Pilot Navigation

Pilot Navigation

Objectives

  • To teach you to prepare for and be able to conduct safe cross-country flights.

Why?

  • It’s time to go somewhere!

Link

  • Take-off and landing.
  • Range and endurance.
  • Straight and Level flight.

Review questions

  • When reducing power in level flight, what control movement will be necessary to maintain straight and level flight ?
  • What Attitude + Power = Performance means?
  • Why is trimming the aircraft important?

Document on board.

  • Certificate of Airworthiness.
  • Certificate of Registration.
  • Radio Station Licence (for the aircraft).
  • Pilot Operating Handbook (P.O.H)
  • Weight and Balance.
  • Interceptor Order.
  • Crew Licences.
  • Proof of Insurance.
  • Journey log book.

Chart

VNC (Canada)/ Sectional Aeronautical Charts (USA):
  • Lambert conformal conic projection.
  • scale is 1:500,000
  • Straight line = great circle.
  • The standard chart.
VTA (Canada)/ TCA (USA) :
  • Visual Terminal Area chart.
  • Transverse Mercator projection
  • scale is 1:250,000
  • Straight line = rhumb line
  • To satisfy special operational requirement at certain high density traffic airports having complex airspace structure.

Weather

  • METAR
  • TAF
  • FD
  • GFA
  • NOTAM
  • ATIS
  • VISUAL.

Weather minima for VFR aircraft

  • Uncontrolled Airspace.
  • Controlled Zone.
  • Other controlled airspace.
  • SVFR.
  • Night.
  • VFR Over-the-Top:
    • VFR-OTT qualified
    • Day only.
    • Operated at least 1000’ vertical distance from cloud.
    • Visibility must be at least five miles.   
    • When operating between two layers, those layers must be at least 5000’ apart. 

Weight and Balance

  • An airplane must only be flown within certificated limits of weight and balance to ensure that it remains controllable, performs adequately and is not overstressed.
  • Correct weight and balance means:
    • Maximum allowable weight is not exceeded
    • Center of gravity (CG) is within a specified range.
  • Calculate
    • Take-off and landing weights
    • Make sure aircraft is within C of G limits.

Aft Center of Gravity
  • More efficient but decreases stability.
  • Less than usual back pressure on take off and landing.
  • Chance of tail strike on landing.
  • Lower stall speed but stall characteristic can be dangerous. (recovery may even be impossible because the pilot is running out of elevator control).
  • Tail may drop instead of the nose.
Forward Center of Gravity
  • Decreases performance.
  • Apply more than usual back pressure at rotation.
  • Apply more than usual back pressure for landing and  makes flaring for landing more difficult.
  • Chance of wheelbarrowing or even pop strike.
  • Higher stall speed.
  • The nose will tend to drop more than usual at stall.

Performance: calculate take off distance

  • Determine the weight of aircraft for take-off
  • Determine the pressure altitude for the aerodrome (METAR/TAF).
  • Determine the temperature at the aerodrome (METAR/TAF).
  • Determine the wind component (METAR/TAF, RUNWAY, CROWWIND GRAPH)

Performance: calculate Time, fuel and distance to climb

  • Determine pressure altitude on the ground.
  • Determine pressure altitude for the cruise altitude.
  • You may need to interpolate between the number if your pressure altitudes are not even 1000’s feet.

Calculate cruise performance

  • With :
  • Pressure altitude.
  • Temprature.
  • Power (RPM).
  • refer to POH diagram to get
    • airspeed
    • fuel consumption.

Performance: calculate landing distance

  • Determine the weight of aircraft for landing.
  • Determine the pressure altitude for the aerodrome (METAR/TAF).
  • Determine the temperature at the aerodrome (METAR/TAF).
  • Determine the wind component (METAR/TAF, RUNWAY, CROWWIND GRAPH)

Airspeed calibration

  • Calculate the TAS by using Performance chart.
  • Calculate CAS using the flight computer to correct our TAS for temperature and pressure.
  • Calculate IAS by corrected our CAS with airspeed calibration chart.

Definition

  • Track = without wind.
  • Heading = with wind.
  • True track:
    • The patch the aircraft follows over the ground relative to the true north (line draw on the map).
  • Magnetic track:
    • The patch the aircraft follows over the ground relative to the magnetic north.
  • True heading:
    • The direction of the aircraft is pointing relative to the true north.
  • Magnetic heading:
    • The direction of the aircraft is pointing relative to the magnetic north. (It’s this heading that you follow during your navigation).
  • Variation:
    • Degrees difference between true north and true heading.

Navigation preparation: Part1

Select route:
  • Find set heading point.
  • Make it as straight as possible.
  • Note Airspace Restrictions
  • Check airport advisory for destination.
  • Draw line to SHP.
  • Draw line from SHP to Destination/Turn Point.
  • Draw 10° drift lines.
  • Make mark at the midpoint of each leg.
  • Make mark at 10 NM intervals.
  • Make mark for each check points.
  • Determine MOCA for each leg.
  • Determine True Track for each leg.
  • Determine average variation for each leg.
  • Note alternate airports enroute
  • Mark airport frequencies.

Navigation preparation: Part 2

  • Check:
    • Weather.
      • Make GO/NO GO decision.
    • Notams.
  • Calculate:
    • Weight and Balance.
    • Determine cruising altitudes.
    • Take-off distance, time and fuel distance to climb.
    • Crosswind components
    • Landing distance.
    • Fuel burn + reserve fuel and add 20%.
    • Cruise performance : TAS/ CAS/ IAS.
    • True heading.
    • Magnetic heading.
    • Ground speed.
    • Departure time.
    • ETE – Estimated Time Enroute. (for each leg).
    • ETA – Estimated Time for Arrival.
    • Complete the flight planning form.
    • Flight plan/itinerary complete and file.

Departure procedures

Overhead departure:
  • Set heading over the airport
  • Advantage:
    • If you are unfamiliar with area and there are no obvious landmark near by.
  • Disadvantage:
    • Use time and fuel to circle over the airport.
    • It can be difficult to get clearance for this type of departure within a control zone.
Enroute Climb:
  • Take off, climb to a safe altitude and turn to intercept track
  • Advantage:
  • Most direct way.
  • Useful when departing from unfamiliar airports.
  •  using  first check point to confirm track.
  • Disadvantage:
  • easy to fly past your track.
Set heading point:
  • Set heading at a distinct landmark or a familiar point near the airport.
  • Advantage:
    • Most efficient method to use.
    • Allows you to concentrate on departure procedures.
  • Disadvantage:
    • Can be difficult at unfamiliar airport with no obvious landmarks nearby.

Set Heading Procedure

  • Reset and set Heading Indicator.
  • Take time over SHP.
  • Turn to planned course.
  • Track (check departure angle).
  • Set Power to cruise trpm and lean mixture.
  • Revise ETA.

Enroute procedure

  • Hold a constant heading.
  • Reset Heading Indicator every 15 minutes.
  • Revise ETA with Checkpoints
  • Cockpit checks (carb icing, engine gauges…).
  • Map oriented to direction of flight.
  • Check position (landmark).
  • Correct for Wind Drift
  • File flight Log entries (time over check points, groundspeed, revised ETA…).
  • Obtain Revised Weather Forecasts (FSS)
  • Maintain Listening Watch on Appropriate Frequency. weather updates from FSS.
  • Lookout for Emergency Landing Areas

Descent and Arrival Procedures

  • Descent:
    • Cabin check (seats, baggage, etc).
    • Mixture rich.
    • Start descend at 500 fpm.
    • Avoid obstacles.
  • Joining the circuit:
    • Make radio calls.
    • Plan the approach.
    • Join the Circuit and Land.
    • Close Flight Plan (within 60 minutes through tower or FSS).

Drift correction

  • Visual Alteration.
  • Double Track Error.
  • Opening and Closing Angles.
Visual Alteration
  • Establish your position
  • Fly to a known feature along the track.
  • Once back on track apply necessary correction to maintain track.
Double Track Error
  • This method only works before your half way point. Otherwise, by the time you get back on track, you will be past your destination.
  • Estimate track error by using your drift line from the Set Heading Point.
  • Determine the time flown since departure from the Set Heading Point, it will take about the same time to get back on track.
  • Double error to get back to track.
  • Once on track subtract half correction to maintain track again.
  • Determine your new ground speed and ETA.
Opening and Closing Angles.
  • Only if you are past your half way point.
  • This method only get you to destination, it will not get you back on track.
  • Determine your position with relation to track.
  • Determine your opening angle off track.
  • The opening angle of track is the angle between your position and your track using your 10° drift line from your point of departure.
  • Determine your closing angle off track.
  • The closing angle off is the angle between your position and your 10° drift line from your destination.
  • Add your opening angle and your closing angle together to determine your drift correction and turn toward the track by this amount.
  • Fly the new heading until arrival at destination.
  • If you have drifted to the left: add your drift angle.
  • If you have drifted to the right: subtract your drift angles from your heading.

Diversions

  • There are various reason for one to divert.
    • Deteriorating weather on intended route.
    • Fuel shortage, possibly due to strong wind.
    • Mechanical problems.

Diversion: basic theory

Distance:
  • 1 degree fo latitude = 60 nm.
  • 1 minute of latitude = 1nautical mile.
  • Approximately half thumb = 8nm/VNC and 4nm/VTA. (measure your own thumb).
Time:
  • For 90kt average:
    • Time = (distance /3) * 2
    • Example: (12 nm / 3) * 2 = 8 minute to fly 12 nautical miles.
    • Make correction based on wind.
Fuel:
  • Fuel = Time * Fuel flow.
Estimate track and heading:
  • Determine where you are and where you want to go.
  • Draw Line and half way point.
  • Use VOR radials on the map or latitude/ longitude line.
  • Follow roads, rivers, shorelines etc.
  • Compass rose.
  • Correct for crosswind.
Altitude:
  • Moca
  • Weather.
  • Circle any obstacles
Radio:
  • Inform FSS /FIC:
    • New destination
    • new ETA.

Diversions procedures

  • Slow down.
  • Circle where you are and new destination.
  • Establish a new track over a check point or a landmark.
  • Drawn a line and mark half way point. (mark checkpoint as weel).

Over the check point:

  • Set heading Indicator (reset every 15 minutes).
  • Cruise rpm.
  • Mixture Lean.
  • Record time over check point.
  • Estimate:
    • Distance.
    • Time.
    • New ETA.
    • Fuel.
  • Inform FSS/FIC of your new destination and ETA.
  • Record time over half way point.

Lost procedure

  • Climb to see better and further.
  • Note what your last know position was on the map and circle it or do circle of uncertainty.
  • Slow the aircraft.
  • Maintain heading and look for a know landmark.
  • if you find it, you are not longer lost.
  • Reach this point and begin the diversion procedure to come back on your track.
  • If you are unable to use landmark to determine location:
    • Use all available navigation system (VOR, DF steer…).
    • Contact ATC or FSS for help (try to locate the closest airport with DF equipment).
    • Plan a precautionary landing if low in fuel or unable to maintain VFR conditions.
    • PAN PAN call.

Review questions

  • How do you determine your true track ?
  • What is the difference between true track and true heading ?
  • what lost procedure can you perform ?
  • What is the diference between  geographic north and magnetic north ?
  • What are the three type of departure proocedures ?
  • What are some factors in determining a suitable point for a diversion?
  • What procedure can we follow if we are lost?