Fly adverbs are provided in this article. The words listed here are commonly found along with the verb fly in sentences. This reference page helps answer the question what are some adverbs that describe or modify the verb FLY.
actually, commonly, directly, easily, fairly
freely, frequently, generally, gladly, hardly
immediately, instantly, literally, naturally, occasionally
possibly, precipitately, probably, quickly, rapidly
really, safely, simply, slowly, suddenly
surely, swiftly, usually
Hope this word list had the fly adverb you were looking for. In addition to adverbs used with fly, other example verb adverb pairings can be found on this site.
Eagerly