I was just thinking the same thing. If there is a way to undetectably bring down a single plane, why not hold back on claiming credit until you can do it to 10 or 12 (US- & Israeli-flagged) planes simultaneously. Mid-atlantic location perfect for disposing of the evidence of your trial run...
Minister says cannot rule out terrorism in Air France plane crash
www.chinaview.cn 2009-06-06 00:46:57 P
PARIS, June 5 (Xinhua) — French Defence Minister Herve Morin said Friday that the possibility of a terrorist attack on Air France Flight 447 cannot be ruled out.
“We have no right to exclude terrorism,” he told journalists, but adding that he had not heard of any threats to the flight or of any group or individual claiming responsibility for bringing down the aircraft.
http://news.xinhuanet.com/english/2009-06/06/content_11496193.htm
There are any number of reasons for not claiming a successful attack right away. People sitting around waiting for terrorists to follow some non-existent playbook to the letter are in for a rude awakening.