1. A combined bleed air and hot section component cooling air system for a gas
turbine engine, the combined bleed air and hot section component cooling air
system comprising:
a high-pressure bleed air line configured to receive high-pressure bleed air from a high-pressure stage of a compressor;
a first precooler operatively connected to the high-pressure bleed air line to receive at least some of the high-pressure bleed air, transfer heat from the high-pressure bleed air to ambient air, and discharge cooled high-pressure bleed air;
a high-pressure discharge line operatively connected to the first precooler to receive the cooled high-pressure bleed air;
a first pressure regulator in the high-pressure discharge line, the first pressure regulator being configured to receive at least some of the cooled high-pressure bleed air and discharge pressure-regulated cooled bleed air;
a pneumatic systems supply line operatively connected to the high-pressure discharge line downstream of the first pressure regulator to receive the pressure-regulated cooled bleed air; and
a hot section component cooling air line operatively connected to the high-pressure discharge line upstream of the first pressure regulator and configured to convey at least some of the cooled high-pressure bleed air to a hot section component for use as hot section component cooling air.
2. The combined bleed air and hot section component cooling air system of
claim 1, further comprising
an intermediate-pressure bleed air line configured to receive intermediate-pressure bleed air from an intermediate stage of the compressor and supply the intermediate-pressure bleed air to the first precooler, the first precooler being configured to receive the intermediate-pressure bleed air, transfer heat from the intermediate-pressure bleed air to ambient air, and discharge cooled intermediate-pressure bleed air;

an intermediate-pressure discharge line operatively connected to the first precooler to receive the cooled intermediate-pressure bleed air;
a second pressure regulator in the intermediate-pressure discharge line, the second pressure regulator being configured to receive at least some of the cooled intermediate-pressure bleed air and discharge pressure-regulated cooled bleed air to the pneumatic systems supply line.
3. The combined bleed air and hot section component cooling air system of claim 2, wherein the first precooler comprises a first compartment for cooling the high-pressure bleed air and a second compartment for cooling the intermediate-pressure bleed air.
4. The combined bleed air and hot section component cooling air system of claim 1, further comprising
an intermediate-pressure bleed air line configured to receive intermediate-pressure bleed air from an intermediate stage of the compressor and supply the intermediate-pressure bleed air to the first precooler, the first precooler being configured to receive the intermediate-pressure bleed air, transfer heat from the intermediate-pressure bleed air to ambient air, and discharge cooled intermediate-pressure bleed air; and
an intermediate-pressure discharge line operatively connected to the first precooler to supply the cooled intermediate-pressure bleed air to the first pressure regulator;
where the first pressure regulator is configured to receive at least some of the cooled intermediate-pressure bleed air and discharge pressure-regulated cooled bleed air.
5. The combined bleed air and hot section component cooling air system of
claim 4, wherein the first precooler includes a first compartment for cooling the
high-pressure bleed air and a second compartment for cooling the intermediate-
pressure bleed air.

6. The combined bleed air and hot section component cooling air system of
claim 1, further comprising
an intermediate-pressure bleed air line configured to receive intermediate-pressure bleed air from an intermediate stage of the compressor;
a second precooler operatively connected to the intermediate-pressure bleed air line to receive the intermediate-pressure bleed air, transfer heat from the intermediate-pressure bleed air to ambient air, and discharge cooled intermediate-pressure bleed air;
an intermediate-pressure discharge line operatively connected to the second precooler to receive the cooled intermediate-pressure bleed air;
a second pressure regulator in the intermediate-pressure discharge line, the second pressure regulator being configured to receive at least some of the cooled intermediate-pressure bleed air and discharge pressure-regulated cooled bleed air to the pneumatic systems supply line.
7. The combined bleed air and hot section component cooling air system of claim 6, wherein the first precooler and the second precooler are disposed approximate one another to comprise a two-compartment precooler.
8. The combined bleed air and hot section component cooling air system of claim 1, further comprising a bypass line operatively connecting the high-pressure bleed air line and the hot section component cooling air line to supply at least some of the high-pressure bleed air from the compressor to the hot section component without cooling in the first precooler, the bypass line including a bypass line valve configured to selectively allow or prevent flow.
9. A combined bleed air and hot section component cooling air system for a gas turbine engine, the combined bleed air and hot section component cooling air system comprising:
a high-pressure bleed air line configured to receive high-pressure bleed air from a high-pressure stage of a compressor;

a first precooler operatively connected to the high-pressure bleed air line, the first precooler being configured to receive at least some of the high-pressure bleed air, transfer heat from the high-pressure bleed air to ambient air, and discharge cooled high-pressure bleed air;
a high-pressure discharge line operatively connected to the first precooler to receive the cooled high-pressure bleed air;
an intermediate-pressure bleed air line configured to receive intermediate-pressure bleed air from an intermediate stage of the compressor;
a second precooler operatively connected to the intermediate-pressure bleed air line, the second precooler being configured to receive the intermediate-pressure bleed air, transfer heat from the intermediate-pressure bleed air to the ambient air, and discharge cooled intermediate-pressure bleed air;
an intermediate-pressure discharge line operatively connected to the second precooler to receive the cooled intermediate-pressure bleed air;
a first pressure regulator operatively connected to at least one of the high-pressure discharge line and the intermediate-pressure discharge line, the first pressure regulator being operative to discharge pressure-regulated cooled bleed air;
a pneumatic systems supply line operatively connected to the first pressure regulator to receive the pressure-regulated cooled bleed air; and
a hot section component cooling air line operatively connected to the high-pressure discharge line upstream of the pressure regulator and configured to convey at least some of the cooled high-pressure bleed air to a hot section component for use as hot section component cooling air.
10. The combined bleed air and hot section component cooling air system of claim 9,
wherein the first pressure regulator is in the high-pressure discharge line and is configured to receive at least some of the cooled high-pressure bleed air; and

further including a second pressure regulator in the intermediate-pressure discharge line, the second pressure regulator being configured to receive at least some of the cooled intermediate-pressure bleed air and discharge pressure-regulated cooled bleed air to the pneumatic systems supply line.
11. The combined bleed air and hot section component cooling air system of claim 10, wherein the first pressure regulator is operatively connected to both the high-pressure discharge line and the intermediate-pressure discharge line via a precooler discharge header.
12. The combined bleed air and hot section component cooling air system of claim 9, further comprising a bypass line operatively connecting the high-pressure bleed air line and the hot section component cooling air line to supply at least some of the high-pressure bleed air from the compressor to the hot section component without cooling in the precooler, the bypass line including a bypass line valve configured to selectively allow or prevent flow.
13. A method of operating a combined bleed air and hot section component cooling air system associated with a gas turbine engine, the method including:
withdrawing high-pressure air from a high-pressure stage of a compressor of a gas turbine engine via a high-pressure bleed air line;
cooling at least a first portion of the high-pressure air using a precooler operatively connected to the high-pressure bleed air line to provide cooled high-pressure air via a high-pressure discharge line;
supplying a first portion of the cooled high-pressure air to a hot section component of the gas turbine engine for use as hot section component cooling air via a hot section component cooling air line operatively connected to the high-pressure discharge line;
supplying a second portion of the cooled high-pressure air to a pressure regulator via the high-pressure discharge line, the pressure regulator providing pressure-regulated cooled air to a pneumatic systems supply line; and

supplying the pressure-regulated cooled air to at least one pneumatic system via the pneumatic systems supply line.
14. The method of claim 13, further including supplying a second portion of the high-pressure air to the hot section component for use as hot section component cooling air via a bypass line such that the second portion of the high-pressure air does not flow through the precooler.
15. The method of claim 13, wherein supplying the pressure-regulated cooled air to the at least one pneumatic system comprises supplying the pressure-regulated cooled air to at least one of an environmental control system, an engine starting system, and an anti-icing system.
16. The method of claim 13, wherein cooling the first portion of the high-pressure air using the precooler includes transferring heat from the high-pressure air to ambient air flowing through the precooler.
17. The method of claim 13, further comprising
withdrawing intermediate-pressure air from an intermediate-pressure stage of the compressor;
cooling the intermediate-pressure air using the precooler to provide cooled intermediate-pressure air; and
supplying the cooled intermediate-pressure air to the pressure regulator.
18. The method of claim 13, further comprising
withdrawing intermediate-pressure air from an intermediate-pressure stage of the compressor;
cooling the intermediate-pressure air using the precooler to provide cooled intermediate-pressure air; and
supplying the cooled intermediate-pressure air to a second pressure regulator, the second pressure regulator providing pressure-regulated cooled air to the pneumatic systems supply line.

19. The method of claim 18, wherein the precooler comprises a two-compartment precooler having a first compartment associated with high-pressure air and a second compartment associated with intermediate-pressure air.