KSHN RNAV (GPS) RWY 23

Here’s video from a recent IFR proficiency flight in my Beechcraft A36, a 1989 model with updated avionics, including a Garmin G500 PFD/MFD and Garmin GTN 750.

Video of an approach at KSHN

I departed Boeing Field (KBFI) in Seattle for the quick hop to Sanderson Field in Shelton, WA (KSHN).

The basic route on a VFR chart

This video picks up after Seattle Approach cleared me to HOOME, an IAF for the RNAV (GPS) RWY 23 approach.

My avionics are capable of flying this procedure to LPV (localizer performance with vertical guidance) minimums. In other words, this RNAV (GPS) procedure offers approved vertical guidance–a GPS-derived glidepath. Flying to LPV minimums effectively uses the same techniques as flying an ILS.

Note, however, that this procedure includes two lines of LPV minimums. The decision altitude (DA) for the first line is 523 ft with a visibility requirement of 3/4 sm.

The second LPV line has higher minimums: 667 ft and 1-1/4 sm.

Why the difference? Note the # next to the DA in the first line. It leads you to a note in the description near the top of the chart:

#LPV missed approach requires minimum climb of 244 feet per NM to 1700.

To use the minimums of DA of 523 and 3/4 sm visibility, you must be able to climb at 244 feet per NM during the initial stages of the missed approach. That’s a slightly higher climb gradient than the standard 200 feet per NM.

Note that the climb requirement is for a climb gradient in feet per NM, not a rate of climb in feet per minute. To determine if your aicraft is capable of achieving the required climb gradient, you must check the Climb/Descent Table in the supplement to the Terminal Procedures Publication or calculate the climb gradient that corresponds to your groundspeed and rate of climb when you fly the missed approach portion of the procedure.

In my A36, climbing out at 110 KIAS, with a groundspeed of about 100 KIAS given the headwind component, and an initial (conservative) climb rate of about 600 fpm, my climb gradient is about 300 ft/nm, so I can use the lower DA and visibility when flying this approach.

You can find more videos from this IFR flight at my YouTube channel, BruceAirFlying.

New GTN Guides

Pilot Workshops has published updated versions of its Pilot-Friendly manuals for the Garmin GTN 750 and GTN 650 touch-screen navigators. More details and samples here.

Full disclosure: I was the primary author of the new GTN editions, with a lot of help from the editors and graphics staff at Pilot Workshops. I also contribute to the company’s IFR and VFR training scenarios.

The books are available both in spiral-bound print editions and as PDFs.cover-gtn750

Videos: A Couple of Instrument Approaches

I took my A36 Bonanza out for some instrument practice. Here are a couple of longish videos, with ATC, that show the RNAV (GPS) RWY 20 approach at Bremerton National (KPWT) and the ILS RWY 14R at Boeing Field (KBFI).

The aircraft is equipped with a Garmin G500 PFD/MFD and GTN 750 WAAS navigator. I use ForeFlight on an iPad Mini 5 for flight planning, charts, ADS-B weather (FIS-B) and traffic (TIS-B). A good source of information about using tablets in the cockpit is iPad Pilot News.

You can find the videos on my YouTube channel, BruceAirFlying, or watch them via the direct links below.

An RNAV Approach at Walla Walla

Here’s video of the RNAV (GPS) RWY 20 approach at Walla Walla, WA (KALW). Because my A36 Bonanza is equipped with WAAS-capable Garmin GTN 750, I can fly to the ILS-like LPV (localizer performance with vertical guidance) minimums. Given the choice between an ILS and an RNAV procedure with LPV minimums, I usually choose the RNAV approach. It’s easier to set up with no CDI switching required.

AIM Updates 28 February 2019

FAA has published changes to the AIM effective 28 February 2019. You can download the PDF that lists the changes and includes all of the updated text. The updates of most interest to general aviation pilots focus on the following sections.

1−2−1. General

1−2−2. Required Navigation Performance (RNP)

5−2−9. Instrument Departure Procedures (DP) − Obstacle Departure Procedures (ODP), Standard Instrument Departures (SID), and Diverse Vector Areas (DVA)

5−4−1. Standard Terminal Arrival (STAR) Procedures

5−4−5. Instrument Approach Procedure (IAP) Charts

There was not enough adequate information concerning Performance−Based Navigation (PBN) and Advanced Required Navigational Performance (A−RNP) available to flight crews and operators in the AIM. This expansion in the description and advantages of these navigation specifications (NavSpecs) will provide better guidance as to what A−RNP is, how it will be applied, and its applicability in the PBN NAS. Additional information is being added to better clarify NavSpecs, RNP, and PBN understanding in AIM Chapter 1. Associated paragraph changes are necessary to ensure harmonization between all the paragraphs in the AIM.

5−1−8. Flight Plan (FAA Form 7233−1) − Domestic IFR Flights

This change updates pilot guidance to incorporate air traffic control (ATC) procedures for GNSS−equipped aircraft operating on area navigation (RNAV) air traffic service (ATS) routes and on random point−to−point and random impromptu routes in airspace in which ATC procedures are applied, excluding oceanic airspace. This change also incorporates the use of the term GNSS in place of RNAV for space−based positioning and navigation systems.

Area Navigation, RNAV, RNP, and A-RNP

AIM 1−2−1 includes new explanations of RNAV and performance-based navigation (PBN). Before reviewing the new information in this section of the AIM, it’s important to remember that AIM 1−1−17. Global Positioning System (GPS) notes that:

(5) Aircraft navigating by IFR−approved GPS are considered to be performance−based navigation (PBN) aircraft and have special equipment suffixes.

The specific capabilities of the GNSS (GPS) in your panel are described in the AFM Supplement and operating handbooks for the equipment (as updated when new system software is installed). You can find more information about RNAV and RNP specs in AC 90-105 and at RNP Procedures and Typical Part 91 Pilots here at BruceAir.

With that in mind, it’s important to understand that if your airplane is equipped with, say, a Garmin GNS530W/GNS530W or GTN 750/650 (with an appropriate AFM supplement), you can fly RNAV SIDs and STARs based on RNP-1 criteria. And you can also fly en route segments that require RNP-2 accuracy. No special authorization is required at these RNP levels.

For more information about RNP levels, see “Required Navigation Performance” in the Instrument Procedures Handbook (2-34).

IPH-RNP Levels

Figure 9-41 in the Instrument Flying Handbook is also helpful.

IFH-Fig9-41

Update to AIM 1−2−1. General

Here’s the new language in AIM 1-2-1, the introduction to PBN. Note that RAIM, used to validate the accuracy and reliablity of non-WAAS GPS for use under IFR, qualifies as “onboard performance monitoring and alerting capability” for purposes of PBN and basic RNP. WAAS, which incorporates its own performance and accuracy checking system, also provides onboard performance monitoring and alerting capability.

a. Introduction to PBN. As air travel has evolved, methods of navigation have improved to give operators more flexibility. PBN exists under the umbrella of area navigation (RNAV). The term RNAV in this context, as in procedure titles, just means “area navigation,” regardless of the equipment capability of the aircraft…Many operators have upgraded their systems to obtain the benefits of PBN. Within PBN there are two main categories of navigation methods or specifications: area navigation (RNAV) and required navigation performance (RNP). In this context, the term RNAV x means a specific navigation specification with a specified lateral accuracy value. For an aircraft to meet the requirements of PBN, a specified RNAV or RNP accuracy must be met 95 percent of the flight time. RNP is a PBN system that includes onboard performance monitoring and alerting capability (for example, Receiver Autonomous Integrity Monitoring (RAIM)). PBN also introduces the concept of navigation specifications (NavSpecs) which are a set of aircraft and aircrew requirements needed to support a navigation application within a defined airspace concept. For both RNP and RNAV NavSpecs, the numerical designation refers to the lateral navigation accuracy in nautical miles which is expected to be achieved at least 95 percent of the flight time by the population of aircraft operating within the airspace, route, or procedure. This information is detailed in International Civil Aviation Organization’s (ICAO) Doc 9613, Performance−based Navigation (PBN) Manual and the latest FAA AC 90−105, Approval Guidance for RNP Operations and Barometric Vertical Navigation in the U.S. National Airspace System and in Remote and Oceanic Airspace.

Required Navigation Performance (RNP)

Here’s the new language in AIM 1−2−2.

a. General. While both RNAV navigation specifications (NavSpecs) and RNP NavSpecs contain specific performance requirements, RNP is RNAV with the added requirement for onboard performance monitoring and alerting (OBPMA). RNP is also a statement of navigation performance necessary for operation within a defined airspace. A critical component of RNP is the ability of the aircraft navigation system to monitor its achieved navigation performance, and to identify for the pilot whether the operational requirement is, or is not, being met during an operation. OBPMA capability therefore allows a lessened reliance on air traffic control intervention and/or procedural separation to achieve the overall safety of the operation. RNP capability of the aircraft is a major component in determining the separation criteria to ensure that the overall containment of the operation is met. The RNP capability of an aircraft will vary depending upon the aircraft equipment and the navigation infrastructure. For example, an aircraft may be eligible for RNP 1, but may not be capable of RNP 1 operations due to limited NAVAID coverage or avionics failure. The Aircraft Flight Manual (AFM) or avionics documents for your aircraft should specifically state the aircraft’s RNP eligibilities. Contact the manufacturer of the avionics or the aircraft if this information is missing or incomplete. NavSpecs should be considered different from one another, not “better” or “worse” based on the described lateral navigation accuracy. It is this concept that requires each NavSpec eligbility to be listed separately in the avionics documents or AFM. For example, RNP 1 is different from RNAV 1, and an RNP 1 eligibility does NOT mean automatic RNP 2 or RNAV 1 eligibility. As a safeguard, the FAA requires that aircraft navigation databases hold only those procedures that the aircraft maintains eligibility for. If you look for a specific instrument procedure in your aircraft’s navigation database and cannot find it, it’s likely that procedure contains PBN elements your aircraft is ineligible for or cannot compute and fly. Further, optional capabilities such as Radius−to−fix (RF) turns or scalability should be described in the AFM or avionics documents. Use the capabilities of your avionics suite to verify the appropriate waypoint and track data after loading the procedure from your database.

RNP Approach (RNP APCH) and RNP AR APCH

The new language in this section of the AIM intends to address confusion about RNP and approaches. Unfortunately, because FAA continues to use RNAV in procedure titles, many pilots remain puzzled about the differences between the terms RNAV, RNP APCH, and RNP AR APCH. As this part of the revised AIM 1−2−2 notes:

In the U.S., RNP APCH procedures are titled RNAV (GPS) and offer several lines of minima to accommodate varying levels of aircraft equipage: either lateral navigation (LNAV), LNAV/vertical navigation (LNAV/VNAV), Localizer Performance with Vertical Guidance (LPV), and Localizer Performance (LP).

A helpful guide from FAA, Required Navigation Performance (RNP) Approaches (APCH), succinctly explains the different lines of minimums and provides helpful links to ACs, the AIM, and other sources.

Here’s the detailed language in the updated AIM:

(1) RNP Approach (RNP APCH). In the U.S., RNP APCH procedures are titled RNAV (GPS) and offer several lines of minima to accommodate varying levels of aircraft equipage: either lateral navigation (LNAV), LNAV/vertical navigation (LNAV/VNAV), Localizer Performance with Vertical Guidance (LPV), and Localizer Performance (LP). GPS with or without Space−Based Augmentation System (SBAS) (for example, WAAS) can provide the lateral information to support LNAV minima. LNAV/VNAV incorporates LNAV lateral with vertical path guidance for systems and operators capable of either barometric or SBAS vertical. Pilots are required to use SBAS to fly to the LPV or LP minima. RF turn capability is optional in RNP APCH eligibility. This means that your aircraft may be eligible for RNP APCH operations, but you may not fly an RF turn unless RF turns are also specifically listed as a feature of your avionics suite. GBAS Landing System (GLS) procedures are also constructed using RNP APCH NavSpecs and provide precision approach capability. RNP APCH has a lateral accuracy value of 1 in the terminal and missed approach segments and essentially scales to RNP 0.3 (or 40 meters with SBAS) in the final approach. (See Paragraph 5−4−18, RNP AR Instrument Approach Procedures.)

(2) RNP Authorization Required Approach (RNP AR APCH). In the U.S., RNP AR APCH procedures are titled RNAV (RNP). These approaches have stringent equipage and pilot training standards and require special FAA authorization to fly. Scalability and RF turn capabilities are mandatory in RNP AR APCH eligibility. RNP AR APCH vertical navigation performance is based upon barometric VNAV or SBAS. RNP AR is intended to provide specific benefits at specific locations. It is not intended for every operator or aircraft. RNP AR capability requires specific aircraft performance, design, operational processes, training, and specific procedure design criteria to achieve the required target level of safety. RNP AR APCH has lateral accuracy values that can range below 1 in the terminal and missed approach segments and essentially scale to RNP 0.3 or lower in the final approach. Before conducting these procedures, operators should refer to the latest AC 90−101, Approval Guidance for RNP Procedures with AR. (See paragraph 5−4−18.)

Advanced RNP (A−RNP)

If you’re keeping up so far, the new language in AIM 1−2−2 provides more details about Advanced RNP (A-RNP), not to be confused with RNP (AR). Some features of A-RNP, such as the ability to fly some RF legs, are available if you have the current system software installed in a Garmin GTN navigator. For more information, see Garmin GTN Avionics and RF Legs here at BruceAir.

(4) Advanced RNP (A−RNP). Advanced RNP is a NavSpec with a minimum set of mandatory functions enabled in the aircraft’s avionics suite. In the U.S., these minimum functions include capability to calculate and perform RF turns, scalable RNP, and parallel offset flight path generation. Higher continuity (such as dual systems) may be required for certain oceanic and remote continental airspace. Other “advanced” options for use in the en route environment (such as fixed radius transitions and Time of Arrival Control) are optional in the U.S. Typically, an aircraft eligible for A−RNP will also be eligible for operations comprising: RNP APCH, RNP/RNAV 1, RNP/RNAV 2, RNP 4, and RNP/RNAV 10. A−RNP allows for scalable RNP lateral navigation values (either 1.0 or 0.3) in the terminal environment. Use of these reduced lateral accuracies will normally require use of the aircraft’s autopilot and/or flight director. See the latest AC 90−105 for more information on A−RNP, including NavSpec bundling options, eligibility determinations, and operations approvals.

NOTE−
A−RNP eligible aircraft are NOT automatically eligible for RNP AR APCH or RNP AR DP operations, as RNP AR eligibility requires a separate determination process and special FAA authorization.

(5) RNP 1. RNP 1 requires a lateral accuracy value of 1 for arrival and departure in the terminal area, and the initial and intermediate approach phase when used on conventional procedures with PBN segments (for example, an ILS with a PBN feeder, IAF, or missed approach). RF turn capability is optional in RNP 1 eligibility. This means that your aircraft may be eligible for RNP 1 operations, but you may not fly an RF turn unless RF turns are also specifically listed as a feature of your avionics suite.

(6) RNP 2. RNP 2 will apply to both domestic and oceanic/remote operations with a lateral accuracy value of 2.

PBN Requirement Boxes

AIM 1−2−2 now includes language about equipment requirement boxes on procedures that include PBN elements. For more information, see New Equipment Required Notes and An ILS that Requires GPS here at BruceAir.

(c) Depiction of PBN Requirements. In the U.S., PBN requirements like Lateral Accuracy Values or NavSpecs applicable to a procedure will be depicted on affected charts and procedures. In the U.S., a specific procedure’s Performance−Based Navigation (PBN) requirements will be prominently displayed in separate, standardized notes boxes. For procedures with PBN elements, the “PBN box” will contain the procedure’s NavSpec(s); and, if required: specific sensors or infrastructure needed for the navigation solution, any additional or advanced functional requirements, the minimum RNP value, and any amplifying remarks. Items listed in this PBN box are REQUIRED to fly the procedure’s PBN elements. For example, an ILS with an RNAV missed approach would require a specific capability to fly the missed approach portion of the procedure. That required capability will be listed in the PBN box. The separate Equipment Requirements box will list ground−based equipment and/or airport specific requirements. On procedures with both PBN elements and ground−based equipment requirements, the PBN requirements box will be listed first.

Flying and Flying Direct with GNSS (GPS)

AIM 5−1−8 now provides more details for pilots flying under IFR with GNSS about filing direct routes or requesting direct clearances from ATC. The new text focuses on direct routes that include legs that exceed navaid service volumes and provides more details about filing direct routes.

In particular, if you plan a direct flight you should:

  • File and fly point-to-point using published waypoint names (airports, navaids, intersections, and RNAV waypoints) to define the route of flight.
  • Include at least one named waypoint within each ARTCC through which the flight will pass.

4. Increasing use of self−contained airborne navigational systems which do not rely on the VOR/VORTAC/TACAN system has resulted in pilot requests for direct routes that exceed NAVAID service volume limits. With the exception of GNSS−equipped aircraft, these direct route requests will be approved only in a radar environment, with approval based on pilot responsibility for navigation on the authorized direct route. Radar flight following will be provided by ATC for ATC purposes. For GNSS−equipped aircraft, ATC may approve a direct route that exceeds ground based NAVAID service volume limits; however, in a non−radar environment, the routing must be “point−to−point,” defined as navigation from a published point to a published point, and navigational assistance will not be available. (See subparagraph 5−1−8d below.)

5. At times, ATC will initiate a direct route in a radar environment that exceeds NAVAID service volume limits. In such cases ATC will provide radar monitoring and navigational assistance as necessary. For GNSS−equipped aircraft, if the route is point−to−point, radar monitoring and navigational assistance is not required. (See subparagraph 5−1−8d below.)

d. Area Navigation (RNAV)/Global Navigation Satellite System (GNSS) 1. Except for GNSS−equipped aircraft, random impromptu routes can only be approved in a radar environment. A random impromptu route is a direct course initiated by ATC or requested by the pilot during flight. Aircraft are cleared from their present position to a NAVAID, waypoint, fix, or airport. Factors that will be considered by ATC in approving random impromptu routes include the capability to provide radar monitoring and compatibility with traffic volume and flow. ATC will radar monitor each flight; however, navigation on the random impromptu route is the responsibility of the pilot. GNSS−equipped aircraft are allowed to operate in a non−radar environment when the aircraft is cleared via, or is reported to be established on, a point−to−point route. The points must be published NAVAIDs, waypoints, fixes, or airports recallable from the aircraft’s database. The distance between the points cannot exceed 500 miles and navigational assistance will not be provided…

(f) File a minimum of one route description waypoint for each ARTCC through whose area the random route will be flown.

VOR Status–Another Update

FAA provided another update on its plans to reduce the VOR network at the October 2018 meeting of the Aeronautical Charting Meeting. The latest Very High Frequency Omnidirectional Range (VOR) Minimum Operational Network (MON) Program update (PDF) includes the following key details:

  • 311 VORs (about 30 percent) will be shut down by 2025
  • 585 VORs will remain operational
  • Most of the VORs to be deactivated are in the East (133) and Central (163) regions; in the West, only 15 navaids are on the list to be turned off.
  • As of September 2018, 34 VORs, VOR/DME, and VORTACs have been shut down.
  • At the end of 2018, 34 of the 74 Phase 1 VORs have been shut down.
  • FAA plans to enhance the service volume of remaining VORs from 40 nm to 70 nm beginning at 5000 AGL. The enhanced VORs will be classified as VOR Low (VL) and VOR High (VH).  Documents such as the AIM will be updated as the enhancement program gets underway. The illustration below shows the coverage that the enhanced VORs will provide at or above 5000 AGL.

VOR-MON-70NM.jpg

As I’ve noted in several previous posts (e.g., here), the VOR MON program is designed to provide backup to GNSS (GPS). Specifically, within the contiguous United States the MON program will support conventional navigation in the event of a GPS outage by ensuring that pilots can:

  • Tune and identify a VOR at an altitude of 5,000 feet above site level and higher
  • Conduct VOR navigation through a GPS outage area
  • Navigate to a MON airport within 100 nautical miles to fly an Instrument
    Landing System (ILS), Localizer (LOC) or VOR instrument approach without
    GPS, DME, Automatic Direction Finder (ADF), or radar
  • Navigate along VOR Airways, especially in mountainous terrain, where
    Minimum En-route Altitudes (MEAs) make direct-to navigation impracticable

MON airports (i.e., those with conventional instrument procedures as described above) will be identified on en route charts, FAA Chart Supplements, and included in the National Airspace System Resource (NASR) Subscriber File data set for developers of electronic charts, apps, and so forth.

The FAA’s detailed policy for the transition was outlined in the Federal Register, here. More information about the program to reduce the VOR neworks is available at AOPA, here.

Here’s the list of next round of VORs scheduled to be shut down. I have provided links to the navaids at SkyVector.com so that you can see each location on a sectional chart. Note that in each case, several nearby VORs will remain in service:

BUU (BURBUN) Burlington, WI – Nov. 8, 2018
RUT (RUTLAND) Rutland, VT  – Nov. 8 2018
VNN (MT VERNON) Vernon, IL – Nov. 8, 2018
TVT (TIVERTON) Tiverton, OH  – Nov. 8, 2018
CSX (CARDINAL) St. Louis, MO – Jan. 3, 2019
ISQ (SCHOOLCRAFT CO) Manistique, MI – Jan. 3, 2019
MTO (MATTOON) Mattoon, IL – Jan. 3, 2019
ORD (CHICAGO O’HARE) Chicago, IL – Jan. 3, 2019
RID (RICHMOND) Richmond, IN – Jan. 3, 2019
FRM (FAIRMOUNT) Fairmont, MN – Feb. 28, 2019
GNP (GLENPOOL) Tulsa, OK – Feb. 28, 2019
LSE (LA CROSSE) La Crosse WI – Feb. 28, 2019
MTW (MANITOWOC) Manitowoc, WI – Feb. 28, 2019
GTH (GUTHERIE) Guthrie, TX – Apr. 25, 2019
HUB (HOBBY) Hobby, TX – Apr. 25
CZQ (CLOVIS) Clovis, in Fresno, CA – Apr. 25, 2019

Another Update on IPCs

Changes to the wording of 14 CFR Part 61.57(d) in July 2018 caused confusion among some flight instructors about which tasks are now required when administering an instrument proficiency check (IPC). I earlier wrote about a question that I posed to FAA and the agency’s response in Clarification of IPC Requirements.

As that post notes, the FAA still requires an IPC to include the tasks listed in Appendix A of the Instrument Rating-Airplane ACS.

FAA released an editorial update to AC 61-98D Currency Requirements and Guidance for the Flight Review and Instrument Proficiency Check, but Appendix J of that document still referenced the old language of 14 CFR Part 61.57(d), so I wrote FAA again to point out the error and ask for clarification.

Here’s part of the response that I received via email:

Background. As stated in the preamble discussion addressing the revised regulatory text language in § 61.57(d), “The FAA finds that this revision is not a substantive change because the areas of operation and instrument tasks required for an IPC remain unchanged. Thus, an IPC is still driven by the standards for the instrument rating practical test.” For instance, just as § 61.65(c) describes the areas of operation that a pilot must meet to complete the instrument rating practical test successfully, the ACS provides the required tasks, details, and level of proficiency for successful completion of that practical test. The Instrument Rating ACS also include the tasks that a pilot must accomplish for the successful completion of an IPC, as well as providing the associated proficiency standards applicable to the areas of operation identified in §61.57(d). Bear in mind that § 61.43(a)(3), Practical tests: General procedures, require examiners to conduct evaluations under approved standards. It states, “(a) Completion of the practical test for a certificate or rating consists of—3) Demonstrating proficiency and competency within the approved standards.” Applicable ACS/PTS documents provide FAA approved standards. In this same manner, the FAA provides the standards by which an authorized instructor must conduct an IPC. Therefore, the FAA still requires the use of applicable ACS/PTS to provide the tasks and standards for an IPC. The tasks required for an IPC are still driven by the approved standards for the instrument rating practical test.

Response. In review of your feedback, our office determined that your observation is correct. The FAA did not update the regulatory reference to § 61.57(d) in AC 61-98D, Appendix J, which can cause confusion. To correct this inaccuracy, we will:

  1. Revise AC 61-98D by correcting its reference to § 61.57(d) containing obsolete regulatory text and replace it with the current regulatory text in § 61.57(d);
  2. Provide additional information explaining the basis for the requirement to use the approved standards provided by ACS/PTS, as applicable, in the conduct of an IPC; and
  3. Submit an editorial revision correcting this matter at the time of the next approved revision period for AC 61-98D.