The Burnelli Web Site
Evidence of Suppression and Official denial is overwhelming
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... continued from Part 1

The comparison reveals that the Martin 404 airframe is at least 55 per cent heavier than the CBY-3 of the same gross weight class.

There are several factors responsible for the structural economy of the Burnelli Loadmaster. They are:

Lifting Body v. Conventional Aircraft graph

  1. The airfoil-shaped fuselage contributes to lift in direct proportion to its plan area over the total lifting area at the high angle of attack position. The level flight contribution is a function of the angle of incidence between the fuselage and the wing. Thus, the primary cargo structure also is a lifting component.
  2. Because of this lift contribution of the fuselage, wing panels are of reduced size. The FAA has authorized a span loading distribution of one-third of the lift on the fuselage and one-third on each wing panel. The bending moments at the wing root are further reduced because the moment arm is reduced by half the body span.
  3. The box-like structure of the fuselage allows greater concentration of load at the center of lift. It also very rapidly provides for the required volume, allowing the same load capability for a smaller physical article. The size of this primary structure permits installation of engines and landing gear at a minimum weight increase. The main bulkhead that takes the air loads also may take the landing shock loads, since they do not occur simultaneously.
  4. Because the engine and landing gear compartments are in the fuselage, the wings do not contain large cutouts and are not subject to torsional, bending and shock loads that result from them. Consequently, wing structure is much lighter.
  5. The tail section is supported by two thin booms.

Perhaps the most remarkable feature of the Burnelli design is that the structural economy upon which it is based is not diminished with an increase in the size of the plane itself.

In a recent Air Force competition for a turbo-prop airplane of 155,000 pounds gross weight, the C-130, with an empty weight of 61,163 pounds, was declared the winner. The Burnelli design for a plane of the same gross weight would scale empty at only 45,549 pounds empty. Because all other considerations are equal, the difference of 15,614 pounds would be reflected as increased payload for the Burnelli.

When one realizes that the payload of the C-130 is but 20,000 pounds, the difference afforded by the Burnelli design in this class becomes even more startling.

Bristol Brabazon A design study by Dr. Max Munk of airplanes in the 220,000-pound gross weight category compared the Burnelli "lifting body" design to one of a conventional type similar to the Brabazon. Dr. Munk found that a Burnelli Loadmaster of this size could carry a payload one and one-half times greater than the conventional type at the same speed and range.

In such large aircraft as this, the increase in capability of the Burnelli as compared to other types is of tremendous economic significance.

Further bearing out this payload differentiation is a comparison of the Burnelli Loadmaster with three currently used medium-weight class planes. In the following table, gross weights are determined by regulation 04-B for all aircraft except the C-46. The table shows an increased capability for the Burnelli of from 70 to 90 per cent at the conservative gross weight of 42,000 pounds.

BURNELLI
C-82
404
C-46
Engine
R-2800
R-2800
R-2800
R-2800
Gross Weight 42,000 lbs. 43,000 lbs. 42,750 lbs. 44,900 lbs.
Empty Weight 22,000 lbs. 30,000 lbs. 29,330 lbs. 30,500 lbs.
Disposable Weight 20,000 lbs. 13,000 lbs. 13,420 lbs. 14,400 lbs.
Fuel, crew 4,865 lbs. 4,865 lbs. 4,865 lbs. 4,865 lbs.
Payload Weight 15,135 lbs. 8,135 lbs. 8,555 lbs. 9,490 lbs.

This payload capability advantage of the Burnelli Loadmaster design would permit a reduction in the present air ton-mile rate to one which would be competitive with that of first class truck transportation while still retaining the dollar return per unit operation.

The provisional CBY-3 with 2XR-2600 engines gave the following performance in a test at Hagerstown, Md:

Gross Weight 32,500 lbs.
Empty Weight 20,128 lbs (with structural margin of 1,610 lbs.)
Disposable Weight 12,372 lbs.
Payload 7,507 lbs. (with above excess, 8,117 lbs.)

During the test, the CBY-3 demonstrated a single-engine capability of 22 pounds per horsepower. This is equivalent to that of the Martin 404, the Convair 340, the C-82 and the C-119, and seems to be a practical limit of asymmetrical power capability in present aircraft.

Previously, however, in Canada, the Burnelli had demonstrated a single-engine capability of 24 pounds per horsepower. The latter airplane was considerably "cleaner," having wheel well doors, better engine cowling, the large wing root fillet and proper propellers. I have chosen the lower demonstrated value only to remain conservative.

1935 UB-14 crash No discussion of the Burnelli Loadmaster design should ignore the many safety factors not found in conventional types. Location of fuel tanks in the wing panels, far removed from engines, greatly reduces fire hazard. In any wheels-up landing, the principal shock would be taken by the airfoil fuselage owing to the high wing arrangement. In the turbo-prop version, engines are mounted sufficiently ahead of the main structure so that they can burn off without endangering the structural integrity of the plane itself. I need not say how vital a consideration this is in turbo-prop planes. The box-like fuselage itself offers tremendous resistance to telescoping in the event of a crash, a principal fault in conventional designs.

The Burnelli Loadmaster is also designed to save time and effort in loading and unloading cargo. It is ideally suited for the pre-loaded container type of operation and its cubic interior lends itself equally well to other loading schemes.

In summary, I may say that the Burnelli Loadmaster design incorporates two main considerations. The first is aerodynamic.

Tunnel work by N.A.C.A., M.I.T. and N.Y.U. have proven this design aerodynamically competitive with more conventional types. Flight tests have proven the Burnelli's equality in asymmetric power flight at 22 pounds per horsepower (50 per cent toatl horesepower inoperative, all on one side).

The second consideration is structural. The Burnelli design affords an empty weight approximately 30 per cent lighter than that of conventional types for the same gross weights. This weight savings manifests itself in a vastly increased payload.

Briefly, the Burnelli Loadmaster "lifting body" design may be described percentage-wise as follows:

Gross Weight 100 per cent
Empty Weight 40 per cent
Payload Weight 40 per cent
Fuel Weight 20 per cent

This means that a Burnelli plane of 250,000 pounds gross weight can carry a payload of 100,000 pounds.

A conventional plane large enough to transport the same cargo would weigh approximately 350,000 pounds.

This constitutes a 100,000-pound weight difference between the Burnelli and conventional planes designed to carry half that amount.

With these facts in mind, there can be no doubt about the plane America needs.

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