Member of IDF on a 9/11 aircraft. Which one and what was his name?

I have heard that there was a member of the IDF on board one of the doomed flights. Is this true and what was his name? Is there any evidence to support that he tried to fight off the hijackers

Do you mean the Israeli Defense Forces?

Danny Lewin was his name and he was on American Flight 11

http://en.wikipedia.org/wiki/Daniel_M._Lewin
Says the 9-11 commission
http://govinfo.library.unt.edu/911/report/911Report_Ch1.htm
QUOTE
*
We do not know exactly how the hijackers gained access to the cockpit; FAA rules required that the doors remain closed and locked during flight. Ong speculated that they had “jammed their way” in. Perhaps the terrorists stabbed the flight attendants to get a cockpit key, to force one of them to open the cockpit door, or to lure the captain or first officer out of the cockpit. Or the flight attendants may just have been in their way.26

At the same time or shortly thereafter, Atta-the only terrorist on board trained to fly a jet-would have moved to the cockpit from his business-class seat, possibly accompanied by Omari. As this was happening, passenger Daniel Lewin, who was seated in the row just behind Atta and Omari, was stabbed by one of the hijackers-probably Satam al Suqami, who was seated directly behind Lewin. Lewin had served four years as an officer in the Israeli military. He may have made an attempt to stop the hijackers in front of him, not realizing that another was sitting behind him.27 *

Prior to 9/11, were members of the Israeli armed forces given different advice to that given to the US armed forces regarding hostage situations that occur when they are off-duty ? That is, to keep a low profile and avoid doing anything that could identify you as a member of the military, and hence a target. I would imagine they would have similar instructions, given how much more of a target an Israeli serviceman would make.

Not really. I mean, an Israeli service member is no more of a target than any other Israeli, so the standing orders - more of a standing understanding, actually - are to prevent anyone being taken hostage, at all costs. And I mean at ALL costs.

Military service is mandatory in Israel, so if you think about it, this isn’t remarkable at all. It’s reasonable to assume he completed his service before coming to the U.S. in 1995, so he probably hadn’t been an actual member of the IDF in something like six years.

And the most notable thing about Lewin at the end of his life was not that he was formerly a member of the IDF, but that he had a PhD from MIT and was co-founder and CTO of Akamai Technologies, a pretty big-hitter company in the commercial Internet.