Professor AK Dewdney told Barrie Zwicker that he had immediate doubts about 9/11:
Subsequently Dewdney has become best known amongst 9/11 researchers for his study claiming to show that ordinary cellphones are most unlikely to be able to make calls above 8,000 feet, and so implying that the 9/11 calls cannot have been made as described. His work is significantly flawed, however. Read more in our pages on "AK Dewdney and Project Achilles", Mobiles at altitude and a discussion on the supposed means of faking the calls.
Dewdney is also known as the founder of the Scientific Panel Investigating Nine-Eleven (SPINE). The SPINE web site hosts various 9/11 articles and can be found at physics911.net.