Comparison between the 9/11 "plane" impact vs a bunker buster missile vs jet crash test vs plane crash test through wooden poles.
The 9/11 "plane" resembles the bunker buster missile with the ability to penetrate steel and concrete before a delayed explosion, rather than the extremely fragile thin aluminum plane that can't even cut through wood.
Note that this doesn't necessarily mean that an actual cloaked conventional bunker buster missile was used on 9/11, but that the visual appearance of impact and delayed explosion are comparable.