Offsets

[Let'sgoflying!]

I understand in some countries they use parallel offsets as a standard technique to increase separation; ie 3nm right of airway. Anyone know where? Has it been discussed for the US? Can most boxes do this now?

 

[SCCutler]

I understand in some countries they use parallel offsets as a standard technique to increase separation; ie 3nm right of airway. Anyone know where? Has it been discussed for the US? Can most boxes do this now?

My 430W can, though I don't know how.

 

[Areeda]

My 430W can, though I don't know how.

It's in the Flight Plan. Hit menu:

Select Parallel Track:

 

[SCCutler]

Geez, that looks easy-peezy!

Thanks.

 

[poadeleted20]

FWIW, I can find nothing in the ATC Handbook referring to parallel offset routing.

 

[Laurie]

We use it in the Gulf of Mexico on OSAP rig approaches, but I hadn't heard of it being used anywhere else.

 

[Greg Bockelman]

We use it in China.

 

[poadeleted20]

We use it in China.

Don't think 7110.65 applies there.

 

[ScottM]

We use it in China.

What about any other Asian countries?

Is China still a little strange to fly in? I had from guys that the last bastion of ATC civilization was Japan when one is heading west. I have been in the old Beijing IAP control tower when it was several chairs and two radios pulled from an old airplane that were run on a 28VDC power supply. YIKES!!! It was a little scary looking. But I know things were changing in anticipation of the Olympics

 

[airdale]

We use it in the Gulf of Mexico on OSAP rig approaches, but I hadn't heard of it being used anywhere else.

We used on an air rally last summer. Everyone loaded the same flight plan from the departure to destination airports, then we spread out laterally after we launched. Typical call was " 46 Xray is 84 miles out, 2 miles left of course, five thousand five hundred"

It worked great even with 15-20 airplanes. My standard 430 wouldn't help but it was easy enough to set 2 miles on the CDI and use the heading bug and the AP to hold the offset.

 

[Joe B]

I understand in some countries they use parallel offsets as a standard technique to increase separation; ie 3nm right of airway. Anyone know where? Has it been discussed for the US? Can most boxes do this now?

I've seen discussions of it on some fora, but in the US you're still expected to be centered on an airway (if you're IFR and not going direct someplace.) There are some captains who program in a small offset (ie: a tenth or so) just so they aren't *exactly* centered on the airway. It reduces their chances of hitting someone who's magic box does have them exactly centered. The Gol Transportes Aéreos Flight 1907 v. Embraer crash down in Brazil convinced some that this might be a good idea.

 

[Everskyward]

Coincidentally I learned about offsets today and I remembered this thread.

Strategic lateral offsets are used in oceanic airspace and some other remote areas. Airplanes can fly on the centerline of a route or offset either 1 nm or 2 nm to the right of the track. This can be done without telling ATC. Presumably the reason for doing this is so that you are not following in somebody's wake 1,000 feet below them.

According to ICAO DOC 4444 "PANS ATM" strategic lateral offsets shall only be authorized in en-route oceanic or remote continental airspace. The routes or airspace where application of strategic lateral offsets is authorized, and the procedures to be followed by pilots, shall be promulgated in aeronautical information publications AIP(s) by the concerned State(s) or, as applicable, by the authorised ANSP(s).

Furthermore, PANS ATM specifies that the strategic lateral offset shall be established parallel to the designated ATS route at a distance of 1.85 km (1 NM) or 3.7 km (2 NM) to the RIGHT of the centre line relative to the direction of flight. These two "track" options become available in addition to the track centreline, not instead of it. All ATC route clearances are made without reference to the lateral offset option and flight crew do not need to obtain permission from ATC to use these offset tracks or advise ATC of their decision to do so. If there are areas of radar surveillance, within trans-oceanic or remote continental areas, designated for lateral offset procedures, then it is expected that aircraft will be allowed to initiate or continue offset tracking in exactly the same way as the rest of the designated area.

http://www.skybrary.aero/index.php/Strategic_Lateral_Offset

 

[Let'sgoflying!]

Thks for the info, all. And the skybrary, a cool addition to my favorites Mari.
Funny how things seem to get your attention then its everywhere, I see a thread on the red board about it now too.

 

[Speed]

FWIW, I can find nothing in the ATC Handbook referring to parallel offset routing.

When I first started flying an airplane with a box that could do that I thought it was cool... Flying along one day and a row of thunderstorms just looked like the perfect excuse to ask ATC if I could 'offset my route by 10 miles south'. ATC - 'you want to do what?' I tried to explain it again, and the response was 'deviation south of course is approved, advise when able to go direct xxx'.

 

[Greg Bockelman]

Presumably the reason for doing this is so that you are not following in somebody's wake 1,000 feet below them.

That is part of it. Another reason is to minimize the chance of a nose to nose encounter on airways that are bi-directional, as opposed to one way.