Turbine engines installed in rotocraft have an exhaust system that is designed and produced by the aircraft manufacturer. The primary function of the exhaust The exhaust system may consist of a tallpipe, which is attached to the engine, and an exhaust fairing, which is part of the rotorcraft. The engine manufacturer specifies a baseline "referee" tallpipe design, and guarantee engine performance is based upon the use of the referee tallpipe and tallpipe exit diameter. The configuration used on the rotocraft may differ from the referee tallpipe, but it is intended to minimize additional losses attributed to the installation.