VOR approach + DME

What is VOR approach?

A non-precision approach using VOR for lateral guidance

What does VOR provide?

Azimuth (bearing) information relative to the station

What does CDI show in VOR navigation?

Deviation from selected radial/course

What is a radial?

A magnetic bearing FROM the VOR station

Difference between “tracking” and “intercepting”?

• Intercepting = capturing the radial

• Tracking = maintaining it

What does TO/FROM indicate?

Whether you are flying towards or away from the station

Does VOR sensitivity change with distance?

No - it’s constant

Typical VOR full-scale deflection?

± 10 degrees (total ~ 20 degrees)

When do you descend in VOR approach?

At FAF or procedure-defined point

What altitude must you respect?

MDA ( Minimum Descent Altitude)

Can you descent below MDA without visual?

No

How are fixes identified in VOR approach?

• DME

• Timing

• Crossing radials

What is the FAF usually based on?

Distance (DME) or cross a radial?

When to go around?

• No visual at MAPt

• Unstable approach

MAPt defined by?

• DME

• Timing

• Over VOR station

What does VOR give you?

Lateral guidance via radials

How does sensitivity compare to localizer?

VOR is constant, localizer increases near runaway

Advice for LOC and VOR

• LOC - don’t overcorrect (sensitivity trap)

• VOR - don’t drift (wind trap)

VOR letter meaning

VHF omnidirectional range

VOR relies on what?

It relies on LOS (line of sight) propagation, meaning signals travel in a straight line

LOS is affected by and blocked by?

• Terrain

• Obstacles

• Or the earths curvature

What DME measures?

Slant range, not horizontal (lateral) distance

What is Slant range?

Is the straight-line distance between the aircraft and the DME station

(hypotenuse)

Rule of thumb for slant range is?

Key points for DME?

• Closer to the station at high altitude, DME distance is greater than ground distance

• The error is most significant overhead the station

• At long range, altitude has negligible effect on DME distance

• As lateral distance increases, slant range ~ ground distance

How to calculate slant range?

Slant Range =√(Ground Range² + Height Separation²)

Height separation is in NM (6080’ft = 1NM)

What is the cone of confusion?

It’s a cone shaped, inverted, and expanding volume of airspace directly above a VOR station where navigation signals become unreliable

What is VORTAC?

VOR - Military Tactical Air navigation (TACAN)