Well, its neither coincidence or planned. Its purely a hoax. The real flight and tail numbers of flights involved in the 9/11 attack are: American Airlines Flight 11 (N334AA) United Airlines Flight 175 (N612UA) American Airlines Flight 77 (N644AA) United Airlines Flight 93 (N591UA)
Even more ironic is how the shipped off the WTC steel to be recycled in China around November / December 2001. And they wonder why people ask questions.
Listen dudes ICT... Internet conspiracy theory... No factual evidence whatsoever... It is cool though....