Hi Welch,
>Was the P-47 wing that weak in reality? I thought it was extremely tough, even from cannon shells, and was fairly unlikely to break apart in mid air.
I don't know if a P-47 wing was unusually weak, but generally the wings were considered profitable target for cannon shells of the mine shell type at least.
These shells carried a large amount of explosive (for the MG FF and MG 151/20, about twice as much as the heavier Hispano high explosive shell carried), and upon pentrating into the target aircraft's structure, would blow up to generate a strong blast effect. This blast effect destroyed a large area of the aircraft skin, which in a stressed-skin aircraft meant that the structure lost some of its load-bearing ability.
Depending on the amount of skin that was destroyed and the load put on the damaged wing, structural failure can occur as a result of the hit.
One of the reasons for the Germans to adopt mine shell ammunition was that it eliminated the need to hit the small (and possibly armoured) critically vulnerable spots of an arcraft as almost the entire aircraft was vulnerable against mine shell hits.
The effect of the mine shells increased when they hit parts with a smaller internal volume as this would mean that the destructrive pressure on the skin would be greater, and as the wings had little internal volume (between the ribs), they were considered escpecially vulnerable.
(Though fuselage hits were not as effective as wing hits due to the larger internal volume, 30 mm mine shells were powerful enough to structurally destroy a fuselage as well - the British test-fired them against 10 Spitfire fuselages and considered all of them to be destroyed or likely destroyed as a result of the 30 mm hit.)
However, it's my experience that video game designers are obsessed with parts coming off aircraft because it visualizes the damage so unambiguously, so please don't mistake my post as a defense of Il-2
Regards,
Henning (HoHun)
