Z, Y, X in Approach Titles

I’ve recently noticed questions popping up about the letters Z, Y, X appearing in the titles of instrument approach procedures. Titles that include “-A,” “-B,” or “-C” are familiar–they designate procedures that have only circle-to-land minimums, such as the VOR-A at Olympia, WA (KOLM). But letters from the other end of the alphabet puzzle many pilots.

KPAE-ILSorLOCDMEYRWY16R-Title

For example:

The most detailed explanation of this naming convention is in “Straight-In Procedures” in Chapter 4 of the Instrument Procedures Handbook (updated in October 2017):

When two or more straight-in approaches with the same type of guidance exist for a runway, a letter suffix is added to the title of the approach so that it can be more easily identified. These approach charts start with the letter Z and continue in reverse alphabetical order. For example, consider the (RNAV) (GPS) Z RWY 13C and RNAV (RNP) Y RWY 13C approaches at Chicago Midway International Airport…Although these two approaches can be flown with a global positioning system (GPS) to the same runway, they are significantly different (e.g., one is a Required Navigation Performance (RNP) Authorization Required (AR) … one has circling minimums and the other does not; the minimums are different; and the missed approaches are not the same). The approach procedure labeled Z has lower landing minimums than Y…

In this example, the LNAV MDA for the RNAV (GPS) Z RWY 13C has the lowest minimums of either approach due to the differences in the final approach required obstacle clearance (ROC) evaluation. This convention also eliminates any confusion with approach procedures labeled A and B, where only circling minimums are published. The designation of two area navigation (RNAV) procedures to the same runway can occur when it is desirable to accommodate panel mounted GPS receivers and flight management systems (FMSs), both with and without vertical navigation (VNAV). It is also important to note that only one of each type of approach for a runway, including ILS, VHF omnidirectional range (VOR), and non-directional beacon (NDB) can be coded into a database. (4-9)

FAA Order 8260.3C (i.e., TERPS) includes additional information:

Alphabetical suffix. When more than one procedure to the same runway uses the same type of navigation system for lateral guidance within the final approach segment, differentiate each procedure by adding a non-repeating alphabetical suffix using the letters “S” through “Z.” Suffixes are normally assigned in reverse order starting with “Z,” but may be assigned as needed to meet operational needs [for example, all RNAV (RNP) approaches at an airport assigned “Z” suffix, all RNAV (GPS) approaches assigned “Y” suffix, etc.]. (1-9)

As noted above, approaches to the same runway can be labeled Z, Y, or X… for several reasons.

For example, consider the ILS RWY 27 at KYKM, which is published as both the ILS Y RWY 27 and ILS Z RWY 27.

The Z version requires a non-standard climb gradient of 250 ft/nm on the missed approach procedure (see the note in the plan view), but it provides a DA of 1268 (200 AGL) with RVR 2400.

KYKM-ILSZ-Plate

KYKM-ILSZ-PlanView

The DA on the Y version of the approach is 1725 (657 AGL) with visibility of 2 sm. So you can go much lower and to the equivalent of 1/2 sm visibility if you can achieve the steeper climb gradient on the miss.
KYKM-ILSY-Plate.jpg

There are two versions of the ILS RWY 16R–but for a different reason–at Snohomish County–Paine Field (KPAE) north of Seattle.

Both procedures offer the same basic DA and visibility minimums (although the Z version allows a reduction to RVR 1800 with a flight director, autopilot or HUD). But the FAF (ITIPE) for the Y edition is 4.4 nm from the PAE VOR.

KPAE-ILSorLOCDMEYRWY16R-Plate

The Z version, which also has published minimums for category C and D aircraft, has a FAF (JUGBA) at 7.6 nm from the VOR.

KPAE-ILSorLOCDMEZRWY16R-Plate

If you’re flying a typical light GA aircraft, the Y version is much more efficient, while the Z version is better suited to jets (like the shiny new Boeings emerging from the factory at KPAE) that need more room to get established on final.

As pointed out earlier, Z, Y, and X versions of the same basic procedure may require different equipment or missed approach segments. For example, using your favorite chart-viewing app, compare the ILS Y or LOC RWY 20 and the ILS Z or LOC/DME RWY 20 at Walla Walla, WA (KALW).

The key to flying such approaches is a careful review of the entire procedure, including notes lurking on the chart. When you contact ATC, it’s also important to request the specific procedure–including the letter–that you want to fly.

And, if you’re using an IFR-approved GPS–even for situational awareness or to act as a substitute for DME or ADF  when flying a ground-based approach– ensure that you load the correct procedure and verify the key fixes before you begin flying the approach.

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New Simulation and Training Rules Due in December 2017

The November/December 2017 issue of FAA Safety Briefing (dedicated to flight simulation) indicates that new FAA regulations proposed in May 2016 will be published in December 2017. In particular:

With another new rulemaking effort in the works, expected in December 2017, the FAA proposes to allow pilots to accomplish instrument currency pilot time in a FFS, FTD, or ATD without an instructor present to verify the time, as well as allow ATD time to accomplish instrument currency requirements to be identical to the tasks and requirements described for an aircraft, FFS, or FTD.

The other big change for many flight schools is allowing TAA to be used for commercial/CFI training in lieu of aircraft with retractable landing gear. The new rules would define TAA as “including a PFD, MFD and an integrated two axis autopilot.”

You can read more about the NPRM published in May 2016 at my blog, here.

 

 

My Perscription for Stall/Spin Training

My feature about stall and spin training in the November issue of AOPA Flight Training is now available online, here.
AOPAFT-Stall-Spin

RVR 1800 with AP, FD, or HUD

On May 30, 2017, FAA updated Order 8400.13D to allow “CAT I approaches with a DH of 200 feet and visibility minimums of RVR 1800 [a reduction from the typical 2400 RVR value] at runways with reduced lighting, using an aircraft flight director (FD) or autopilot (AP) with an approach coupler or head-up display (HUD) to DA.”

This change applies to ILS and RNAV (GPS) approaches with LPV minimums. (GBAS approaches are also included, but those procedures are, at present, rare.)
RVR1800-SatNews

The policy update was announced in the summer 2017 edition of SatNav News.

Here’s an example of the RVR 1800 minimums on the chart for the ILS or LOC Rwy 20 at KALW (Walla Walla, WA).

KALW-ILS-RWY 20-full

This typical category 1 ILS approach has an RVR of 2400 and a DA of 200 ft (1394 MSL).

KALW-ILS-RWY 20-mins
But as the notes for the procedure explain, the # symbol next to the S-ILS 20 minimums means that RVR 1800 is authorized with use of a flight director (FD) or autopilot (AP) or HUD to the DA.

KALW-ILS-RWY 20-notes
FAA Order 8400.13D adds the following information about reducing CAT 1 minimums to RVR 1800:

  • To be eligible for CAT I approaches to RVR 1800, runways must have or be qualified for a Title 14 of the Code of Federal Regulations (14 CFR) part 97 Standard Instrument Approach Procedure (SIAP).
  • Runways must have or be qualified for CAT I DH of 200 feet or less and visibility minimum of not more than 2400 RVR.
  • The runway must have a declared landing distance of 5000 feet or greater.
  • The runway also must have a simplified short approach lighting system with runway alignment indicator lights (SSALR), medium intensity approach lighting system with runway alignment indicator lights (MALSR), or approach lighting with sequenced flashing lights (ALSF-1/ALSF-2)
  • HIRL
  • TDZ sensor of an RVR reporting system.

The order adds that:

Any existing part 97 CAT I SIAP which did not qualify for 1800 RVR due to the absence of TDZ or RCL lighting can be amended to include 1800 RVR visibility.

When 1800 RVR operations are authorized, FAA will update the approach chart. If RVR 1800 minimums are authorized before a chart is updated, a NOTAM will be issued which authorizes RVR 1800. CAT I operations to RVR 1800 will be added to existing CAT I SIAPS in accordance with a schedule established by the Regional Airspace and Procedures Team.

The ILS OR LOC/DME RWY 21R at KPSC (Pasco, WA) is another example of RVR 1800 minimums authorized for an ILS.

KPSC-ILS-RWY 21R

The S-ILS 21R minimums line includes two asterisks that point to the notes section, which authorizes RVR 1800 with use of a FD, or AP, or HUD to DA.

KPSC-ILS-RWY 21R-Mins
KPSC-ILS-RWY 21R-Notes
The RNAV (GPS) Y RWY 21R at KPSC, updated in August 2017, shows the RVR 1800 minimums applied to an RNAV approach with LPV minimums. On this chart, the # note reference appears next to DA.

KPSC-ILS-RNAV 21R-Mins
KPSC-ILS-RNAV 21R-Notes

New Edition of Instrument Procedures Handbook

FAA has published a new edition of the Instrument Procedures Handbook (FAA-H-8083-16B). You can download a PDF of the IPH at the FAA website here.

The IPH is a complement to the Instrument Flying Handbook (FAA-H-8081-15B), available for download here.

A summary of changes in the new edition of the IPH is available as a PDF in my Aviation Documents folder, here.

IPH-Cover-2017

Transiting Airspace with Flight Following

Pilots who are receiving radar advisories, better known as VFR Flight Following, often wonder if they will be cleared to enter airspace along their route.

For example, assume you’re flying VFR between Albany, OR (S12) and Scappoose, OR (KSCP).

(To see the route below on charts at SkyVector.com, click here.)

As you can see on the chart below, the direct route takes you over Salem (KSLE), a Class D airport; just west of the Class D airspace at Aurora, OR (KUAO); and later through the Class D airspace at Hillsboro (KHIO). The course also tracks just west of the busy Class C airspace that surrounds Portland International Airport (KPDX).

Albany-Scappoose.jpg

After takeoff, you contact Cascade Approach for flight following, get a squawk code, and, without restrictions from ATC, proceed on the direct route to KSCP. An overcast layer at 3000 ft. MSL restricts your cruise to at or below 2500 ft.

Do you have to contact the towers at KSLE and KHIO for permission to transit their airspace? Although you’ll remain legally clear of the Class D airspace at KUAO if you can remain on the direct course, what if you need to zig and zag to avoid clouds? Should you contact Aurora Tower? What about the Class C airspace at KPDX?

The September 2017 issue of Air Traffic Procedures Bulletin (PDF), a newsletter for air traffic controllers published by the FAA, clarifies the roles of pilots and air traffic controllers when pilots are receiving flight following. The bulletin notes that pilots and controllers have shared responsibility.

VFR Aircraft Receiving Radar Advisories (VFR Flight Following) Approaching Class D

What are ATCs responsibilities? Who is responsible for the pilot’s communication responsibility within the Class D surface area?

Many times, pilots receiving VFR Radar Advisories believe that as long as they are talking to one ATC facility, they have fulfilled their responsibility for entering a Class D airspace. Pilots may believe that controllers will tell them when/if they are approaching a Class D surface area. As controllers, we have a responsibility to coordinate with the appropriate ATC facility having jurisdiction over the airspace.

First, controllers must follow the guidance in Air Traffic Control (JO 7110.65, PDF available here):

As controllers, we have a responsibility to coordinate with the appropriate ATC facility having jurisdiction over the airspace, FAA Order JO 7110.65W states:

2-1-16. SURFACE AREAS

b. Coordinate with the appropriate control tower for transit authorization when you are providing radar traffic advisory service to an aircraft that will enter another facility’s airspace.

NOTE− The pilot is not expected to obtain his/her own authorization through each area when in contact with a radar facility.

But the bulletin notes that pilots also have a regulatory requirement to establish two-way communications before entering Class D or Class C airspace, as noted in the AIM and other sources.

The pilot’s responsibility to meet their radio communication requirement to enter Class D airspace is NOT eliminated when receiving VFR Radar Advisories. The Aeronautical Information Manual, 3-2-1, states:

d. VFR Requirements. It is the responsibility of the pilot to ensure that ATC clearance or radio communication requirements are met prior to entry into Class B, Class C, or Class D airspace. The pilot retains this responsibility when receiving ATC radar advisories. (See 14 CFR Part 91.)

To resolve this conflict, the bulletin goes on to explain:

Since both the controller providing VFR Radar Advisories and the pilot who is receiving the advisories have a clear responsibility, there can be some confusion about which party is communicating with the ATC facility having jurisdiction over the Class D surface area. 14 CFR 91.129 includes language that specifies that it is the pilot’s overall responsibility for complying with the Class D communications requirement.

There are a few ways controllers can assist pilots when providing VFR Radar Advisories that will ultimately help with controller workload. Since the pilot is responsible for their Class D communication requirement, if the controller coordinates with the ATC facility having jurisdiction over the surface area, let the pilot know, so they do not query you. If you are too busy to coordinate, you are required to terminate VFR Radar Advisories in a timely manner so the pilot is able to contact the Class D ATC facility prior to entry.

It’s also important to note that air traffic control facilities have letters of agreement (LOA) to establish local procedures, such as entry and exit routes at busy airports, handoffs between facilities, and similar matters. These LOA are not typically published for pilots. An LOA may allow an approach facility to send aircraft under its control through a Class D surface area at specific altitudes and along certain routes. Or the LOA may streamline the coordination required before one controller allows an aircraft to enter another controller’s airspace.

For more information about your obligation to follow ATC instructions, see Compliance with ATC Clearances and Instructions—Even When VFR.

For more information on this topic, see BruceAir’s Guide to ATC Services for VFR Pilots.

An ILS that Requires GPS

You can still fly IFR in the U.S. without an IFR-approved GNSS (i.e., GPS), but being “slant G” (/G in the soon-to-be obsolete FAA domestic flight plan format) increasingly offers advantages, even if you fly only conventional procedures based on ground navaids. And sometimes an IFR-approved GNSS is required to fly even an ILS.

Consider the ILS Z OR LOC Z RWY 16R approach at Reno/Tahoe International Airport (KRNO). This procedure is not an Authorization Required approach–RNP doesn’t appear in the title, and you won’t find that restrictive note on the chart. (For more information about RNP procedures, see RNP Procedures and Typical Part 91 Pilots.)

KRNO-ILSorLOCZRwy16R

But the equipment required notes for this ILS approach include “RNAV-1 GPS required.”

KRNO-ILSorLOCZRwy16R-notes
A review of the plan view and missed approach track show why GPS is necessary to fly this procedure.

KRNO-ILSorLOCZRwy16R-Plan

First, you need GPS to fly transitions from most of initial fixes, which are RNAV waypoints marked by a star symbol.

RNAV-Waypoint-Symbol

Only LIBGE, directly north of the runway, is a non-RNAV IAF.

For example, HOBOA, KLOCK, BELBE, and WINRZ are all RNAV waypoints that serve as IAFs or IFs. Now, NORCAL Approach might provide vectors to the final approach course, but if you want to fly this procedure you should be prepared for a clearance direct to one of those fixes (see Avoiding the Vectors-to-Final Scramble).

Note also that entire missed approach track requires use of GNSS.

Two of the transitions are of special note. The “arcs” that begin at ZONBI and SLABS are radius-to-fix (RF) legs that are part of the transitions that begin at HOBOA and KLOCK. Each of those fixes is distinguished by the notes “RNP-1 GPS REQD” and “RF REQD.”

The first note means that your GPS must meet the RNP 1 standard, which is used for terminal procedures such as SIDs and STARs, the initial phases of approaches, and missed-approach segments. (For more information about RNP, see RNP Procedures and Typical Part 91 Pilots.)

Until recently, RF legs were included only in Authorization Required (AR) procedures. But as I explained in Garmin GTN Avionics and RF Legs, certain RF legs are now available if you have an appropriate GNSS navigator, updated system software, an electronic HSI, and other equipment. Some limitations on flying such RFs also apply, as described in that earlier post.

Suppose that you choose the less intimidating ILS X or LOC X RWY 16R to the same runway. A review of the notes and the plan view shows that even this conventional-looking ILS also requires RNAV 1 GPS, both to fly the transition from WINRZ and the missed approach track.

KRNO-ILSorLOCXRwy16R.jpg