I had assumed that all flights between western Europe and North America would use the North Atlantic Tracks (NATs) but this answer says that, actually, only about half do. What reasons might a flight have for not using the tracks?

Wikipedia says that Concorde didn't use the tracks because it flew above them but I'd expect all commercial transatlantic flights these days to be within the band covered by the tracks (FL290–410).

  • $\begingroup$ If you read that answer it explains that not all traffic in the North ATlantic crosses between Europe and America. It also gives examples of flights over the NAT that don't use the Oceanic Track System. $\endgroup$
    – DeltaLima
    Commented Sep 5, 2015 at 21:13
  • 1
    $\begingroup$ What you abbrevintend as NAT is OTS in that answer. NAT means North ATlantic in that answer. That is perhaps where the confusion comes from. $\endgroup$
    – DeltaLima
    Commented Sep 5, 2015 at 21:15
  • 3
    $\begingroup$ I don't know what the current system entails, but prior to my retirement in 1999, you had to have additional certification for your aircraft, your pilots, and your check airmen over and above what was normally required. Additionally you had to follow procedures that you would normally not do. All of that cost money, so for many the additional cost was not worth the benefit. $\endgroup$
    – Terry
    Commented Sep 6, 2015 at 2:22
  • $\begingroup$ Many of the crossings are done in smaller jets (Gulfstream, Falcon, Bombardier) which can take advantage of higher altitudes and so do not use the NATs. $\endgroup$
    – Steve H
    Commented Sep 6, 2015 at 17:54

2 Answers 2


The answer doesn't state that half of the flights between western Europe and North America use the North Atlantic Oceanic Track System (OTS). It states that half of the flights over the North Atlantic use the OTS.

Part of the flights over the North Atlantic don't cross between western Europe and North America and they don't use the tracks. Examples are flights to/from Iceland or the Azores. Also flights crossing between Ireland and the North Western point of Spain are entering the North Atlantic Region.

Also part of the flights that do cross between western Europe and North America and vice versa may use random routing for various reason.

On some days the winds are such that favourable tracks to North America are within the Reykjavik control area, which allows for random routings.

Some combinations of origin / destination are better served by avoiding the OTS area at all. For example flights between the Iberian peninsula and Florida are generally South of the OTS.


I think improvements in aircraft performance has a lot to do with it. Business jets regularly cruise at FL430-450, and newer model airliners are now scraping the low 40's. If you can climb above the tracks, random routing can be a real advantage.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .