and so I dedicate it to him on this site.

Floating Paper airplane This paper airplane is really very good. With its wide wing span and the stabilising winglets at the end of wings it is very stable and flies very far.

An improvement on the Worst ever paper airplane OK ! I was a little harsh on the worst paper airplane it is reasonable but I altered the design myself to create this plane, it looks the same but it flies so much better.

Medium Difficulty Paper Airplanes

[Easy to make Medium difficulty Hard to make ]

Dragon Plane - This is my own design of paper airplane. If you make the wings completely level and throw it hard overarm it will fly fast and level indoors for 30 meters or more and it is quite good outside too. So try it out.

The Edmonton Shadow - I designed this plane about 3 hrs out of heathrow in an airliner on the way to Calgary canada. It is a really fun plane and I am really pleased with it I hope you like it too.

The Swallow This is a paper airplane my father was making when he was a small boy and the design has stood the test of time it works very well.

Trapezium Paper airplane This paper airplane is all wing with a heavy nose. The structure of the nose is quite unusual but very effective. Even if thrown as hard as possible at a wall it will be undamaged. The last time I saw the first one of these I made it was flying towards the Severn estuary from the top of a tall tower in Bristol.

Chris' Paper airplane This plane was sent to me in an email by a visitor to my site and I thought it was so good that I would post it for you all to have a go. It is a very good glider and well worth a fly!

Nose Heavy Plane I think this plane is great and it flies equally as well as the floating paper airplane. I think this is a great plane!

Napkin Paper Airplane This is a simple design to make but in order for it to fly properly you must practise and that is why it is of medium difficulty. This unusual plane is one of a family of designs and hopefully I will bring you more tubular paper airplanes in the future.

Hard to Make Paper Airplanes

[Easy to make Medium difficulty Hard to make ]

Cobra Paper airplane This is another of my designs. I am really proud of this one it will fly straight and fast if thrown hard but it also glides fantastically. There are a few tough folds but I am sure by this stage you will have mastered all the skills required!

Origami Paper airplane/Dart It is hard to decide if this is a airplane or dart. It is very dense at the front and if thrown hard will fly far. This is a hard exercise in folding and also for me in writing and drawing instructions. Hope you like it!

The Lightning This is my own design which appears identical to the original Sabertooth paper airplane but is a totally different design. This paper airplane will fly superbly if made well, try it out.

Sabertooth paper airplane The sabertooth paper airplane flies fantastically if thrown straight up into the air or as a normal glider. It is great!