The role of early synthetic materials degradation in the downfall of the Ansaldo A.1, an Italian World War I biplane fighter

Abstract

From the Pioneer Era of the aviation to World War I the evolution of aircraft technology and chemical synthesis enabled a unique coexistence of traditional craftsmanship, artistic decoration practices, and technological advancements. The study of the materials used in these early years of aviation is still an uncharted territory: a vast portion of remaining planes has been partially or completely repaired and restored, usually by total replacement of the fabric. The Italian biplane Ansaldo A.1 (1918) is a fighter aircraft and is one of the few planes in the world that still preserves its own original materials. In the last years, the fabric sections of the airplane have started to become brittle and loose cohesion, severely compromising the integrity of the aircraft, and resulting in a general alteration of the pictorial layers of the painted sections. A chemical investigation was undertaken to unveil the materials, and to elucidate the causes of the degradation. This study presents one of the first steps into the study of early historical aircrafts, defining the background for the conservation plans to preserve these objects for future generations.

Figure 1

Early photography of the Ansaldo A.1 Balilla.

Figure 2

State of conservation of the Ansaldo A.1 Balilla in 2020 before the conservation campaign.

Figure 3

Materials identified in the different sections of the Ansaldo A.1 Balilla; (a): Py-GC–MS chromatogram obtained for a sample containing both silk and the dope layer; (b) Py-GC–MS chromatogram obtained for a paint sample with hexamethyldisilazane as derivatizing agent; (c) Extracted ion chromatograms obtained for the dichloromethane extract of a paint sample from the “Saint George and the dragon” painting; the triacylglycerols were detected as sodium adducts ([M + Na]⁺); Acyl substituents abbreviation list: M: myristyl (C₁₄); P: palmityl (C₁₆); L: linoleyl (C_18:2); O: oleyl (C_18:1); S: stearyl (C₁₈); For the oxidized acyl substituents: C_x:y,zOH with x: n° of carbon atoms, y n° of unsaturation, and z n° of hydroxy groups.