Aircraft fabric covering
The de Havilland Mosquito is an example of this technique, as are the pioneering all-wood monocoque fuselages of certain World War I German aircraft like the LFG Roland C.II in its wrapped Wickelrumpf plywood strip and fabric covering.
The purposes of the fabric covering of an aircraft are: Pioneering aviators such as George Cayley and Otto Lilienthal used cotton-covered flying surfaces for their manned glider designs.
[2] The advent of cellulose dopes such as "Emaillite" was a major step forward in the production of practical aircraft, producing a surface that remained taut (eliminating the need for frequent re-covering of the flying surfaces)[3] The air battles of World War I were mainly fought with fabric-covered biplanes that were vulnerable to fire due to the flammable properties of the cloth covering and nitrocellulose dope.
By the World War II era many aircraft designs were using metal monocoque structures due to their higher operating airspeeds, although fabric-covered control surfaces were still used on early mark Spitfires and other types.
With the development of modern synthetic materials following World War II, cotton fabrics were replaced in civil aircraft applications by polyethylene terephthalate, known by the trade-name Dacron or Ceconite.
[4][12] Many ultralight aircraft are covered with pre-sewn envelopes of 3.9 oz Dacron that are simply screwed, bolted or laced into place.
These are produced in a wide variety of colours and patterns and are commonly flown untreated or with an anti-ultraviolet radiation finish to resist sun damage.
[18] Oratex differs from previous systems, which all require the application of many layers of special coatings (many of them toxic) along with the time, skill, equipment and safety precautions necessary to apply them.
The covering would then be treated with tautening dope to remove wrinkles and increase structural strength, finish coats often containing aluminium powder would serve to protect the surface from ultra-violet light.
Large fabric panels of the World War I era aircraft were often laced together through eyelets to ease access to the internal structure for maintenance.
Some disadvantages compared to modern methods are the relatively short service life of the covering due to biological effects such as mildew and the labour required to achieve the end result.
A side effect of using modern covering materials on wooden structured aircraft is that due to the much longer life the structure remains covered and un-inspected for much longer time periods, this has resulted in special periodic inspections being mandated by aviation regulatory bodies.
[4][22] With both methods of covering it is normal for the aircraft to be re-weighed after renewal of the fabric to determine any change in mass and centre of gravity.
