CNS/ATM resource kit – Chapter 7: Flight planning

An important aspect of any flight away from home base is thorough flight planning. Having a well thought-out plan before you get airborne will help you enjoy the flight, arrive refreshed and return alive.

Even if you are going somewhere familiar, have some key details worked out beforehand. Getting the most up-to-date weather and NOTAMs is a must.

This chapter will cover the eight phases of flight, use of electronic flight bags, GNSS operations and requirements, applying RAIM predictions and use of alternate routes.

Eight phases of flight

There are eight phases in every flight for every aircraft. Each phase has its own significance in flight planning and each must be managed successfully.

As Benjamin Franklin once said, ‘If you fail to plan, you are planning to fail.’ As technology becomes more sophisticated, it becomes even more critical to plan your flights carefully. Where will your flight go, what route will you follow, what will the weather be like at your destination and along your route, how much fuel will you carry, what potential diversions or delays might you encounter, and are you fit to fly?

While technology needs to be considered in all phases of flight, remember that technology is not a substitute for proper planning.

Complete a quick review of the eight phases of flight below.

  1. Planning: make decisions and calculations about your route: the weather; how much fuel to carry; your load; and any potential diversions, delays or emergencies.
  2. Pre-flight: inspect the aircraft: analyse any faults or conditions and if these will affect the flight plan.
  3. Pre-departure: check the operation of the aircraft: set systems for take-off and climb, assess if you are fit to fly.
  4. Post-departure: commence navigation procedures: configure the aircraft for cruise flight, fly accurately on your outbound route.
  5. En route: monitor navigation, weather, fuel management and consumption, other traffic.
  6. Pre-approach: fly a stable and accurate descent, obtain ATIS or AWIB information.
  7. Approach: sight the airport, communicate with ATC or other traffic, assess airport and wind conditions.
  8. Landing: land, exit the runway, taxi, shut down the aircraft.

Electronic flight bags

Electronic flight bags (EFBs) can store and retrieve documents required for flight operations, such as maps, charts, the flight crew operations manual, minimum equipment lists and other control documents.

Physical EFB displays may use various technologies, formats and forms of communication. The capabilities of electronic flight bags increase, almost by the month, but even their developers warn that these computer programs are no substitute for basic flight-planning skills.

Australia has two major EFB providers for general aviation: OzRunways and AvPlan EFB. Both are available for Apple iOS and Android tablets and both offer the ability to plan a flight, get weather and NOTAMs and navigate, with maps, En route supplement Australia (ERSA), Departure and approach procedures (DAPs) and Aeronautical Information Package (AIP) at the pilot’s fingertips. Both allow the pilot to fetch or enter winds, store aircraft profiles, submit to National aeronautical processing system (NAIPS) and create custom waypoints.

Some EFB products display nearby traffic, derived either from a portable ADS-B IN receiver carried on board or uploaded from the provider’s ground system, in which case the traffic displayed may be limited to aircraft that use the same EFB provider. The ability of EFBs to provide a range of information to and from aircraft is expected to continue to improve in future. Pilots should contact their EFB service provider for information about specific current capabilities.

Screens

The screen size and resolution needs to display information in a manner comparable with the paper aeronautical charts and data it is intended to replace.

The recommended minimum size of the screen is about 200 mm measured diagonally across the active viewing area.. If the intent of the installation is to display charts and maps, the device should be suitably sized to display the image without excessive scrolling.

Mobile devices with a minimum size of screen approximately 200mm diagonal
The paperless cockpit is now a reality—screen size does matter

Mounting devices

EFBs which use temporary mounts that attach to the aircraft, such as suction mounts and Velcro pads, are regarded as class 1 devices and must be stowed during take-off and landing. They should also be stowed during periods of turbulence.

Temporary mounts are not considered to be airworthy and may constitute a hazard on the flight deck in certain circumstances. The equipment, when mounted and/or installed, must not present a safety-related risk or associated hazard to any flight crew member. EFBs attached to kneeboard holders do not need to be stowed.

The mounted EFB must not obstruct:

  • external vision
  • physical access to aircraft displays or controls
  • visual access to aircraft displays or controls.

The required cabling for an EFB should be a sufficient length to prevent damage or hazards.

Pilots need to consider stowage for EFBs which are not mounted to the aircraft or to a kneeboard. They must be designed and used in a way which prevents the device from jamming flight controls, damaging flight compartment equipment or injuring flight crew members.

All EFB mounts attached to the aircraft structure will require airworthiness approval. See Subpart 21.M of the Civil Aviation Safety Regulations 1998.

Software

The operator should ensure the operating system and programs meet the intended function. Unauthorised modification of any database or the loading of any new or additional software is not permitted unless the software complies with the manufacturer’s specifications.

Information provided to the pilot needs to be a true and accurate representation of the charts or documents they replace.

GNSS operations and requirements

  • Plan the route using charts.
  • Enter the plan into the GNSS unit or retrieve a saved plan from volatile memory.
  • Check the information in the GNSS database and the user waypoint information against charts or a flight plan containing waypoint names, identifiers, latitude/longitude, tracks and distances.
  • Cross check both latitude/longitude information and bearing/distance information to prevent a charted error being carried over to the GNSS.
  • Where available, get two crew members to check the inputs are accurate and reasonable when entering data manually. If the information is suspect, check it against appropriate documents.
  • If you are flying single pilot, do your own cross-checking by comparing GNSS computer tracks and distances against current chart data.
  • Use ‘Flight plan mode’ to compare GNSS-derived distance and bearing information with your own flight plan.
  • Examine each route leg for track and distance as a double check for input errors.

Check that manually entered and database-derived position tracking information is reasonable in the following cases:

  • before each compulsory reporting point
  • at or before arrival at each en route waypoint
  • every hour during area type operations when deviating from established routes
  • after insertion of new data, such as the creation of a new flight plan.

And ensure that you:

  • check GNSS NOTAMs and other warning information
  • check that the data is current—this is often displayed at start-up
  • carry the GNSS operating manual for the unit installed in your aircraft.

Don’t take off without it!

You must carry operating instructions for your GNSS unit on board, and, if a commercial operator, incorporate them into your company operations manual.

You must also follow the operating instructions and any additional requirements specified in the approved aircraft flight manual or flight manual supplement.

In addition to GNSS, the aircraft must be equipped with serviceable radio navigation systems as required.

GNSS prediction

Before planning to use GNSS for IFR approaches, get a RAIM prediction from the Airservices Australia briefing website. RAIM outages are predicted at 1400 UTC each day and when new satellite outage information is received. RAIM predictions are based on satellite geometry, equipment RAIM capability (fault detection or fault detection and exclusion) and certification status (C129 or C146).

Selecting operational modes

TSO-specified GNSS equipment has several different modes used in flight planning and in flight, including:

  • ‘nav’ or ‘map’ mode—the primary navigation mode used in flight
  • ‘waypoint’—enabling you to access waypoint information
  • ‘flight plan’, in which flight plans can be created, edited, stored and recalled
  • other modes that allow you to access information on equipment status, the satellite constellation and other features, such as winds aloft.

Recalling categories of information from ‘nav’ database

GNSS navigation databases contain several waypoint types, including airports, VORs, NDBs, intersections, SIDs, STARs and approaches. Take care to select the correct waypoint.

You can usually customise the worldwide database within your receiver to access information on the Australasian region only.

Predicting RAIM in flight

  • Most TSO-specified GNSS equipment can predict the availability of RAIM at the destination.
  • You may use this function before commencing an RNAV GNSS approach.
  • The prediction function typically indicates RAIM FD availability at the destination 15 minutes either side of the specified time.

See RAIM prediction and NOTAMs later in this chapter for more information.

Entering and checking user-defined waypoints

You can create user waypoints and store them in the system, but you should validate them against published information, such as ERSA and charts, or cross check them using bearing and distance information from a known waypoint.

Entering, retrieving and checking flight plan data

When you enter or retrieve a flight plan from the GNSS database, cross check each route segment for track and distance with your own flight plan and current charts.

Interpreting typical GNSS nav displays lat/long, distance and bearing to waypoint—course deviation indicator (CDI)

GNSS equipment can display navigation information in several formats, including bearing and distance to known waypoints, and latitude and longitude data. It also uses a CDI-style display, which represents a distance, not an angular displacement, from track. For example, full-scale deflection on a GNSS CDI might indicate 5 nm off track rather than 10° off track, as would be the case for a VOR. You can select the sensitivity of the CDI to suit your requirements. Learn how to access the settings to determine the display’s sensitivity and change the scale if necessary.

Intercepting and maintaining GNSS-defined tracks

The navigation display includes the current track made good to help you maintain the desired track. Some GNSS displays have a track error graphic to help you intercept the desired GNSS track. Track made good, ground speed, ETA, time and distance to waypoint are in the ‘nav’ or ‘map’ fields.

If an air data computer is connected to the unit, wind velocity in-flight is calculated automatically. If you don’t have an air data computer, you will have to enter TAS and present heading manually to enable the unit to compute winds aloft.

Indications of waypoint passage

The GNSS display indicates arrival at a waypoint. Monitor it when approaching a waypoint as the indication might be brief. You can change the duration of the indication through the set-up function.

Use of ‘direct to’ function

You can use the ‘direct to’ or ‘go to’ function to navigate directly from your current position to a nominated waypoint. This function is most useful when ATC instructs to ‘track direct’ from present position or that a weather diversion is required.

Be aware of the new track’s possible proximity to controlled airspace and restricted area boundaries when using this function, and cross check against current maps, charts and NOTAM information. The ‘direct to’ function will usually take you off a published en route chart (ERC) track and you will need to reassess lowest safe altitude along the revised track.

‘Nearest airport’ function

GNSS equipment can give you a list of the nearest airports, VORs, NDBs, intersections and approaches. The nearest airport function can be useful in finding a safe haven in an in-flight emergency.

Use of GNSS, and GNSS or DME arrival procedures

When using GNSS for IFR navigation:

  • the GNSS database must be current and endorsed by the receiver manufacturer and must be immune to modification by crew
  • RAIM must be available below the LSALT/MSA when conducting operations in IMC
  • if there is a contradiction between any sources of information, climb to the LSALT/MSA as soon as possible.

RAIM prediction and NOTAMs

There are three sources of RAIM prediction generally available to civil aviation users.

  1. Receiver: TSO receivers have a built-in approach RAIM prediction function available to the pilot. This is useful for in-flight use. However, these systems are usually not capable of FDE prediction and use the last issue of the constellation almanac to predict RAIM. The resulting prediction therefore becomes progressively less accurate over time and is thus unsuitable for flight planning purposes.
  2. Software: GPS oceanic and remote area approval requires an appropriate en route RAIM prediction, using the software provided by the receiver manufacturer, to be conducted prior to flight. This analysis takes into account the required navigation performance for the route or centreline spacing. Australian operators must retain a record of the GPS prediction analysis.
  3. NOTAM: Having the latest NOTAMs is very important. Read the NOTAMs carefully, highlighting the ones that will affect your flight.

GPS Status reports

Airservices Australia makes GPS status reports available via the AVFAX system. These reports are issued by the US Coast Guard and contain details of the satellites in orbit, notice advisory to NavStar users (NANU) and other general remarks.

RAIM prediction service

The Airservices Australia RAIM prediction service (RPS) uses NANU and the current almanac to provide GPS NOTAMs for flight planning purposes.

Approach RAIM outages are given for 72 hours from the UTC prediction time shown in the first line of the prediction message. RPS has been upgraded to facilitate the differences between TSO-C129 and TSO-C146 equipment.

Sample text of the RAIM prediction output is:

  • BUTLER (YBUT)
  • GPS RAIM PREDICTION 071401 YBUT
  • TSO-C129 (AND EQUIVALENT) FAULT DETECTION
  • 03080610 TIL 03080615
  • 03090606 TIL 03090611
  • 03100602 TIL 03100607
  • GPS RAIM FD UNAVBL FOR NPA
  • TSO-C146A (AND EQUIVALENT) FAULT DETECTION ONLY
  • NO GPS RAIM FD OUTAGES
  • FAULT DETECTION AND EXCLUSION 03080610 TIL 03080613
  • GPS RAIM FDE UNAVBL FOR NPA

Alternate routes

While in the preliminary flight-planning phase, you should make provision for at least one other safe alternate route—a plan B. In planning this route, take the same level of care as you do with your primary route. Having a well-researched plan B takes a lot of pressure off if the weather deteriorates and you have to use it.

IFR

The approvals for use of GPS under IFR in the AIP specify that GPS may be used to satisfy any of the IFR requirements for provision of an alternate aerodrome provided that it is certified to TSO-C145a or C146a, and a valid prediction of approach FDE availability is used. This applies to the requirements for navaids at both the destination and the alternate aerodrome.

When using a TSO-C129 receiver, or a C146a receiver with a prediction that FDE will not be available, and the forecast weather is below the alternate weather minimums, the alternate must be suitable for visual approach or an instrument approach using ground-based navigation aids.

The following table gives examples of alternate requirements for aircraft fitted with TSO GNSS receivers with and without fault detection and exclusion (FDE).

Operation of CHTR/AWK/PVT
Onboard navaids Weather at destination Approaches at destination Alternate required? Alternate requirements

1 TSO C146 or later GPS (FDE available)

1 ADF

1 VOR

Above alternate minimums

RNP APCH LNAV

VOR

NDB

No None
Operation of AWK/PVT
Onboard navaids Weather at destination Approaches at destination Alternate required? Alternate requirements

1 TSO GPS (no FDE available)

1 ADF

1 VOR

Above alternate minimums RNP APCH LNAV Yes—due navaids

Must have an NDB and/or VOR IAL and forecast weather above alternate minimums, or

By day only, have no IAL
and forecast weather better than LSALT + 500 ft and 8 km visibility

Night VFR

When both pilot and aircraft meet the AIP requirements, a pilot may not need to provide for an alternate aerodrome to a ‘no-aid’ destination under night VFR.

AIP requires that the pilot provides for an alternate within one hour’s flight time of the destination unless:

  • the destination is served by a radio navigation aid (NDB or VOR) and the aircraft is fitted with the appropriate radio navigation system capable of using the aid
  • the aircraft is fitted with a GNSS receiver appropriate for an aircraft operated at night under VFR and the pilot is appropriately qualified.

Key points

  • If you fail to plan, you are planning to fail. As technology becomes more and more sophisticated, it is critical to plan your flights carefully.
  • The roll of CNS technology needs to be considered in all phases of flight. When assisted by technology—seen with the adoption of GNSS and ADS-B—even experienced pilots can forget important steps.
  • Establish key details beforehand, then get the most up-to-date weather and NOTAMs.
  • Electronic flight bags (EFBs) can electronically store and retrieve documents required for flight operations, such as maps, charts, the flight crew operations manual, minimum equipment lists and other control documents.
  • There are generally three sources of RAIM prediction available to civil aviation users: TSO receivers, the NAIPS website and NOTAMs.
  • While in the preliminary flight-planning phase, you should make provision for at least one other safe alternative route—a plan B.

Resources

Further reading

  • Airservices Australia (2016). OneSKY Australia program. Retrieved April 2017.

References

  • CASA (2006). Civil Aviation Advisory Publication 179A-1(1). Navigation using Global Navigation Satellite Systems (GNSS). Canberra.
  • CASA (2009). Focus on flight planning. Flight Safety Australia, March–April. Retrieved April 2017.
  • CASA (2010). Flight planning kit.
  • CASA (2014). Dry but not high. Flight Safety Australia, September–October. Retrieved April 2017.
  • CASA (2014). Global aviation growth and safety. Flight Safety Australia, November–December. Retrieved April 2017.
  • CASA (2015). Tablets of wisdom. Flight Safety Australia, November–December. Retrieved April 2017.
Published date: 23 June 2021
Online version available at: https://www.casa.gov.au//node/52904
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