Written By: Anna Smythe
Part one: Bye, Plane: Transition from Biplane to Monoplane
History Walking through the museum, a first-time visitor may be surprised to encounter a number of older airplanes with two wings: biplanes. We have seven biplanes, most of which are from the 1930s and earlier — an exception being the Tiger Moth, a World War II training aircraft. In fact, only one of our airplanes from 1925 or earlier sport one wing. Currently in restoration, the Fokker D.VIII was part of the German Eindecker (monoplane) series, which were one of the few monoplanes to fight in the biplane-dominated battlefield of World War I (Brooks 1951, 99 and 105-107). Monoplanes are the standard for airplane design and have been since the 1930s (Anderson, Graham, and Williams 2011, 144 and 145). Why, then, were biplanes so prevalent during the first decades of aviation? Why did monoplanes supersede them? And which is better: the monoplane or the biplane?
The latter question was a source of tension for the aviation industry, especially in the years before the monoplane’s ascent to dominance. This article will look at not only the development of the monoplane and biplane but also of the opinions surrounding aircraft design. To do so, I will use primary sources from the 1920s to the modern day, which will provide examples of contemporary opinions on the efficacy of both types of aircraft. These opinions’ contrasts and similarities will help answer the questions posed above.
I will begin with a 1926 technical memorandum from NACA (National Advisory Committee for Aeronautics), the precursor to NASA, detailing the development of light and small airplanes since the end of World War I. G. Lachmann’s subsection on the differences between a biplane and monoplane, under the “Special Structural Considerations” section, details how, as of 1925, there was “a decided trend toward the monoplane” (1926, 37). He attributes this trend primarily to the monoplane’s more streamlined design (Lachmann 1926, 40). A significant disadvantage of the monoplane, according to Lachmann, was that it needed more engine power to carry weight than biplanes, which created more lift with their two wings, increasing their possible payload (40). Weighing these and other advantages and disadvantages, Lachmann concludes that the best structural form of an aircraft is situational, rather than absolute, despite the monoplane’s aerodynamic superiority (40).
The museum’s full-scale airworthy reproduction of a Fokker D.VIII. The aircraft departs from being an authentic reproduction in a number of ways.
The next two sources, the similarly named “Monoplane or Biplane” (1928) by Chatfield and “Monoplane or Biplane?” (1929) by W.S. Farren, are especially indicative of how hotly debated this topic was at the turn of the decade. Both sources include, following the body of the article where the author argues their perspective, a discussion section where leading aviation experts, including Anthony Fokker and Frederick Handley Page, debate the validity of the author’s arguments (Chatfield 1928, 221; Farren 1929, 522).
Chatfield argues that both the biplane and the monoplane have their advantages, as Lachmann (1926) did. He claims that biplanes are more stable, maneuverable, and structurally sound (Chatfield 1928, 216-219). Having two wings was more structurally sound for wooden aircraft; early monoplanes experienced higher risk of a wing falling off or breaking without the same strength of a biplane’s supporting struts and trusses (Anderson, Graham, and Williams 2011, 144). In the museum, the Curtis Stinson Special biplane was built specifically for Katherine Stinson’s signature loop-de-loop by making both wings with ailerons and the airfoil shape. Double the wing control surfaces and lift creation gave the Curtis Stinson Special maneuverability.
But, Chatfield also emphasizes the biplane’s aerodynamic and material disadvantages: it is slower, creates more parasitic drag, and, most importantly, its wings cannot be made of metal without decreasing its strength-to-weight ratio to an inefficient degree (1928, 218). Either a biplane’s wing would need to incorporate such thin sheets of metal that it would become brittle, or would be too heavy to fly well. Of wood and fabric aircraft, the biplane was superior, but of metal ones, it was not even a contender (Chatfield 1928, 217 and 218). Chatfield does not directly assert that the monoplane’s superiority is near due to its possible metal construction. He does, however, conclude that “the monoplane evidently is gaining and there seems to be a distinct tendency among builders developing new and original types of construction to give most of their attention to monoplanes” (220), implying that it would be the primary stage for aviation development in the near future. Ultimately, Chatfield claims impartiality in the “rivalry between the monoplane and the biplane” (217), asserting, like Lachmann, that the answer is contextual (220).
This impartiality extends to the commenters’ opinions as well. Anthony Fokker asserts that bi- and triplanes are better for war because of their greater maneuverability, and that biplanes are superior pursuit planes and were easier to make structurally sound, but does not claim their general superiority over monoplanes (Chatfield 1928, 221-222). Archibald Black summarizes the commenters’ opinions aptly: “[t]his question of biplanes versus monoplanes seems to be one of the riddles of the universe; I suppose we shall never have it settled” (221).
An airshow in Edmonton on Sept 17 1930, featuring a Fairchild KR-34 (CF-ANW) and possible an Avro Avian (CF-CDI or CF-CDT?), amongst other biplanes. The airshow’s directory can be found here: Peel 10320: “Edmonton Airshow.” In the background is the first hangar built for the new Blatchford Field Airport.
Breaking through the wall of passive non-arguments, Farren storms in one year later to argue that monoplanes would never be superior to biplanes in a commercial setting. Farren claims monoplanes will not be the better commercial airplane because they have a lower gross payload, lower torsional strength and rigidity, and a similar cruising speed to biplanes. Biplanes’ increased drag from having two wings would be offset by an increase in payload and a decrease in the weight of the airplane (Farren 1929, 502-506). In essence, he claims that it is not possible to build a wing big enough and strong enough that it could carry a large passenger load aircraft.
As is fitting for a more assertive paper, the comments on Farren’s argument are more divisive. The then President of the Royal Aeronautical Society, William Forbes-Sempill, began the discussion by disagreeing with Farren’s conclusion. Referencing Chatfield’s paper, he claimed that “[f]rom the commercial and civil aspect[…] the practical advantages offered by the monoplane would gradually secure its wide adoption” (Farren 1929, 517). The next commenter, Captain G. T. R. Hill, also “heartily disagreed with the main conclusions set out in the paper” (517), criticizing Farren’s monoplane examples as unrepresentative of all monoplanes, biasing his conclusion against them, and offered his own comparison in contrast (517-520). “In his view Mr. Farren was on a sinking ship, though in his lecture he had tried to show how much buoyancy it had; at the same time he had given an opportunity for a few holes to be bored in it, and he (Captain Hill) hoped it would be agreed that some of the holes he had bored were well below the water line” (520).
Read about our collection at the museum: https://albertaaviationmuseum.com/collection/aircraft-collection-restoration-area/
References
Alberta Biplanes. n.d. “Alberta Biplanes.” Accessed August 7, 2024.
https://www.albertabiplanes.ca.
Anderson, Dale, Graham, Ian, and Williams, Brian. 2011. Flight and Motion: The History and
Science of Flying. Armonk: Taylor & Francis Group. Accessed August 7, 2024. ProQuest Ebook Central. https://ebookcentral.proquest.com/lib/ualberta/detail.action?docID=3569946.
Brooks, Peter W. “II. The Development of the Aeroplane.” Journal of the Royal Society of Arts
107, no. 5030 (1959): 97–116. http://www.jstor.org/stable/41368727.
Chatfield, C. H. “Monoplane or Biplane.” SAE Transactions 23 (1928): 217–64.
http://www.jstor.org/stable/44437123.
Farren, W. S. “Monoplane or Biplane?” The Journal of the Royal Aeronautical Society 33, no.
223 (1929): 489–540. https://doi.org/10.1017/S0368393100138325.
Lachmann, G. 1926. “Technical Memorandums. No. 370. Development of Light and Small
Airplanes.” From Berichte und Abhandlungen der Wissenschaftlichen Gesellschaft fur Luftfahrt (1925): 84-95. Translated by Dwight M. Miner. Washington, D.C: National Advisory Committee for Aeronautics (NACA). https://ntrs.nasa.gov/api/citations/19930090701/downloads/19930090701.pdf.
Peel 10320. 1930. “Edmonton Airshow.” Official Directory. Edmonton: Edmonton Air Show.
Accessed August 8, 2024. http://peel.library.ualberta.ca/bibliography/10320.html.