An oil delivery system is provided that includes a tank for a gas turbine engine, where the tank is positioned radially outward from a compressor section, a combustor section, and/or a turbine section of the gas turbine engine. The tank is configured to store oil for the gas turbine engine. The oil delivery system further includes a primary lubrication system including a sump of a power gearbox, a pump, and an oil feed line. The oil feed line extends from the tank to the primary lubrication system. The oil feed line is configured to allow a flow of oil to pass from the tank to the pump and from the pump through the power gearbox to the sump of the power gearbox.