Category Archives: Early Flight

1985: MY PRIVATE HISTORY OF THE DAVIS-WING

I got interested (again) in aviation history when I bought thirty years ago at a jumble sale an old scrap book with photographs of the Dornier Do-X. The picture shown above carried the caption (in Dutch):

1929
THE BIGGEST AIRPLANE IN THE WORLD, the Do X, has recently been completed in the halls of Dornier in Friedrichshafen and will make soon its first test flight. This immense aeroplane has a length of almost forty meters; the span of its wings comes to 48 meters and its height is 8.5 meters. The giant will be propelled by no less than 12 large Siemens Jupiter engines with a total power of 6200 hp. The fuel tanks are in the bottom of the airplane reducing the danger of fire almost completely. The number of passengers that can be transported is astounding: no less than 100!
There is a crew of twenty needed to control the airplane and serve the passengers. The creator of this enormous colossus, Ir. Dornier, has stated that three or four of the engines may be stopped during flight without problems. However, the crossing of the ocean is not yet possible with this giant – it is not more than a step forward on the difficult road to trans-oceanic air traffic. On the photograph the immense monoplane is shown in the assembly hall of the Dornier factory.

The Germans have always been very proud of their Do-X – and rightly so – but of course in 1932, as predicted, it failed where five years earlier Charles Lindbergh had succeeded without apparent effort:
a simple non-stop jump across the Atlantic.


I wondered why this would be so and started to read (+ collect) books about 1930-flying boats and airliners. What were the factors that determined their long-range performance? How fascinating that era was!

Next I got into a correspondence with a certain Don Middleton, a British aviation journalist, who had stated in an English monthly that the amazing long range of the Consolidated Catalina patrol boat was due to its ‘Davis-wing’. Based on general data from Jane’s ‘Fighting Aircraft of WWII’ edition I undertook to compare four contemporary transport planes: the Douglas DC-3 and DC-4, and the Consolidated Catalina and B-24 Liberator, and proved to him that Catalina’s extreme performance was based on two factors: its light construction (empty weight approximately 50% of take-off weight) and its slow cruising speed, which was right at the optimal economic flight point (maximum  CL/CD ratio). The other three planes, for commercial or operational reasons, all cruised faster than their most economic speed and as a consequence had a comparatively shorter range. The Cats were slow, real slow, to the exasperation of their crews. However, slowness could also be advantageous: they were able to shield the ships they were escorting by circling tightly around them, outmaneuvering in this way attacking German and Japanese aircraft that were much faster.

Consolidated PBY Catalina

The PBY Catalina had no Davis-wing and I think I proved it, but Middleton never entered into a serious discussion and suggested I submit my paper to the Royal Aeronautical Society, which of course was a bit much. Later on I learned he disliked smart asses like me who argued from theory: he had been a skilled aircraft worker at de Havillands himself and a RAF engineer during the war.
Of course the Davis-wing was used on the B-24 Liberator. Next blogs will summarize what I know about it. The inventor, David R. Davis, [1] appeals to me because he was obviously a maverick: he worked outside the official circuits of Universities and NACA. Apparently he had a mind of his own.
As a result however, descriptions of his work are hard to find in official literature (like Abbott & Doenhoff; maybe Durand mentions him?). Apparently his wing had extreme low drag at small angles of attack (laminar flow?), which is remarkable, because long range (like Catalina’s) is usually associated with low engine power and therefore relative large angles of attack. So there were things here which were not quite clear to me. I wanted to know more about the wing profile: it must have been very thin with maximum depth near the middle of the chord. How can thin wings be made strong enough for long spans? This was the state of my comprehension (and confusion) until I found more information.

[1] A word of warning: there have been other aviators of fame with the name Davis. So is our man not to be confused with the unfortunate pilot Noel Guy Davis, who crashed short after take-off for a trans-Atlantic flight in 1927, aboard a Keystone Pathfinder (N-X179) airplane called American Legion.
[2] picture: PBY5 Catalina; credit: Wiki.

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2004: Boeing 747-206 Last Journey

Don't be shy 747, why sneak thru the canals at night? Ah, you're missing your wings....
Don’t be shy 747, why sneak thru the canals at night?     Oi, you’re missing your wings….

70 years after the previous photograph was taken, this
Boeing 747-206, the KLM airliner PH-BUK Louis Breguet , navigated the nightly waters of Amsterdam on its way to Aviodrome, the national aviation museum at Lelystad. This particular airplane, with combined passenger/cargo capacity, had flown before retirement
98 million kilometers during more than 100,000 hours of flight.

Restored to its full glory (complete with tail, wings and engines)
Louis Breguet may now be visited and studied inside/out at Aviodrome, Lelystad:

Boeing 747 Jumbo Jet

 

1934: SCHATZKI REVISITED

In the 1930’s the above traffic situation occurred frequently in the canals of Amsterdam: the Fokker Aircraft factory was located in Amsterdam North, a residential and industrial section of town without an airfield, while Schiphol Airport was to the south of the city, on the bottom of a reclaimed lake. For flight tests newly built Fokkers had to be transported through the wondrous and winding canals of the old city. Sometimes, after heavy rainfall, Schiphol was too marshy and flight tests had to be relocated to Welschap, near Eindhoven, a distance of 70 miles or so to the south.

You can read about the tests at Welschap in the revised ‘album’ of Erich Schatzki’s life, when you click here:  alifeofflight2.pdf

Erich Schatzki loved the new country that he had settled in for a short interval of time. Relentlessly moved on by the unfolding of history, events took him eventually to the United States and then to Israel and back again to the USA – like a pendulum, going multiple times back and forth.

For the new data which I was able to add to the earlier description of Schatzki’s life, I am indebted to my old friend Wim Snieder, the writer of the only comprehensive bibliography of Dutch aviation history: “In Vogelvlucht” / Geannoteerde bibliografie over de Nederlandse luchtvaart, vanaf 1784. Uitgever; Canaletto/Repro Holland; 486 pages, ISBN 9789064697340

1939: Erich Schatzki Album

Fokker_g1

As a little boy in Holland I was enraptured by the original shape of the Fokker G-1 fighting plane of 1939. A few years later I became a (small) close witness to the atrocities of the war, as some of my schoolmates and good neighbors in the street where I lived in Amsterdam were deported because they were Jews. (They never returned.)
Dr.Erich Schatzki

While living now in California and enjoying my own ‘Indian Summer’, I found on the web the designer of the G-1, Erich Schatzki. I also learned that he was a Jewish exile and that he and his family had been on the run for the Nazi’s since 1934. I set out to find more facts about his life.
I have collected these in an ‘Album’, a collection of factual items and a description of some of the fascinating people that he met in his long, adventurous life.

I have added my findings in a new file on my website today. If anybody can tell me more, or if somebody wants to correct an error, please leave a note!

 

1670: METAL SPHERES IN THE SKY

800px-Magdeburg
[from Wikipedia]
The ancient peoples of Babylon and Egypt have presented us with many valuable scientific and technical innovations. In the fields of arithmetic, geometry and astronomy they made major contributions and in the art of erecting barehanded buildings from huge stone blocks they are unsurpassed to this day. But as far as I know they did not get involved in the theory of gases, nor did they build machines to conquer the sky.

The history of the balloon starts with Greece, where Archimedes (287-212 B.C.) formulated the principles of sinking, rising and floating and Hero (20? A.D.) invented the plunger type water pump. In our own seventeenth century there was Torricelli (1608-1647), who demonstrated the phenomenon of a vacuum by upending a long glass tube filled with mercury and Von Guericke (1602-1686) who adapted Hero’s pump to pump air. In this way he could evacuate his famous Magdeburger Half Spheres and demonstrate the surprising force exerted by the pressure of the column of air above us.

One result of all these experiments with vacuum was that the idea that air had weight became generally accepted.
Magdeburger balls emptied of their inside air were somewhat lighter than air-filled ones. Giovanni Alfonso Borelli (1608-1679, see my previous post), Italian physiologist, mathematician and friend of Galileo, speculated that if one would make very light spheres, for instance out of very thin copper plate and draw all the air from their insides, they would float in the air according to the law of Archimedes. Unfortunately spheres formed out of very thin plate would not be able to withstand the atmospheric pressure from outside and would be flattened by it.

Flying_boat
[from Wikipedia]
Undaunted by considerations like these the Jesuit father Lana de Terzi (1631-1687), who longed to go to heaven, made the same fatal flaw in his thinking. In his book ‘Prodromo Overo Saggio de Alcune’ of 1670 he describes a true ship of the air, an open gondola lifted by four copper spheres of almost 25 feet diameter that have no air inside. The ship is drawn forward by a span of twelve geese. De Lana was probably the first to be concerned that this invention, like all other man made instruments, could be misused for war. An airship such as this would make war even more brutal and horrifying than de Lana had experienced in his own lifetime. He therefore concluded that God would prevent the construction of this sort weapons. He certainly was he a naive optimist.

Of course his idea of the twelve geese was endearing. In flight it must have looked somewhat like the picture hereafter, which shows the Canadian Joseph Duff flying southward with a flock of cranes that have as much trust in their pilot as de Lana had in his god.

whoopcrane
[from link below]
Do read:

https://centennialjournalism.wordpress.com/2012/06/06/operation-migration-founder-still-flying-to-save-endangered-birds-whooping-cranes-not-canada-geese/