MagSafe Airline Adapter

The Apple MagSafe Airline Power Adapter, or simply MagSafe Airline Adapter, was released by Apple on October 24, 2006 to allow MacBooks with the original MagSafe port to draw power from or 20mm ports found on commercial airliners.

Functionality
The airline adapter would let a supported MacBook models to run without drawing battery power, but it would not charge the battery as a safety precaution for the aircraft.