Contingencies in Oceanic Airspace

[Sammy]

The special procedures for in-flight contingencies in oceanic airspace that are published in the atlantic orientation charts and also published in the latest FAA class II NOTAMS booklet deal with contingencies for handling aircraft performance, pressurization and meteorological conditions that require a rapid descent and/or turn-back or diversion. These procedures are the same for the atlantic and the pacific areas and basically tell you to turn left or right 90 degrees and establish in either direction a 15nm offset to your current route or track you are flying. My question is whether this offset set is always required for the above contingencies or is it only required when your current route/track is on, over or in close proximity to a NAT/PACOTS track or charted ATS airway? In other words, if I am on a random route not near another ATS airway or NAT/PACOTS track why should I establish a 15nm offset??? Appreciate any guidance.

 

[Spooky 2]

The special procedures for in-flight contingencies in oceanic airspace that are published in the atlantic orientation charts and also published in the latest FAA class II NOTAMS booklet deal with contingencies for handling aircraft performance, pressurization and meteorological conditions that require a rapid descent and/or turn-back or diversion. These procedures are the same for the atlantic and the pacific areas and basically tell you to turn left or right 90 degrees and establish in either direction a 15nm offset to your current route or track you are flying. My question is whether this offset set is always required for the above contingencies or is it only required when your current route/track is on, over or in close proximity to a NAT/PACOTS track or charted ATS airway? In other words, if I am on a random route not near another ATS airway or NAT/PACOTS track why should I establish a 15nm offset??? Appreciate any guidance.

Yes Sammy you would still need to perform the offset. Remember that just because you are on the random route, you might not be the only one filed that way during that period of time. Random routes are usually structured for min time just as the NATS are so there is every reason to believe that there are other aircraft following that same random route that your on and quite possibly just fifteen minutes behind you.

 

[Sammy]

Spooky2, Thanks much. Your reasoning makes sense.

 

[Sammy]

One more question Spooky2, It seems to me these in-flight contingencies should only be implemented while outside of radar coverage or when using HF for communications. Is that sound logic or flawed??? Thanks!

 

[Spooky 2]

Well not exactly. The whole theater of operations can be fairly dynamic and a case in point would be areas in the No. Pac. where you might be talking on VHF and yet not in radar contact. The off set and drift procedures would still apply. Keep in mind that if the off set is driven by say an engine loss, not only are you going to be doing the off set, but the drift down to at least something at or below your SE service ceiling or in the case of a depressurization, something around 10,000 or below assuming you do not have a supplemental oxygen system on your aircraft. The ETOPS scenario calls for a catastrophic engine loss (rotor burst) combined with a subsequent prerssurization loss due to engine fragmantation. So in most cases the critical ETP is one that will get you down quickly to 10,000 leaving you with enough fuel to get to your designated alternate. There are several variation on this so you need to keep an open mind on how it applies to your specific operation.

 

[Sammy]

Thank you Spooky2