The first 100 or so Tu-154s were prematurely removed from service in the early 1970s due to cracks appearing in the structure… ouch, pretty expensive…

Was this a manufacturing or a design issue? I have to admit that I was unaware of this. I always understood that the withdrawal of these machines was due to upgrading to ‘B’ spec and not to any major flaw in the aircraft itself. However I am more than happy to be corrected on this or any other topic here, if the correction is right, then thats more knowledge for me!:D Interesting that until the arrival of the Tu154 and the Il62, the Soviets favoured the ‘porthole’ design in their pressurised airliner construction.