What is the maximum allowable differential pressure at touchdown during initial landing?

The maximum allowable differential pressure at touchdown during initial landing is crucial for ensuring that the aircraft's structure and systems remain intact and function within safe limits. The correct answer of 1.0 PSI refers to the allowable differential pressure that should not be exceeded when the aircraft is in the landing phase, particularly during the initial touchdown.

During landing, the pressure differential between the interior and exterior of the aircraft can affect the operation of doors and hatches, particularly the passenger and cargo doors. If this pressure differential exceeds the specified limit, it could prevent these doors from operating properly, potentially leading to structural stress or other safety issues. Therefore, maintaining a differential pressure of no more than 1.0 PSI at touchdown is essential for ensuring a safe landing procedure and is reflective of the designed operational limits established for the CRJ 900.

In contrast, other choices provided are either too low or unrealistically high for a safe aircraft operation. A differential pressure of -0.5 PSI or 0.1 PSI is within lower limits that do not align with operational needs during landing. The choice of 25,000 PSI is not applicable as it far exceeds any realistic or operational parameters for aircraft structural integrity and is not a feasible value for differential pressure in any aviation context