I have seen the movie twice, and will see it again. I was, in a distant way, involved in the investigation. I was in the union at a level that was dealing with both the press and the investigation.
As to villains, there really aren't any. If however, you are naive enough to think that the special interests don't circle their wagons immediately after an accident like this, there is a bridge in Brooklyn I would love to sell you. Airbus immediately started having pilots fly the immediate return scenario and very quickly submitted their findings, that a return to LGA was doable, to protect themselves. CFM submitted certification test data proving that the size of the birds, based on recovered remains, were outside of the certification limits for both EU and US. US Airways was very quick to close ranks on maintenance and performance data. They were slow getting it to the NTSB, not slow illegal, but very slow and deliberate and many high level meetings went on and there were behind the scenes negotiations over what data was pertinent tot the investigation.
The union did what it was supposed to do and that is; protect the crew. If the crew is at fault the information will come to light. There are criminal penalties for interfering or attempting to falsify information in an accident investigation. However you must remember that all the other parties have million dollar stakes in the outcome of an investigation like this. To say that they are all "just seeking the absolute truth" is simply not true. They are all attempting to protect themselves to what ever extent they can. Sully, Jeff and the back end crew, different unions, had legal representation on site within an hour of the crash. USAPA's law firm at that time was NY based. The senior counsel met the crew at the hospital and was with them for a week. Later the law firm advised on various aspects of the investigation and reviewed all replies and prepped Sully and Jeff for depositions and interviews.
Some outside the US may say that this all seems overly legalistic, and they may be right. The US legal system has evolved into a monster that is very good at extracting money from people and giving it to lawyers. That being said, when you are in an investigation interview and the room is packed with lawyers form Airbus, CFM, the company, the New York Port Authority and everyone else and their brother, you are a fool to go in without representation. Everyone there has an interest to protect. Investigations, as in both civil and criminal law, are at their heart, adversarial proceedings. That's just the way it is.
The only criticism I have of the movie is that the investigation timeline is very compressed. A full on NTSB investigation is a long process. The findings were not formally published until May 4, 2010, almost 16 months after the accident occurred on January 15, 2009.
The players and names were all real and correct. However Arnie Gentile is bald and does not have a beard. Everyone else was a very close facsimile of the real life person. The simulator scenes were flown by real US Airways pilots. One was a union committee chairperson active in the investigation and others were Airbus check airmen.
There was a line in the film about "I didn't know I had so many cousins" spoken by Hanks. It reflected the persistence of the press to get at the crew by any means possible. They tried to get into the union office in Charlotte, into crew rooms at various bases and into the hospital and hotel were the crew was staying. The union moved the crew several times to the press guessing and at bay.
There was another accident at US Airways, in 1994, where the investigation took a great deal of time to uncover the probable cause. This was US Air 427 in Pittsburgh, PA. The final determination of that accident was that a rudder reversal and hard over occurred and at low altitude and the crew was unable to recover the aircraft. All aboard perished. In that accident the NTSB took almost 5 years to find a probable cause.
The NTSB released its final report on March 24, 1999.[1][7] The NTSB concluded that the accident was due to mechanical failure: The National Transportation Safety Board determines that the probable cause of the USAir Flight 427 accident was a loss of control of the airplane resulting from the movement of the rudder surface to its blowdown limit. The rudder surface most likely deflected in a direction opposite to that commanded by the pilots as a result of a jam of the main rudder power control unit servo valve secondary slide to the servo valve housing offset from its neutral position and overtravel of the primary slide
It is a great movie but simplistic as to how an actual NTSB investigation is conducted. FYI, the current NTSB senior aviation investigator, Robert Sumwalt is a former US Airways pilot.