Low pressure environmental control system with safe pylon transit

Abstract

A gas turbine engine includes a fan section delivering air into a compressor section. The compressor section compresses air and delivers air into a combustion section. Products of combustion pass from the combustion section over a turbine section to drive the fan section and main compressor sections. A gearbox is driven by the turbine section to drive the fan section. An environmental control system includes a higher pressure tap at a higher pressure location in the compressor section, and a lower pressure tap at a lower pressure location. The lower pressure location being at a lower pressure than the higher pressure location. The lower pressure tap communicates to a first passage leading to a downstream outlet, and having a second passage leading into a compressor section of a turbocompressor. The higher pressure tap leads into a turbine section of the turbocompressor such that air in the higher pressure tap drives the turbine section to in turn drive the compressor section of the turbocompressor. A combined outlet of the compressor section and the turbine section of the turbocompressor intermixes and passes downstream to be delivered to an aircraft use. A pylon supports the engine. The pylon defines a lowermost surface and the higher pressure tap extends above a plane including the lowermost surface. The higher pressure tap includes a double wall tube above the plane for preventing leakage from impinging on a portion of the pylon. An environmental control system is also disclosed.

Dependencies are inferred from the claim text.