Definition
Bumps, ruts, holes, soft spots, rocks, tall grass, or other uneven features on the runway or takeoff surface that disturb the airplane's smooth ground roll and can damage the airplane, increase rolling resistance, or upset directional control.
Plain English
Anything on the takeoff surface that isn't smooth and flat — bumps, dips, soft patches, debris, or tall grass that the wheels have to roll over or through.
Context Anchor
Used during soft-field and rough-field takeoff discussions, especially while the airplane is accelerating on an unpaved, grass, gravel, or damaged surface.
Derivation
Irregular comes from a Latin idea meaning “not according to rule” or “not even.” In this aviation use, the surface is not smooth and uniform, so the airplane may not roll over it evenly.
Why Pilots Care
They can cause loss of directional control, propeller strikes, or landing-gear damage if the pilot does not maintain proper pitch attitude and airspeed during the takeoff roll.
Grounding Statement
Picture the airplane rolling across a bumpy grass strip where the wheels hit small dips and raised spots instead of a smooth paved runway.
Intuition Check
Do not think of surface irregularities as just cosmetic roughness. In this context, they are uneven ground features that can affect control, acceleration, and the airplane’s structure.
Example Sentence 1
Before departing the grass strip, the pilot walked the runway to check for surface irregularities such as gopher holes and soft patches.
Example Sentence 2
Before the soft-field takeoff, the instructor briefed the student on the surface irregularities visible along the first third of the runway.