Originally Posted by aerospacepilot

United has 50+ 777's, 30+ 747's, and 30+ 767's. All of them will need to be replaced one day, but certainly the 767's and 747's are up first on the replacement block.

United buys aircraft at the absolute bottom of the market (this is something management did right!) They get a favorable deal in terms of discount pricing, as well as financing and delivery timing terms, both of which are very important for UAL in the current environment. But as you can see from above, United is going to need more than 25+25 of these types of aircraft. So you take delivery of both. Then down the line, depending on what manufacturer has been the most favorable (in terms of pricing, offering better financing, being more flexible on delivery dates, etc..), you order the remainder from that supplier. I think United did a really good job getting the best leverage they could in the current market.

Someone somewhere has ran the cost/benefit analysis of operating a single fleet type (savings in maintenance, training, etc..) versus operating two types of aircraft (flexiblity in markets, revenue, and ability to negotiate favorable supplier terms). For United, I am sure the benefits of two aircraft outweighed just a sole replacement. Lets just hope their assumptions are correct!