Var det ett designfel i tankarna på MiG-15/17/19/21?

Wikipedia-artikeln på MiG-15 :

Another major design deficit was that the tank could develop under-pressure if more than half the fuel had been used, which could easily lead to tank implosions, destroying the aircraft.

MiG-17 :

Like its forebear, the MiG-17 inherited the major design deficit which could cause the fuel tanks develop to under-pressure if more than half the fuel had been used, which could easily lead to tank implosions, crushing the main fuselage of the aircraft mid-fight, with almost always fatal results.

MiG-19 :

Initial enthusiasm for the aircraft was dampened by several problems, the most alarming inherited from MiG-15/MiG-17 was the danger of mid-air tank implosions when more than half of the fuel had been used - the leaking fuel of the crushed fuselage fuel tanks located between the engines would then ignite, leading to a fatal explosion;

MiG-21 :

Additionally when more than half the fuel was used up, violent maneuveurs prevented fuel from flowing into the engine, thereby causing it to shutdown midflight.3 and risking tank implosions (a problem inherited from MiG-15/MiG-17 and MiG-19).

Ingen av dessa poster har en citat.

Jag skulle vilja veta om dessa flygplan verkligen hade en designfel i bränsletankarna, och i så fall vad var det? Vad var fel med tanken som gjorde det känsligt för implosioner en gång mer än 50% bränsle var borta?