Workers from the LWF factory in College Point, Queens, New York City, demonstrate the strength of the laminated wood fuselage of the Model V.

One of the earliest examples of molded wood fuselages was the LWF Engineering Company in College Point, Queens, New York City. The LWF company was formed in 1915 by Edward Lowe, Jr., Charles Willard, and Robert Fowler, with each member contributing the initial of his surname to form the company name. The chief asset of the company was the "laminated wood fuselage" developed by Charles Willard. After the pioneering founders had been forced out the company by large financial interests, the legend was promoted that LWF stood for Laminated Wood Fuselage.
The only surviving example of the LWF Model V is in the National Technical Museum in Prague, Czech Republic. The Model V was used by the early Czechoslovakian Air Force in 1919.

 

The Loughead Aircraft Manufacturing Company's bid for "a poor man's airplane" was the Loughead S-1, designed by Jack Northrop. The fuselage was molded plywood.

Another application of molded plywood construction was used by Jack Northrop in the construction of the Loughhead S-1. For the S-1. They used a 21-foot-long concrete mold. In this mold were placed three thicknesses of spruce plywood strips, alternately laid, and well saturated with casein glue. Once the strips were in position, the mold was covered with a rubber bag and then a cover was bolted to the bottom mold. The rubber bag inside was inflated and pressure was maintained for twenty-four hours. The half shells produced could be joined, making clean, smooth, bullet like fuselages.
The S-1 was a distinct departure from pioneer and wartime aircraft. Northrop's experiments resulted in a unique cigar-shaped, streamlined fuselage that was of monocoque (French for "single shell") construction, in which strength comes from the outside skin rather than internal bracing. Northrop, Stadlman, and the Lougheads devised and patented a process to make molded plywood monocoque fuselage shells (US Patent #1,425,113, August 8,1922).

Concrete mold in which monocoque wooden shell of the S-1 Loughead sport biplane of 1919 was formed.

 

Composite Materials

Various composite materials are used in structures such as the Boeing 777 because of their strength, and weight savings. Composites also offer resistance to fatigue, corrosion and impact damage.

Composites are different from metals. They are combinations of materials differing in composition or form. The constituents retain their identities in the composites and do not dissolve or otherwise merge completely into each other although they act together. Reinforced concrete is an excellent example of a composite structure in which the concrete and steel still retain their identities. The steel bars carry the tension loads and the concrete carries the compression loads. In aircraft construction the term composite structures refers to fabric resin combinations in which the fabric is embedded in the resin but still retains its identity.
Advanced composite materials consist of new high strength fibers embedded in an epoxy matrix. These composites provide for major weight savings in airplane structures since they have high strength to weight ratios. When replacing aluminum structure with graphite/epoxy composite weight reductions of 20% or better are possible. Weight reduction is the greatest advantage of composite material and is one of the key items in decisions regarding its selection. other advantages over conventional structure include its high corrosion resistance and its resistance to damage from cyclic loading (fatigue).
The major disadvantage of using advanced composite materials in airplane construction is the relatively high cost of the materials.
Composite Hybrids: Hybrids are made by the addition of some complementary material such as fiberglass or kevlar to the basic carbon fiber/epoxy matrix. The added materials are used to obtain specific material characteristics such as greater fracture toughness and impact resistance, and should be considered for areas subject to foreign object damage. The addition of carbon / epoxy to fiberglass structure is used to provide additional stiffness.