The list has 12, and includes the questionable 9/11 FDR losses. There is testimony by Mike Balone, that they really were found at the WTCs.
http://www.youtube.com/watch?v=JqewYask17o
Even 12 is a small number out of the hundreds of airline crashes.
http://www.planecrashinfo.com
My statement still stands:
Dale Leppard, Air Crash Investigator for 48 years, said "never once" had he heard of a crash where the black boxes were not found.
http://www.youtube.com/watch?v=JqewYask17o 3:45 minutes in
I found Dale Leppard on the web and emailed him this link.
Still it is suspicious that on the same day so many black boxes were not found. Even more suspicious, or should be to critical thinkers, is that none of the data from the WTC FDRs have been made public.