philo beddoe said:
That being said, I think the following logic applies.
If you flying feeder route you are very likely non-radar.
It follows that it is very unlikely that there is going to be another aircraft anywhere near you. If you are all alone in the area, it makes no difference if you descend to the feeder altitude or not, since you know you have obstacle protection,, and the only other reason to wait would be traffic separation.
(With this one caution: if ATC left you hanging a few thousand feet higher as you hit the feeder route, it might be wise to find out why.)
I don't follow the logic, nor do I think it matters. I don't see any suggestion in the directives that would have me treat the altitudes any differently based upon radar coverage.
This approach,
NDB RWY 09 Memphis Intl (MEM) shows two feeder facilities, GQE (Gilmore) and HLI (Holly Springs). Let's say I'm approaching HLI from the southeast (I just enjoyed a nice layover in Atlanta

) and I'm cleared direct to HLI. I'm at 3,000', my last assigned altitude.
Two possible clearances:
1) "FedEx 357, Cleared the NDB RWY 09 Approach"
- - I continue to HLI at 3,000 feet, at which point I am legal to descend to the MEA of 2,100'. Upon reaching the LOM, ELVIS, I commence the procedure turn and begin a descent to 1,900'.
2) "FedEx 357, Cleared the NDB RWY 09 Approach, maintain 3,000' until established."
- - I continue to HLI at 3,000 feet, and then proceed along the HLI 299 radial outbound at 3,000'. I maintain 3,000' until I reach ELVIS because that's where the approach begins, and I'm not "established" until I get there. Being on the feeder route does not constitute being established on a segment of the published approach.
I could have received either clearance with radar coverage or without radar coverage. In either case I would transit quite near to Memphis International Airport, and would likely fly near other airplanes. I really don't see where you're getting the "non-radar" twist to the question.
The distinction that I think needs to be made is in regards to the clearance received.
Back to the post that began this thread:
RJFlyer said:
As an example, I am looking at BPT (Beaumont, TX) ILS 12. There is a feeder frrom the BPT VOR (which is not an IAF) to the LOM, which is the IAF. The altitude listed on the feeder is 1700'. The profile view shows a descent outbound from the IAF on the procedure turn to 1700' (implying you should be above 1700' when you cross the LOM/IAF).
The question is, if ATC clears you to the LOM via the feeder, cleared for the approach, when can you descend to 1700'? When established on the feeder, or after passing the LOM/IAF outbound?
ILS RWY 02 BEAUMONT-PORT ARTHUR / SOUTHEAST TEXAS REGIONAL (BPT)
Absent any other altitude constraints, you may descend to 1,700' once established on the feeder routing from BPT to BP (KAZOO - the LOM/IAF).