9/11's Fifth Plane Pilot Says Government's Silence Is Frustrating

The pilot of a United Airlines plane that he says was targeted by terrorists on 9/11 is opening up about how frustrated he's been with the government's deafening silence.

Tom Mannello joined us on "TMZ Live" Friday -- the 25th anniversary of 9/11 -- to discuss what went suspiciously sideways on his flight ... and how he tried to put the events of the day out of his mind.

We told you all about United Flight 23 in our documentary "TMZ Investigates 9/11: The Fifth Plane" ... the plane was scheduled to take off from JFK at 9:00 AM for LAX ... but it never got off the ground. A total of 7 people on board raised suspicion.

With evidence that people were hiding in the plane's hatch, the FBI secretly interviewed the whole crew ... even showing them a lineup.

Tom says he feels helpless and frustrated by the lack of information about what really went down ... with no resolution a quarter-century later.

The only information he says he has obtained since that fateful day has been from a couple news stations.

He says United is also faced with the same situation ... the government just hasn't spoken about this -- ever.