Simulating Partial-Panel with a G500/G600

I schedule an annual instrument proficiency check before the Pacific Northwest skies turn gray as fall arrives. The tasks that you must accomplish to complete an IPC are outlined in the practical test standards for the instrument rating and in an appendix to Instrument Proficiency Check (IPC) Guidance, published by FAA.

Instrument Proficiency Check. 14 CFR part 61, section 61.57(d), sets forth the requirements for an instrument proficiency check. The person giving that check shall use the standards and procedures contained in this PTS when administering the check. A representative number of Tasks, as determined by the examiner/instructor, must be selected to assure the competence of the applicant to operate in the IFR environment. As a minimum, the applicant must demonstrate the ability to perform the Tasks as listed in the [chart below]. The person giving the check should develop a scenario that incorporates as many required tasks as practical to assess the pilot’s ADM and risk management skills during the IPC. See Appendix 2 for IPC AATD Credit Table. (FAA-S-8081-4E with Changes 1, 2, 3, 4, & 5)

As you can see, the required items include VII–Emergency Operations, Task D: Approach with Loss of Primary Flight Instrument Indicators. The notes for that task in the PTS specify that the pilot, “Demonstrat[e] a non-precision instrument approach without the use of the primary flight instrument using the objectives of the non-precision approach Task (Area of Operation VI, Task A).”

In an airplane with conventional instruments (the so-called steam gauges), the instructor covers the attitude indicator with a suction cup, business card, or sticky note.

Like many pilots, however, I’ve updated my instrument panel. It now features a Garmin G500 electronic display that replaces six traditional primary flight instruments (airspeed indicator, attitude indicator, altimeter, vertical speed indicator, heading indicator, and turn coordinator). I have a backup attitude indicator, ASI and altimeter in the self-contained Mid-Continent SAM.

Now, avionics manufacturers and the FAA have advised against pulling circuit breakers to simulate failures of electronic displays and the behind-the-scenes gizmos that drive them (e.g., attitude-heading reference systems). Plastering expensive displays—especially touch-screens–with sticky notes isn’t a good idea. So, how to simulate the failure of the PFD (the left side of the G500)—or, indeed the entire GDU 620, the two-panel display that shows the flight instruments and a map?

For more information about using CBs to simulate failures, see Garmin’s G1000 Guide for Designated Pilot Examiners and Certified Flight Instructors. That document notes in part:

Cessna does not recommend pulling circuit breakers as a means of simulating failures on the Garmin G1000. Pulling circuit breakers—or using them as switches—has the potential to weaken the circuit breaker to a point at which it may not perform its intended function. Using circuit breakers as switches is also discouraged in Advisory Circulars 120-80, 23-17B, and 43.13-1B. Additionally, a circuit breaker may be powering other equipment (such as avionics cooling fans) that could affect the safe operation of other equipment.

For the map side, it’s easy—select a page that shows, say, A/FD information or one of the AUX pages. They’re useless as references during an approach.

After much deep thought, I came up with the following solution for the PFD side: A piece of cardboard taped above the display. Here’s the item lying in wait in the holder that I use for my iPad.

And here it is in place, covering most of the PFD.

Inelegant to be sure. I’ll trim it to size next time. But it’s simple, non-destructive, cheap, and easy to put in place and remove. In a aircraft used primarily for training, I’d consider a strip of Velcro above the PFD.

If you wanted to “fail” just the attitude indicator and leave the ASI, altimeter, VSI, HI, CDI, bearing pointers, and other information visible, you could trim the cardboard so that it covers only the AI portion of the PFD.

Today, however, I wanted to simulate a complete failure of the GDU 620 to see how well I could fly an approach using the SAM and the navigation information on the GTN750 and the chart on my iPad. Per the PTS, I was flying a non-precision approach, so I didn’t need a glideslope indicator.

To set up descents on each segment of the approach, I applied the Pitch+Power+Configuration=Performance equation, knowing that at a specified power setting and pitch in a given configuration (flaps and landing gear positions), I would descend at approximately 600 fpm at a stable airspeed. Tracking the courses was a bit more difficult than when using the HSI, but this was a simulated emergency, so I used all available sources, including the depiction of my airplane on the GTN750 moving map and the approach chart displayed (via ForeFlight) on my iPad. By making small, coordinated turns based on the SAM, I never wandered more than about a dot off the centerline of any segment of the approach. The graphical information made meeting altitude restrictions easier. And the trend vectors that show how your current track relates to the required course were also a big help in making smooth, small heading changes.

I plan to use this high-tech failure simulator in the future when I practice flying instrument procedures (in VMC, of course) to maintain my proficiency. Note that this device would also work well in ATDs and FTDs that feature glass cockpits.

New Edition of the Instrument Procedures Handbook

The FAA has published a new edition of the Instrument Procedures Handbook (FAA-H-8083-16). You can download the free PDF from the FAA website, here.

This is first major update to the IPH since 2007. As the preface notes:

It is designed as a technical reference for all pilots who operate under instrument flight rules (IFR) in the National Airspace System (NAS). It expands and updates information contained in the FAA-H-8083-15B, Instrument Flying Handbook, and introduces advanced information for IFR operations. Instrument flight instructors, instrument pilots, and instrument students will also find this handbook a valuable resource since it is used as a reference for the Airline Transport Pilot and Instrument Knowledge Tests and for the Practical Test Standards. It also provides detailed coverage of instrument charts and procedures including IFR takeoff, departure, en route, arrival, approach, and landing. Safety information covering relevant subjects such as runway incursion, land and hold short operations, controlled flight into terrain, and human factors issues also are included.

FAA Proposed Policy for Discontinuance of Certain Instrument Approach Procedures

Here’s the link to the notice in the Federal Register. Excerpts:

As new technology facilitates the introduction of area navigation (RNAV) instrument approach procedures over the past decade, the number of procedures available in the National Airspace System has nearly doubled. The complexity and cost to the Federal Aviation Administration (FAA) of maintaining the existing ground based navigational infrastructure while expanding the new RNAV capability is not sustainable. The FAA is considering the cancellation of certain Non-directional Beacon (NDB) and Very High Frequency (VHF) Omnidirectional Radio Range (VOR) instrument approach procedures (IAP) at airports that have multiple instrument approach procedures. The FAA proposes specific criteria to guide the identification and selection of appropriate NDB and VOR instrument approach procedures that can be considered for cancellation. The VOR IAPs associated with this cancellation initiative would be selected from the criteria outlined below. This Notice is not a part of the FAA’s VOR minimum operating network (MON) initiative…

By this notice, the FAA seeks comments on proposed criteria that would facilitate the FAA’s determination of which procedures can be considered for cancellation. After reviewing the comments submitted to this notice, the FAA will use the criteria for selection of potential NDB and VOR procedures for cancellation. Once the criteria are established and the FAA considers IAPs for cancellation, the FAA will publish a list of potential IAPs in the Federal Register for notice and comment. Submitted comments will be reviewed and addressed in the final list of subject IAPs published in the Federal Register. The criteria proposed in this notice does not affect any NAS navigational back-up plans and is not a part of the FAA’s VOR minimum operating network (MON) initiative…

The NDB and VOR IAPs recommended for cancellation would be selected at airports using the following criteria. It must be noted that all airports that have existing RNAV and ground-based IAPs would maintain at least one RNAV and one ground-based IAP.

Airports that would be considered for NDB or VOR IAP cancellation:

— All airports with an NDB IAP.

—All airports with a VOR/DME RNAV IAP, unless it is the only IAP at the airport.

—All airports with two or more ground-based IAPs and an RNAV IAP.

—All airports with multiple, redundant ground-based IAPs (e.g., three VOR procedures).

Additional consideration would be given to the following factors in determining the list of potential candidates for cancellation:

—Prevailing wind runways.

—Prevailing runway alignment during adverse weather operations.

—If an airport has a published ILS IAP and additional ground-based IAPs, cancel the procedure to the same runway as the ILS.

—For airports with multiple VOR and NDB IAP’s, retain the IAP with the lowest minimums (if minimums are within 20 feet of each other retain the procedure that allows optimum use by all customers (i.e. VOR and VOR/DME retain VOR because there are no equipage limitations).

Airports that would not be considered for NDB or VOR IAP cancellations:

—Airport with only RNAV/RNPs IAPs published.

—Airport with only one ground-based procedure.

—Airports will not be considered if cancellation would result in removing all IAPs from the airport.

Lastly, the FAA is not considering the following types of procedures for cancellation:

PBN Procedures (RNAV or RNP).

ILS procedures.

Localizer procedures.

TACAN procedures.

Standard Instrument Arrivals (STARs).Show citation box

Standard Instrument Departures (SIDs).

New ATC Phraseology for RNAV Aircraft

The FAA has updated its Air Traffic Control handbook (JO 7110.65) with changes to approach clearances issued by controllers. The new procedures and phraseology, which primarily affect RNAV-equipped aircraft, were published in this notice (PDF), are effective June 3, 2013.

Here’s a summary of the key changes:

• This change provides guidance when a controller does not require an aircraft to fly the hold-in-lieu-of procedure turn but requires the aircraft to fly the straight-in approach.
• Vectoring to a fix along the final approach course prior to the final approach fix (FAF) is permitted. Appropriately -equipped area navigation (RNAV) aircraft may be cleared to the intermediate fix (IF) on conventional and RNAV instrument approach procedures when the IF is identified with an “IF” on the instrument approach procedure. Procedures and graphics are provided for an aircraft on unpublished routes cleared direct to a fix between the IF and FAF.
• Guidance is provided for when an aircraft will fly a radius to fix (RF) leg, published on an RNAV approach.

The first item should eliminate confusion among many pilots when a approach chart shows a holding pattern in lieu of a procedure turn. Controllers will now explicitly clear aircraft “straight-in” when they don’t want the pilot to fly the holding pattern.

The second item will reduce radio chatter and make it easier for RNAV-equipped aircraft to fly efficient approaches. Pilots may want to review how they load approaches into GPS navigators to avoid what I call the vectors-to-final scramble. The last item in the summary refers to RF legs, which at present are part of authorization-required RNP approaches that aren’t available to typical GA pilots.

LP Approaches are now Available

The 7 February 2013 NavData update from Jeppesen includes RNAV approaches with LP (localizer performance) minimums. You can read more about LP at my blog here and in AIM 1-1-20 (b)(3):

A new nonprecision WAAS approach, called Localizer Performance (LP) is being added in locations where the terrain or obstructions do not allow publication of vertically guided LPV procedures. This new approach takes advantage of the angular lateral guidance and smaller position errors provided by WAAS to provide a lateral only procedure similar to an ILS Localizer. LP procedures may provide lower minima than a LNAV procedure due to the narrower obstacle clearance surface.

NOTE–WAAS receivers certified prior to TSO C-145b and TSO C-146b, even if they have LPV capability, do not contain LP capability unless the receiver has been upgraded. Receivers capable of flying LP procedures must contain a statement in the Flight Manual Supplement or Approved Supplemental Flight Manual stating that the receiver has LP capability, as well as the capability for the other WAAS and GPS approach procedure types.

As noted above, you must have a WAAS-capable, IFR-approved GPS navigator to fly LP procedures. In addition, your unit must have the correct operating system software installed, and the supplement to your AFM must permit you to fly to LP minimums based on the equipment installed in your aircraft.

At present, there are 624 Localizer Performance (LP) approach procedures in the U.S. The map below is a bit out of date, but it gives you a general idea of where these procedures are located. You can find lists of approaches with LP minimums at this FAA website. The information is in Microsoft Excel worksheets that you can filter and sort.

Substituting GPS for Ground-Based Navigation Aids

Questions continue about when and how a pilot may substitute GPS for indications and information from ground-based navigation aids, such as VORs, DME, and NDB, including intersections and fixes defined by ground-based navaids. I provided background on this topic in October 2011. But the latest edition of the Instrument Flying Handbook (described here) consolidates and expands on the guidance offered in the AIM and AC 90-108, and it bears mention here.

(The simple explanation is straightforward. If you have an IFR-approved GPS, and absent restrictions in the AFM supplement for that GPS, you can use it instead of a VOR, DME, or NDB indicator, even when a charted navaid is out of service or noted as “required” on an approach chart. GPS can also substitute for fixes (e.g., step-down-fixes) that are part of a conventional approach, such as an ILS. The ground-based navaids and defined fixes must be in the GPS database. You cannot, however, use GPS for lateral guidance along the final approach course of an IAP that is based on a localizer.)

FAA updated its guidance on this issue with the May 26, 2016 update to the AIM. For more information, see this item here at BruceAir.

Chapter 9 of the IFH (see p. 9-27) includes the following information.

GPS Substitution
IFR En Route and Terminal Operations
GPS systems, certified for IFR en route and terminal operations, may be used as a substitute for ADF and DME receivers when conducting the following operations within the United States NAS.
1. Determining the aircraft position over a DME fix. This includes en route operations at and above 24,000 feet mean sea level (MSL) (FL 240) when using GPS for navigation.

2. Flying a DME arc.
Navigating TO/FROM an NDB/compass locator.

3. Determining the aircraft position over an NDB/compass locator.

4. Determining the aircraft position over a fix defined by an NDB/compass locator bearing crossing a VOR/LOC course.

5. Holding over an NDB/compass locator.

GPS Substitution for ADF or DME
Using GPS as a substitute for ADF or DME is subject to the following restrictions:

1. This equipment must be installed in accordance with appropriate airworthiness installation requirements and operated within the provisions of the applicable POH/AFM or supplement.

2. The required integrity for these operations must be provided by at least en route RAIM or equivalent.

3. WPs, fixes, intersections, and facility locations to be used for these operations must be retrieved from the GPS airborne database. The database must be current. If the required positions cannot be retrieved from the airborne database, the substitution of GPS for ADF and/or DME is not authorized.

4. Procedures must be established for use when RAIM outages are predicted or occur. This may require the flight to rely on other approved equipment or require the aircraft to be equipped with operational NDB and/or DME receivers. Otherwise, the flight must be rerouted, delayed, canceled, or conducted under VFR.

5. The CDI must be set to terminal sensitivity (1 NM) when tracking GPS course guidance in the
terminal area.

6. A non-GPS approach procedure must exist at the alternate airport when one is required. If the non-GPS approaches on which the pilot must rely require DME or ADF, the aircraft must be equipped with DME or ADF avionics as appropriate. (For an update on filing alternates with an IFR-approved GPS, see New FAA Policy on IFR Alternates with GPS.)

7. Charted requirements for ADF and/or DME can be met using the GPS system, except for use as the principal instrument approach navigation source.

NOTE: The following provides guidance that is not specific to any particular aircraft GPS system. For specific system guidance, refer to the POH/AFM, or supplement, or contact the system manufacturer.

To Determine Aircraft Position Over a DME Fix:

1. Verify aircraft GPS system integrity monitoring is functioning properly and indicates satisfactory integrity.

2. If the fix is identified by a five-letter name that is contained in the GPS airborne database, select either the named fix as the active GPS WP or the facility establishing the DME fix as the active GPS WP. When using a facility as the active WP, the only acceptable facility is the DME facility that is charted as the one used to establish the DME fix. If this facility is not in the airborne database, it is not authorized for use.

3. If the fix is identified by a five-letter name that is not contained in the GPS airborne database, or if the fix is not named, select the facility establishing the DME fix or another named DME fix as the active GPS WP.

4. When selecting the named fix as the active GPS WP, a pilot is over the fix when the GPS system indicates the active WP.

5. If selecting the DME providing facility as the active GPS WP, a pilot is over the fix when the GPS distance from the active WP equals the charted DME value, and the aircraft is established on the appropriate bearing or course.

To Fly a DME Arc:
1. Verify aircraft GPS system integrity monitoring is functioning properly and indicates satisfactory integrity.

2. Select from the airborne database the facility providing the DME arc as the active GPS WP. The only acceptable facility is the DME facility on which the arc is based. If this facility is not in your airborne database, you are not authorized to perform this operation.

3. Maintain position on the arc by reference to the GPS distance instead of a DME readout.

To Navigate TO or FROM an NDB/Compass Locator:
1. Verify aircraft GPS system integrity monitoring is functioning properly and indicates satisfactory integrity.

2. Select the NDB/compass locator facility from the airborne database as the active WP. If the chart depicts the compass locator collocated with a fix of the same name, use of that fix as the active WP in place of the compass locator facility is authorized.

3. Select and navigate on the appropriate course to or from the active WP.

To Determine Aircraft Position Over an NDB/Compass Locator:
1. Verify aircraft GPS system integrity monitoring is functioning properly and indicates satisfactory integrity.

2. Select the NDB/compass locator facility from the airborne database. When using an NDB/compass locator, the facility must be charted and be in the airborne database. If the facility is not in the airborne database, pilots are not authorized to use a facility WP for this operation.

3. A pilot is over the NDB/compass locator when the GPS system indicates arrival at the active WP.

To Determine Aircraft Position Over a Fix Made up of an NDB/Compass Locator Bearing Crossing a VOR/LOC Course:
1. Verify aircraft GPS system integrity monitoring is functioning properly and indicates satisfactory integrity.

2. A fix made up by a crossing NDB/compass locator bearing is identified by a five-letter fix name. Pilots may select either the named fix or the NDB/compass locator facility providing the crossing bearing to establish the fix as the active GPS WP. When using an NDB/compass locator, that facility must be charted and be in the airborne database. If the facility is not in the airborne database, pilots are not authorized to use a facility WP for this operation.

3. When selecting the named fix as the active GPS WP, pilot is over the fix when the GPS system indicates the pilot is at the WP.

4. When selecting the NDB/compass locator facility as the active GPS WP, pilots are over the fix when the GPS bearing to the active WP is the same as the charted NDB/compass locator bearing for the fix flying the prescribed track from the non-GPS navigation source.

To Hold Over an NDB/Compass Locator:
1. Verify aircraft GPS system integrity monitoring is functioning properly and indicates satisfactory integrity.

2. Select the NDB/compass locator facility from the airborne database as the active WP. When using a facility as the active WP, the only acceptable facility is the NDB/compass locator facility which is charted. If this facility is not in the airborne database, its use is not authorized.

3. Select non-sequencing (e.g., “HOLD” or “OBS”) mode and the appropriate course in accordance with the POH/AFM or supplement.

4. Hold using the GPS system in accordance with the POH/AFM or supplement.

Garmin Radius to Fix Leg Project Report

The accuracy provided by GPS (especially with WAAS augmentation) has vastly expanded the number and quality of instrument approaches available to properly equipped aircraft, including procedures that provide guidance comparable to the ILS. For example, as of January 10, 2013, in the U.S., there were 3,052 approaches with LPV (localizer performance with vertical guidance) minimums, more than double the number of category 1 ILS approaches (the current inventory of instrument flight procedures in the U.S. is available here).

At present, however, approaches that take full advantage of the capabilities of satellite-based navigation remain in a special “authorization required” category. Flying these RNAV (RNP) procedures requires additional crew training and approved avionics, such as flight management computers, autopilots, and cockpit displays, as described in AC 90-101A and AIM 5-4-18. At present, RNAV (RNP) (required navigation performance) procedures, like Category II ILS approaches, are available to authorized airline crews and pilots flying business jets equipped with the appropriate avionics, but not to typical instrument-rated pilots, even those flying aircraft with WAAS-capable IFR GPS navigators such as the Garmin GNS430W/530W and newer GTN750/650 series boxes.

Garmin released system software 6.11 for the GTN series on March 1, 2016. That update includes the ability to fly RF legs on approaches that are not classified as Authorization Required procedures.

The presence of RF legs no longer automatically classifies an approach as an AR procedure. For more information, see AC 90-105A and the updated Pilot’s Guide and other documentation related to the March 1, 2016 update of the system software for the Garmin GTN series navigators.

Garmin, working with the FAA and Hughes Aerospace Corporation, has recently completed the first part of a study that may persuade the FAA to change the requirements and make some RNP procedures available to most pilots flying aircraft equipped with WAAS-capable avionics. You can download the complete Garmin Radius to Fix Leg Project Report (PDF) published January 15, 2013, here.

A key feature of RNP procedures is the radius-to-fix (RF) leg, a curved flight path that resembles the familiar DME arc. The Instrument Procedures Handbook describes RF legs this way:

Constant radius turns around a fix are called “radius-to-fix legs,” or RF legs. These turns, which are encoded into the navigation database, allow the aircraft to avoid critical areas of terrain or conflicting airspace while preserving positional accuracy by maintaining precise, positive course guidance along the curved track. The introduction of RF legs into the design of terminal RNAV procedures results in improved use of airspace and allows procedures to be developed to and from runways that are otherwise limited to traditional linear flight paths or, in some cases, not served by an IFR procedure at all. (5-23)

Figure A-13 from Appendix A of the IPH shows a hypothetical RF leg.

Unlike DME arcs, RF legs are defined by points in space, not distances from a ground-based transmitter. They can be strung together into sinuous paths, that, as noted above, provide lower minimums while avoiding obstacles, airspace conflicts, and noise-sensitive areas. The plan view from the RNAV (RNP) Z RWY 13R approach at Boeing Field in Seattle (KBFI) shows such RF legs.

You can find examples of RF legs in non-RNP approaches at Carlsbad, CA (KCRQ) and Ketchikan, AK (PAKT) [thanks to John D. Collins for those references]. Because of the restrictions placed on flying RF legs, however, those procedures are not currently available to typical IFR pilots. RF legs are also features of some RNAV instrument departure and arrival procedures (SIDs and STARs).

FAA includes RF legs in procedures assuming that an aircraft can follow the curved path with great precision, hence the detailed requirements spelled out in AC 90-101A, AC 90-105A, and AIM 5-4-18. Chief among those requirements are a flight director and/or a roll-steering autopilot, stipulations that rule out many, if not most, light general aviation aircraft.

The new Garmin study demonstrates, however, that:

Instrument-rated general aviation pilots are able to hand fly RF legs and meet the 0.5 nm 95% FTE [standard flight technical error]  target and RF leg altitude restrictions without the aid of a flight director or autopilot in Part 23 Category A and B aircraft that are either minimally equipped or technically advanced…All pilots demonstrated acceptable proficiency on both straight legs and RF legs. The increase in RF leg FTE over straight leg FTE can be expected to be about the same magnitude from a minimally equipped aircraft to a technically advanced aircraft.

In other words, pilots were able to remain well within the boundaries specified for an RF leg, whether flying a Cherokee equipped with just a Garmin 430W and basic instrumentation or a speedier Cessna 400 outfitted with Garmin’s latest G2000 integrated glass cockpit and autopilot. The pilots achieved this performance while hand-flying challenging procedures that incorporated multiple RF legs specifically designed to stress-test both the avionics and their flying skills. You can see diagrams of these special procedures in the Garmin report.

Based on the findings (described in great detail in the Garmin document), Garmin concludes that:

Garmin recommends FAA revise its installation and operational guidance for RF legs to make clear that applicants may obtain airworthiness approval for installations without flight director/autopilot. To preclude the need to demonstrate adequate FTE margin for aircraft flying RF legs at greater than 200 knots without flight director/autopilot, Garmin recommends FAA revise its installation and operational guidance for RF legs to allow applicants to utilize an Aircraft Flight Manual limitation that restricts flying RF legs to 200 knots or less.

Furthermore, the study showed that a moving map, while a great benefit to situational awareness, isn’t necessary to fly RF legs accurately:

As this project has shown, FTE is decreased when a moving map is available and is thus consistent with the MLS curved path study conclusion that led to the FAA installation and operational guidance that “an aircraft must have an electronic map display depicting … RF legs.” However, this project has also clearly shown that a moving map is not required to maintain acceptable RF leg FTE, even during complex procedures and missed approaches.

The executive summary of the Garmin report outlines additional conclusions and recommendations that address specific issues related to flying RF legs in typical light GA aircraft.

The FAA isn’t saying when or if it will adopt the recommendations in Garmin’s report. So far, the agency has said only:

This demonstration project has shown early success and will continue with more flight testing and data collection.

But the well-designed study and detailed analysis suggest that many more pilots may in future be able to take advantage of some advanced RNP procedures, if the FAA agrees with the recommendations and avionics manufacturers and database providers include RF legs in future updates to the WAAS units now common in light GA aircraft.

Garmin released system software 6.11 for the GTN series on March 1, 2016. That update includes the ability to fly RF legs on approaches that are not classified as Authorization Required procedures. For more information, see also AC 90-105A.

Database Currency for IFR Operations

Most instrument-rated pilots now fly with GPS-based navigation equipment (according to AOPA, at least 78 percent of its members rely on GPS as their primary navigation tool).

To use an IFR-approved GPS when operating IFR, the unit’s database must be current or you must verify the accuracy of the data.

For more details, see note 4 in AIM 1-2-3: Use of Suitable Area Navigation (RNAV) Systems on Conventional Procedures and Routes and AC 90-108.

Keeping a typical GPS unit up-to-date usually involves downloading fresh data to a card every 28 days.

Of course, the effective dates of databases don’t always fall conveniently between trips, and FAA has outlined procedures to help pilots ensure that the data in GPS avionics matches the key information on current charts, especially instrument approach plates.

You must also review either the AFM or the AFM Supplement for the avionics installed in your aircraft. For example, the latest AFM Supplement (190-01007-A2_08) for the Garmin GTN series (750, 650, etc.) notes:

2.8 Navigation Database
GPS/SBAS based IFR enroute, oceanic, and terminal navigation is prohibited unless the flight crew verifies and uses a valid, compatible, and current navigation database or verifies each waypoint for accuracy by reference to current approved data.

“GPS”, “or GPS”, and “RNAV (GPS)” instrument approaches using the Garmin navigation system are prohibited unless the flight crew verifies and uses the current navigation database. GPS based instrument approaches must be flown in accordance with an approved instrument approach procedure that is loaded from the navigation database…

If the navigation database cycle will change during flight, the flight crew must ensure the accuracy of navigation data, including suitability of navigation facilities used to define the routes and procedures for flight. If an amended chart affecting navigation data is published for the procedure, the database must not be used to conduct the procedure.

Regarding instrument approaches, the key information for matching the database to the chart is the procedure amendment reference date, not necessarily the date printed at the top of the chart. On charts published by the FAA, the procedure amendment reference date appears in the lower-left corner, next to the amendment number.

The best description of the procedure amendment reference date and how to use it is in Jeppesen Briefing Bulletin JEP 09-C (PDF)–even if you use charts published by FAA Aeronautical Information Services. The Jeppesen briefing bulletin includes a simple flow chart that helps you use the procedure reference date.

FAA published a safety alert (PDF) in 2009 that explains the difference between chart dates and procedure amendment dates.

Update on WAAS Approaches from FAA

By the end of 2016, every runway in the U.S. that qualifies for an approach with LPV minimums will have one. According to the fall 2012 edition (PDF) of SatNavNews, published by FAA:

The agency intends to publish another 2,500 procedures by 2016, which will allow every runway in the nation that qualifies for an LPV to have one.

The latest data available from FAA, as of September 20, 2012, show the total number of approaches with LPV minimums has reached 2,989. By comparison, there were 1,281 category 1 ILS approaches in the inventory as of that date. More than 50 percent of the so-called LPV approaches serve airports that have no approaches that rely on ground-based navigation aids (i.e., ILS, localizer, VOR, or NDB). LPV procedures truly are expanding the options for instrument-rated pilots who fly aircraft equipped with IFR-approved, WAAS-capable GPS navigators.

LPV approaches can serve runways that may not meet the requirements for an ILS–indeed, many of those runways are suitable only for small general aviation aircraft. To learn about some of the criteria, see Table K-1. Criteria to Support Instrument Flight Procedure Development and the associated notes (from AC 150/5300). For example, the minimum runway length for an LPV approach is usually 3200 feet; the comparable number for an ILS is 4200 feet.

Now, the minimums for an LPV approach to a 3200-ft runway are at least 1 statute mile visibility and a DA of 350-400 feet. If an LPV procedure is to match the best minimums for a typical ILS (1/2 statute mile visibility and a DA of 200 feet), the LPV procedure must be to a runway that meets criteria for a conventional precision approach, including runway length, lighting, parallel taxiways, and markings.

For more details about the runway requirements for non-precision and precision approaches, see sections 2.6.4.2, 2.6.4.3, and 2.6.4.3 in AC 150/3500.

2.6.4.2 Non-Precision Approach (NPA).

An NPA is an instrument approach based on a navigation system that provides course deviation information, but no glidepath deviation information. NPA runways:
1. Support IFR approach operations to visibilities of ½ statute mile (0.8 km) or greater and have a HAT no lower than 250 feet (76 m).
2. Rely on NAVAIDs providing lateral only guidance for instrument approaches such as Very High Frequency Omnidirectional Range (VOR), non-directional beacon (NDB), Area Navigation (RNAV) Lateral Navigation (LNAV), localizer performance (LP), and localizer (LOC).
3. Generally, have lengths at least 3,200 feet (975 m) long, with a minimum width based on RDC.
4. Have runway edge lights using LIRL or MIRL.
5. Have non-precision runway markings, as defined in AC 150/5340-1.

2.6.4.2 Approach Procedure with Vertical Guidance (APV).

APV is an instrument approach based on a navigation system that is not required to meet the PA standards of the ICAO Annex 10, but that provides course and glidepath deviation information. Runways classified as APV handle instrument approach operations where the navigation system provides vertical guidance down to 200 feet (61 m) HAT and visibilities to as low as ½ statute mile (0.8 km). APV runways:
1. May apply to the following approach types: Vertical Navigation (VNAV), Localizer Performance with Vertical Guidance (LPV), or RNAV/Required Navigation Performance (RNP).
2. Typically have a length of at least 3,200 feet (975 m) in length and a typical width of at least 60 feet (18.3 m).

2.6.4.3 Precision Approach (PA).

A PA is an instrument approach based on a navigation system that provides course and glidepath deviation information. Runways classified as precision, handle instrument approach operations supporting an instrument approach with a HAT lower than 250 feet (76 m) and visibility lower than ¾ statute mile (1.2 km), down to and including Category (CAT) III. Precision Instrument Runways (PIRs):
1. Support IFR operations with visibilities down to and including CAT-III with the appropriate infrastructure.
2. Have navigational systems capable of supporting precision operations that include instrument landing system (ILS) and Ground Based Augmentation System (GBAS) Landing System (GLS). (FAA Order JO 6850.2 contains descriptions of various approach lighting systems.)
3. Have runway lengths of at least 4,200 feet (1280 m).
4. Have minimum runway width of at least 75 feet (22.9 m) with the typical width being 100 feet (30.5 m).
5. Have High Intensity Runway Lights (HIRL).
6. Have precision runway markings, as defined in AC 150/5340-1.

Of course, an LPV procedure is essentially just data in a GPS navigator. To establish an LPV procedures, the owners of an airport don’t have to invest in or maintain ILS transmitters. Once the FAA has the required obstacle surveys and gathered related information, publishing LPV procedures to both ends of an eligible runway (indeed, to the ends of all eligible runways at an airport) requires little incremental investment (for example, to cover the costs of designing and flight-testing each additional procedure). That’s the main reason that the FAA can publish so many new LPV procedures and plan to meet the goal, in four years, of making LPV approaches available to all eligible runways.

Localizer Performance (LP) Procedures

Instrument rated pilots have started noticing a new type of RNAV (GPS) procedure appearing in their chart updates. These localizer performance (LP) procedures are described, among other places, in AIM 1-1-20 (b)(3):

A new nonprecision WAAS approach, called Localizer Performance (LP) is being added in locations where the terrain or obstructions do not allow publication of vertically guided LPV procedures. This new approach takes advantage of the angular lateral guidance and smaller position errors provided by WAAS to provide a lateral only procedure similar to an ILS Localizer. LP procedures may provide lower minima than a LNAV procedure due to the narrower obstacle clearance surface.

NOTE–WAAS receivers certified prior to TSO C-145b and TSO C-146b, even if they have LPV capability, do not contain LP capability unless the receiver has been upgraded. Receivers capable of flying LP procedures must contain a statement in the Flight Manual Supplement or Approved Supplemental Flight Manual stating that the receiver has LP capability, as well as the capability for the other WAAS and GPS approach procedure types.

In other words, LP procedures are non-precision approaches (they don’t offer vertical guidance) that use WAAS signals and data to emulate a localizer-only procedure. Don’t confuse LP approaches with LPV procedures; LPV approaches offer vertical guidance like an ILS.

According to the FAA’s summary of IAPs, there were 344 published LP procedures at the end of July 2012.

But as of September 2012, you still can’t fly these procedures, because the data needed to fly them haven’t been added to the Jeppesen NavData updates that most IFR-approved GPS units use. A notice from Jeppesen (PDF) reported that the company anticipated adding LP data in “mid-2012,” but the data still aren’t available, and Jeppesen hasn’t updated its plans to include LP procedures.

When the LP procedures are available in the database (and assuming the box you’re flying is approved for LP procedures and that you have the approved supplements to your AFM), you’ll be able to select an LP approach from the list of procedures for an airport and you’ll see an LP annuniciation when an LP approach is available. In this respect, preparing to fly an LP approach will be like loading other RNAV (GPS) procedures, and you’ll fly the procedure to the LP line of minimums printed on the approach chart.

You can find additional information about LP approaches elsewhere in the AIM (e.g., 5-4-5):

LP will be published in locations where vertically guided minima cannot be provided due to terrain and obstacles and therefore, no LPV or LNAV/VNAV minima will be published…

(d) LP. “LP” is the acronym for localizer performance. Approaches to LP lines of minima take advantage of the improved accuracy of WAAS to provide approaches, with lateral guidance and angular guidance. Angular guidance does not refer to a glideslope angle but rather to the increased lateral sensitivity as the aircraft gets closer to the runway, similar to localizer approaches. However, the LP line of minima is a Minimum Descent Altitude (MDA) rather than a DA (H). Procedures with LP lines of minima will not be published with another approach that contains approved vertical guidance (LNAV/VNAV or LPV). It is possible to have LP and LNAV published on the same approach chart but LP will only be published if it provides lower minima than an LNAV line of minima. LP is not a fail−down mode for LPV. LP will only be published if terrain, obstructions, or some other reason prevent publishing a vertically guided procedure. WAAS avionics may provide GNSS−based advisory vertical guidance during an approach to an LP line of minima (reference section 9.b for further information on advisory vertical guidance). Barometric altimeter information remains the primary altitude reference for complying with any altitude restrictions. WAAS equipment may not support LP, even if it supports LPV, if it was approved before TSO C−145B and TSO C−146B. Receivers approved under previous TSOs may require an upgrade by the manufacturer in order to be used to fly to LP minima. Receivers approved for LP must have a statement in the approved Flight Manual or Supplemental Flight Manual including LP as one of the approved approach types.