Definition
The range of altitudes within which a pressurized aircraft maintains a constant pressure difference between the cabin interior and the outside atmosphere. Once the aircraft climbs high enough that the pressurization system reaches its maximum allowable differential pressure, the system holds that difference constant. From that altitude upward, the cabin altitude rises with the aircraft rather than staying fixed, because the structure cannot safely withstand a larger pressure difference.
Plain English
The band of altitudes where the cabin keeps a steady pressure gap between inside and outside air. Below this band the system is still building up the gap; above it, the aircraft can't increase the gap any further without overstressing the fuselage, so the cabin slowly climbs with the airplane.
Context Anchor
Seen in aircraft operating manuals, pressurization system descriptions, and limitation discussions for pressurized aircraft.
Derivation
Differential simply means 'the difference between two things' — here, the difference between cabin pressure and outside pressure. Range refers to the span of altitudes over which this difference stays at its designed maximum.
Why Pilots Care
Staying inside the certified range protects the fuselage structure from overstress while keeping cabin altitude comfortable and safe for passengers and crew.
Grounding Statement
As the aircraft climbs, outside air pressure drops, so the pressurization system must control how much higher the cabin pressure is than the air outside.
Intuition Check
Range does not mean flying distance here. It means the allowed span between the lower and upper pressure-difference limits.
Example Sentence 1
Within the aircraft's differential-pressure range, the cabin altitude held steady at 6,500 feet even as the aircraft climbed from 25,000 to 35,000 feet.
Example Sentence 2
Before flight the crew verifies that the aircraft's differential-pressure range of aircraft cabin pressurization has not been exceeded on previous legs.