Here is what U.S. airline taxes and fees are used for, according to the FAA:
DOMESTIC PASSENGER TICKET TAX
This goes into the government's Aviation Trust Fund, which finances FAA operations. Since 1997 this congressionally mandated tax has been reduced from 10 percent of the base fare (the ticket price before taxes) to 7.5 percent, where it is to remain until 2007, says FAA spokesman William Shumann.
DOMESTIC FLIGHT SEGMENT FEE
(This might be coded separately on your ticket as ZP or be listed as "federal excise tax" in airline advertisements.) This tax, first imposed in 1997, also goes into the Aviation Trust Fund. But instead of diminishing as the domestic passenger ticket tax, it has been increasing. At first it was $1 per "segment," or leg, of the flight. (A round trip with one stopover each way has four segments; a nonstop round trip has two segments.) By 2001 it had increased to $2.75 per segment, and on Jan. 1 it went to $3. From now on, increases are supposed to be linked to the Consumer Price Index, Shumann says.
PASSENGER FACILITY CHARGE, OR PFC
(This might be coded separately on your ticket as XF or be listed as "local airport charge" in airline ads.) This is imposed by U.S. airports, subject to approval by the FAA, and is collected on their behalf by airlines. The FAA regulates how the money can be used, generally for infrastructure such as safety improvements or noise reduction. The charge, first authorized in 1990, was capped at $3 per airport, generally assessed each time a passenger departs. In April the cap was increased to $4.50, and many airports wasted little time in reaching it. By the end of October more than 90 had been approved for $4.50, according to the Airports Council International. (Some don't begin charging that rate until this year.) Expect more $4.50 charges to be approved soon, thanks to the Sept. 11 attacks. The Aviation and Transportation Security Act passed by Congress in November calls on the FAA to expedite the airports' applications for the charge to pay for added security. You can find the per-airport PFC charge on your ticket, but it's not obvious. In the example above, it appears at the end of a long block of letters and numbers as XFLAX3 PHX3ABQ3PHX3. The XF is the code for the tax, followed by the airport (also in code, for example, LAX for Los Angeles International Airport, PHX for Phoenix, ABQ for Albuquerque) and the amount (in this case, $3 at each airport).
SECURITY SERVICE FEE
This new fee, part of November's Aviation and Transportation Security Act, will appear Feb. 1 on airline tickets, according to the DOT. The fee is $2.50 per segment, with a maximum of $5 allowed one way or $10 round trip. It goes to the newly created Transportation Security Administration within the Department of Transportation to finance airport security.