ILS — Instrument Landing System | Working Principle, Frequencies & Components | PPL CPL DGCA Theory

In this video, we do a complete technical deep-dive into the Instrument Landing System — ILS. This is the radio navigation system that guides aircraft to the runway in near-zero visibility, and we cover everything: the working principle, the exact frequencies each component operates on, and how the Localiser, Glide Slope, and Marker Beacons work together to bring an aircraft down safely in conditions where human eyes simply aren't enough. Whether you're a student pilot preparing for your PPL or CPL ground exams, an aviation enthusiast, or just curious about how planes land in thick fog — this video covers it all with full technical accuracy. 📌 WHAT YOU'LL LEARN — The DDM (Difference in Depth of Modulation) working principle — How the 90 Hz and 150 Hz tones create lateral and vertical guidance — The Localiser — VHF frequency range (108.10 to 111.95 MHz), beam width, range, and accuracy — The Glide Slope — UHF frequency range (329.15 to 335.00 MHz), the 3-degree path, and how it pairs with the Localiser — Marker Beacons — all on 75 MHz — Outer, Middle, and Inner Marker explained — How all three components integrate during a real ILS approach — ILS Categories — CAT I, II, IIIa, IIIb, IIIc — and what each one means for the pilot — Decision Altitude and what the pilot must do at that exact moment ⏱ TIMESTAMPS 00:00 — Intro 00:35 — What is ILS? 01:10 — Working principle — DDM explained 02:00 — The 90 Hz vs 150 Hz modulation zones 02:45 — Component 1: The Localiser (VHF — 108.10 to 111.95 MHz) 03:45 — Component 2: The Glide Slope (UHF — 329.15 to 335.00 MHz) 04:40 — Component 3: Marker Beacons (75 MHz) 05:30 — Decision Altitude — the critical moment 06:00 — How all three components work together 07:00 — ILS Categories — CAT I, II, III 07:40 — Summary and revision card 08:00 — Outro 🔔 Subscribe for daily aviation theory — every system explained with full technical depth, in plain English. ▶ NEXT VIDEO: VOR Navigation Explained — [link when published] 📚 USEFUL FOR — DGCA PPL / CPL Ground School exams — Aviation theory students worldwide — Pilots refreshing systems knowledge — Aviation enthusiasts and sim pilots #ILS #InstrumentLandingSystem #AviationTheory #PPLTheory #CPLTheory #DGCAExam #HowPlanesLand #Localiser #GlideSlope #MarkerBeacon #AviationIndia #PilotTraining #GroundSchool #AviationExplained #LearnAviation ~-~~-~~~-~~-~ Please watch: "The Truth About Pilot Life in India Nobody Tells You"    • The Truth About Pilot Life in India Nobody...   ~-~~-~~~-~~-~