Definition
An additional collision that occurs after an initial impact, typically when occupants, unsecured objects, or aircraft components continue moving and strike the interior of the aircraft, the ground, or other surfaces following the first collision event.
Plain English
After a crash, things keep moving for an instant. The second hit — when a person slams into the panel, or loose gear flies forward into someone — is the secondary collision.
Context Anchor
Used in basic aviation safety discussions about crash survival, seat belts, shoulder harnesses, securing loose items, and emergency landing preparation.
Derivation
Secondary comes from Latin secundarius, meaning 'following' or 'second in order.' The term names the collision that follows the first one, not a less important one. The 'secondary' hit is often what actually injures or kills, even though the primary impact gets the attention.
Why Pilots Care
Recognizing the risk of secondary collisions helps pilots choose emergency landing sites that reduce the chance of additional impacts after the first touchdown.
Analogy
In a car crash, the car stops first, but your body still moves forward until the seat belt, airbag, or dashboard stops it. A secondary collision in an airplane works the same basic way.
Intuition Check
Do not assume “secondary collision” means a second accident with another aircraft. In this safety context, it usually means what people or objects inside the airplane hit after the airplane’s first impact.
Example Sentence 1
He cinched his shoulder harness tight before takeoff to reduce the risk of a secondary collision with the instrument panel if anything went wrong.
Example Sentence 2
Investigators determined the secondary collision with a fence line caused the fatal injuries after the initial gear-up landing.