Procedure NA arrival on airway radials 230 CW 310

[PhillipR]

ILS RWY 20 for KPWT has "Procedure NA for arrival on SEA VORTAC airway radials 230 CW 310."

R282 from SEA is a valid feeder route, because it has altitude, direction, distance and is the medium thickness line. Ostensibly, you could use it to enter this approach.

But it's not an airway.

In fact, looking at the IFR enroute charts, there isn't even an airway between 230 and 310, clockwise.

So what does this prohibition apply to? Can you do the procedure or not?

-- apologies ahead of time for this question; still looking for a CFII locally, and it's theoretically related to PE and Pilots.

[Peter Grey]

The 230 and 310 restrictions are inclusive vs exclusive.

So in this case V27 and V4-495 are affected by this restriction.

[Scott Medeiros]

To put it in clearer terms, the NA is basically saying "turns from V27 or V4-495 onto the SEA R-282 would be too drastic to be safely established on the radial for the approach". All other airways can feed into the R-282 without needing an almost 180° turn around to get established.