1-6 and 1-7).
You find the precooler located in the left sponson area between the
the bleed air flow and between the air cycle machine fan and the
overboard exhaust in the cooling air flow.
The design of the
precooler makes it a single pass cross-flow, plate-fin unit,
constructed of high temperature alloys.
Manufacturers use nickel alloy fins for both the hot and cold
passages and stainless steel for the remainder of the precooler. The
core of the unit has an air flow length of 10 inches for bleed air
and 7.5 inches for the cooling air.