It really depends. If you fly straight down to the equator, it would take 2-3 hours. However, if you decided to fly to the equator on the other side of the world, that might take just a little...
A random search for flights from New York Kennedy (JFK) to Bahrain (BAH) shows:
12hr 30min via Kuwait (KWI) by Kuwait Airways.
14hr 55min via London Heathrow (LHR) by British Airways.
15hr 55min...