True North vs. Magnetic NorthAnthony McKayAVP, Air Traffic ServicesNAV Canada

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MAGNETIC VSTRUE NORTH

Vision to 2030Anthony MacKay

AVP Air Traffic Services

04/04/2019

NAV CANADA

The magnetic variation changes with time affecting the set declination of navigation aids and instrument procedures.

These changes can be quite large.

The east and west coasts of North America are changing continuously.

On the other hand, the center of North America, Western Europe and Africa are changing very little.

THE ISSUEWhich way is North?

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Pho

to c

ourte

sy o

f

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WHICH WAY IS NORTHTHE ISSUE WITH MAGVAR

B737 AE320 CRJ

SVS CERTIFICATION

DH8

B757

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THE ISSUESmall Errors make a Big Difference (1 in 60 Rule)

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CANADA’S EXPERIENCEMagnetic & TRUE

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A STRAIGHT LINE PROBLEM

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› Working with the International Association

Of Institutes Of Navigation (IAIN) and RIN to gain worldwide exposure

› Working with CANSO and other ANSPs

› Working with ICAO

› Working with IATA

CHANGING TO TRUEOvercoming years of magnetic pull…

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› Pick a date way out in the future (2030 – 2035)

• IRU equipped aircraft could go to True with MAG/TRUE switch

• New AHRUs (Fibre Optic Gyro (FOG), Micro Electromechanical Systems (MEMS) technologies do not need flux valves for magnetic sense)

• VFR - GA aircraft can still use a magnetic compass and convert to True when setting the directional gyro – simple math

CHANGING TO TRUEWhen and how?

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CHANGING TO TRUE

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CHANGING TO TRUEANSPs & AIRPORTS

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› VFR users technically still use track/drift lines on VNCs although many use some form of GNSS and electronic moving map

› IFR GA aircraft would need to have a procedure to deal with East/West variation between the heading observation from the wet compass to setting the HSI

• Most procedures are now track based with the exception of vectors, NDB IAPs and heading based legs in vector SIDs and downwind legs on STARS

THREE USER SEGMENTSGeneral Aviation – Light Aircraft

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› The challenge is many out-of-production aircraft use a magnetic sense to feed the AHRU

› The addition of IRUs to replace current AHRUs would also be the foundation for RNP-AR operations supporting PBN implementation

› With an implementation date out to 2030-2035 the regional carriers should be able to adapt

THREE USER SEGMENTSRegional Aircraft

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› Large aircraft generally have Inertial Reference Units on board today – many have the ability to switch from MAG to TRUE to bypass the mag var values

› Some operators indicate they operate in Remote/Oceanic Airspace in True

› Operators on Polar Routes operate in the Keyhole in True but not necessarily in Canadian NDA in True

› Savings to be had for IATA carriers with the elimination of 5 years Epoch updates

THREE USER SEGMENTSAirline Narrow Body and Wide-body Aircraft

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THE CASE FOR CHANGEModern aircraft systems, surveillance systems, IAPs are all designed in TRUE

$21m200 Aircraft

$1.2m32 Aircraft

$1.1m1 Airport

$800k/year1 ANSP

$500k1 Aircraft

BUT …

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Safety Impact

ICAO INTERESTS & CONSIDERATIONS

Financial Impact

Security Impact

Magnetic Mode True North Mode

Between 50°S and 50°N ±2° Worldwide ±1°

Between 50°N and 73°N ±3°

Between 73°N and 79°N ±5°

Between 79°N and 82°N ±8°

Environmental Impact

Efficiency Impact

Expected Implementation Time

Positive

Positive

For aircraft, airports and ANSPs in the long term

Neutral

Positive

Positive

Positive

NAV CANADA

Anthony MacKayAVP Air Traffic Services

THANK YOU

QUESTIONS ?