2.2.3. Environmental Factors

MMEL development cannot be complete without the assessment of the varying environmental conditions in which aircraft would operate. Commercial aircraft operate between di fferent regions; thus, their availability must not be impacted by the environment since designing an aircraft for a particular region would not be cost-e ffective [23]. Therefore, designers must obtain adequate knowledge of the environment so that to design aircraft that can withstand varying environmental conditions [24] while observing various local and international environmental standards and regulations.

Furthermore, concerning MMEL development and justification, there must be measures to reduce environmental impact on aircraft dispatch, e.g., impact of rain and icing conditions. With provisions such as e ffective anti-ice and wiper systems, aircraft dispatch is not limited/restricted in these conditions. In addition, it is important to consider the aircraft's flight envelope to specify the aircraft's maximum and minimum altitudes quantitatively when systems or components underperform or are out of service and define dispatch conditions (i.e., GO–IF items) to facilitate aircraft operations.
