What is the maximum duration for which emergency engine fuels can be used?

The maximum duration for which emergency engine fuels, such as Jet A or Jet A-1, can be used in the King Air 350 is specified as 150 hours. This limitation is crucial because it ensures the safe operation of the aircraft by preventing the use of fuel that may not meet the standards for longer intervals, potentially impacting engine performance or reliability. Each fuel type has specific characteristics, and emergency fuels may not contain the same additives or quality as the primary fuels, which can lead to issues over extended use. Ensuring adherence to this limit is part of standard operational procedures for maintaining safety and efficiency in flight operations.