LOC approach

What is Localizer (LOC) approach?

A non-precision instrument approach providing LATERAL GUIDANCE ONLY (no vertical guidance)

What frequency band does the localizer use?

108.10 - 111.95 MHz

Where is the localizer antenna located?

At the departure end of the runway, aligned with runway centreline

What happens if you go above glide path on a LOC approach?

No glide path exist - pilots must use manage descent manually

What does the localizer indicate?

Aircraft position LEFT or RIGHT of the runway

How does the localizer indicate deviation?

By comparing modulated signals (90 Hz and 150 Hz)

What does “fly left” indication mean?

You are RIGHT of the centreline, correct left

Is the localizer more sensitive closer to runway?

Yes - very sensitive near threshold, small corrections needed

What replaces glide path in LOC approach?

STEP-DOWN FIXES or descent profile

What altitude restrictions you must respect?

MDA (Minimum Descent Altitude)

Can you descend below MDA without visual reference?

No

What happens if you descent too early?

“Risk of terrain/obstacle conflict - must respect published altitudes”

When can you descend below MDA?

When required visual reference are in sight

What happens is you reached MAPt without visual?

Execute missed approach immediately

How do you identify fixes on LOC approach?

Using:

• DME

• Timing

• Cross radials

• GNSS (if approved)

What is FAF (Final Approach FIX)?

Where the final descend begins

What happens at FAF on LOC approach?

Start descent to MDA

What is common tracking mistake?

OVERCORRECTING due to high sensitivity?

Why is LOC harder than ILS sometimes?

No vertical guidance therefore higher workload

What happens if you chase the needle aggressively?

Leads to oscillation and unstable approach

When autopilot is useful in LOC approach?

During high workload phases (tracking + descent + coms)

What should you say if using autopilot?

Using autopilot for workload management

When you must go around?

• No visual at MAPt

• Unstable approach

• Safety concerns

What is critical during missed approach?

Power → attitude → navigation → communication

What’s your priority on LOC final?

• Track centreline

• Maintain stable descent

• Stay ahead mentally

Key phrases

• “Localizer alive.. approaching course.. correcting to intercept”

• “Established on localizer”

• “Approach checks completed ready to descent”

• “ Correcting localizer left/right”

• “Stable at 1020ft min baro …”

If no visual GOING AROUND

What is the Localizer scale?

• Full scale deflection ~ 2.5degrees either side

• Total width ~ 5 degrees

• 1 dot ~ 0.5 degree deviation

Far from RWY needle moves slowly

Close to RWY needle becomes very sensitive

Why does sensitivity increases?

• Signal is angular (not linear)

• Same needle movement = smaller distance on ground when closer