Compartment cooling for a gas turbine engine

A gas turbine engine includes a first pump (86) driven by a spool (30), an air-oil cooler (88) downstream of the first pump (86), a second pump (90) driven by the spool (30) and an air-air precooler (92) downstream of the second pump (90). The air-air precooler (92) is downstream of the air-oil cooler (88). A compartment is downstream of the precooler (92) to receive a cooling air from the precooler (92).