In addition to providing thrust for flight, the engines also provided bleed air for the pressurization, ice protection, and air conditioning systems. The aircraft's DC electrical generators were also driven by the engines. Napier Spraymat electric heaters were installed in the engine inlets to prevent engine damage due to ice. The shape of the engine inlets were long rectangular slots in the first prototype, whereas production Valiants had oval or "spectacle" shaped inlets designed to pass greater airflow for the more powerful engines that were installed. The jet exhausts emerged from fairings above the trailing edge of the wings.