I’ve been testing the latest system software in my Garmin avionics and checking out the A36 after its annual inspection. A break in the weather allowed a scenic VFR flight from Boeing Field (KBFI) to Tillamook, OR (KTMK) and a practice RNAV RWY 13 approach using the automation available with the Garmin GTN 500Txi, GTN 750Xi, and GFC 600 autopilot.
Enjoy the spectacular scenery along the Oregon coast south of Astoria as I descend into KTMK.
BruceAir, LLC 
156. The TAA at Tillamook has initiated a debate regarding what is or isn’t considered as the minimum altitude to use on the TMK approach. One faction says that unless the altitude is stated on the approach chart, then only the TAA minimum applies. Since the airway is not depicted on the chart, the pilot needs to stay at his last assigned altitude until the IAF regardless of the received clearance. Another faction says that since an airway intersects the IAF, the pilot can descend to the MEA of the airway since it is a “published” segment after he has been cleared for the approach. But the airway is not depicted on the chart. We seldom fly airways here in North Texas except when they are part of a DP or STAR. The round table folks didn’t seem disturbed by the “expert answer” that said the TAA minimums did not have to be obeyed in this case. What say you?
If you are on the airway and at one of the charted MEAs (VOR or G based) and cleared for the approach via a fix that’s both on the airway and on the chart as an IF, you should maintain the MEA until you reach the IF and then continue down to the altitudes depicted on the approach chart. ATC would be surprised if you climbed from the MEA to the altitude for a TAA sector. As noted in AIM 5-4-5d, Terminal Arrival Area (TAA), the arrival areas are used most often when an airway does not provide a path from onto the procedure. If an airway that does not pass through a TAA, procedure designers include a transition (feeder) route from the airway into the TAA (see paragraph 8 in that section of the AIM). As always, however, if you’re in any doubt about the altitude ATC expects you to fly or any other part of your clearance, just ask.
You said ” cleared for the approach via a fix that’s both on the airway and on the chart as an IF, you should maintain the MEA…”
So, if I am maintaining a higher altitude than the MEA, and I am on the airway, then I can commence my descent to the to the MEA prior to the IAF AFTER I am cleared for the approach. Correct?
Finally, I seem to recall reading that in this type of approach, the airway can be considered an integral part of the approach even though it is not depicted on the approach chart. Where might this be in the AIM?
If a fix on the approach chart is also part of an airway, it will typically be designated as an IAF and a feeder route will be published. Your approach clearance should include an altitude to maintain until you’re on a published segment. But again, if you’re in doubt about altitudes to maintain, just ask ATC. Don’t try to parse the AIM and other guidance while flying.