Within a turbine engine a heat exchanger may be provided to cool compressor air flows to be utilized for cabin ventilation or other functions. The transfer cylinder has an intake valve and two transfer valves alternately feeding the two power cylinders. The spiral rod haven defines an interior compartment when in its extended position. Some memory and computation are still required, but these are dramatically reduced, compared to systems that do not exploit this method. A versioning schema enforced by the application development environment enables the runtime environment of a terminal device to evaluate a software update to identify potential compatibility issues and control installation of the update. The cavity guides fuel spray which has been injected by an injector and passed by an electrode part of a spark plug, to arrive near the electrode part of the spark plug again in the form of an air-fuel mixture.