Cause of the crash, terrorists flew into a building/ground on purpose
... “The identities of the airplanes hijacked in the September 11 attacks was never in question,....” the FBI and NTSB World Trade Center site investigators dispensed with forensically analyzing the aircraft wreckage they recovered and absconded with in the days and weeks following those attacks. ...
You know why the planes identities were never in question? Are you completely in the dark? Let me start with the simple stuff.
If you had a friend who regularly flew Flight 11 or 175 for business on the west coast!, what is the first thing on 9/11 you would have done? My niece is one of those people who flew on one of the flights out of Boston on business all the time, and also her office mates too. As she explains, she and her office mates called everyone as soon as it was announced Flt 11/175 were hijacked and missing, when they impacted the WTC.
Oh, not good enough. You parents, or sister, or bother, or aunt, or friend flew on 175 or 11 on 9/11, and now they are not alive.
Not good enough? Radar proves it was 11 and 175 which impacted the WTC towers.
Not good enough? Only four planes in the whole of USA failed to land at airports in the USA on 9/11. Guess which four planes failed to reach their destination on 9/11.
You have no idea what the NTSB does, as you think they need to do a forensic analysis of the crashes. NTSB does not do crime, the FBI does crime. As soon as it was verified by crew testimony before the crews died on 9/11, the crashes were on purpose. The NTSB does accidents, not on purpose crashes, aka Crime. When a pilot/terrorist crashes a plane on purpose, murder, a crime, the NTSB does not have to look for why the plane crashed, it was a Crime.
The NTSB investigates crashes to find the cause of the Accident. The cause of the crashes on 9/11 was a terrorists pilot flying planes into buildings and the ground. NTSB has no job, the cause is known, they are done.
For 9/11 the NTSB was used as needed to supply products to the FBI. These product also are proof of which planes when where.
If you don't think the planes are the planes the FAA knows were used, then you don't trust the FAA, better stop flying.
Summary, NTSB investigate the cause of a crash, an accident - the moment the NTSB finds evidence the crash was on purpose, a crime, they bring in the police/FBI - and then the prime on the investigation is the Police/FBI. Thus, the cause of the crashes on 9/11 is known to be terrorists flying planes into building and the ground.