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Alternate Airports

It is very important to know what equipment is installed in the aircraft. GPS-based FMS/RNAV units certified to TSO-C145A or TSO-146A may be used when an alternate airport is required in the flight plan for the approaches at the destination and alternate airport if the WAAS is operational. No other navigation avionics would be required. Units certified under TSO-C129 are not authorized for alternate approach requirements. The aircraft must have stand-alone navigation equipment, such as VOR, and there must be an approved instrument approach at the alternate airport based on that equipment. (However, once diverted to the alternate airport, the pilot could fly a GPS-based approach there, as long as there is an operational, ground-based navaid and airborne receiver in the aircraft for use as a backup.)

Aircraft Equipment Suffixes

Since air traffic control (ATC) issues clearances based on aircraft equipment suffixes, consult the Aeronautical Information Manual (AIM) Table 5-1-2, Aircraft Suffixes, to ensure that the flight plan includes the correct equipment suffix for a particular aircraft. Use the suffix that corresponds to the services and/or routing that is needed. For example, if the desired route or procedure requires GPS, file the suffix as “/G” or “/L,” as appropriate to that aircraft, and operational equipment installed. (Remember that minimum equipment list (MEL) deferred items can change the status of the aircraft.)


Navigation Database Currency (Part Six) Coupling the FMS to the Navigation Indicator(s)

Every advanced avionics cockpit features one or more navigation instruments used for course guidance. The navigation indicator (e.g., a horizontal situation indicator (HSI) or electronic HSI) may include one or more course deviation indicators (CDIs), as well as one or more radio magnetic indicators (RMIs). When automatic course/ en route/ approach tracking is desired, you must couple (or connect) the FMS to […]

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Navigation Database Currency (Part Five) Catching Errors: Using the FMS Flight Planning Function To Cross-Check Calculations

Using the FMS’s flight planning function to check your own flight planning calculations is one example of how advanced cockpit systems can decrease the likelihood of an error. Alternatively, cross-check the computer’s calculations against your own. (Remember the old computer programmer’s adage, “Garbage in, garbage out (GIGO).”) The flight planning page can also be used to review the route that you […]

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Navigation Database Currency (Part Four) The Flight Planning Page

Every FMS unit includes a page dedicated to entering a flight plan. Typically, entering a flight plan is a simple matter of “filling in the blanks”—entering the en route waypoints and instrument procedures that make up the planned route. En Route Waypoints and Procedural Waypoints Entering a flight route into the FMS unit requires you to enter the waypoints […]

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Navigation Database Currency (Part Three) Programming the Flight Route

The procedures used to program an FMS with your intended route of flight are fundamentally the same in all types of systems, yet many differences are evident. The primary difference between systems lies mainly in the “knob or switchology”—the specific design features, operational requirements, and layout of the controls and displays used to operate the avionics. Be thoroughly familiar with the procedures […]

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Navigation Database Currency (Part Two) NOTAMs Relevant to GPS and GPS Signal Availability

NOTAMs Relevant to GPS There are numerous notices to airmen (NOTAMs) that apply specifically to users of navigation aids. For example, when anomalies are observed in the behavior of the global positioning system, or when tests are performed, a GPS UNRELIABLE NOTAM is issued. Similarly, published instrument procedures that rely on RNAV equipment sometimes become “Not Available” when safety concerns arise, such […]

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Navigation Database Currency (Part One) Alternative Means of Navigation

The navigation database contained in the FMS must be current if the system is to be used for IFR navigation and approaches. Some units allow en route IFR operations if the navigation waypoints are manually verified by the pilot and accepted. The effective dates for the navigation database are shown on a start-up screen that is displayed as the FMS cycles […]

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Flight Planning

Preflight Preparation Title 14 of the Code of Federal Regulations (14 CFR) part 91, section 91.103 requires you to become familiar with all available information before beginning a flight. In addition to the required checks of weather, fuel, alternate airports, runway lengths, and aircraft performance, there are a number of requirements unique to the use of avionics equipment.  Many of […]

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FMS/RNAV/Autopilot Interface: Display and Controls (Part Two)

Integrated Avionics Systems Some systems integrate FMS/RNAV display and controls into existing cockpit displays usually called PFDs and MFDs. In this case, there is no separate display to point to and call the RNAV display. Figure 3-6 shows a system that uses the PFD to provide controls and a display for the FMS. This type of system utilizes the same […]

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