RNAV approach from the "wrong" direction

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jm67
Posts: 5
Joined: Sat Apr 14, 2018 4:27 pm

RNAV approach from the "wrong" direction

Post by jm67 »

I’m sure this will be covered when I start my real world Instrument training, but this was confusing me the other day on PE, so I thought I’d ask now.

Let’s say I’m coming from the west into KRAL, and I want to fly the RNAV (GPS) 27 approach. The plate specifically says “Procedure NA for arrivals at BANDS via V372 northeast bound and via V16-370 eastbound”, presumably because of the tight turn required at BANDS to head back west on the approach.

How do I deal with that situation? I can think of a couple of options:
- file for a routing that includes an intermediate way point that takes me north or south of BANDS, so that the procedure is authorized;
- file direct or via the TEC route, but when ATC asks me what approach I want, request vectors to BANDS for the RNAV 27
- give up on the RNAV 27 - ask for the RNAV 09 and circle to 27.

What's the correct procedure to follow when an approach is NA for your direction of flight, and no procedure turn is available?
zerofay32
Posts: 131
Joined: Tue Aug 19, 2014 8:34 am
Location: Grove City, Ohio

Re: RNAV approach from the "wrong" direction

Post by zerofay32 »

All depends on the weather and how efficiently you want to fly. If the weather allows then the visual approach would be first.

But say the visual won't work, next would be the GPS RWY 09. That approach has circling minimums that are almost as low as the LPV on the GPS 27.

But now lets say that its 500' overcast. No circling today. So it's either a strait in approach with a tailwind or the approach with a headwind. Depending on the conditions/airplane a tailwind landing may not be a bad idea for efficiencies sake.

Say the wind is howling, and oh by the way ATC won't allow an opposite direction approach. Then the best option would be vectors for the GPS 27

It all comes down to knowing your options vs. the conditions that you are encountering.
Andrew Fay
PilotEdge V-3; CAT-11; I-11; Skyhigh 10
Commercial Pilot/Instrument ASEL/AMEL- KOSU / Commercial sUAS
jm67
Posts: 5
Joined: Sat Apr 14, 2018 4:27 pm

Re: RNAV approach from the "wrong" direction

Post by jm67 »

Thanks - makes sense. Sounds like there is some degree of flexibility in picking the approach, and working with ATC to get vectored for that approach.
jx_
Posts: 526
Joined: Wed Jan 22, 2014 12:15 am

Re: RNAV approach from the "wrong" direction

Post by jx_ »

hello.

First thing to understand is that you must know where your altitude guidance is coming from. Here are your options:

1) ATC vector (MVA)
2) off route (OROCA, 14 CFR 91.119)
3) published route (MEA, MCA, MOCA, etc)
4) approach route (segment to glideslope intercept -or- segment to MDA/DH)


As an IFR aircraft you must be operating under one of those at all times unless you're on a visual/contact approach, departing uncontrolled airspace, VFR climb, VFR on top, or otherwise instructed to maintain VFR conditions.

An important note about #4, the approach segments are not to be used for any portion of a course reversal/PT. You can use them once over the IAF inbound, or if already established on a feeder route to the PT (including a No PT route). Do not use them until you will not make ANY turns to depart the inbound course. This rule is what applies to your situation. If an ATC altitude is unavailable use the highest IFR altitude that applies.

With that being said the note "Procedure NA for arrivals at BANDS via V372 northeast bound and via V16-370 eastbound" simply means you can not use [#3 published route] altitude guidance to BANDS from those two airways. Usually you'll see a VOR radial quadrant like "Procedure NA for arrivals on PDZ VORTAC airway radials 012 CW 07". Same deal. No #3. By default, airways are published routes. You can always go direct [off route].


This leaves you with the following scenarios:

a) request ATC vectors to final, or vectors to BANDS or WENVA (90 degree or less intercept)

b) In the absence of ATC, proceed DIRECT to BANDS (or any fix on the approach; even direct to RAL airport then to BANDS), starting at or above the OROCA, execute a course reversal, then cross BANDS at or above the OROCA (you can use 91.119 altitude if you have the charts and knowledge, but I'd leave that to trained navigators.) It is important to remain above the OROCA from: the moment you depart the published route (#3 altitude guidance) to the moment you cross an appropriate fix inbound (#4 altitude guidance). In between you are off route (#2 altitude guidance). At no time can you be below the current one that applies.

c) get a different route clearance such as PDZ V388 PSP V16 BANDS, assuming ATC allows it. In this case you're (#3 published route) altitude will remain active until reaching BANDS inbound [no ATC] -or- ATC would need to assign an altitude to start the approach and anticipate your turn radius to maintain terrain compliance should you leave the airway.

excerpt from AIM that applies to this situation:
When operating on an unpublished route or while being radar vectored, the pilot, when an approach clearance is received, must, in addition to complying with the minimum altitudes for IFR operations (14 CFR Section 91.177), maintain the last assigned altitude unless a different altitude is assigned by ATC, or until the aircraft is established on a segment of a published route or IAP. After the aircraft is so established, published altitudes apply to descent within each succeeding route or approach segment unless a different altitude is assigned by ATC. Notwithstanding this pilot responsibility, for aircraft operating on unpublished routes or while being radar vectored, ATC will, except when conducting a radar approach, issue an IFR approach clearance only after the aircraft is established on a segment of a published route or IAP, or assign an altitude to maintain until the aircraft is established on a segment of a published route or instrument approach procedure. For this purpose, the procedure turn of a published IAP must not be considered a segment of that IAP until the aircraft reaches the initial fix or navigation facility upon which the procedure turn is predicated.
One more note, you cannot do a "procedure turn" unless the barb or holding pattern is depicted on the approach. Since there is none depicted here, we are doing a "normal course reversal" which is not part of the approach. When you think of it this way, the AIM reference and altitude guidance makes more sense. You can turn around using the other forms of altitude guidance. The approach doesn't apply.
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