From the West End, take the Piccadilly line; estimate around 50 minutes to Terminal 5
https://andyhiic885.tearosediner.net/london-to-heathrow-transport-best-route-by-time-of-day-and-budget-1
From the West End, take the Piccadilly line; estimate around 50 minutes to Terminal 5, and consider traveling off-peak for a more comfortable journey.