Aviation Week and Boyd have reported that the 747-400's are being parked as they come due for C and D checks. United apparently is too cash strapped to use their liquidity to keep them airworthy. What a shame.
From aviationplanning.com
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Aircraft Lessors:
A lot of financial institutions will find their aircraft collateral sinking faster than McCain doing one-liners on Saturday Night Live. United is already parking 747-400s as they come up for D-checks. Maybe a dozen are in the desert already, or on their way. In this environment, it's not very likely that all of these out-of-time behemoths will be picked up by other airlines. United isn't likely to pony up the cash to get them into heavy maintenance, either. The result is that the next time the public sees some of these planes, it will be in a Budweiser display at their local supermarket. The point is that these aircraft are ending their careers years early and their projected residual values are dropping into the tank. Big hits for the financial institutions and lessors who are holding the paper on these machines. Some may be wounded lethally. Outcome: when the industry begins to recover, the cost of financing new aircraft will be much higher, if they can find anybody wanting to take the risk.