Philadelphia's airports just received a major influx of capital for infrastructure improvements.

The 15 airlines that service Philadelphia International Airport, led by American Airlines, have collectively invested $900M for a combination of maintenance, repairs, modernization and a new air traffic control tower. About $26M of the funds are earmarked for Philadelphia Northeast Airport, with the rest for Philadelphia International, the Philadelphia Business Journal reports.

The new control tower will reportedly make up $197.5M of the $894M investment, the second-biggest slice of the funds, behind maintenance and repair. Other projects to be funded by the entirely private investment are an expansion of the fuel farm, a revamping of the concessions area and $27.1M for land acquisitions.

All improvements to be paid by the funds are expected to be completed within five to seven years, and spokespeople from American Airlines and Philadelphia International expect the renovations to bring in $4B of revenue for the region over that period.