All maritime aircraft interacting with ships or with other maritime aircraft will benefit from having an airborne AIS transponder onboard. As AIS data transmissions (VHF) from maritime surface traffic and airborne AIS equipped aircraft are available broadcasted in the air, it can be utilized by maritime airborne operators.

Most frequent airborne AIS users include:

• Search and Rescue Aircraft (SAR)
• Maritime Patrol Aircraft (MPA)
• Offshore Helicopter Traffic

Airborne AIS has become an obligatory for well equipped SAR and MPA aircraft. A dedicated SAR message including altitude is implemented in the AIS standard. Silent Mode is an optional feature with receive/no transmit operation.

For offshore and other airborne maritime aircraft, AIS brings significant safety improvements and a number of useful applications. AIS is also a new tool for National coastal surveillance and security monitoring. In addition, the system is very useful and cost effective for fleet tracking and management.

Tomado de: http://www.avionetics.se/airborne_AIS.htm