The Burnelli Controversy
Was this designer a genius or his own worst enemy?
- By David Noland
- Air & Space magazine, November 1989
Burnelli (front) designed conventional aircraft like the 1916 Continental Pusher before turning to lifting-fuselage airplanes with the RB-1.
NASM
(Page 4 of 5)
Since there are no Burnelli airplanes in flying condition, it’s difficult to evaluate Goodlin’s claims of superior performance. According to contemporary editions of Jane’s All the World’s Aircraft, performance of the early Burnelli CB-16 and UB-14 was comparable to similar aircraft of the day. The most modern Burnelli, the CBY-3, though close in power and payload to the Douglas Super DC-3, was a good 40 mph slower.
On the other hand, Goodlin points out with glee that Boeing’s own spec sheet shows that the 754 Husky would have had greater payload capacity than the 767. But the Husky had 31 percent more wing area and a higher aspect ratio—the ratio of span to average chord, a measure of the “skinniness” of the wing—than the 767, two factors that, entirely aside from its Burnelli-style fuselage, would give it a big weight-lifting advantage. Moreover, the Husky would have cruised at just Mach 0.74, compared with the 767’s Mach 0.80.
According to standard aerodynamic theory, the “extra lift” provided by a Burnelli fuselage is, under most conditions, beside the point. A Boeing 767 cruising at 41,000 feet doesn’t need extra lift from the fuselage. Its wing easily provides all the lift necessary to balance its weight. (In engineering terms, the aircraft cruises at well below the wing’s maximum lift coefficient.) The designer’s task is to get that lift with the least drag. It happens that a high-aspect-ratio wing (long and skinny) has inherently less induced drag than a low-aspect-ratio lifting surface (short and fat, like a Burnelli fuselage). In cruising flight, the less the fuselage lifts, the lower the inducted drag.
Conventional wisdom also dictates that a Burnelli jetliner would suffer drag penalties because of its larger frontal area, larger wetted area (the area over which air flows), and the discontinuity between the lifting fuselage and the wings. NASA aerodynamicist Jerry Hefner comments: “I would think the induced drag would be horrendous. And your skin friction drag is going to go up because of the larger wetted area.” An engineer from a major aerospace firm who asked to remain anonymous (to avoid angry letters from Goodlin) estimates the drag penalty of a Burnelli-style jet transport at about 20 percent more than that of an airplane like a 767. That may be a reasonable compromise for a bulky cargo carrier like the Husky, but not for a passenger jet.
Slick Goodlin, of course, has never let conventional wisdom get in his way. “Boeing and Douglas and all the rest of them are simply wrong,” he declares flatly. “The aerodynamics textbooks have been misinterpreted for 50 years.”
Goodlin and established aeronautical theory do agree on one thing, however: the extra lift of a broad, flat, airfoil-shaped fuselage can theoretically reduce landing speed. Goodlin correctly cites the takeoff and landing speeds of current jetliners—typically 140 to 180 mph—as potentially dangerous. All of Burnelli’s airplanes, by contrast, had low landing speeds.
But an airplane’s landing speed is essentially a market decision, one of the tradeoffs in aircraft design. If Boeing had wanted the 747 to take off at 100 mph in 3,000 feet, it could have simply enlarged the wing and limited the weight. But since the major cities of the world all have 10,000-foot runways and since there is no great public clamor for slower, safer landing speeds, Boeing saw no reason to pay the speed, payload, and cost penalties of a short-takeoff-and-landing 747, Burnelli or otherwise.
Goodlin may not win many converts to his aerodynamic theories, but he’s on much firmer ground when he criticizes the modern jetliner’s crashworthiness. Goodlin says the Burnelli’s rigid box-like fuselage would protect passengers in a crash, pointing proudly to the 1935 crash of the UB-14. The airplane hit the ground, wingtip down, at 130 mph and cartwheeled. Engines, wings, and tail were ripped off, but the boxy fuselage remained intact and the crew walked away. One vocal Burnelli proponent, Edmund J. Cantilli, professor of transportation planning and engineering at the Polytechnic Institute of New York, has decried the poor crashworthiness of the modern jetliner and proposed a Burnelli-style craft it its stead.
Single Page « Previous 1 2 3 4 5 Next »





Comments (4)
The article covers both sides of the debate pretty well considering the lack of commentary from Boeing and the military, and total absence of flight data from testing. One seeming contradiction that is rather obvious to me is that doubling the payload, even on passenger aircraft, would indicate a twofold increase in payment for freight or passengers with significantly less cost accrued due to extra fuel expenditure due to slower airspeeds. This would negate the contention that there is no profit increase in using the lifting body design, if it truly is capable of such a claim.
Surely we should also be considering the safety of passengers in our aircraft design, especially commercial airliners, and since speed translates more than proportionally to fatality during a crash, lowering landing and takeoff speeds could significantly reduce airline fatalities. Especially considering that the vast majority of fatal accidents happen during these two events. I notice that the article only talks about this consideration from a public outcry standpoint, completely ignoring the fact that most of the public expects its air carriers and government regulators to already be looking out for their safety and well-being. After all, you can't complain about a problem that you don't know exists. Wouldn't it be embarrasing to explain that a much safer design has been available for 70 years but that, since the public didn't know about it, the industry didn't feel compelled to act on it? Better late than never is the applicable rule here.
It is time for all parties in this debate to start doing some relevant scientific research and engage much less in the turf war that seems to be waging. It would truly be shameful, although predictable, if we were to find the claims of the Burnelli design faction to be true, in whole or in part, and the resistance to the design be purely motivated by greed or giant egos. Only testing will tell.
Dan Mannion, ARFF Captain, BFD
Posted by Daniel Mannion on April 6,2010 | 06:12 PM
My father covered transportation stories for the Washington Post before WWII and was a friend of Vincent Burnelli. I recall as a young boy visiting Mr. Burnelli at his residence outside of Washington, D.C. I was fascinated by his models of past and speculative designs that surrounded him in the small apartment. Several were of balsa and I spent my time launching them from his steps onto the grass. I remember feeling bad about breaking the wing on one but he didn't mind. Many of the models and photographs in Mr. Goodlin's collection, dating back to the war years, bear an uncanny resemblance to some of the designs now being suggested by designers at Boeing. Although he never received credit in life, I would hope that those who denied his concepts and now embrace them, give credit to his vision.
Posted by Tom Barrows on July 18,2010 | 09:17 PM
My understanding is that the big drawback of lifting-body designs is increased cross-section, resulting in greater drag. Wings have been getting thinner since the early days of aviation, when mechanics could travel through a wing to access an engine. If lifting bodies worked, we would have them. Conspiracy? What's the gauge of aluminum in your foil hat?
Posted by Denton Warn on July 20,2010 | 10:52 PM
I found this page, with the same idea. Mine came with the idea of a flying hovercraft. Why not, it could work, a flat bottom airfoil should make good platform for a hovercraft system. Not knowing very much about airplane design, or for that matter hovercraft, I set about to learn what I could, very little research, or photos (that I could find). I'll keep trying, there has been nothing to suggest that this will not work, if anything it seems as if it's to good to have been over looked. If any can help Feel free to contact me.
Posted by ray sigler on December 5,2012 | 12:03 PM