Required fields are indicated with a red star.
Providing online training for business aviation professionals globally.
Author: Shawn Scott
Today’s North Atlantic oceanic equipment requirements are oftentimes confusing. Let us take a simplified look at what we are dealing with.
It is perhaps well understood that CPDLC and ADS-C go hand-in-hand with Reduced Lateral Separation Minimums (RLatSM), but where do you fit in the NAT High Level Airspace (HLA) structure today and in the near future without data link equipage?
When a company must decide whether to equip to the mandate, the cost benefit analysis can be daunting. Let’s look at where one would fit today without the required equipment and then look at the future plans.
If an aircraft is not currently equipped with CPDLC and ADS-C, then operations on the tracks from FL350 up to and including FL390 are not allowed.
Today, one of the options for a NAT crossing without data link would be on the tracks below FL350 or track routing above FL390. The latter may present a challenge on a hot day, as conditions may force an aircraft lower than expected, possibly at FL390, wherein that routing would be denied and a significant reroute may be a reality. For those who prefer the track routing above the track system to take advantage of the jet stream eastbound, are the winds such a benefit on track routing that it would overshadow the negatives of a contingency forcing a descent into the RLatSM routings? Or a reroute, given possible ISA conditions?
If data link is not equipped, another option is a random route at any altitude. The wind might present less of an advantage, but overall, even though one might expect longer crossing times (20- 25 minutes), the availability of the optimum altitude may be of a greater benefit, while having to deal with fewer aircraft given a contingency.
The CPDLC and ADS-C mandates, known as the Data Link Mandate, will change in December 2017, where the entire NAT region from FL350 up to and including FL390 will require CPDLC and ADS-C. Although ADS-B has not been specifically addressed in any mandate for the NAT, we can derive those requirements by looking at the CPDLC and ADS-C requirements. If an aircraft is not equipped with data link, then there are two options for a crossing. Fly above or below the mandate, or make the crossing in the NAT HLA surveillance corridor. To qualify for this routing (Blue Spruce Routes), the aircraft routing must be fully contained inside this area and the aircraft must be equipped with ADS-B. The aircraft may fly at any altitude and would expect significant reduction in separation standards being applied against the aircraft.
Moving forward to 2020, the entire NAT HLA from FL290 and above will require data link equipage. At that point, the only option for non-data link equipped aircraft would be the surveillance corridor at any altitude.
So in reality, after 2020, ADS-B equipped aircraft may route via the surveillance corridor, but once in Europe, the mandate for both CPDLC and ADS-B will be in full effect.
Shawn Scott is the co-owner and co-founder of Scott International Procedures, LLC. The company provides International Procedures training to professional pilots within the business aviation community.