There were two significant issues, which I believe were triggered by airborne structural failures in the 1960s.

One was the deterioration and failure of some wooden structures which had deteriorated and begun to rot under fabric coverings. This partly was due to age and equally because many aeroplanes had lived either out of doors or in damp conditions during war years.

There were also significant issues with casein-based glues that were used in the 1930s, 40s and early 50s. These deteriorated both with age and moisture ingress and were (rightly) treated with a high level of suspicion.

Both the above were reasons why a large number of aeroplanes such as Moths, Miles Magisters, Messengers, Geminis and Percival Proctors simply disappeared as the cost of inspection, let alone repair, was way above the value of a tired old aeroplane.

Thankfully (he says touching wood-literally!) these issues are now less likely to affect airworthy survivors. By now, they’ll have been rebuilt with modern formaldehyde or acrylate adhesives, while almost all such grand old ladies are cossetted in nice dry hangars.

Mind you, every annual check, I still have all the inspection panels off the fuselage, wings and tail of my Tipsy Trainer, for a good look inside. Not to mention sniffing for a giveaway musty smell that might give an early warning of potential trouble!