The FAA and its tower operations are funded by fuel taxes. This way the more you fly the more you contribute to the mantaince of the system.
Charging for each service rendered is a idea that will either kill pilots or general aviation.
If you charge for filing a flight plane then there will be a number of pilots (Me Included) who rather then filing a flight plan with flight service will plan out a flight and then leave the plan with a friend who if you don't get back in time would then call in for help locating you. A lot of people I know who fly into hunt do this because it isn't unusual for a trip to take a couple hours or days longer then usual and flight plans work strictly with the clock. You of course are going to have more guys who arn't even going to leave a plan with anybody at all. Either way not as many people are going to be filing so either the FAA with have to raise the price (in effect forcing more people not to file) or you are going to have to make it mandatory.
Ditto for IFR clearences. If you charge for them you will have more people flying MVFR, Which can be done safely but not by somebody who doesn't do in regularly or not flying at all in. Either way they are going to be taking the cheeper way and you are going to increase the accident rate.
Don't belive all of this stuff that is coming out of captial hill about how the airways system is on the verg of colapse. With the current fuel taxes that are in place the trust fund the access money goes into is worth right now 8.1 billion. At least that is the number I got this off ABCnews the other night. Airlines want to lower their fuel taxes so they are pushing this idea that general avaition is getting their services for free. But if you think about it a general avation pilot is paying his fuel taxes entirely out of his pocket, a airline is splitting the cost of it's taxes amoung the twenty,hundred or four hundred people in the back of the airplane. With the current system everybody who flies is paying their share.
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.