'Alpha, Bravo, Charlie' exists because 'B' and 'D' sound nearly identical over static

Radio letters like B, D, and P are easily confused over noisy connections, so after years of competing military and airline systems, the International Civil Aviation Organization standardized the NATO phonetic alphabet in 1956. Each word was tested across languages and accents specifically for how well it survived poor audio.

— International Civil Aviation Organization, NATO phonetic alphabet — Standardized 1956