The NTSB is underfunded and understaffed. So it investigates accidents using the "party system." That means the NTSB relies on those who may have caused the accident for help in investigating the accident's cause. Unfortunately, the "party participants" seldom point the NTSB towards evidence in their files that would tend to incriminate them. As a result, NTSB reports go easy on the industry players.
From time to time, I've offered examples of cases (like the ones here and here) where the real cause of the accident was found by plaintiffs lawyers -- sometimes well after the NTSB report is published.
Here’s yet another example, this time arising out of the crash of the Continental (Colgan) Flight 3407. According to a recent CBS News report, lawyers for the families uncovered emails showing that Colgan Air knew the captain was not qualified to fly the Q400, but put him in the left seat anyway.
According to an ABC report, in one of the emails a Colgan Vice President states that the captain
had a problem upgrading” and, taking that into consideration, “anyone that does not meet the [minimums] and had problems in training before is not ready to tackle the Q.”
The “Q” is a reference to the Bombardier Q400. Despite Colgan's concerns about the captain's ability to fly the Q400, they promoted him anyway. Just five months after that, the new Q pilot crashed his aircraft in Buffalo, killing 50.
This wasn't merely a case of "pilot error," it was the result of an airline that didn't take safety seriously enough. The newly released emails are critical to understanding why the accident happened, and how similar accidents can be avoided in the future. Yet, an NTSB spokesman confirmed that Continental did not provide these emails to the NTSB at any time during its year long investigation of the crash.
It looks like the company's emails tell the story of why Continental Flight 3407 crashed. And it was the plaintiffs' lawyers, not the NTSB, who found them.