Aircraft Building materials
An aircraft can be constructed out of any material that is light and strong enough for flight. Common
construction methods are detailed below.
Wood and fabric
This Bowers Fly Baby is a typical wood and fabric construction
This Pietenpol Air Camper under construction, shows the wooden frame structure that will be covered with
This is the oldest construction, seen in the first aircraft and hence the best known. For that reason,
amateur-built aircraft associations will have more specialists for this type of craft than other kinds.
The most commonly used woods are Sitka spruce and Douglas fir, which offer excellent strength-to-weight ratios.
Wooden structural members are joined with adhesive, usually epoxy. Unlike the wood construction techniques used in
other applications, virtually all wooden joints in aircraft are simple butt joints, with plywood gussets. Joints
are designed to be stronger than the members. After the structure has been completed, the aircraft is covered in
aircraft fabric (usually aircraft-grade polyester). The advantage of this type of construction is that it does not
require complex tools and equipment, but commonplace items such as saw, planer, file, sandpaper, and clamps.
Examples of amateur-built wood and fabric designs include:
- The classic Pietenpol Air Camper, a homebuilt that has been built since the 1920s
- The Bowers Fly Baby, a low-wing monoplane which has been popular since the 1960s
- Fisher Flying Products (built with geodetic cross-bracing)
- The Ison miniMAX
- The Jodel models, including the bébé D-9, D-112, and the more recent D-18, D-19, and D-20
- The Piel CP-30 Émeraude
- The VP-1 and VP-2, designed by Bud Evans in the late 1960s and commonly called Volksplanes
A recent trend is toward wood-composite aircraft. The basic load carrying material is still wood, but it is
combined with foam (for instance to increase buckling resistance of load carrying plywood skins) and other
synthetic materials like glass and carbon fibre (to locally increase the modulus of load carrying structures like
spar caps, etc).
Examples of wood-composite designs include:
- Ibis experimental aircraft project, designed by Roger Junqua
- KR series of homebuilts designed by Ken Rand
- PIK-26 designed by Kai Mellen
The inside of this Murphy Moose tail cone shows the all-metal semi-monocoque design.
Van's Aircraft like this RV-4 on the right are the most common metal homebuilt type.
Planes built from metal use similar techniques to more conventional factory-built aircraft. They can be more
challenging to build, requiring metal-cutting, metal-shaping, and riveting if building from plans. "Quick-build"
kits are available which have the cutting, shaping and hole-drilling mostly done, requiring only finishing and
assembly. Such kits are also available for the other types of aircraft construction, especially composite.
There are three main types of metal construction: sheet aluminum, tube aluminum, and welded steel tube. The tube
structures are covered in aircraft fabric, much like wooden aircraft.
Examples of metal-based amateur aircraft include:
- The Murphy Aircraft SR3500 Moose, Rebel and SuperRebel, Maverick, Elite, JDM-8, and Yukon. Murphy Aircraft
is a Canadian manufacturer that offers kits for selfconstruction.
- The Vans RV-4, RV-8, RV-10 and other models produced by Van's Aircraft, are the most popular metal
- Chris Heintz's Zenith CH601 Zodiac and Zenith STOL CH701
- Sonex Aircraft's Sonex, Waiex, and Xenos kit planes
Metal and Fabric
The advantages of a metal tubular frame and fabric covering are
- There is no metal fatigue of the outer skin because it is fabric
- When the frame is treated for rust and the outer fabric covering is replaced, the result is a virtually new
- Fabric is cheaper to replace than metal
On the left is the Cirrus VK-30 which is a composite construction.
The Quickie Q2 on the right is a fiberglass/foam construction.
Composite material structures are made of cloth with a high tensile strength (usually fiberglass or carbon
fiber, or occasionally Kevlar) combined with a structural plastic (usually epoxy, although vinylester is used in
some aircraft). The fabric is saturated with the structural plastic in a liquid form; when the plastic cures and
hardens, the part will hold its shape while possessing the strength characteristics of the fabric.
The two primary types of composite planes are molded composite, where major structures like wing skins and
fuselage halves are prepared and cured in molds, and moldless, where shapes are carved out of foam and then covered
with fiberglass or carbon fiber.
The advantages of this type of construction include smooth surfaces (without the drag of rivets), the ability to
do compound curves, and the ability to place fiberglass or carbon fiber in optimal positions, orientations, and
quantities. Drawbacks include the need to work with chemical products as well as low strength in directions
perpendicular to fiber. Composites provide superb strength to weight. Material stiffness dependent upon direction
(as opposed to equal in all directions, as with metals) allows for advanced "elastic tailoring" of composite
Examples of amateur craft made of composite materials include:
- Canard designs such as the VariEze and Long EZ designed by Burt Rutan
- The Jabiru range
- All Lancair designs
- The pusher propeller Cirrus VK-30
- The Europa Aircraft range.