Describe the techniques and procedures for:
a) Re-establishing position if lost or unsure of position;
b) Diverting from the pre-planned route or destination;
c) Navigating at low level when forced to do so by bad weather.
d) Navigating in mountainous terrain.
Unsure of position
When lost and you cannot find any relationship between features on the ground and those on the chart, attempt to work out your position using last known locations and time on heading since.
Check the DI against the compass – if there is a discrepancy between them
1) apply the error to the required track from your last known position giving you an approximate idea of location then
2) synchronise the DI and compass and make a heading change equal to the discrepancy aiming to intercept the required track
If DI and compass were synchronised the uncertainty is probably due to having missed a checkpoint – then note the wrong heading that you have maintained and make a similar heading in the opposite direction
Lost Procedure
Don’t panic, be positive and formulate a plan of action
– Climb to a greater Altitude – the higher you are the more you can see – though cloud often prevents this
– Put the aircraft in the poor visibility configuration to give yourself more time and a tighter turn radius
– Find features on the ground, and try to find them on the map
– Once you have figured out your location, plan a route to regain track or track to the nearest airfield
– Reverse Track – turn back in the direction you came
– Geography – flying to the coast in a relatively short time (unless mid central NI) – once coast intercepted should be easy to get to a suitable destination
– Air Traffic Service Assistance – most of NZ covered by radar – for assistance or if severe situation select on transponder emergency frequency 7700
– Initiate procedures to calculate Most Probable Position (MPP) within a general area (Most Probable Area – MPA)
Be aware of the main causes and prevent the following;-
-inadequate / incorrect flight planning
– incorrect application of Variation and Deviation
– poor or absent record keeping on flight log / chart
– wrong application of drift correction
– insufficiently maintaining a required heading
– DI and compass not synchronised
– failure to avoid adverse weather
– insufficient checkpoints
– incorrect identification of 1 or more checkpoints
– compass reading incorrectly due to metals placed in vicinity
– actual wind grossly different from the forecast
Navigating in bad weather
If showers are inland for example you can divert round the coast. If there are no such features then you must carry out a diversion relying on Dead Reckoning over terrain unplanned for
Divert from your track at a given angle and plan to re-join the track afterwards at the same angle.
Make appropriate allowance for wind factors
In Summary
Make a timely decision to divert
Check the DI against the compass
Turn off track onto a heading 60 degrees to the left
After appropriate time interval turn 120 deg right to re-join the track but 60 deg right if you intend to parallel track
At the end of the same time interval turn left to maintain the flight-planned track
Navigating at low level (not lower than 500ft AGL)
Consider the following:
– Obstructions will appear at short notice e.g cliffs, birds
– Checkpoints – more checkpoints are needed at low level flight – select as many suitable checkpoints as possible and mark clearly on chart. Tick them off as the flight progresses and calculate estimated elapse times between checkpoints
– Aircraft Management – Pay more attention to aircraft handling and less to navigation. Adopt the bad visibility configuration at reduced speed and partial flap extended
-Log-keeping – make brief notes due to a higher work load – using the chart as a log is a good ide
Carry out proper flight preparation
Extensive day-before pre-flight planning
Obtain a thorough Met briefing
Obtain a thorough operational briefing
Thoroughly prepare operational flight plan
Fly headings, altitudes and speeds accurately- have aircraft trimmed at all times
Record accurate events and times
Ensure DI is synchronised with the compass
Look for checkpoints 2-3 minutes ahead of ETA at the points
Keep thorough record of fuel
Plan arrival at destination with at least 1 hour of daylight left
