ADS-B In Trail Procedures (ITP)
What it does
ITP is an ADS-B In application which allows ITP-equipped aircraft that desire flight level changes in procedural airspace to achieve these changes on a more frequent basis. This results in aircraft flying more often at optimal or less turbulent flight levels during oceanic flights.
Benefits
- Improved fuel economy
- Reduced emissions
- Avoiding turbulent altitudes
Aircraft operating in oceanic airspace are, at times, held at non-optimal flight levels due to traffic conflicts at flight levels between their current flight level and more efficient flight levels. Instead of burning excess fuel at inefficient altitudes for long periods of time, aircraft equipped with ITP can make beneficial altitude changes which save fuel and reduce emissions. Aircraft equipped with ITP can also more easily leave a turbulent altitude, reducing risk to cabin crews and giving passengers the smoothest ride possible. During operational trials, due to enhanced traffic situational awareness, ITP-equipped aircraft saved an average of 573 pounds of fuel per flight, even when no ITP maneuvers were performed.
Availability
ITP avionics standards are complete and ready for manufacturers to produce the necessary avionics (FAA Technical Standard Order - C195a and later versions). FAA guidance regarding ITP operations exists in Advisory Circular 90-114B (and later versions). Airbus, Boeing, and various avionics companies offer products which include ITP functionality.
ITP may be used by any ITP-equipped aircraft in all oceanic airspace managed by Oakland, Anchorage and New York Air Route Traffic Control Centers.
How it works
Maintaining optimal cruise altitudes on oceanic crossings requires many altitude changes to compensate for fuel burn, save fuel with better wind conditions, and improve ride quality at less turbulent altitudes.
ITP uses precise ADS-B location data to allow for altitude changes that would otherwise be blocked by non-radar separation procedures.
Flight crews flying ITP-equipped aircraft have cockpit displays and special algorithms that calculate "ITP distance" for the flight crew to determine if a safe climb or descent can be performed. Instead of being "trapped" by the proximity of other aircraft, ITP-equipped and trained flight crews can request ITP maneuvers to their preferred flight level. Air traffic control, which has the total traffic picture, can authorize the requests. Because of ADS-B precision, less separation is required for ITP maneuvers so they can happen more often.