Do you have to ensure “glide slope intercept” using cleared direct cross clear as in Chp 4. Not vectoring to final. I have also noted the Navaid use limitation in chapter 2. Chapter 4 does not specify like chapter 5 when vectoring. Is direct the IAF considered an “impromptu route”?
Chp 4 rnav application approach clearance
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32andBelow
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Cross IAF at or above whatever is higher the MIA or the first segment of the approach
4-8-1b Note1 and Note3 are relevant: "The altitude assigned must assure IFR obstruction clearance from the point at which the approach clearance is issued until established on a segment of a published route or instrument approach procedure" and "An aircraft is not established on an approach until at or above an altitude published on that segment of the approach."
Obviously 5-9-1d requires you to vector so as to intercept "at an altitude which will allow descent in accordance with the published procedure." To my reading, though, there is no such requirement when issuing a clearance direct to the IAF. Common sense would still tell you that the pilots don't want to be too high... but as long as you meet the IFR obstruction clearance requirement, I don't think anything prevents you from having them lower than the published crossing altitude.
The only issue I could see is that they aren't "established" until they are at-or-above the published segment altitude, but I just typed out a couple scenarios and I couldn't come up with one where that would actually cause a violation of Note1. As long as they don't fly into a higher MVA/MIA area before they meet that "published altitude" requirement, you'll never bust.
Obviously 5-9-1d requires you to vector so as to intercept "at an altitude which will allow descent in accordance with the published procedure." To my reading, though, there is no such requirement when issuing a clearance direct to the IAF. Common sense would still tell you that the pilots don't want to be too high... but as long as you meet the IFR obstruction clearance requirement, I don't think anything prevents you from having them lower than the published crossing altitude.
The only issue I could see is that they aren't "established" until they are at-or-above the published segment altitude, but I just typed out a couple scenarios and I couldn't come up with one where that would actually cause a violation of Note1. As long as they don't fly into a higher MVA/MIA area before they meet that "published altitude" requirement, you'll never bust.
I generally always ask if they can make their decent if they appear a little high and offer vector/ procedure turn for decent and 99% of the time the pilot says they will make it. Just wanted to get other controllers/pilot opinions. People often mix Chapter 4 and chapter 5 when it’s two separate applications.
slater
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If they don't make the descent and something happens by asking; you acknowledge you were aware of the unstable approach.
1 in million, but I'd rather just get them down. 4000 or lower from 10 mile final than assume any furthet responsibility than necessary.
That is not acknowledging I am aware of an unstable approach. If the pilot feels the approach would be unstable they can execute a procedure turn or request a vector for decent. 100 percent the easier thing would be to just ensure they are low enough and I usually alway do make sure they are. Again this was asked as a hypothetical question. If an aircraft is at 5000 and glide slope is 4500, the aircraft is cleared direct, cross at, cleared approach within how chapter 4 reads I believe is legal. Especially when the pilot specifically requests for direct.
slater
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I hear what you are saying, I guess as long as you don’t include "cleared straight in" with the clearance. "You appear to be above, would you like to continue?" Seems simple enough, but a lawyer will rip that apart in my opinion, just like the altimeter. This was a big topic at my last facility.
