I reckon you're right Vernon. The requirement to use instrument approaches in incliment weather is typically promulgated at controlled terminals via atis.

 

As to your rnav approach, a circling approach would be conducted, so long as it is approved by the company, and circling conditions (min altitude/radius) is promulgated on the chart for your category aircraft (737 is category c, usually).

 

As far as selecting a non-precision over a precision; well I think there are many factors that would determine which would be selected and why. I'll leave that for another discussion.

 

Brian Nellis.

Its common sense really lol

Right but all the Part 121 stuff is all based off of the company-approved OpSpec, so that's the airline's prerogative, and it's their own call to not allow it. Sure, it cuts out a lot of discretion that could end up getting them smacked with a lawsuit, but the blame can't be passed back to the FAA on that restriction. The FAA makes no restriction on it, Part 91 or Part 121. The operator is adding in "prohibited" or restricting it in some way, and the FAA simply approves that.

 

AIM 5-4-20 covers the basics, and here is an excerpt:

 

Also, 91.175's references treat it similar to the portion of visual flight at the terminus of any other instrument approach: maneuver as you must within the protected area, but you must maintain a visual on the airport environment.

 

The reference in 121 (121.567) simply refers to the airline's approved OpSpec. Since Part 91 is so permissive, I'd argue that any operator could submit and get approved an OpSpec just using Part 91 as a basis. It's easier to say circling approaches are not approved as an operator and not have to worry about all of that, though.

 

Note: the circling area isn't defined in the FARs - it's defined in all of the ACs that make up the TERPS standards, if I recall correctly, but it's a varying radius based on aircraft app category (and now altitude of the MDA, as it was changed in 2012).

 

 

 

Finally, as somewhat of a trump card / TL;DR catch all:

Why would they publish circling minimums for CATs A through E if they didn't expect them to be used? CAT C and D aren't usually seen outside of the 121 realm.

My point is this : If you're cleared for a straight in approach, you don't circle. If you want to circle, get clearance for a circling approach.

 

TERPS and OPS-SPECs aside, if I circle the Space Needle on my way to 16L tonight, I'm going to be calling you as my expert witness at my hearing.

Away with all the TERPS and OPS-SPECs stuff lol were simmers and don't need to know it and I will never fly. I'm already bogged down with rules, with being a train driver. But i can still call myself a ground level pilot

Vernon, I actually find the dialogue between Matt and Kyle to be a valuable insight to flight practices from an ATCO's perspective and a practicing type pilot's perspective.

 

Thanks for raising this thread, but if you have nothing constructive to offer to the subject matter, please keep it to yourself. I don't give a toss that you drive trains.

 

Despite how it may read, I do genuinely offer my view, with respect, to you and your profession.

 

Brian Nellis.

 

 

My point is this : If you're cleared for a straight in approach, you don't circle. If you want to circle, get clearance for a circling approach.

 

Agreed.  If a controller is doing things based on your actions, you'd better do what's asked of you.  The reason I used JYO in my example, though, was that it's uncontrolled, and radar controllers are prohibited from giving circling clearances to non-towered fields.  I didn't make that clear enough in my points at all in that post, though.

 

 

 

TERPS and OPS-SPECs aside, if I circle the Space Needle on my way to 16L tonight, I'm going to be calling you as my expert witness at my hearing.

 

haha - oh man...

 

 

 

Away with all the TERPS and OPS-SPECs stuff lol were simmers and don't need to know it and I will never fly. I'm already bogged down with rules, with being a train driver. But i can still call myself a ground level pilot

 

No offense, but you asked a question based on real world procedures, which were written according to real world rules, so we're expanding upon the points that surround your question.

 

...if real world stuff is unimportant, then why even ask about the real world procedures in the first place to begin with?

 

If you want to tune out, then tune out, but other people do occasionally want to learn, so let learning happen.

Matt and Kyle to be a valuable insight to flight practices from an ATCO's perspective and a practicing type pilot's perspective.

 

In the interest of truthiness, I have to offer up a small correction:

Potential ATCO.  I did consulting for a lot of ATC-related projects (collaborative planning and traffic management stuff mostly, but also the STARs update), so I have a lot of the background, but I don't work in a facility.  That, and I have some friends who work training at the Potomac TRACON, so they've all imparted their wisdom on me.  I hate to bring up VATSIM, since it's nowhere near the real world in many respects, but it definitely gives you incentive to jump into the 7110.65 and learn more about that side if you truly want to enjoy controlling and offer realism to the pilot crowd there.  It did for me what simming did for my study/practices of real world flying, so I can't knock it too much.

Lads i wasn't sounding like a prat and telling where to put your spec ops stuff, oops! Thats why i put a lol at the end. Sorry if it did seem that way though!

 

Yes, i also appreciate alot of valuable information that kyle and matt do put into these forums. To help us ALL

I stand corrected. And thanks for the understanding Vernon.

 

Brian.

If the RNAV GP starts at 50ft above the runway and its 3 degrees and also works backwards, why can't it be like a precision app?

Because it cannot be flown with the same precision and consistency. There's LPV approach with minimums very close to ILS ones, but you need special equipment on board and on ground, such as WAAS/EGNOS.

Ok thankyou. You just would think all this GPS signals and satellites it would be precise.

 

Is the 737 ngx capable of PRNAV been looking into that...

Yes, you can fly PRNAV SID/STARS (except of final approach). You can fly RNAV (GPS/GNSS/RNP) provided you are in compliance with conditions annotated on charts (OAT, RF...) and minimums. You cannot fly RNAV (GPS) with LPV minimum because 737NG doen't have required equipment, and you cannot fly RNAV approaches with radius to fix legs because PMDG doesn't support that.   

 

IRL, aircraft has to be certified for such operations.

Right so PRNAV is basically an RNAV dept and arrival?

In most simple way P-RNAV is equal to RNP-1. As I understand, it's suitable for en-route application too.

 

If P-RNAV is required, it's written at chart.

 

 

Here is ICAO's PBN (Performance Based Navigation) manual, doc 9613.

http://www.eurocontrol.int/sites/default/files/field_tabs/content/documents/single-sky/mandates/20120705-pbn-manual-advanced-fourth-edition.pdf

I found this, Ryanair is PRNAV approved, meaning RNAV SID's and STARS can be flown in LNAV, subject to ANP+raw data back-up

i see you need RNP1 for PRNAV