Offsetting from SIDs / STARs

[welliewanger]

Hi Everyone,
It is my understanding that to ensure separation from terrain and other routes, you must adhere to SID / STAR routes within the tolerances of whichever RNP you are operating under, unless cleared for the deviation due to weather.

However today (like many other times here in China) ATC instructed me to offset 2 miles right just as I was about to start the STAR. One airport we frequent always tells us to offset 15 miles left for the STAR. In both cases the SID is the same route as the STAR and by offsetting they essentially get a two way street.

So - is this legal? How accurately do we really have to fly SIDs / STARs?

Thanks

[Microburst2002]

If above the MSA, and if you have the required terminal RNP (1, I guess) then it is not much different than a "fly direct to..."

however, they should clarify if you have to respect any altitude constraints

[hvogt]

Knowing nothing about Chinese air law, I can only say it is clearly against ICAO provisions. According to 16.5.2 of PANS-ATM, SLOP shall only be authorized in en-route oceanic or remote continental airspace.

[Capt Chambo]

According to 16.5.2 of PANS-ATM, SLOP shall only be authorized in en-route oceanic or remote continental airspace.

welliewanger is asking about ATC initiated offsets whilst on a SID or STAR. Chinese ATC also require you to fly offsets whilst on airways. In both instances you are under ATC/RADAR control.

Pilot initiated SLOPs are entirely different.

[ImbracableCrunk]

SOP for China. I think I'd be worried if I didn't get an offset by ATC.

"XZY123, offset 3 mires reft, rima side."

[FlightPathOBN]

WW,

First off, there are very, I mean very few RNP SID's in China...

That said, the box has the ability to fly on offset RNP track and maintain RNP.

A 15 nm offset is not RNP...the 'poor mans' RNP relies on vectors, and this may be the case in your example....

[9.G]

welliewanger, it's a standard practice in SE Asia nothing wrong with that as long as you're above MSA. You'd have to cancel offset at the IAF, of course. :ok:

[zonnair]

"XZY123, offset 3 mires reft, rima side."

Hahaha you, mean "offset thlee mile light, lomeo side" hehe. Chinese pronouncing the letter "r" is like a cat that barks. Impossible hehe.

[Ministry_Cork]

Still laughing :-D
YouTube - ‪Cat gets caught barking by a human and resumes meowing‬‏