Help needed with English grammar ... gad but my mother tongue is confusing!  

I'm no grammar expert (which is sad because I'm an English major), but I do believe you have it correct here. "it is headed" should be correct because the 'it' is taking the place of the noun 'generation', am I right? You're saying that the new generation of RC helicopters is headed by that one helicopter? So, I believe it is correct.

However, I do hope that someone who is a bit more knowledgeable in the area of grammar can help you. It's always been my weak spot.

I agree that you have it right. It refers to generation and "is" is the proper form for that.

What I would do is substitute "it" with what "it" refers to. So the second part of the sentence would read "and the technology is headed by...". Any confusion is thus avoided. Or you could write "and the helicopters are headed by..." Both versions are grammatically correct, and the reader does not have to track back to the beginning of the sentence to figure out what "it" or "they" refers to.

I would use the singular, "it is", as it pertains to one design, not a number of designs. That's the way I was taught, anyhow. It's one design of one helicopter, rather than a whole group, if you get my drift.

Good luck with your review, Sue. I know you can make it. Brightest Blessings, my friend.

The top poster is correct-- You want to say 'it is'. Don't worry; many many many people have English as a first language mess this up and don't even care. Generation is in fact what the word 'it' is replacing, and the words 'of RC Electric Helicopters' only modify the word 'generation'. Think of it like saying 'A group of dogs'-- even though 'dogs' is plural, you start the whole phrase with the word 'a' because 'group' is singular, so it would be 'A group of dogs is...' In almost any case, if you start the phrase with the word 'a', then you will use 'is'.