The cost of building new airplane hangars and replacing part of a main runway figures into a proposed Des Moines International Airport budget that calls for a 15.5 percent increase in expenditures next year.

The Des Moines Airport Authority Board is expected to vote on the budget next month.

The proposed budget calls for increases in parking fees, rental rates for airlines, and landing fees. For example, long-term daily parking would rise to $14, up from $13. Economy parking would cost $7 a day, up from $6.

A $12 million capital improvements budget that includes replacement of the main runway, and the $3.7 million construction of T-shaped hangars as part of shuffling things for a proposed new terminal, led to a projected cash reserve of $3.8 million, down from the typical goal of $6 million to help cover the airport's share of the terminal construction. (This year's capital improvements budget was $7.4 million.)

Some airport board members questioned proposed rents for T-hangars at the airport, noting that they lose money. Some suggested the airport raise the rates more quickly, given that there is a waiting list for the facilities.

The new parking rates should help the airport take in $12.1 million, up from $11 million. Landing fees are projected at $8.7 million, up from $8.4 million. Facility rentals are projected at $6.8 million, up from $6.6 million. Concessions and other airfield revenues are expected to hold fairly steady at about $6.1 million.

Overall, cash basis income would rise to $41.2 million, from $38.5 million. Expenditures would be $37.4 million, up from $32.4 million.

The operating cost per passenger -- considered a key reflection of thriftiness -- would fall again, to $8.36, down from $8.47.