Merlin
Through Roosevelt I met Professor Langley of the Smithsonian, an old man who had designed a model aeroplane driven – for petrol had not yet arrived – by a miniature flash-boiler engine, a marvel of delicate craftsmanship. It flew on trial over two hundred yards, and drowned itself in the waters of the Potomac, which was cause of great mirth and humour to the Press of his country. Langley took it coolly enough and said to me that, though he would never live till then, I should see the aeroplane established.5
This mockery by the press may have provoked the Smithsonian into their later claims of success on the part of their colleague. Langley’s models flew further and further until his No. 6 flew for nearly a mile. The Smithsonian then granted him $20,000 to develop a full-sized man-carrying machine. To this the US War Department added $50,000, a huge sum of money at the time. The stakes were correspondingly high.
Langley called his pilot-carrying machine ‘The Aerodrome’, which translates as ‘air runner’ in Greek. The name has lived on to denote the runways that aircraft fly from. The younger man Langley hired to be the pilot was a brilliant American engineer, Charles Manly. And realising that the power-to-weight ratio of a steam engine was too low to propel a full-sized aircraft, Langley looked for someone to build him one of the exciting new Otto-cycle engines.
Professor Langley commissioned a Hungarian-born engineer, Stephen Balzer, to build him an engine for the Aerodrome. Balzer had built his first motor car in New York, a car that featured a lightweight rotary three-cylinder engine which he thought he could enlarge for the Aerodrome. Car and motorcycle engines are usually too small for aircraft. His five-cylindered prototype was disappointing, only producing 8 to10 horsepower compared with the minimum of 12 hp that Langley needed. It only ran for a few minutes. As many engineers have found to their cost, simply enlarging a design doesn’t always work.
Langley asked his engineer/pilot Charles Manly to intervene, and so he took on the mammoth job of redesigning the engine. A trip to Europe in 1900 to speak to other engine designers convinced him that the rotary design was not the way to go. So he designed the engine with fixed radial engine cylinders. And he designed a masterpiece.
Charles Manly made, largely with his own hands, a five-cylindered four-stroke radial engine, nearly 9 litres in total cylinder capacity. Five cylinders would give smooth running, and they were laid out somewhat like Leonardo’s Vitruvian Man, in a star shape.
He put a cast-iron liner into each spun-steel cylinder, something his local machine shops said couldn’t be done, and so he did it himself. He also welded steel water jackets around the cylinders for cooling and brazed ports on for the valves. In so doing he permanently damaged his eyesight.
Why the need for cooling? It may shock the reader to be told that the average petrol engine is as little as 25 per cent efficient. That means that up to 75 per cent of the expensive fuel we buy disappears as wasted heat from the cylinders and down the exhaust. This has enormous consequences now in a warming world, but the problem for an early engine designer was how to remove all this excess heat without melting pistons and cylinders together in a red-hot mass. One solution was to put cooling fins on the outside of the cylinders, and this worked well enough for small motorcycle engines: we call this air-cooled. But when there are rows of cylinders, the rearmost do not receive enough cooling draught. The other solution is to place a jacket of cooling water around the cylinder and pump the near-boiling water away to a radiator well away from the engine: water-cooled. This was the route that Manly took.
The rest of his engine was no less remarkable. Manly had to make every part himself, as there were no lightweight aircraft-engine accessories available off the shelf. His ignition system using a high-voltage coil and spark distributor was the first of its kind. His sparking plugs featured a platinum electrode, a choice of material years ahead of time. But his carburettor was a chamber filled with wooden balls soaked in petrol which produced a vapour that was drawn into the cylinders. This was like someone building a Concorde out of corrugated iron: Manly simply didn’t have specialised materials such as aluminium, and so he had to make the crankcase out of steel and the pistons out of cast iron. He invented a drum-type cam to open the valves and evolved the idea of having a master connecting rod and the remaining rods as slaves. The results were outstanding: the performance of this engine was prodigious. Aircraft builders are obsessed with the weight-to-power ratio of the engines they buy for obvious reasons: every extra pound or kilogram in the engine has to be supported by thin air. For a dry weight of 125 pounds, Manly’s engine gave over 52 horsepower, a weight-to-power ratio of 2.4 pounds per horsepower, which was not beaten until 1916 by an engine designed and built in a fully equipped factory during wartime. Furthermore, his engine ran reliably for ten hours without getting hot and bothered.
Not only did Manly produce the world’s first purpose-made aircraft engine, he did it largely on his own. L. J. K. Setright,‡ the sage of aero engineering, wrote this: ‘As an example of brilliant originality in design and virtuoso ability in workmanship, the Manly radial remains to this day one of the most outstanding aero-engines in history.’6
The sequel to this story is a sad one. After this jewel of an engine was fitted into Professor Langley’s Aerodrome, the aircraft was loaded onto a catapult mounted onto a houseboat moored on the Potomac River. It was 7 October 1903. But the aircraft had been scaled up from models and was structurally far too weak. Control was virtually non-existent, with two sets of wings in tandem and a central rudder. Manly took the controls, the engine roared, the whole contraption slid down the ramp … and promptly flopped into the water. Manly had to be rescued.
On the second attempt on 8 December Manly tried again, and this time the Aerodrome nearly killed him. It collapsed into the water again, trapping him under a tangle of wires and canvas. He was dragged out just in time.
Professor Langley made no further attempts, and the whole expensive project was ridiculed by the press. Then just nine days afterwards on 17 December 1903, Wilbur and Orville Wright conducted four successful flights near Kitty Hawk, North Carolina with an engine of their own construction.
We are not quite finished with the Aerodrome. Professor Samuel Langley was clearly an honourable man, and when a colleague was found to have been embezzling funds from the Smithsonian he held himself responsible and refused his salary. The pressure proved too much, he suffered a stroke and died in 1906.
In a dubious alliance, the Smithsonian allowed the aircraft manufacturer Glenn Curtiss to make extensive modifications to the Aerodrome to enable it to fly. Curtiss wanted to prove it was the first flying machine so that he could defeat the Wright brothers’ patent lawsuits against him after he appropriated their ideas. And the Smithsonian wished to salvage their deceased secretary’s aeronautical reputation. After a few short hops by Curtiss during which daylight was seen under the Aerodrome, the Institution was sufficiently emboldened to display the machine in its museum. ‘The first man-carrying aeroplane in the history of the world capable of sustained free flight,’ the placard boasted. ‘Invented, built and tested by Samuel Pierpont Langley in 1903.’ This relegated the Wright Brothers’ 1903 Kitty Hawk Flyer to also-ran status.
‘It was a lie pure and simple, but it bore the imprimatur of the venerable Smithsonian and over the years would find its way into magazines, history books, and encyclopaedias, much to the annoyance of those familiar with the facts,’ wrote the aviation historian Fred Howard.7 ‘To Orville Wright it was more than an annoyance. It was the culmination of Glenn Curtiss’s campaign to demean and devalue all that the Wright brothers had accomplished.’
Orville Wright was quite rightly furious (his brother Wilbur had died two years previously), and he accused the Institution of misrepresenting American aviation history. He found out the extent of the Curtiss modifications from a close friend of the Wright brothers, Griffith Brewer, who had photographed the tests. He then refused to donate the original Flyer to the Smithsonian, instead giving it to the Science Museum of London, which had a more objective view of aviation history. The feud eventually ended, but not until the Smithsonian published details of the Curtiss modifications to their Aerodrome and recanted their claims for precedence.
At last, the executors of Orville’s estate signed an agreement for the Smithsonian to purchase the Wright Kitty Hawk Flyer for one dollar. At the insistence of the executors, their agreement included conditions for display of the aeroplane: if any associated institution dared to claim precedence for any other aircraft, then the Flyer would be forfeited to the heir of the Wright brothers.
* A glance at an online animated graphic will explain it all: https://en.wikipedia.org/wiki/Internal_combustion_engine.
† The Watt is an SI unit created in 1882 to measure power – usually electricity. It was named for James Watt.
‡ Setright was the paragon of technical writers: car journalism’s Prospero to Jeremy Clarkson’s Caliban. Concert musician, Jewish scholar and epicure, in appearance he was a gaunt Old Testament prophet draped in a Savile Row suit. More English than the English, he smoked Black Russian Sobranie cigarettes and drove a Bristol motor car.
Chapter Two
Nobody ever understands what
a pioneer is doing1
‘Surely we’re flying this in the wrong direction?’ – Wilbur Wright on the Wright Flyer in 1903. (Wikimedia Commons/US Library of Congress)
So how did two humble bicycle mechanics from Dayton, Ohio change history? A host of French, British and German engineers and inventors knew that powered heavier-than-air flight was coming and were racing to be the first. There was also a horde of frauds, stuntmen and profiteers. They all thought that the new petrol engine was going to provide the breakthrough they craved, but what they didn’t know was how they were going to control the aircraft once it left the ground. And that is exactly what Orville and Wilbur Wright figured out.
Like Einstein’s steam engine, it’s another story of an inspirational toy: when they were boys their father Milton brought home a toy flying machine. It was a form of helicopter based, like Professor Langley’s, on a design by Alphonse Pénaud. It was powered by a rubber band that drove a rotor. Wilbur and Orville were fascinated and played with it until it broke, and so they built their own. Like Albert Einstein, they later maintained that it was this toy that initiated their lifelong interests.
After a career together building a printing press and running a newspaper, the brothers, neither of whom married, turned their attention to the new craze of bicycling and built up their own safety bicycle manufacturing company. This funded their new interest in flight, triggered by Professor Langley’s steam-driven model aircraft flights at the Smithsonian and the exploits of the German hang-gliding pilot Otto Lilienthal, who was killed in August 1896. Wilbur said of him: ‘Lilienthal was without question the greatest of the precursors, and the world owes to him a great debt.’
The brothers decided that pilot control was vital and first learned to build gliders. They evolved the idea of banking, or leaning the aircraft into turns – rather like riding a bicycle. They achieved this by twisting the ends of the wings, or ‘warping’ as they called it. They experimented with gliders at an area of sand dunes called Kill Devil Hills at Kitty Hawk, North Carolina, using a local boy as pilot, as did Sir George Cayley. They then tested 200 types of wing in their home-made wind tunnel, and also figured out the best kind of propeller, which they eventually realised was a form of rotating wing.
After their experience with bicycles and studying the observations of predecessors such as Sir George Cayley, the Wright brothers realised that pilot control was essential for such a dangerous and unstable machine as an aircraft. Wilbur Wright acknowledged Cayley’s importance to the development of aviation: ‘About 100 years ago, an Englishman, Sir George Cayley, carried the science of flight to a point which it had never reached before and which it scarcely reached again during the last century.’2 The Wrights’ inventive breakthrough was three-axis control, which is still used to this day. In their earlier unpowered gliders they learned how to control roll, pitch and yaw, partly by twisting the wings, partly by using a rudder.
Compared with Manly’s jewel their engine was fairly unremarkable, but it did the job. The first engine to propel a heavier-than-air machine was not the best of those early engines, but it was the first. They could not buy one that would do the job, so they set about building one out of local materials. Largely following the contemporary 1900s automobile practice of ‘4x4x4’, it had four cylinders measuring 4 inches in diameter with a 4-inch piston stroke. These were laid flat in a row and a four-throw crankshaft was carved out of a solid billet of steel by the Wrights’ machinist, Charlie Taylor. Here’s Taylor’s story in his own words:
We didn’t make any drawings. One of us would sketch out the part we were talking about on a piece of scratch paper, and I’d spike the sketch over my bench. It took me six weeks to make that engine. The only metal-working machines we had were a lathe and a drill press, run by belts from the stationary gas engine.
This single-cylindered engine was one they had built earlier to test their skills:
The crankshaft was made out of a block of machine steel 6 by 31 inches and 1-5/8 inch thick. I traced the outline on the slab, then drilled through with the drill press until I could knock out the surplus pieces with a hammer and chisel. Then I put it in the lathe and turned it down to size and smoothness …
This crankshaft was literally hacked out from the solid by Taylor. It lacked any balance weights, so the vibration must have been numbing for the pilot, lying prone next to the engine.
… the ignition was the make-and-break type. No spark plugs. The spark was made by the opening and closing of two contact points inside the combustion chamber. These were operated by shafts and cams geared to the main camshaft. The ignition switch was an ordinary single-throw knife switch we bought at the hardware store. Dry batteries were used for starting the engine, and then we switched onto a magneto bought from the Dayton Electric Company.3
The engine’s capacity was 3.3 litres. It had an overhead camshaft, which opened the exhaust valves only, as the spring-loaded inlet valves were sucked open automatically by the descending pistons, which was common practice at the time.
What was remarkable was the material used for the crankcase. Unlike Manly, the Wrights managed to find the latest precipitate-hardened aluminium, and this was also a first in aircraft construction. They contracted a local Dayton foundry, the Buckeye Iron and Brass Works, to cast the aluminium crankcase. Buckeye acquired their raw aluminium from the nearby Pittsburgh Reduction Company, which was renamed Alcoa in 1907 and later became the world’s leading producer of aluminium. Here’s Charlie Taylor again:
The body of the first engine was of cast aluminum and was bored out on the lathe for independent cylinders. The pistons were cast iron, and these were turned down and grooved for piston rings …4
Amazingly, the engine had no fuel pump and no carburettor, but a crude form of fuel injection which allowed a trickle of petrol to leak into a water-heated inlet manifold where it vaporised and was sucked in through the automatic inlet valves. So the pilot had no throttle to control the engine power, just an ordinary tap, and therefore the engine ran at full speed or not at all. Presumably the pilot was otherwise occupied in learning how to fly the world’s first aeroplane on its very first flight.
All of this hard work and inventiveness resulted in a dry weight of 179 pounds, quite a bit more than Manly’s engine at 125 pounds. The specific power was 15 lb/hp instead of his 2.4 lb/hp. It also only produced 12 horsepower instead of Manly’s 52 horsepower, and it couldn’t produce that power for long. After a few minutes heat would build up and the inlet manifold would get too hot, reducing the density of the air and thus reducing power to around 8 horsepower.5 It was enough power – but only just.
The Wright engine was first run on the bench on 12 February 1903, but on the very next day (Friday the 13th, as it happened) it overheated and seized up on a test run. Overheating was to be a constant bugbear of aero-engine manufacture over the next century, as we will discover. New castings had to be ordered from the foundry, and Charlie had their engine rebuilt and ready to go in early June.
What was even more impressive than building an engine literally from scratch is that the brothers realised the importance of running the two propellers slower than the engine and revolving them in opposite directions to counteract gyroscopic forces (these two facts didn’t dawn on some aircraft manufacturers until well into the Second World War). They did this by the simple expedient of using long bicycle-style chains and different-sized sprockets to gear down the 8-foot (2.5-metre) spruce propellers, then simply twisting just one of these chains into a figure-of-eight to reverse the direction! The brothers’ bicycle experience had certainly paid off. The result of all this was just 90 pounds (40 kg) of thrust (the most recent Rolls-Royce Trent jet engine generates 97,000 pounds (44,000 kg), well over a thousand times as much as that first aircraft engine).
This historic engine came to a sad end. After powering the Flyer on four flights at Kitty Hawk on 17 December 1903, it suffered serious damage, splitting the crankcase when a gust of wind overturned the aircraft. It wasn’t perhaps the best engine built for pioneer flight – that was Manly’s. But it was the first engine to fly.
We are nearly at the point of lift-off. In 1903 the brothers built their aeroplane, the Wright Flyer, adding Charlie Taylor’s engine. The whole aircraft cost less than a thousand dollars, in contrast to the $70,000 total of government and Smithsonian funds spent by Professor Langley on his Aerodrome.
Finally, on 14 December 1903 Wilbur and Orville tossed a coin to see who would go first. Wilbur won the toss and the two brothers shook hands. John T. Daniels, a lifesaver crewman, was struck by the feelings between the two brothers: ‘After a while they shook hands, and we couldn’t help notice how they held on to each other’s hand, sort o’ like they hated to let go; like two folks parting who weren’t sure they’d ever see each other again.’6
The two brothers wouldn’t see each other again, not in a flightless world. A few minutes later Wilbur lay down on the lower wing, the Flyer’s engine roared, the aircraft trundled down the launch rail and an aircraft took off under its own power for the first time in history. The Age of Aviation had begun.
Chapter Three
Prometheus’s gift
The first successful flight of the Wright Flyer, 1903. Wilber has just let go of the wing. (Wikimedia Commons/US Library of Congress)
After a three-and-a-half-second flight the Wright Flyer lurched up steeply, stalled and crashed nose-first into the sands of Kill Devil Hills. Wilbur was slightly shaken, but the canard elevator at the front had taken most of the impact. He wrote home: ‘the power is ample, and but for a trifling error due to lack of experience with this machine and this method of starting, the machine would undoubtedly have flown beautifully … there is now no question of final success.’
So was this the first successful flight? Or not? This is a problem for historians who try to hammer solid markers into the ever-shifting sands of time. Geologists also like to mark the transition between geological eras with what they call the ‘golden spike’, referring to the ceremonial gold final spike that was used to join two railway tracks when they met in the middle of the US in 1869, forming the transcontinental railroad.
The two men made a far more successful flight on their next outing: on their next test day, 17 December 1903, the Wrights arrived on site in a freezing wind of 27 mph (43 km/h), and with the damaged elevator repaired Orville took off at 10.35 a.m. The over-sensitive front elevator caused the Flyer to swoop up and down in a sickening way, but it landed safely after a flight of 120 feet (36 metres) in 12 seconds. This flight was the subject of the famous photograph (his first) taken by John T. Daniels. This is generally accepted as the first heavier-than-air flight in history. Significantly the aircraft landed at the same level as the take-off: it hadn’t just floated off a hill like a glider.
Wilbur managed 175 feet (52 metres) on the second flight, again struggling for control. On the third flight Orville achieved 200 feet (60 metres) in 15 seconds. And the fourth and final flight of Flyer 1 was more controlled. Orville recorded what happened:
Wilbur started the fourth and last flight at just about 12 o’clock. The first few hundred feet were up and down, as before, but by the time three hundred feet had been covered, the machine was under much better control. The course for the next four or five hundred feet had but little undulation. However, when out about eight hundred feet the machine began pitching again, and, in one of its darts downward, struck the ground. The distance over the ground was measured to be 852 feet; the time of the flight was 59 seconds. The frame supporting the front rudder was badly broken, but the main part of the machine was not injured at all. We estimated that the machine could be put in condition for flight again in about a day or two.1
This was more like it. Wilbur Wright had managed nearly a minute of sustained, controlled flight. The engine had run reliably throughout. They had a photograph and five witnesses, and Flyer had done her duty. Unfortunately the fragile aircraft was then caught by a huge gust of wind and rolled over several times, despite desperate attempts to hang on to it. As we have seen, the engine crankcase was split in half, and that was the end of the engine. This is the aircraft that Orville donated to the Science Museum in London and that now resides in the Smithsonian.
The brothers now had to capitalise on their invention, and that proved much harder. The Wrights began applying for a patent, but it described the 1902 warping wings on their glider, not the 1903 powered Flyer. It took over three years to be granted, and this patent was to be the basis for the many patent-infringement suits which exhausted the brothers (and probably led to Wilbur’s premature death at only 45). In 1904 they built another Flyer with an enlarged version of the same engine and managed to fly in a large circle for one and a half minutes, but still the aircraft was difficult to control. There was a reason for that.
An amateur might be forgiven for thinking that the Wright Flyer 1 was flying backwards.* It had no tail, but instead a large appendage at the front. The propellers were at the back, pushing forwards. The Wrights were trying to fly their contraption in the wrong direction, in fact the whole thing was dangerously unstable, as modern analysis shows. An attempt to re-stage the hundredth anniversary of the first flight on 17 December 2003, using an exact replica, failed because the pilot simply could not control it. It was like a flying shopping trolley.