Under what conditions does auto ignition occur in the Tradewind aircraft?

The occurrence of auto ignition in the Tradewind aircraft is specifically linked to certain thresholds of Interstage Turbine Temperature (ITT) and N1 or NG (Gas Generator Speed). The correct answer states that auto ignition occurs when the ITT is less than 500 degrees Celsius and NG is more than 10%.

This condition reflects the operational parameters that ensure the engine can initiate combustion without the need for an external ignition source. A lower ITT combined with a sufficiently high NG suggests that the engine is capable of producing enough airflow and compression to facilitate the ignition of the fuel-air mixture effectively.

Other options present conditions that fall outside the operational safety margin for auto ignition. For instance, higher ITT values or lower NG percentages would indicate that the engine may not be operating efficiently or within safe parameters for auto ignition to reliably occur. Therefore, understanding these parameters is crucial for safe aircraft operation and maintenance.