VDL Mode 4 jury still out, I believe. Would be good to know the reliability and timeliness of this feature in the real world.
UA FANS equipage was, I hear, a bust.
There is some testing going on in Miami area, not sure if it is Center or TRACON
Eurocontrol marketing adverts say it is going in in Europe
My questions would be:
1. It is a VHF link, hence line of sight, what kind of infrastructure is needed to support it and when will it be in and do you trust your life to it.
2. how long does it take for a controller to create, send, and confirm receipt of a message by the intended addressee (or vice versa from air to ground)
3. how reliable is the VDL 4 link.
When the fecal matter hits the rotary air circulation device and the crew is dealing with TCAS RAs and possibly systems problems and trying to maintain the plot (excuse me, maintain situational awareness) the first thing they will want to do will be to type data link messages and read messages on the little screen ?