1.1.1.2 Downlink Message Delivery-Operational Scenarios
The various airline contractual situations described above,give rise to a number of operational scenarios.Again it is stressed that the term,“Contracted Service Provider”refers to the Service Provider contractcd by the CAA for FANS-1/A datalink service.
1.1.1.2.1 Scenario-1:Downlink Delivery via the Contracted Service Provider
This will apply under the following conditions:
1. If VHF is available and the aircraft successfully delivers the message via VHF.
2. If VHF is available and the first attempt to deliver a message via VHF was unseccessful and the aircraft is contracted with the service provider for satellite service.
3. VHF is not available and the aircraft is contracted with the service provider for Satellite service.
1.1.1.2.2 Scenario-2:First delivery attempt via the Contracted Service Provider and the second attempt via the alternate Service Provider.
This will apply under the following conditions:
1.If VHF is available and the first attempt at delivery failed and the aircraft is a satellite customer of another service provider.
1.1.1.2.3 Scenario-3:Delivery via the alternate Service Provider.
This will apply under the following conditions:
1. If VHF is available via the altrenate service provider and delivery is successful.
2. If VHF is available via the alternate service provider and the aircraft is logged-on to the alternate service provider's satellite service.The second delivery attempt will be made via the satellite scrvice of the altrenate service provider.
3. If VHF is unavailable and the aircraft is logged-on to the satellite service of the alternate service provider.
1.1.1.2.4 Scenario-4:First delivery attemlpt via another Service Provider and the second attempt via the contracted Service Provider.
This will apply under the following conditions:
1. If VHF is avalable via another service provider and the first attempt at delivery is unsuccssful and the aircraft is logged-on to the satellite service of the contracted service provider.
