Learn Italian: Il miliardario userebbe il suo elicottero. - The billionaire would use his helicopter.

Userebbe is the third-person singular present conditional form of the regular verb usare (to use). For regular -are verbs, you change the -are ending to -er- to make the stem (giving us user-), and then add the conditional ending -ebbe.

Why do we say il suo instead of just suo?

In Italian, possessive words like suo (his/her) almost always need a definite article in front of them. While in English we just say "his helicopter", Italian literally says "the his helicopter" (il suo elicottero). The main exception is with singular close family members, but objects like a helicopter always require the article.

If it were a female billionaire (la miliardaria), would we change il suo to la sua?

No, it would still be il suo elicottero! In Italian, possessives always match the gender and number of the thing being owned, not the owner. Because elicottero is a masculine singular noun, it requires il suo regardless of whether the owner is a man or a woman.

Why isn't there an "h" at the beginning of elicottero?

Unlike the English word "helicopter", the Italian word elicottero doesn't start with an "h". Even if it did, it wouldn't change the pronunciation, because the letter "h" is always silent at the beginning of Italian words.