1. Instrument Ground Training Module 3 Randy Schoephoerster www.airtreknorth.com

2. Summary ADF – Moveable Card – Fixed Card RMI – Slaved – Non Slaved VOR – VOR, VOR/DME, VORTAC HSI – Back Couse/Front Course DME – Slant Range – Equipment

3. 3.8GLOBAL POSITIONING SYSTEM (GPS) You should refer to the flight manual supplement to determine if a installed GPS is approved for IFR en route and IFR approaches. a. Hand-held GPS systems and GPS systems certified for VFR operation may be used during IFR operations only as an aid to situational awareness. Portable GPS unit are not approved to fly a GPS approach. They are allowed to help you with situational awareness RAIM: RAIM test allows us to see if there are any GPS satellites out of service that would cause us to not be able to fly via GPS During IFR en route and terminal operations using an approved GPS system for navigation, the aircraft must be equipped with an approved and operational alternate navigation system that is appropriate to the route.

4. a.Any ground-based navigational facilities required for use with the alternate navigation system (e.g., VORs, NDBs, etc.) must be available and operational along the entire route of flight. b.It is not necessary to actively monitor an alternate means of navigation unless the GPS is not equipped with Receiver Autonomous Integrity Monitoring (RAIM), or RAIM becomes unavailable or predicts an outage. One of the primary benefits of satellite based area navigation (e.g., GPS or RNAV) is that it permits aircraft to fly optimum routes and altitudes.

5. RAIM Failure During an Approach If a RAIM failure occurs prior to the final approach waypoint (FAWP), the approach should not be completed since GPS may no longer provide the required accuracy. If RAIM is not available, another type of navigation and approach system must be used. A waypoint is a predetermined geographical position used for route/instrument approach definition, progress reports, visual reporting points, and other purposes. It may be defined relative to a VOR station or in terms of latitude/longitude coordinates.

14. 3.1DISTANCE MEASURING EQUIPMENT (DME) AND GPS 1.DME displays slant range distance in nautical miles. 2.Ignore slant range error if the airplane is 1 NM or more from the ground facility for each 1,000 ft. AGL. a.The greatest slant range error comes at high altitudes very close to the VORTAC. b.EXAMPLE: If you are 6,000 ft. AGL directly above a VORTAC, your DME will read 1.0 NM. 3.A pilot can check the Airplane Flight Manual Supplement to determine if a GPS (LORAN C) equipped aircraft is approved for IFR operations.

15. 1)The DME identifier is transmitted one time for each three or four times the VOR identifier is transmitted. 2)A single coded identification transmitted every 30 sec. indicates that the DME is operative but the VOR is inoperative. a)The absence of the single coded identification every 30 sec. indicates the DME is inoperative. 2. The DME in the airplane includes a transceiver and a small shark fin-type antenna. The DME display is on the face of the transceiver and may be part of the VOR receiver or a separate unit, as shown below. Source: AlliedSignal General Aviation Avionics

16. b.The mileage readout is the direct distance from the airplane to the DME ground facility. This is commonly referred to as slant-range distance. 1) The difference between a measured distance on the surface and the DME slant- range distance is known as slant-range error. a)Slant-range error is smallest at low altitude and long range. b)This error is greatest when the airplane is at a high altitude close to or over the ground station, at which time the DME receiver will display altitude in NM above the station. c)Slant-range error is negligible if the airplane is 1 NM or more from the ground facility for each 1,000 ft. of altitude above the elevation of the facility. c.To use the groundspeed and/or time-to-station function of the DME, you must be flying directly to or from the station. 1) Flying in any other direction will provide you with false groundspeed and time-to- station information.

17. Go to online Questions for DME

18. Summary ADF – Moveable Card – Fixed Card RMI – Slaved – Non Slaved VOR – VOR, VOR/DME, VORTAC HSI – Back Couse/Front Course DME – Slant Range – Equipment

19. Instrument Ground Training Module 3 Randy Schoephoerster www.airtreknorth.com

20. 7.Time/distance to station formula. When tracking inbound, make a 90° turn and measure time and degrees of bearing change. 60 x Min. between bearings Degrees of bearing change a. Min. to station = Degrees of bearing change TAS x Min. between bearings b.Distance to station = Degrees of bearing change 1) You may also use your flight computer to calculate the distance.