Translation:The plane is taking off soon!
She'll soon be here./She'll be here soon. https://dictionary.cambridge.org/dictionary/english/soon
要 in this context is part of the 快要…了 construction meaning "…will happen soon." It means "will," not "need"/"have to."
However, I suppose we need a native speaker to tell us whether your translation is technically also correct, even though that's not what this sentence usually means.