I’m starting a new series here on Frequently Flying analyzing award availability in markets where U.S. carriers compete with each other. This first installment looks at the Chicago O’Hare to London Heathrow nonstop market and I’ve researched availability from American Airlines and United Airlines in February 2012.

I specifically searched for award seats at the minimum amount of miles required, namely MileSAAver awards on American and Saver awards on United. Any available seat is open for premium redemptions requiring double the miles and is therefore outside the scope of my research. The data below was captured on Monday, December 26, 2011 using ExpertFlyer.

While slightly apples to oranges as American doesn’t offer First Class on every flight – only their single daily Boeing 777 offering – I was particularly interested in seeing how Business Class would compare, as I assume most people are keen on redeeming miles as a couple for a memorable trip in a premium cabin.

American offers two nonstop flights per day to London through February 8^th, then has an equivalent three nonstops daily as United has all month to Heathrow. First, here are total award seats available for the month of February:

I wasn’t surprised to see the differences in First Class award availability between American and United given the disparity of service. Coach seat availability was seen every day in both directions – except United had no seats ORD-LHR on February 18^th – and the numbers reflect the minimum amount of seats open for redemption. American shows a maximum of seven seats via Sabre and United nine seats via Apollo/Galileo, but more were likely open in economy.

On the Chicago to London segment, both carriers allocated a similar amount of seats to each cabin:

But on the return from London to Chicago, United was significantly more generous in each cabin:

Not everyone flies like I do – a single seat in a premium cabin – so I took interest into just how many flights offered at least two seats in Business Class. Both American and United have the same amount of days with zero Business seats available, but American wins out with the most days with at least two seats open for MileSAAver awards on the outbound:

That said, however, you’d have a very difficult time getting back on American. They currently only have two days in February where two seats are available for MileSAAver award space on the return vs. United’s nine flights:

Winner: United Airlines. With similarly configured airplanes and greater availability throughout the month, United offers far more options for award redemption on their nonstop flights. February isn’t a desirable month to visit London, so stay tuned for further posts in this series as I’ll also research peak travel periods.