En Route Navigation The en route phase of flight is defined as that segment of flight from the termination point of a departure procedure to the origination point of an arrival procedure.Governing Bodies The procedures employed in the en route phase of flight are governed by a set of specific flight standards established by Title 14 of the Code of Federal Regulations (14 CFR) [Figure 2-1], Federal Aviation Administration (FAA) Order 8260.3, United States Standard for Terminal Instrument Procedures (TERPS), and related publications. These standards establish courses to be flown, obstacle clearance criteria, minimum altitudes, navigation performance, and communications requirements.The FAA publishes charts for each stage of Visual Flight Rules (VFR) and Instrument Flight Rules (IFR) air navigation including training, planning, and departures, enroute (for low and high altitudes), approaches, and taxiing charts. For Procurement, contact an Authorized FAA Chart Sales Agent. The Purpose of the United States Standard for Terminal Instrument Procedures is to prescribe the criteria for the formulation, review, approval and the publishing of procedures for IFR (Instrument Flight Rules) operations to and from civil and military airports. TERPS criteria have been established for the following Instrument Procedures: Precision Approach (PAR, ILS, MLS), Non-Precision Approach (VOR, TACAN, LNAV, NDB, ASR), Approach with Vertical Guidance (LDA, LPV, VNAV), Required Navigation Performance (RNP) and for Departure Procedures (DP).Aeronautical Charts

Aeronautical charts provide important information to the pilot. Sectional charts show topographic details, relief features and aeronautical information of the selected area and are updated regularly. Other types of charts display routes, airways and ground terminal locations. The direction and distance come from a map or chart. To navigate when driving a car one uses a map with printed routes, and you verify your position using landmarks and signs posted along the way. For air navigation your intended course is plotted on a map or chart and your position is verified along the way with any number of interesting methods. By the way, a chart is a map on which you plot a course. Anaeronautical chart provides pilots with a representation of a section of the Earth's surface (hence their name "Sectional Chart"). This section shows many of the same features on a road map. These emphasize landmarks and other special land features that would be easy for pilots to spot from the air. It delineates cities, tall structures, geographical features and major roads. It is also color-coded. Yellow areas depict cities, green areas indicate hills, brown is used to show mountains and magenta denotes roads. The intensity of the color corresponds to the object's

height. The greater the intensity of the color, the higher or taller the object. These charts are updated and revised every six months. Pilots are encouraged to plot their course using the most recent and updated chart. The aeronautical chart is designed for convenient navigational use by pilots. It is intended to be written on and marked up as needed by the pilot to plot the course and/or solve navigational problems such as calculations of direction and distance. 

Sectional Chart The scale of a "sectional" is 1/500,000 so one inch is about seven nautical miles. It usually gives enough detail to fly by ground reference or pilotage. A sectional shows highways and railroads, power transmission lines and television and radio towers. It shows lakes, quarries, race tracks and other landmarks. Sectionals also show information you cannot see on the ground such as Prohibited, Restricted, Warning, and Alert Areas that have their own special flight rules. Sectionals show Federal Airways commonly known as Victor Airways that are highways in the sky connecting Very High Frequency Omnirange Stations (VOR) stations. A sectional also shows topography or relief using contour intervals and color differentiation. Blue indicates the lowest elevations and brown indicates the highest. The highest obstruction in an area bounded by latitude and longitudes are shown with a numeral for thousands of feet with another numeral as a superscript for hundreds of feet. The highest terrain elevation is shown on the front of the chart. Isogonic lines showing Magnetic Variation are also shown on aeronautical charts.

World Aeronautical Chart (WAC) WAC charts scale is 1/1,000,000 making one inch about fourteen miles. Since WAC charts cover a larger area not as much detail is shown. WAC charts are used for flights of long distances.

 VFR Terminal Area Chart If you plan to fly in or near a large metropolitan area a VFR Terminal Area Chart may be available. A VFR terminal Area Chart has everything asectional chart has but in greater detail. The scale is 1/250,00. Open circles with points at the top, bottom and both sides show VFR way points. Flags indicate a visual checkpoint. An air traffic controller may tell a VFR pilot to report over the golf course for instance. The golf course will be indicated on sectionals and VFR Terminal Area Charts with a flag icon. Small black squares indicate easily identified places on the ground.

 IFR ChartsIf the flight will be flown under instrument meteorological conditions, there are two types of instrument charts. Pilots also have to file an IFR Flight Plan to fly in IMC conditions.En Route Low Altitude Charts are used for IFR flight planning by mostpropeller driven aircraft flying below the higher flying jet aircraft. Low altitude charts show Victor Airways, minimum altitudes, distances, magnetic courses, reporting points, and related data.

 En Route High Altitude Charts portray Jet routes, distances, time zones, special use airspace, radar jet advisory areas, and other data. IFR flight plans are necessary for all flights above 18,000 feet.

 

Altitude ReferencesThere are 4 altitude references and 1 pressure reference that SoarPilot can display and use. These are explained on the diagram below.

MSL - Altitude above Mean Sea Level AGL - Height above the ground (requires a Terrain database to be loaded) FL - Flight level altitude (assumes sea level pressure is 1013.2mb or 29.92 in Hg) QFE - Height above an specific reference. QNH - The local air pressure at sea level.This most important of these is the MSL setting. This is the height of a point above the Mean Sea Level. All the elevations of waypoints should be a MSL height. All SoarPilot final glide calculations are based on MSL height.Also important for airspace display and warnings is FL or flight level. This is the altitude shown on an altimeter with the sub-scale set at 1013.2mb or 29.92 in Hg. Many airspace areas have FL altitudes, and the pilot needs to be aware that the actual MSL height of these areas will change with the local air pressure at the time of the flight.At first this may seem strange, but if you are flying long distances across weather systems, the local air pressure on the ground will change, so a constant reference is required to ensure that everyone has the same understanding for the altitude.

If the local pressure is high, the flight levels will be higher. So FL45 will be greater than 4500ft MSL. Conversely if the pressure is low, the flight levels will be lower.Flight levels are always in feet.AirwaysAirway routing occurs along pre-defined pathways called airways . Airways can be thought of as three- dimensional highways for aircraft. In most land areas of the world, aircraft are required to fly airways between the departure and destination airports. Most airways are eight nautical miles (14 kilometers) wide, and the airway flight levels keep aircraft separated by at least 500 vertical feet from aircraft on the flight level above and below when operating under VFR(Visual Flight Rules). When operating under IFR(Instrument Flight Rules), between the surface and an altitude of Flight Level (FL) 290,no aircraft should come closer vertically than 1,000 feet. Above FL290 , no aircraft should come closer than 2,000 feet except in airspace where Reduced Vertical Separation Minima (RVSM) can be applied in which case the vertical separation is reduced to 1,000 ft. Airways usually intersect at NAVAIDs that designate the allowed points for changing from one airway to another. Airways have names consisting of one or more letters followed by one or more digits (e.g., V484 or UA419).The en route airspace structure of the National Airspace System (NAS) consists of three strata:

The first stratum low altitude airways in the United States can be navigated using NAVAIDs, have names that start with the letter V, and are called Victor Airways. They cover altitudes from approximately 1,200 feet above ground level (AGL) up to, but not including 18,000 feet above mean sea level (MSL).

The second stratum high altitude airways in the United States all have names that start with the letter J, and are called Jet Routes. These routes run from 18,000 feet to 45,000 feet.

The third stratum allows random operations above flight level (FL) 450. The altitude separating the low and high airway structure varies from county to countryAirway and Route System There are three fixed route systems established for air navigation purposes. They are the Federal airway consisting of VOR (low victor airways, high jet routes), NDB (low or medium frequency) and the RNAV route system. These route systems are aligned in an overlying manner to facilitate transition between each. The majority of the airways are made up of victor airways, jet routes, and RNAV, but some low/ medium frequency (L/MF) airways and routes are still being usedAirway/Route DepictionIFR en route navigation information is provided on three charts:

IFR en route low altitude chart - provides aeronautical information for navigation under IFR conditions below 18,000 feet MSL.Low altitude charts [Figure 2-25] include the following information: o Airways [Figure 2-25A]o RNAV routes [Figure 2-25B]

o Limits of controlled airspace [Figure 2-25C]o VHF radio aids to navigation (frequency, identification, channel, geographic coordinates) [Figure 2-25D]o Airports that have an instrument approach procedure or a minimum 3,000 foot hard surface runway [Figure 2-25E]o Off-route obstruction clearance altitudes (OROCA) [Figure 2-25F]o Reporting points [Figure 2-25G]o Special use airspace areas [Figure 2-25H]o Military training routes [Figure 2-25I]IFR aeronautical charts depict VOR airways (airways based on VOR or VORTAC NAVAIDs) in black, identified by a “V” (Victor) followed by the route number (e.g., V12).LF/MF airways (airways based on LF/MF NAVAIDs) are sometimes referred to as colored airways because they are identified by color name and number (e.g., Amber One, charted as A1). Green and red airways are plotted east and west, and amber and blue airways are plotted north and south. Regardless of their color identifier, LF/MF airways are depicted in brown.

Low altitude RNAV only routes are identified by the letter “T” prefix, followed by a three digit number (T-200 to T-500). RNAV routes are depicted in aeronautical blue, as well as the RNAV route data, which includes the following:o Route lineo Identification boxeso Mileageso Waypointso Waypoint nameso Magnetic reference bearingso MEAs Minimum En Route Altitude

IFR en route high altitude chart- En route high altitude charts provide aeronautical information for navigation under IFR conditions at and above FL180 . [Figure 2-31] High altitude charts include the following information: o Jet route structure

Jet routes are depicted in black with a “J” identifier followed by the route number (e.g., “J12”) and are based on VOR or VORTAC NAVAIDs.o RNAV Q-routes

RNAV “Q” Route MEAs are shown when other than 18,000 feet. [Figure 2-34] MEAs for GNSS RNAV aircraft are identified with a “G” suffix. MEAs for DME/DME/IRU RNAV aircraft do not have a “G” suffix. All RNAV routes and associated data is charted in aeronautical blue and magnetic reference bearings are radar monitoring capabilities. For aircraft that have DME/DME/IRU RNAV equipment, refer to the A/FD for specific DME information.o VHF radio aids to navigation (frequency, ID, channel, geographic coordinates)

VHF Airways -Victor airways are a system of established routes that run along specified VOR radials, from one VOR station to another. The purpose is to make flight planning easier and they help ATC to organize and regulate the air traffic flow. Almost all commercial flights

are routed along these airways but they are available for use by any pilot provided that the proper altitudes are employed. Victor Airway Navigation Procedures - The procedure for getting established on a victor airway is to either fly directly to a nearby VOR or to intercept an airway radial along the route of flight. Once the pilot is established on an airway, it is important to follow the procedures and guidelines put in place to ensure air traffic separation and optimal safety on the airway. When using victor airways for navigation, procedures do not allow the pilot to jump from one VOR to another, but must navigate from one to the next by using the alternating outbound/inbound procedure of linking VORs

o Selected airports o Reporting points o Navigation reference system (NRS) waypoints [Figure 2-32]

AREA NAVIGATIONArea navigation (RNAV) is a method of instrument flight rules (IFR) navigation that allows an aircraft to choose any course within a network of navigation beacons, rather than navigating directly to and from the beacons. This can conserve flight distance, reduce congestion, and allow flights into airports without beacons. Area navigation used to be called "random navigation", hence the acronym RNAV.RNAV can be defined as a method of navigation that permits aircraft operation on any desired course within the coverage of station-referenced navigation signals or within the limits of a self-contained system capability, or a combination of these.RNAV was developed to provide more lateral freedom and thus more complete use of available airspace. This method of navigation does not require a track directly to or from any specific radio navigation aid, and has three principal applications:

1. A route structure can be organized between any given departure and arrival point to reduce flight distance and traffic separation;2. Aircraft can be flown into terminal areas on varied pre-programmed arrival and departure paths to expedite traffic flow; and3. Instrument approaches can be developed and certified at certain airports, without local instrument landing aids at that airport.

4.5. Fig. Area navigation (dashed line) vs. navaid-based navigation (solid line)Navigation error components and alertingLateral navigationThe inability to achieve the required lateral navigation accuracy may be due to navigation errors related to aircraft tracking and positioning. The three main errors are path definition error (PDE), flight technical error (FTE) and navigation system error (NSE).Longitudinal navigationLongitudinal performance implies navigation against a position along a track (e.g. 4-D control). However, at the present time, there are no navigation specifications requiring 4-D control, and there is no FTE in the longitudinal dimension. The current navigation specifications define requirements for along-track accuracy, which includes NSE and PDE. PDE is considered negligible. The along-track accuracy affects position reporting (e.g. "10 NM to ABC") and procedure design (e.g. minimum segment altitudes where the aircraft can begin descent once crossing a fix).

AREA NAVIGATION (RNAV) ”T” ROUTE SYSTEM The FAA has created new low altitude area navigation (RNAV) “T” routes for the enroute and terminal environments. The RNAV routes will provide more direct routing for IFR aircraft and enhance the safety and efficiency of the National Airspace System. To utilize these routes aircraft are required to be equipped with IFR approved GNSS. In Alaska, TSO-145a and 146a equipment is required. Low altitude RNAV only routes are identified by the prefix “T”, and the prefix “TK” for RNAV helicopter routes followed by a three digit number (T-200 to T-500). Routes are depicted in blue on the IFR

Enroute Low Altitude Charts. RNAV route data (route line, identification boxes, mileages, waypoints, waypoint names, magnetic reference courses and MEAs) will also be printed in blue. Magnetic reference courses will be shown originating from a waypoint, fix/reporting point or NAVAID. GNSS MEA for each segment is established to ensure obstacle clearance and communications reception. GNSS MEAs are identified with a “G” suffix. Joint Victor/RNAV routes are charted as outlined above except as noted. The joint Victor route and the RNAV route identification boxes are shown adjacent to each other. Magnetic reference courses are not shown. MEAs are charted above the appropriate identification box or stacked in pairs, GNSS and Victor. On joint routes, RNAV specific information will be printed in blue.AREA NAVIGATION (RNAV) ”Q” ROUTE SYSTEM (IFR Enroute HIGH ALTITUDE CHARTS) The FAA has adopted certain amendments to Title 14, Code of Federal Regulations which paved the way for the development of new area high altitude navigation (RNAV) “Q” routes in the U.S. National Airspace System (NAS). These amendments enable the FAA to take advantage of technological advancements in navigation systems such as the GPS. RNAV “Q” Route MEAs are shown when other than FL 180 MEAs for DME/DME/ Inertial Reference Unit (IRU) RNAV aircraft have a “D” suffix. RNAV routes and associated data are charted in blue. “Q” Routes on the IFR Gulf of Mexico charts are shown in black. Magnetic reference courses are shown originating from a waypoint, fix/reporting point, or NAVAID. Joint Jet/RNAV route identification boxes will be located adjacent to each other with the route charted in black. With the exception of Q-Routes in the Gulf of Mexico, GNSS or DME/DME/IRU RNAV are required, unless otherwise indicated. DME/DME/IRU RNAV aircraft should refer to the A/FD or appropriate Supplement for DME information. Altitude values are stacked highest to lowest.VHF AirwaysVictor airways are a system of established routes that run along specified VOR radials, from one VOR station to another. The purpose is to make flight planning easier and they help ATC to organize and regulate the air traffic flow. Almost all commercial flights are routed along these airways but they are available for use by any pilot provided that the proper altitudes are employed.

Victor Airway Navigation Procedures

The procedure for getting established on a victor airway is to either fly directly to a nearby VOR or to intercept an airway radial along the route of flight. Once the pilot is established on an airway, it is important to follow the procedures and guidelines put in place to ensure air traffic separation and optimal safety on the airway.LF/MF AirwaysThe basic LF/MF airway width is 4.34 nautical miles (NM) on each side of the centerline; the width expands by five degrees when the distance from the facility providing course guidance is greater than 49.66 NM.Direct Route Flights Direct route flights are flights that are not flown on the radials or courses of established airways or routes. Direct route flights must be defined by indicating the radio fixes over which the flight passes. Fixes selected to define the route should be those over which the position of the aircraft can be accurately determined. Such fixes automatically become compulsory reporting points for the flight, unless advised otherwise by ATC.

Direct Route NavigationRandom RNAV RoutesRandom RNAV routes are direct routes that are based on RNAV capability between waypoints defined in terms of latitude or longitude coordinates, degree-distance fixes, or offsets from established routes or airways at a specified distance and direction. Radar monitoring by ATC is required on all random RNAV routes. Random RNAV routes can only be approved in a radar environment. Factors that are considered by ATC when approving random RNAV routes include the capability to provide radar monitoring and compatibility with traffic volume and flow. ATC radar monitor each flight; however, navigation on the random RNAV route is the responsibility of the pilot.Off-Airway Routes

Off-airway routes predicated on public navigation facilities and wholly contained within controlled airspace are published as direct Part 95 routes. Off-airway routes predicated on privately owned navigation facilities or not contained wholly within controlled airspace are published as off-airway non- Part 95 routes. In evaluating the adequacy of off-airway routes, the following items are considered: the type of aircraft and navigation systems used; proximity to military bases, training areas, low level military routes; and the adequacy of communications along the route. Commercial operators planning to fly off-airway routes should have specific instructions in the company’s OpSpecs that address en route limitations and provisions regarding en route authorizations to use the GPS or other RNAV systems in the NAS.Flight Level Operations

Flight level operations at or above 18,000 feet MSL require the altimeter to be set to 29.92 inches of mercury (" Hg). A flight level (FL) is defined as a level of constant atmospheric pressure related to a reference datum of 29.92 " Hg. Each flight level is stated in three digits that represent hundreds of feet. For example, FL 250 represents an altimeter indication of 25,000 feet.

The lowest usable flight level is determined by the atmospheric pressure in the area of operation. As local altimeter settings fall below 29.92 " Hg, pilots operating in Class A airspace must cruise at progressively higher indicated altitudes to ensure separation from aircraft operating in the low altitude structure as follows:

Current Altimeter Setting

Lowest Usable Flight Level

29.92 or higher 180 29.91 to 29.42 185 29.41 to 28.92 190 28.91 to 28.42 195 28.41 to 27.91 200

When we are below 10,000 feet, we use our local or area QNH to determine

altitude. When deciding on a flight path or magnetic track, we use altitudes. When

communicating our location, we give the altitude.

Then at 10,000 feet starts something called the Transition Layer. No one is allowed

to just sit and cruise inside the Transition Layer as its mainly for… yep you guessed

it, transitioning! Its a buffer between the cool kids and the babies below. This

“buffer” gets bigger as the air thins out… or as the QNH gets lower. So on a day,

when the air pressure at sea level is above 1013 hPa, the transition level is about

11,000 feet…. so only about 1,000 feet buffer. On a day when air pressure at sea

level is less than 963 hPa, the buffer becomes a lot more with something like a

2,500 feet buffer before you’re out of the transition layer.

All flights above the transition layer change their QNH setting to an international

standard rather than the actual air pressure. Why you ask? well that’s mainly logic if

you’re that way inclined, and a little research if you need to. But if you still don’t get

it…Then I’ll tell you why.. it’s a conspiracy. They are faking the air pressure to win

the elections.

The more important point is that now all altitude numbers are divided by 100 and

called “Flight Levels”. So a flight level 240 is 24,000 feet IF the pressure at sea level

was 1013 hPa… since its most probably not, the actual altitude will be different, but

that won’t concern us since we only call it FL 240 and not by its altitude.

As far as the procedural stuff goes, when you’re climbing up into the transition

layer, the moment you hit 10,000 feet, you have to change your QNH to 1013 and

start calling everything by its flight level rather than it’s altitude. When you’re

descending from above the transition layer, you change the altimeter to the Local

or Area QNH before going through the transition layer.

Now to understand the rule books better..  here are some terms that need defining:

Transition Altitude: The line you draw at 10,000 feet that starts the transition

layer, or the bottom of the transition layer.

Transition Level: The constantly changing upper limit of the transition layer

based on the area QNH, or the top of the transition layer.

Transition Layer: The airspace that you’re not allowed to cruise in, and can

only be used to pass through. Or in other words.. stuff in between the

Transition Altitude and the Transition Layer.

Sample En RoutesUS- CANADA(insert pic)Flights Entering U.S. Domestic Airspace (from or Through Canada) Do not address the FPL to any U.S. domestic facility when entering U.S. domestic airspace from, or through Canada. Current flight plan data will be automatically forwarded from the Canadian Automated Air Traffic System (CAATS) to ERAS, prior to boundary crossing. FPLs addressed to any U.S. domestic ARTCC along the route may create processing problems, including duplicate flight plans and/or flight plan rejections by downstream facilities.

Flights Entering U.S. Domestic Airspace (Except from Canada) An FPL is required when entering U.S. domestic airspace from international or oceanic airspace, except from or through Canada. The FPL should be addressed to the first U.S. domestic FIR in the route of flight. FPLs addressed to any other U.S. domestic ARTCC along the route may create processing problems for downstream facilities. They may also be discarded or rejected by those ARTCCs.

ASIA PACIFIC AIRWAY

This Asia/Pacific Regional PBN Implementation Plan has been produced in line with Resolution A 36/23 adopted by ICAO Assembly in its 36th Session held in September 2007, Conclusion 18/52 adopted by APANPIRG/18 and other relevant resolutions adopted by ICAO Assembly in its 37th Session held in September 2010. The Regional PBN Plan addresses the strategic objectives for PBN implementation based on clearly established operational requirements, avoiding equipage of multiple on-board or ground based equipment, avoidance of multiple airworthiness and operational approvals and explains in detail contents relating to potential navigation applications. The Plan envisages the conduct of pre- and post-implementation safety assessments and continued availability of conventional air navigation procedures during transition. The Plan also discusses issues related to implementation which include traffic forecasts, aircraft fleet readiness, adequacy of ground-based CNS infrastructure etc.

Performance based navigation specifies RNAV and RNP system performance requirements for aircraft operating along an ATS route, on an instrument approach procedure or in an airspace.

AppendixChart1-jan13 (Diagrams)