Yesterday afternoon while practicing circuits in a Citabria for my tailwheel endorsement I went to put the carburettor heat on to start my descent, keeping my eyes outside like a good stick and rudder pilot to make sure I didn’t drop the nose on my turn to base — and instead pulled back on the nearby elevator trim which is pretty direct in a Citabria. The next thing I knew I was squished in my seat with the horizon nowhere in sight. Immediately realising what I’d done I wrestled the nose back down to somewhere more reasonable, accompanied by a few choice invectives. The instructor laughed and said “I’m glad you did that, another student did that a few months ago but on short final (i.e. much closer to the ground) and came close to stalling onto the runway — now you’ll remember”.
The point of this slightly embarrassing anecdote is that control forces in a non fly-by-wire aircraft are a lot more powerful than you might expect from experience with a simulator or game. In fact when first learning to fly I often asked whether or not the instructor was on the controls with me. Where constantly holding a bit of pressure on the elevator or rudder to keep going where you want to go in a simulator is quite possible indefinitely, in a real plane it can quickly get exhausting and demand a lot of attention, as well as making it quite difficult to use equipment or write something down.
Correctly trimmed an aircraft like the Citabria really will fly itself. When taking off, after the aircraft wants to fly I’ll pull back on the stick and line up the top of the engine cowling with the horizon, glance at the airspeed to see that it’s around 70 knots and keeping my right hand on the stick to hold the sight picture, briefly take my left hand off the throttle and slide the elevator trim lever until I feel no force on my hand from the stick. At that point I can take my hands off the stick and the aircraft will happily continue to climb out with no input from me, and most importantly the airspeed will be very stable and not require much attention. I usually do a little “jazz hands” moment for the instructor in the back to show that things are trimmed out nicely.
In an extreme scenario if I tried to take off with the elevator trim stuck full forward or backward it would take almost all my focus and strength to keep the plane in the attitude and speed I wanted, and I think my arms would start to tire in less than a minute. More normally, flying without trimming is considered bad airmanship because there’s plenty of better things to focus your attention on than wrestling the controls.
Elevator is the most important trim control because of its tight relationship with airspeed. Aileron and rudder trim are also a thing but in the light singles I fly I almost never touch them, except perhaps on long cross countries when I develop a feeling that the plane wants to slowly turn one way or the other. In a multi engined aircraft rudder trim becomes critical for engine out scenarios.
Picture from Tailwheel fun in a Citabria showing (top to bottom) throttle, carburettor heat and elevator trim.
This answer is an expanded version of my presentation “Falling With Style: An Intuitive Introduction to Aerodynamics, With Bricks” from Skepticamp Sydney 2012. I’m assuming that it’s ok to introduce new terms, as long as I explain them in layman’s terms first. I’ve marked the key, major principles in italics.
Consider a typical house brick brought into existence for our amusement a few hundred kilometres above the Earth’s surface, outside the atmosphere. It immediately starts falling due to its weight, one of the four key forces considered in aerodynamics. The brick will fall faster and faster until it hits something – above the Earth the first thing it will hit is the atmosphere.
The gas molecules hitting the front of the brick exert a force directly opposing the direction of travel of the brick, which is proportional to the mass of the gas hitting the brick, times the square of the speed of the brick. For example, if the brick falls into a lower, denser part of the atmosphere where two gas molecules are hitting it every second instead of one, or perhaps it falls sideways intercepting twice as many molecules as it does end-on, the force doubles. However if the brick doubles its speed still hitting just one gas molecule a second it feels four times as much force trying to slow it down.
This force is called drag, the second key force of aerodynamics. As the brick approaches the lower, thicker parts of the atmosphere its weight remains the same, but the drag increases until it balances the weight, and the brick settles at a speed called the terminal velocity. According to my flight simulator this is about 250 kilometres an hour for a brick, which is the speed it’s travelling at when it hits the ground.
On my flight simulator if I look at the path through the air left by the brick it has some gentle wiggles in it where it seems to have travelled slightly sideways instead of straight down. Looking closely at the replay it seems that this happens when the brick is oriented at a small angle to the onrushing wind – the brick is deflecting some gas molecules to the sides, and when more of them are deflected to (say) the north, the brick ends up going a bit south. The force an object can generate at right angles to its direction of travel through the air is our third key force (and the most important and interesting one), lift.
Like drag, lift is proportional to the mass of gas hitting our brick times the square of the speed, so you’d think with all this air hitting brick surfaces at speed there should be plenty of lift. However the reason that the wiggles in our flight path are so small is that lift is very sensitive to the shape of the object and the angle at which it’s hitting the air, and in the case of a brick, the shape is absolutely rubbish for generating lift. Or to be more precise, it’s rubbish for generating lift without generating even more drag.
You don’t get something for nothing – lift always goes hand in hand with drag. What we need to escape our vertical plummet from space is a shape that gets lots of lift for very little drag, something with a higher lift-to-drag ratio (L/D). If you had a shape that could generate 10kg of lift for a 1kg increase in drag, you’d have a L/D of 10, and by one of those very elegant and pleasing bits of universe maths you’d find that for every metre of height that you lost, you could glide 10 metres sideways at a constant speed. The drag caused by generating lift is called “induced” drag (the drag we have to have), and the original drag that slowed us down to terminal velocity is called “parasite” drag (the drag we try to get rid off with streamlining). In the case of our brick we have oodles of both, and our L/D will be way less than 1 – getting us a very steep and not particularly recognisable “glide”.
Imagine that we can transform our brick back to clay, squish it into a shape (keeping all the bits and the same total weight), and then bake it back into brick form. Suppose at one point we arrived at a streamlined shape like a paper dart but with very short, stubby wings. The leading edge of the wings are rounded and the trailing edge of the wings are sharp, so that if we sliced through the wing it would have a teardrop cross-section, perhaps eight times longer than it was wide.
Firstly while falling vertically and not trying to generate lift we’d find that we had reduced parasite drag a lot through streamlining, and consequently our terminal velocity would be somewhat higher – not too much, because the drag increases a lot more with speed than it decreases by not hitting the air head-on (which is what streamlining is basically about).
More excitingly we’d find that we had a L/D above one which allowed us to descend at an angle of less than 45 degrees at a constant speed. However as we lifted the nose to try and extend our glide (did I mention this was a radio-controlled brick? More about changing direction below) we’d find that we slowed down very quickly. As we slow down the angle our brick-dart nose is raised into the oncoming air (called the angle-of-attack or AoA) to keep generating enough lift will rise rapidly, and with it the induced drag, slowing us down even more. Eventually at perhaps 30 degrees on our dart the air would suddenly give up trying to follow the shape in a way that generated lift, and our dart would “stall” – essentially returning to sideways-falling-brick mode with no lift until the nose could be lowered to an AoA small enough to start generating lift again. If we’re not high enough when this happens to recover our speed and AoA, or we can’t bring ourselves to counter-intuitively lower our nose while falling we’re going to hit the ground – like a brick.
If this sounds dangerous it is – for hypothetical bricks, and real aircraft. Far, far too many aircraft and people are lost in tragic accidents involving stalls – recent examples include Air France 447 and (as far as I can tell from the video footage) the recent ATR72 crash in Taipei. It’s deeply frustrating to the aviation community because so much pilot training is devoted to avoiding, recognising and recovering from stalls (or even worse “spins”, where one side of the airplane stalls before the other) and yet it still happens.
Back to moulding our brick. As we stretched out the wings to each side to pass through more air, all other things being equal we’d find our L/D increasing – it turns out that for lift it’s more efficient to deflect a lot of air a little bit, than it is to deflect a little bit of air a lot. At a L/D of 4.5 we’d have something similar to the Space Shuttle Orbiter, the world’s most awesome one hundred ton glider. On the way back from space the wings are initially used at high AoA for massive induced drag to slow down from orbital velocity while the lift is used to aim at the destination. Approaching the runway the Orbiter needs to descend in a steep dive to maintain speed, but critically the L/D is high enough that when the Orbiter flares (levels out almost parallel to the ground a few seconds before touchdown) and starts decelerating from the increasing drag it has enough time to get it its wheels on the ground before it runs out of lift.
The same will apply to our brick – if we dive at the ground to keep our speed up and time our flare just right, we can arrive on the runway at a low enough descent rate to skitter across the numbers without shattering and slide along the tarmac, eventually scraping to a stop in a shower of brick dust. How much room we need to stop depends on how fast we’re going when we land. Ideally we’d like this to be as slow as possible to use shorter runways and scrape less clay off our undersides each time we arrive somewhere. The slowest speed we can fly at is the speed at which our brick stalls, but we can’t work this out using just the L/D.
Our brick is currently shaped like the Space Shuttle, but it’s still solid clay and not much larger than an unmodified brick. It is going to have a stall speed well over 100 kilometres per hour and probably need a few hundred metres of runway to stop. Lets say we make it hollow, and keeping the shape and total weight, scale it up so that it’s maybe a metre long. There is a lot more surface area hitting gas molecules to create lift and drag, and we’d find that our stall speed was much lower, because each patch of wing surface has much less weight to generate matching lift to support. The amount of weight supported by each patch of the wing surface is called the wing loading, and it’s measured in kilograms per square metre or pounds per square foot.
Hang gliders and paragliders have low wing loadings around 2-3 pounds per square foot because they’re foot launched and the stall speed has to be below a human’s maximum running speed for launch and landing. Typical light aircraft have wing loadings around 10 pounds per square foot, stall at freeway speeds and can comfortably operate from runways 600-900m long. Jet airliners have wing loadings up to 90 pounds per square foot, stall at racing car speeds and need runways over 1500m long.
One of the funny things about wing loading is that it doesn’t affect L/D. If you have a L/D of 10 then you can glide a kilometre from a 100m height. If your wing loading increases because you’re carrying more weight, then you can still glide a kilometre from a 100m height, you just do it faster.
Why don’t all aircraft have giant wings then, so that they can land on a dime? Well, firstly wings are heavy, and secondly if you want to go fast those big wings will cause a lot of drag (which increases with the square of the speed, remember). This is one of the challenges of aircraft design: aircraft with big differences between the stall and maximum speeds are hard to design.
One of the ways designers get aircraft to do both is to have a wing that can change its cross-sectional shape. Remember our thin teardrop? If we get it to arch its back so that it looks more like a comma, we find that the amount of lift (towards the “stretched” side of the comma) and drag it generates increases, all other things being equal. This is called camber, and most aircraft wing shapes have some built in. Furthermore, by hinging the thin tip of the teardrop and moving it down and up with cables or motors we can respectively increase and decrease the lift of the wing, partly due to changes in camber and partly because (if you imagine a line from the front of the teardrop to the deflected pointy end) you can see that the AoA has also been changed by the deflection, and as noted earlier AoA determines the amount of lift generated.
Flaps are sections of the back of a wing that are deflected down during landing and takeoff to increase the lift of the section of wing they’re attached to. With the lift comes increased drag, which is actually useful for landing because it lowers the L/D, which allows you to come in at a steeper angle (to clear a line of trees, say) without speeding up, and then to come to a stop more quickly on the ground. Because of the increased drag full flap is usually used only for landing.
Flaps are only one of hinged “control surfaces” that you find on the pointy, trailing edge of a wing. Further out on the wings of a typical aircraft you’ll find a pair of surfaces called ailerons that act in opposition (one down, one up) to change the lift of the wings, rolling the aircraft to the left and right.
By the way you’ll always find the flaps closer to the centre of the aircraft than the ailerons, because when they’re deflected they increase the AoA of their bit of the wing, which means that if the wing stalls, the flapped bit of the wing will stall first. If you’re going to loose a chunk of lift suddenly (think of a person jumping off a see-saw) you don’t want it to happen out at the tips of the wings, because that would cause a sudden violent roll towards the wing that lost the lift – the pilot might try to pick up the falling wing with the aileron, which would increase the AoA and stall that wing even more, setting things up for a spin…
This is the wonderful thing about aircraft design – it’s the ultimate form-follows-function style of engineering, and everything is the way it is for a very good reason.
On the horizontal tail you’ll find the elevator, which increases and decreases the lift of the tail to pitch the nose of the aircraft down and up. On a dart shaped aircraft like our brick with no separate tail, the responsibility of the aileron and elevator controls are shared by a pair of “elevons” that move together to control pitch and in opposite directions to control roll.
Finally on the vertical tail fin you’ll find the rudder, which is used to move the nose of the aircraft left and right, but perhaps counter-intuitively not to make large changes in direction. This is done by rolling the aircraft in the direction we want to turn, so that the much larger lift force generated by the wings can be used to start moving us in that direction. The rudder is used more to balance out the drag caused by aileron deflections; pick up a falling wing safely if we’re near a stall, and when we need to fly a bit sideways (landing in a crosswind or impressing people with some aerobatics).
Let’s reshape our brick to look like a light aircraft (L/D around 10) and add all the control surfaces we’ve just talked about. Now lets adjust how it’s hollowed out so that the tail is very heavy, so that if we were to hang it from a string attached to a point somewhere behind the wing it would balance in a level attitude. This point is called the centre of gravity (CoG). If we drop this brick we’ll find that despite everything else we’ve done it just falls backwards or tumbles out of the sky. If we move the CoG to say half way between the front and back of the wing we might find that we can only just control the plane but it’s very twitchy, unstable, and tiring to fly, although perhaps if we had a computer to help us react quickly it would make a very agile aircraft. When the CoG moved to about a quarter of the way from the front to the back of the wing we’d find the plane much more stable, but as we moved the CoG further forward we’d find it hard to raise the nose using the elevator, and eventually we wouldn’t have enough control authority to stop it diving nose-first to earth, like our original brick.
Balance is critical to an aircraft. All aircraft have an allowable range of positions for the CoG, which has to be preserved throughout each flight. Variable weights like fuel, cargo, crew and passengers need to be positioned close to the front of the wing, because like a person standing on the middle of a see-saw they don’t affect the balance point as much when they jump on or off. This is why fuel storage in wings is so popular, and in classic record-breaking single seat aircraft the pilot sat behind the fuel tank further from the wing, the designer assuming that if the pilot was no longer in his seat there was not much point trying to balance the plane any more. The range is very narrow for aircraft with narrow wings (e.g. Gliders) or small/no tails (flying wings) and bigger with broad wings and large tails further back from the wings (e.g. military transports). Aircraft that depend on agility such as fighter jets are now designed with CoGs so far aft that they cannot be flown without computer support.
If we keep refining our brick to minimise drag we’ll wind up with something looking like a graceful, high performance glider, with a L/D of 50:1 (yes, from 100m you could glide 5km, which is incredible). If you could find some hills or mountains with some wind blowing over them, or on a hot day spot a circling hawk in a rising bubble of warm air you could find yourself gliding downwards through air rising faster than you are descending, and you could stay airborne for hours, climb to great heights and travel hundreds of kilometres. But unless you can land back on a hill with room to take off, at some point you are going to be stuck sitting on the runway with no-one to push you.
I have deliberately held back from talking about the fourth and final key force, thrust, because as you can see there’s a lot of interesting aerodynamics stuff going on without it. Basically we can use thrust to augment or cancel out any of the other forces to make our aircraft go where we want it to go, but most commonly it is used to counter it’s arch enemy, drag.
Consider our high performance glider brick. It’s almost flying level, so let’s raise the nose and try to fly level. Because there is still a tiny bit of drag we will start to decelerate, and eventually we will suffer the same fate as our stubby dart and stall, but probably minutes instead of seconds from now, and at a lower AoA around 16 degrees, which is typical for most aircraft with proper recognisable wings. If we could just grab hold of some passing air and throw it backwards we might be able to push ourselves forward to counter the drag and keep flying for ever.
A propeller is really just a wing flying around in a circle, generating lift and drag. The drag is trying to stop the propeller turning, so we use the power of an engine to keep it going. The lift is trying to pull the propeller off its shaft, so we attach it firmly to the engine, attach the engine to our aircraft and the lift becomes thrust to pull our aircraft along in the direction of the propeller shaft. The tips of the propeller are travelling a lot faster than the parts closer to the shaft, in fact the inner 25% or so of the propeller is going so slowly that it generates very little lift and is often covered in a streamlined “spinner” to reduce drag. Each part of the propeller is optimised to meet the oncoming air at an AoA that gets the best L/D, which is how propellers get their beautifully sculpted and twisted shapes, first worked out by the Wright brothers. Aircraft with a wide speed range normally have propeller blade angles that can be mechanically adjusted, for much the same reason that a car has gears – lots of power at low speeds for takeoff, and the ability to cruise without over-revving the engine. At lower speeds the radius of the propeller is important too – big propellers are more efficient at lower speeds, the ultimate example being a helicopter rotor. This is why the Mythbusters (thankfully) couldn’t get airborne in that terrible twin-ducted-fan deathtrap in an early series, when there are perfectly ok ultralight helicopters getting airborne using the same engine they were using.
Thrust can also be delivered by jet turbines and rockets. Both are terrifically light and powerful, but also rather expensive, and in the case of rockets, scary.
Efficient aircraft with high L/D need very little power to remain airborne, which is why record breaking long range and human powered aircraft look like gliders – the first to save fuel, and the second because people make really, really terrible aircraft engines. Any excess thrust left over from resisting drag can be used to accelerate the aircraft or make it climb higher. As the L/D gets worse we need more and more power to stay airborne, to the point where we arrive back at our original brick hanging underneath a helicopter rotor and going wherever it damn well pleases.
That’s a first draft – if people are interested I can add some more diagrams and pictures. Happy to accept corrections and comments.
In still air on the conveyor belt the wheels will be rotating at 2 x 155 knots = 310 knots, which is 106 knots faster than the max rated tyre speed. We need to reduce the ground speed to 204 knots / 2 = 102 knots, so we will need a 155 – 102 = 53 knot headwind to get our required 155 knot airspeed for takeoff. Presumably a person creating a runway-sized conveyor belt will have no problem sourcing a giant fan to create this headwind on demand…
Longer, thinner wings are more efficient, but the further the wing extends outwards,the more bending is experienced at the wing root as the wing lifts, and the heavier the wing root has to be built to counter this bending. If we can make the wing act as if it is longer without increasing the bending at the root, we wouldn’t have to make the root stronger and heavier.
Without the winglet (the sticky-up bit), as other people have mentioned the high pressure air on the bottom of the wing leaks around the wingtip to the top of the wing, reducing the lift on the top of the wingtip and leaving a swirling vortex of air behind the wingtip. Looking at the wingtip in the photo from in front of the plane this vortex would be travelling in a clockwise direction, centred on the wing tip.
The winglet is attached in an upwards direction from the wingtip and designed so that it is trying to lift inwards towards the viewer sitting in the aircraft (if you think of the aircraft as a skier, and the winglets as skis, the winglets are being used to do a “snow plough”). There is higher pressure air on the far side of the winglet and low pressure air on the near side of the winglet. Like the main wingtip, the tip of the winglet has a clockwise vortex trailing behind it, proportionally smaller than the main wingtip vortex but centred higher, at the tip of the winglet. In your imagination If you superimpose the two vortices on each other you will see them running into each other half way up the winglet, like two wheels turning the same direction whose tyres are touching each other. Like the rubbing tyre surfaces, the winglet vortex pushes against the air sneaking around the wingtip from the bottom of the wing, which has the effect of “unwinding” the main vortex slightly, convincing the air near the wing tip that the wing is longer than it actually is and increasing the efficiency of the wing near the tip.
Because the winglet is trying to fly inwards towards the fuselage it compresses the wing towards the fuselage but does not increase the bending moment about the wing root, which is what would have happened if we’d added more wing instead of a winglet. This means the root does not need beefing up to handle more bending and can be built lighter. If you hold your arms out to the side with your palms facing outwards, this is the difference at your shoulder between two people trying to lift you up by your wrists, or pushing your palms towards your head with the same force.
Birds have already solved this problem, but wing root bending moments aren’t their main worry. If efficiency was the only aim all birds would have long wings like an albatross, however manoeuvrability and fitting between obstacles is a conflicting evolutionary pressure, particularly for birds of prey. The wide spread out pinion feathers or “fingers” on the tips of the wings of eagles, hawks, kites etc each have their own discrete wingtip vortices which interfere with each other to reduce the loss of efficiency near the tip. This allows them to have shorter wings while still retaining most of the efficiency required to soar long distances or hover over a field looking for lunch.
This answer is based on an explanation on pages 133-134 of The Design of the Aeroplane by D Stinton 1983. The analogies are my own.
As other answers have pointed out the propeller is a rotating wing. Like a wing, the lift it produces is proportional to the square of the speed it is traveling through the air, so if you compare a section of the propeller near the hub with a section twice as far away from the hub, the section further out will be traveling twice as fast through the air, and produce four times as much lift as the inner section.
The upshot of this summed over all the sections of the propeller blade is that the inner 25% or so of the propeller radius is contributing almost nothing to the thrust (i.e. forward pointing lift) of the propeller. The outer 75% radius is 15/16 ~ 94% of the area of the disc swept by the propeller and is largely unobstructed by the engine cowling, although the standard cowling in the picture above still contributes a fair bit of drag. A popular modification to many light aircraft is a Lopresti cowl, which apart from adding a few knots of airspeed is a beautifully sculpted thing to look at:
I wasn’t going to answer this question, but when I saw the other answers targeted an uncannily accurate selection of my own favourite aircraft I thought I should explain my own criteria for what makes an aircraft ugly before I offered up a candidate.
More than any other machine, the form of an aircraft follows its function. Every curve of the surface, thickness of a spar or shape of a bolt is the way it is because it is lighter, stronger, safer, less draggy, easier to build and operate than any available alternative at the time. There are some exceptions to this rule such as the swept tail on Cessna light aircraft [1] but even in that case you could argue that increasing sales by 30% improved the function of the aircraft for Cessna, if not the owners of the aircraft.
Looking at an aircraft without an idea of what the designers were trying to achieve is like reading every second word in a poem. Let’s look at the B&V141 nominated by Bradley Peterson:
The Luftwaffe[2] was after a light observation aircraft at a time where practical helicopters were still some way off. The asymmetric arrangement of the crew compartment to the right of the engine gave incredible visibility for the pilot and observer, and the engine position was cleverly chosen to balance the torque of the propeller, making it an easy aircraft to fly. Asymmetry is very unusual in an aircraft but I don’t believe it equates automatically with ugliness. The B&V (and its close cousin in asymmetric and glazed cockpit window looks the Millenium Falcon) both have a surprising lopsided, powerful grace:
If you can’t quite find a love of asymmetry in aviation in your heart at this point, here is Burt Rutan’s Boomerang:
Is this ugly? For me, it’s near the top of my list of the most beautiful aircraft ever built – it is to the aeronautical engineer’s art what the Shakespeare Sonnets are to poetry. If you still think it’s ugly, would it help if I said it has a hugely greater range and speed, and is much, much safer in the event of a single engine failure [3] when compared to conventional twins of the same size?
Brian Sanderson’s nomination of the Transavia Airtruk hit close to home for me – I first saw it at an airshow in 1977 as a child and was absolutely entranced. I dreamed for years of using it as a minature cargo plane with a motorbike stored onboard to get into town from whatever airport I’d flown in to. As an agricultural aircraft the Airtruk is designed for crash survivability, and has a huge hopper under the pilot, right on the centre of gravity so that fertiliser loads don’t affect the balance. The hopper is so huge that for a while it was being marketed as a counter-insurgency military aircraft with a rear gunner sitting backwards below the pilot. And of course the two tails allow a truck to drive between them, right up to the hopper for loading, saving the ground handlers from all sorts of loading related strains and injuries and keeping them away from the propeller:
To me the Airtruk is a symphony of constraints followed to a logical conclusion. Like the Venus de Milo it emerged out of a block of marble as all the bits that didn’t fit were chipped away.
The Beluga is intended for carrying bulky yet light airliner components around between the various Airbus factories for assembly:
I was quite surprised to see it in the ugly list, in fact I much prefer it to the A300 airliner that it’s based on, and compared to the 747-based Dream Lifter:
and Guppy (which Airbus previously used):
the “bulge” seems more blended-in with the rest of the hull shape. I’m still mildly surprised that some eccentric royal family hasn’t asked Airbus to fit one out as a travelling palace with cathedral ceilings and a mezzanine, and a split level outdoor BBQ deck under the open cargo door.
As for the Storch, its extraordinary short takeoff and landing capabilities were extolled by all, including the Allies (Churchill toured the Normandy battlefields in one):
The bulged side windows allowed the occupants to look directly down with the windows closed, a feature a lot of Alaskan bush pilots would probably like on their Supercubs. I think it has a charming, leggy blown up rubber-band-powered-model look to it.
Anyway, here’s an aircraft that is to aeronautical engineering what Vogon Poetry [4] is to prose. Ladies and Gentlemen, I present to you the CA 60:
Count Caprioni’s nine winged, eight engined flying houseboat qualifies as an aircraft because it did leave the water briefly. It design was completely insensible to what had been learned about aeronautics at the time. It was viciously unstable and it’s only redeeming grace is that it didn’t kill the test pilot when it inevitably returned to the water in a heap after reaching the grand altitude of sixty feet [5].
I look at it and the ugliness goes deeper than the image – it was a huge waste of treasure and labour, a risk to human life and a monument to arrogance and ignorance. Had a similar level of technology and materials been used to built a flying boat more suitable to both flying and being a boat you could have built two Sikorsky S-40s (featured in the movie Flying Down to Rio, the first of many Fred Astaire and Ginger Rogers outings):
To my mind that is a beautiful aircraft.
Page 82 Roskam’s Airplane War Stories, J Roskam, 2002
I just wanted to acknowledge that this answer is limiting the scope of intent to the designer. If you (properly) widen the scope to consider the intent of those commissioning and operating the aircraft, any aircraft bearing a Nazi swastika is immediately, immensely ugly. The majority of restorers, replica and model builders recognise this and omit the swastika from otherwise faithful reproductions of Luftwaffe aircraft.
An answer first published on Quora on January 3, 2015 with over 380,00 views and 1,100 upvotes. There is an interminably long and deep comment thread, some the new points they raise and my responses are at the end of this post. The main thing I haven’t brought over is the discussion on catapult launches, see the Quora comments for that.
It’s not just the Americans who believe that the Wrights were the first to fly a powered, heavier than air aircraft, remaining far ahead of European (including then resident in Paris Brazillian Santos Dumont) efforts to achieve the same even half a decade later.
The reported reactions of pioneer French aviators to Wilbur Wright’s demonstration flights outside Paris in August 1908 were as follows:
René Gasnier: “We are as children compared to the Wrights!”
Léon Delagrange: “We are beaten! We just do not exist!”
Paul Zens: “Mr. Wright has us all in his hands. What he does not know is not worth knowing” [Gibbs-Smith Rebirth of European Aviation 1974]
“The French Senate extended an invitation to Wilbur and greeted him with a standing ovation. The frying pan Wilbur had used for cooking at his hangar improbably wound up in the Louvre.” [Crouch Bishops Boys]
Of course the French had pioneered lighter-than-air flight and went on to make many great contributions to the history of powered, heavier than air aviation, but at this point they were well behind the Wrights.
Firstly the French had thought that aircraft had to be designed with inherent stability – look at the huge dihedral and lack of ailerons on Dumont’s (a Brazilian) 14-bis for example, which flew in Paris three years after the Wrights:
The Wrights had realised before their first glider that roll control was required to turn, and were the first to give the pilot that control. Note the difference between Dumont’s No.19 (the first Demoiselle) and No. 20, built before and after Wilbur’s visit – the No. 20 was the first of his designs to have roll control, and later versions are widely regarded as classics of early aircraft design. The modern name for the control surface that makes an aircraft roll, “aileron”, is French.
Secondly the Wrights used a wind tunnel to scientifically investigate airfoil shapes for optimal lift/drag, and discovered the effect of aspect ratio (longer, thinner wings) in the improvements between the 1901 and 1902 gliders. The 14-bis and the Voison glider before it did not have shaped airfoils, but flew using Hargrave box kite cells (an invention from my hometown, Sydney Australia by the way – Lawrence Hargrave also invented the layout of the rotary engine, another staple of early aviation, although his was powered by compressed air).
Finally the Wrights were the first to understand that a propeller was a rotating wing, and that it should have an airfoil profile. The propellers on the 1903 first powered flight were almost as efficient as the best wooden propellers we can make today (around 70%) which is a brilliant achievement. Together with the efficient wing design it allowed the Wrights to fly on half the power (12hp) of Dumont’s 14 bis (24hp).
In summary, half a decade after the Wright’s first flight the French in no way could be said to have made the biggest discoveries regarding the airplane, and they said it themselves. Your premise is simply wrong. After Wilbur’s visit however, they made up for it in spades, and leapt well ahead of US aviation, to the point where only a decade later Americans flying in WWI were almost without exception flying French Spads and Nieuports. This was a truly amazing period in aviation – the French may not have invented the aircraft, but they made wonderful contributions to it’s development in science, industry and art, for which the French people should be proud (as Australians should be of Lawrence Hargrave and Harry Hawker — but I digress).
PS: The French are also responsible for an image which has been a favourite of mine since I was very young – it is framed on the wall behind me as I write:
PPS: Thanks for all the interest and comments. I have responded to some of them, but thought it would be more efficient to address some of the more repeated points here:
This answer was originally for the question “Why do Americans believe the Wright Brothers invented the airplane when actually French aviators made the biggest discoveries?” and Quora asked me to move it to this question, which seems to have caused some confusion.
For aircraft, my answer assumes human carrying powered, heavier than air flight independent of the ground, which is what the Wrights are credited with.
Dumont was a Brazilian as I noted in my answer.
Gustave Whitehead’s claim to first flight was first mentioned by Jonathan Smith. He kindly provided this reference [Wrong about the Wrights] which was an interesting read, based on research by Australian aviation historian John Brown. However I find this response by the Scientific American [Scientific American Debunks Claim Gustave Whitehead Was “First in Flight”] addresses the claims made by John Brown pretty succinctly. I would be interested in JB’s response to SA’s points.
Opinion is not fact. Extraordinary claims require extraordinary evidence. I have been a keen reader of aviation history since I was a child. My answer is based on multiple, widely available references which themselves are based on contemporaneous accounts of what actually happened. Feel free to challenge my references for any of the statements that I’ve made and I’ll be happy to provide them, or own up to things that are my own opinion or interpretation. If you want to claim that something else is fact, then like Jonathan or the Richard Pearse supporters (thanks, see below) provide a reference to back up your claim. As far as I’m concerned, comments like “X was the first to fly” without references are tantamount to trolling.
I have no time for conspiracy theories, especially when they show no sign of the comment’s author being aware of the original, widely available, recorded history version of events. The “real” history is a fascinating story, with crazy characters, missed opportunities, monsters, chases, escapes, true love, miracles… (hmm) and tons and tons of detail.
As an antipodean myself I would dearly love Richard Pearse’s claim to be correct. The replica project video on Youtube is fascinating (although I don’t understand the claims about the Wrights having had government assistance and not building their own engine – Charlie Taylor built an engine specifically for the Flyer) and the engine design is a wonderfully inventive approach to getting a lot of power for little weight (the double-sided piston approach was used in steam engines, and the Junkers Juno 205 diesel used in German bombers in WWII had two pistons sharing a single cylinder). I haven’t seen anything to suggest that the replica got to more than a slow taxi under its own power, using a modern propeller. I understand the replica airframe is based on NZ patent 21476 that Pearse submitted in July 1906, but that no parts of the airframe survived or were photographed, and we don’t know whether or not this is the design that he flew, before or after the Wrights. I’d be interested to know if anyone has simulated or flown a model of this design successfully – to my eye it would be very unstable in yaw and pitch. However the elephant in the room, as Matt Conway, Paul Valentine and Andrea Little pointed out in the comments with this reference [When did Richard Pearse fly?], is that the only contemporaneous report of his flying, in a newspaper interview in 1909, has Pearse himself saying that he didn’t start working on his aircraft until 1904. For me personally this holds far more water than eye-witness accounts, given in good faith, but recounted half a century or more after the event.
My original statement that the Wrights invented the wind tunnel was incorrect. See History of Wind Tunnels for a description of what the Wrights did with their wind tunnel in the context of previous experimenters.
I have now disabled comments (on Quora), for the last year or so there haven’t been any new questions, just assertions or repeats of questions elsewhere in the comments I have already addressed and provided references for multiple times, particularly about catapults: they flew multiple times without a catapult in 1904, and in the context of everything else they worked out (efficient airfoils and propellers, practical wind tunnels, three axis control, hundreds of sustained flights of long duration) years before Dumont you may as well say that the lack of landing wheels, tray tables or window shades disqualifies everyone who flew before Sikorsky… (waiting for flood of comments from the Sikorskyists).
Vast Similitude 