I am not familiar with the technological aspects of this but let me just ask this question.
Would technology be an issue if we did this EXACT same deal with Russia.
As they say, “good question”
I can only say that before anything such as this is agreed to, the technology that will be transferred is analyzed by the developers and what will be transferred will be documented and reviewed by the state department. So it is not done without concern.
Would we have a different level of concern before transferring technology to Russia? Clearly, and we would allow transfer to Israel at a different level than the Saudis? Absolutely. One of the things about some technology is that it is so constructed as to be almost impossible to reverse engineer. (Like taking apart a computer chip and discovering how it is programmed.)
As to a helicopter, there are probably instances where our technology has already fallen into the Saudi’s (or our other enemy’s ) hands and therefore there is no concern that we are giving them something they don’t already have.