1. Navigation Procedures
ATC Chapter 5

2. Aim
To introduce the concepts and procedures used for visual navigation

3. Objectives Introduction and definitions
State the method for map reading and position fixes
State the 1 in 60 rule and it’s use
State the in flight work cycle
Discuss applied navigation techniques

4. 1. Introduction and Definitions
For the purposes of this Brief we are interested in the theory behind the dead reckoning navigation techniques you will use planning a flight and in flight.
Detailed information on how to plan a flight from a blank flight plan form through to submitting a flight plan to Air Services will be provided in later Briefings.

5. 1. Introduction and Definitions
Flight Planned Track (FPT) – The planned track to be flown
Track Made Good (TMG) – The actual path of the aircraft over the ground, this is a function of Heading and Wind Drift
Track Error (TE) – The angular deviation between the Flight Planned Track and the Track Made Good
TMG TE A B
FPT

6. 2. Map Reading and Position Fixes
Map (Chart) reading is the art of being able to relate the contours, colours and squiggles on a map to the real world passing beneath you.
Always orientate your map so the track is up, this means that features on your map should be in the same orientation in the outside world
Read from watch, to map, to ground
Determine where you should be on your map using time
Seek features on your map in your expected location
Find them on the ground
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Always start with large features working your way down to small features
When you get a positive fix mark it on your map with a 4 figure time reference

7. 2. Map Reading and Position Fixes
Prominent Features
Ideally we want to use large, prominent features as reference points
Railway lines
Silos
Towns/Cities
Bridges
Large Highways
Aerodromes
Hills/ Mountains
Lakes/Rivers

8. 2. Map Reading and Position Fixes
Prominent Features
Things to avoid
Homesteads
Dirt Roads
Small Airfields

9. 2. Map Reading and Position Fixes
Tracking Your Progress
A Positive Fix - occurs when you can positively identify the position of the aircraft relative to the ground.
Examples include passing overhead or abeam an identified town or geographical feature.
Positive Fix
Positive Fix

10. 2. Map Reading and Position Fixes
Tracking Your Progress
A Position Line is defined as a line along which an aircraft is known to be at a particular time.
Examples would be long narrow features such as roads, railway lines, coastlines. You know you are somewhere along the feature but do not have a Positive Fix.
Major Identified Road – Position Line 1 2 3 4
If you can identify a feature along the Position Line or another Position Line that intersects the Position Line then you can establish a Positive Fix.
Which aircraft have a positive fix?

11. 3. 1 in 60 Rule Tracking Your Progress
During the pre-flight planning stage of your flight you should have a good look at your map and determine where you will be able to get a positive fix
When you arrive at your planned fix you need to assess if the aircraft is on track or not.
– mark this point with a perpendicular line with 1nm increments,
TMG
FPT

12. 3. 1 in 60 Rule Tracking Your Progress
Possible reasons for being off track:
Actual wind is different to planned wind
Track has been incorrectly measured
Magnetic deviation has not been applied to the measured track
Incorrect HDG has been held
Diversion due weather or ATC
Once an off track assessment has been made we must do something about re-gaining the planned track or determine a HDG to hold to ensure we reach our destination.
The most common way to re-gain track or track to our destination is by using the 1 in 60 rule.

13. 3. 1 in 60 Rule
1 in 60
The 1 in 60 rule is based on the assumption that 1nm subtends at an angle of 1⁰ at a distance of 60 nm.
In this case we can say we have a track error of 1⁰. 1⁰
TMG
1 nm
FPT
60 nm

14. 3. 1 in 60 Rule
1 in 60
Based on this principal we can say, for example, that if we are 5 nm off track in 60 nm we will have a track error of 5⁰.
5 nm 5⁰
60 nm

15. 3. 1 in 60 Rule
1 in 60
Or, for example, that if we are 5 nm off track in 30 nm we will have a track error of 10⁰.
10⁰
5 nm
30 nm

16. 3. 1 in 60 Rule
1 in 60
If we were on a flight from A to B and we simply adjusted our heading by our track error we would parallel our flight plan track, never making it to our destination.
Distance Off
Track Error A B
Distance Travelled
Distance To Go

17. 3. 1 in 60 Rule 1 in 60 Distance Off Track Error Closing Angle
In order to reach our destination we must also apply the 1 in 60 rule to the distance to go in order to determine our closing angle
Distance Off
Track Error
Closing Angle A B
Distance Travelled
Distance To Go

18. 3. 1 in 60 Rule
1 in 60
1 in 60 calculations can be done quickly using mental arithmetic or using the flight computer.
When using the mental arithmetic method
Divide distance travelled or distance to go into 60
Multiply the answer by the distance off track to get the track error or closing angle
Add the track error and closing angle to get heading change required
Apply the heading change required to the original heading
When using the flight computer
Set the distance off track on the outer scale against distance travelled or distance to go on the inner scale
Against the time index (60) on the inner scale read off the track error or closing angle on the outer scale
Add the track error and closing angle to get heading change required
Apply the heading change required to the original heading

19. 3. 1 in 60 Rule
1 in 60
Example
We are on a flight from A to B heading 090⁰. At our 1 in 60 point we determine we are 4 nm to the left of track. We have travelled 30 nm and have 20 nm to go.
4 nm 8⁰
16⁰ A B
30 nm
20 nm
Using the mental method we know 60 / 30 = 2 and 2 x 4 = 8, therefore our track error is 8⁰
We know 60 / 20 = 4 and 4 x 4 = 16, therefore our closing angle is 16⁰
Our heading change required = track error + closing angle = = 24⁰
We are left of track so we must change heading to the right, therefore we must add 24⁰ to our original heading = new heading 114⁰

20. 3. 1 in 60 Rule
1 in 60
Example
We are on a flight from A to B heading 090⁰. At our 1 in 60 point we determine we are 5 nm to the left of track. We have travelled 84 nm and have 43 nm to go.
5 nm 4⁰ A B
84 nm
43 nm
For this example we will use the flight computer
Set the distance off track on the outer scale against distance travelled on the inner scale.
Against the time index (60) on the inner scale read off the track error on the outer scale, 3.6⁰ which we can round up to 4⁰.

21. 3. 1 in 60 Rule
1 in 60
Example
We are on a flight from A to B heading 090⁰. At our 1 in 60 point we wind we are 5 nm to the left of track. We have travelled 84 nm and have 43 nm to go.
5 nm 4⁰ 7⁰ A B
84 nm
43 nm
Set the distance off track on the outer scale against distance to go on the inner scale.
Against the time index (60) on the inner scale read off the closing angle on the outer scale, 7⁰.

22. 3. 1 in 60 Rule
1 in 60
Example
We are on a flight from A to B heading 090⁰. At our 1 in 60 point we wind we are 5 nm to the left of track. We have travelled 84 nm and have 43 nm to go.
5 nm 4⁰ 7⁰ A B
84 nm
43 nm
Our heading change required = track error + closing angle = = 11⁰
We are left of track so we must change heading to the right, therefore we must add 7⁰ to our original heading = new heading 097⁰

23. 3. 1 in 60 Rule 1 in 60 Re-gaining track
All of the 1 in 60 calculations we have looked at so far will take us from the off track position directly to a specific point.
In some cases this is not a viable option (CTA or Restricted airspace, weather, etc).
We will be required to re-gain our planned track.
Restricted Airspace A B

24. 3. 1 in 60 Rule 1 in 60 Re-gaining track
The calculations required are the same as for the other 1 in 60’s we have looked at, however, instead of using the distance to the destination to determine the closing angle we will use the distance to the planned intercept point.
Once the planned track is intercepted alter heading by the closing angle to maintain the planned track.
Restricted Airspace A B
Distance flown
Distance to fly

25. 3. 1 in 60 Rule
Groundspeed
The 1 in 60 point is also a good place to check our groundspeed and get a revised ETA for our destination.
The easiest way of doing this is using the flight computer. Refer to flight computer briefing.
We can also check our Groundspeed anytime we have 2 positive fixes.

26. 4. In-Flight Work Cycle Work Cycle
There are a number of items we need to monitor throughout our navigation exercises. Work Cycles ensure all items are checked on a regular basis allowing us to remain ‘ahead’ of the aircraft at all times.
A suggested Work Cycle for each leg of a flight is:
Top of Climb Checks after Departing Airfield or Waypoint
CLEAROFFS
1 in 60 Check and HDG/GS adjustment if necessary
Brief and Plan for Arrival at Airfield or Waypoint
Top of Descent Checks
Where a leg is more than 30 minutes more frequent CLEAROFFS should be performed and after a HDG change due to a diversion or an Altitude change.

27. 4. In-Flight Work Cycle C L E A R O F S
CLEAROFFS should be completed at least every 10 minutes in flight or after changing altitude or heading C L E A R O F S
ompass
Compass and DI are aligned og
Flight log and plan are up to date
ngine
T’s and P’s, correct power setting set, mixture leaned
ltimetry
Correct QNH, maintaining planned altitude, hemispherical, airspace
adios/Nav aids
Frequencies set, standby stations tuned
rientation
Location, mark on map
uel
Calculate burn, check on gauges, cross check on FMS
orced landing
Wind direction, visualize pattern, choose field
AR time
Amend as required

28. 4. In-Flight Work Cycle Flight Log
The Flight Plan you prepare before flight is the basis for your Flight Log.
Your Flight Log is a recording of in flight data you gather as the flight proceeds.
In addition to the on ground calculated TK, HDG, GS, TI it includes
1 in 60 Calculations - distance off track, HDG changes, GS changes
Time of arrival at - waypoints, 1 in 60 points, other checkpoints
Diversions - start and destination points, TK, HDG, distances, time
Fuel consumption - every 30 minutes against planned consumption
SARTIME and SARTIME amendments

29. 5. Applied Navigation Procedures
Top of Descent Point
It is important to be able to work out a Top of Descent point to be able to arrive at your destination at a given altitude.
This can be pre-planned but is often is calculated mid flight.
For navigation flights we typically want to carry out a cruise descent at 500 feet per minute and around 110 Knots
Divide the altitude to be lost by 500, this will give us the time for descent
We will have a ground speed of around 2 nm per minute
Time for descent x 2 = distance required for descent

30. 5. Applied Navigation Procedures
Low Level Navigation
Low level navigation should be avoided by thorough pre-flight planning. Unfortunately it is possible that the forecast may be different from the actual conditions and you may be forced to fly low level to maintain VMC.
Flight at low level can cause a number of problems including:
Obstacles
Poor visibility at low level
Visual illusions
Increased work load
If visibility is reduced establish the aircraft in the poor visibility configuration, 80 KTS and 10⁰ Flap.
Low level navigation should be used as a last resort. Consider an early diversion or if conditions become extremely hazardous a PSL

31. 5. Applied Navigation Procedures
Low Level Navigation Procedure
Get a positive fix and record the time
Select checkpoints along track
Estimate the time you should reach each checkpoint.
We can estimate the time required by using a rule of thumb for the C172
In light/moderate winds assume knots or 2 nm per minute
In strong headwinds assume knots or 1.5 nm per minute
In strong tailwinds assume knots or 2.5 nm per minute
Note: A good trick here is to measure the width of your thumb. If, for example, your thumb is 6nm wide that will equate to around 3 minutes flight time at 2nm a minute (120kts groundspeed)
Record the time as you get to each checkpoint and revise estimates for the remaining points
If you find yourself off track apply the 1 in 60 rule
Note: During low level navigation it is acceptable to read from ground to map.

32. 5. Applied Navigation Procedures
For example, we are on a flight from Blanchetown to Alawoona and are forced low level due weather.
Get a positive fix and mark the time on the map
Select checkpoints along the track. These should be visual features that we expect to see if we are maintaining track
Estimate the time you should reach each checkpoint.
Record the time as you get to each checkpoint and revise estimates for the remaining points
If we find ourselves off track apply the 1 in 60 rule
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0003
0002
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33. 5. Applied Navigation Procedures
Lost Procedure
If you become unaware of your position there is a natural tendency to panic. Keeping calm and apply the correct procedure to reorientate yourself.
Maintain present heading if able
Check:
Read from watch, to map, to ground
Last positive fix and heading
DG and compass are aligned
Variation and 1 in 60 have been applied correctly
Tracks on map and flight plan correlate

34. 5. Applied Navigation Procedures
Lost Procedure
Climb to a higher altitude if able
Conduct a square search pattern
Maintain present heading for 1 minute
Turn 90⁰ and maintain the new heading for 1 minute
Turn 90⁰ and maintain the new heading for 2 minutes
Turn 90⁰ and maintain the new heading for 3 minutes
Continue applying technique until position is determined

35. 5. Applied Navigation Procedures
Lost Procedure
If you have applied the square search pattern and are still unaware of your position:
Fly reciprocal heading to last positive fix if able
If a ground feature is identified track to it
Configure aircraft for max range
Contact centre and request assistance
Perform a PSL

36. A number of these can be avoided by thorough
5. Applied Navigation Procedures
Diversions
There are a number of reason for a diversion including:
Weather
Aircraft serviceability
Avoid controlled airspace
Avoid restricted/danger areas
Terrain clearance
Passenger requirements
Low fuel
Last light
Operational considerations
A number of these can be avoided by thorough
pre-flight planning

37. 5. Applied Navigation Procedures
Diversion Procedure
Find a positive fix and record the time
Estimate heading required to diversion destination, fly estimated heading
Draw track on map, check for controlled or restricted airspace
Measure track (remember variation) and distance, fly measured track
Apply wind to track to find required heading, fly the accurate heading
Choose 1 in 60 point
Determine ETA, amend SAR time and flight plan as required
Record all details on flight plan and flight log

38. 5. Applied Navigation Procedures
Diversion Procedure
For example we are on a flight from Alawoona to Karoonda, the weather is starting to deteriorate so we decide to divert to Murray Bridge.
Find a positive fix and record the time
Estimate heading required to diversion destination, fly estimated heading
Draw track on map, check for controlled or restricted airspace
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39. 5. Applied Navigation Procedures
Diversion Procedure
Measure track and distance, fly measured track
Apply wind to track to find required heading, fly the accurate heading
Chose 1 in 60 point
Determine ETA, amend SAR time and flight plan as required
Record all details on flight plan and flight log
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40. 5. Applied Navigation Procedures
Flight for Maximum Range and Endurance
Maximum range is achieved when we can fly for the maximum distance from the available fuel.
Can be used when we are lost or when we are wanting to avoid intermediate stops for refuelling.
Maximum endurance is achieved when we can remain airborne for the maximum time from the available fuel.
Can be used when we need to hold before landing due weather or other reasons.
Consult you POH for recommended power settings for range and endurance.
This subject is covered in further detail in the Aircraft Operation , Performance and Planning CPL subject.

41. Questions?