Definition
In a helicopter, the control that simultaneously changes the pitch angle of all main rotor blades by the same amount, increasing or decreasing the total lift produced by the rotor system. It is operated by a lever to the left of the pilot's seat, raised or lowered to control vertical movement.
Plain English
The lever a helicopter pilot pulls up or pushes down to make the helicopter climb or descend. Pulling it up tilts every rotor blade more steeply at the same time, so the rotor produces more lift; pushing it down does the opposite.
Context Anchor
You will see this term in helicopter instrument flying, especially when discussing power control, altitude control, and straight-and-level flight.
Derivation
Collective means 'taken together as a group.' The name reflects what the control does -- it changes the pitch of all the blades collectively, at the same time and by the same amount. This contrasts with the cyclic control, which changes blade pitch individually as each blade cycles around.
Why Pilots Care
Directly governs vertical speed, power, and altitude control in helicopters during instrument flight.
Analogy
It is like tilting all the slats of a window blind at once. Each slat changes angle together, so the whole blind changes how much air or light can pass through.
Intuition Check
Collective does not mean a group decision or a general category here; it means the same blade-angle change is made to all main rotor blades together. Pitch does not mean aircraft nose attitude here; it means the angle of the rotor blades.
Example Sentence 1
The pilot raised the collective slightly to begin a gentle climb away from the landing zone.
Example Sentence 2
Reducing collective pitch allowed a controlled descent without changing the helicopter's attitude.