Flight Time Calculation: Washington DC to London

Using the basic distance-speed-time formula:

Time = Distance ÷ Speed

• Distance: 4,800 miles (approximate great-circle distance)
• Speed: 600 mph (typical airliner cruise)

Calculation: 4,800 ÷ 600 = 8 hours

Real-World Context

• Actual flight time: 7–8.5 hours eastbound (tailwinds), 8–9.5 hours westbound (headwinds)
• Great-circle distance: ~3,670 miles (5,900 km) — the 4,800 figure appears inflated
• Typical airliners: B777, B787, A350, A380 cruise at 560–600 mph (Mach 0.85)
• Total travel time: Add 3+ hours for airport processes, security, boarding, taxiing

Note: The 4,800-mile figure likely includes routing deviations or represents an older/slower aircraft scenario. Modern nonstop flights (IAD/DCA → LHR/LGW) average 7-8 hours airborne.