Expert: Laura Laster - 4/26/2010

Question
How can a co pilot who was one of the few individuals to survive a commercial airline airplane crash help the investigation, but a regular passenger can’t?  The pilot and most of the passengers are dead.  

In the Air Florida Flight 90 crash there were five survivors one of them was a passenger with a commercial pilots license, but the pilot & co pilot are dead.  How can he tell that there was something wrong before the pilot & co pilot did?  He as not even in the cockpit and was not even a flight crew, but just a regular passenger, but could tell that the airplane did not have enough speed to take of properly (latter confirmed by the black box).  The pilot & co pilot thought that there was enough speed, because the instruments were wrong and did not notice the mistake.  It toke 45 seconds to get air born instead of 30 seconds.  

http://en.wikipedia.org/wiki/Air_Florida_Flight_90

Answer
Hello,
I may need a little more information from you to adequately answer your question. Is this a theoretical situation or have you read/heard that a survivor from Air Florida flight 90 was a commercial pilot? I looked up the most authoritative source I have on this crash, from the book Air Disaster Vol. 2, and there was no mention of a commercial pilot as one of the survivors.
Now, theoretically, a pilot who was a passenger could notice something that was abnormal during a flight when perhaps the cockpit crew did not know about the situation or realize the danger. A good example of this happening in real life is Air Ontario flight 1363.
Here's a very brief synopsis of this accident: http://en.wikipedia.org/wiki/Air_Ontario_Flight_1363
I must point out that this article is not unbiased and doesn't seem to have many legitimate sources cited.
Before this accident occurred, several passengers on the aircraft including an experienced Air Canada captain and another off-duty Air Ontario pilot, saw the amount of ice and snow that had accumulated on the wings prior to takeoff. A passenger pointed this out to a flight attendant, but she neglected to notify the cockpit crew. This link I have provided discusses this very incident.
http://www.airlinesafety.com/editorials/CockpitCabinPsychology.htm
For a variety of reasons, it is possible for the cockpit crew to be focused on what we would consider the "wrong" things after post-accident analysis. A pilot-rated passenger might be able to notice something that the very focused cockpit crew could miss.
I hope this helps answer your question!
Laura