United Airlines' top international routes by seat availability from Washington

Other noteworthy international routes under 10,000 seats that United operates from IAD include:

- IAD-AMS: 317 operations with a total of 7,533 seats.

- IAD-ATH: Identical to AMS with respect to operations and seats.

- IAD-HND: Also has 318 operations but offers slightly more seats at 8,556.

On the competitive landscape for the IAD-ATH route:

KLM operates non-stop using Airbus A330s with a flight duration of approximately seven hours and thirty minutes. Air Canada offers flights via Toronto using various aircraft including Bombardier Regional Jets and Boeing models with a flight duration of around twelve hours and thirty minutes. Lufthansa flies via Munich using Airbus A380s among other models taking roughly ten hours and forty minutes.

For routes between Washington Dulles International Airport (IAD) with seat availability ranging between 10,000 to 15,000:

United will offer over ten thousand seats across multiple routes such as:

- IAD-BRU: With Brussels Airlines as its competitor.

- IAD-CUN: No competitors offering non-stop flights but Delta Air Lines and American Airlines provide one-stop options.

The airline also provides significant capacity on routes like:

- IAD-CDG: Competing against ITA Airways which uses Airbus A330s while United deploys Boeing models.

In terms of routes exceeding fifteen thousand seats:

The most notable include:

-IAD-LHR: With British Airways operating both Boeing and Airbus aircraft alongside Virgin Atlantic.

-IAD-FRA: Offering nearly twenty thousand seats primarily competing against Lufthansa's Airbus A340 series.

Overall, these figures underscore United Airlines' extensive international reach from Washington Dulles International Airport across various high-demand destinations globally.