Pre-ADS-B Automatic Position Reports?

[Badmachine]

For big Boeing and Airbus jets, ADS-B seems to provide broadcast of automatic position reports for waypoint crossings and course changes.

Prior to ADS-B, did big Boeing and Airbus jet FMSs generate automatic position reports for waypoint crossings and course changes?

[Spooky 2]

I seem to recall that the original ADS trials on the N. Atlantic started sometime around 1998/99 time frame. Prior to that I'm not aware of any
automatic position reporting on the Atlantic although UAL was pioneering
FANS1 on certain routes in the Pacific in the early 90's in conjunction with Oakland ARTCC and other service providors in the South Pacific as well.

[LeadSled]

Spooky 2,
To set the record straight, much of the early FANS 1 work was done by QANTAS and Air New Zealand and Boeing. The actual FAA certification flying was done on QF B744, the first time FAA had conducted basic certification flying "outside" the US, and on "foreign" aircraft.

FANS-1 has been in operation for a long time. I didn't miss the HF, believe me!!

As to the automated position reporting, that is nothing to do with ADS-B at all, and is quite straightforward, the relevant position information at a scheduled reporting point goes from the FMCS system by ACARS (if in range) or by SAT/COMM, either way the position is passed to the controlling centre in a conventional manner for message handling.

Just think of ADS-B as a transponder with a bit more information, it is a position, but not a position report.

Tootle pip!!

[ATCast]

I think you are referring to ADS-C.

ADS - C ( contract ) sends position reports at certain waypoints to ATC or the airlines operations center, when a contract is in place. The contract is initiated by the ground side, and cannot be changed by the air side.

ADS - B (broadcast) on the other hand, sends out position and velocity approximately twice a second. ADS-B reports have no addressee, anyone can receive them.

To my knowledge no position reports were sent out automatically prior to the introduction of ADS - C.

ATCast

[Badmachine]

Prior to FANS, was there automated ACARS reporting of unplanned course changes during domestic flights of big Boeing and Airbus jets?

Prior to FANS what was the protocol?

[HEATHROW DIRECTOR]

Remember that ADS-B uses line-of sight SSR frequencies so would be of no benefit over the Atlantic, or any remote area.

[Spooky 2]

Thanks to all for the updates. I should'a mentioned the Qantas/ ANZ "South Pacific Fans1" trials. :ok:

[ATCast]

Remember that ADS-B uses line-of sight SSR frequencies so would be of no benefit over the Atlantic, or any remote area.Indeed, in general ADS-B uses the SSR frequency (1090 MHz), so it is line-of-sight. But that does not mean it has no benefit in remote areas. Although out of sight for ATC, ADS-B can still provide air traffic situation awareness to the flight crew when the aircraft is able to receive ADS-B signals from other aircraft.

For example, this can reduce the separation required for step climbs in oceanic airspace. Instead of the 80+ miles separation needed today to do a step climb, this can be reduced to 10NM using ADS-B, allowing for much more step climbs being made over the Atlantic.

It might have no benefit to the Heatrow director, but to the airlines it does make a difference.