United Airlines yesterday released their annual 10-K report as required by the U.S. Securities and Exchange Commission – a light 238 pages of company history, industry information, financial statements and more. I geek out reading through these and will take some time to do so as there are often noteworthy nuggets of information not released elsewhere.

While I do that, I thought I’d share the carrier’s operating fleet as it existed on December 31, 2011, which includes Continental and United aircraft, as well as those operated by regional carriers on behalf of UACO (listed as “Capacity Purchase†below).

In addition to the aircraft appearing above, United and Continental own or lease the following aircraft, which are either parked or subleased:

• Five owned 747-400s, including one to be inducted into charter service;
• One leased 767-200, which is being subleased to another airline;
• Three Airbus A330s, which are subleased to another airline (this was news to me);
• Two leased 757-200s, which have been returned to the lessor;
• 16 737-300s, of which four are owned and 12 are leased;
• 18 owned 737-500s; and
• 30 leased ERJ-135s, five of which are leased to another airline.

It’s fun for me to study these tables and add a few items of trivia to my United knowledge. Next week, I’ll be flying on the carrier’s second youngest fleet type – a Boeing 757-300 with an average age of 6.6 years. I hope you find something interesting for yourself.