DGCA Air Regulations: Visual Aids for Navigation Questions

Correct answer: C. Information signs, yellow or black background with black or yellow inscriptions

Information signs at aerodromes have a yellow background with black inscriptions OR a black background with yellow inscriptions. Think of it like a school notice board — information is always in yellow and black. Mandatory signs like STOP or runway holding point) are red with white text, not black.

Correct answer: C. Fixed unidirectional lights showing green in the direction of approach to the runway

Runway threshold lights are fixed not flashing), unidirectional, and show GREEN to an approaching aircraft. Green means GO — you see green as you approach because the runway is ahead of you and it is safe to land. They only shine in one direction: toward the approaching aircraft.

Correct answer: B. 6

A runway width of 23 meters requires 6 runway threshold stripes. These stripes help pilots identify the beginning of the runway, especially during landing. Think of them like the lines on a road that guide drivers where to go. Some might mistakenly think it's 4 or 8, but the number of stripes is specifically designed for different runway widths to ensure safety and clarity.

Correct answer: C. Flashing white

Runway Threshold Identification Lights RTILs) are FLASHING WHITE lights. They help pilots spot the threshold start of the runway) especially in poor visibility. They flash to grab your attention — like someone waving at you to say Hey! The runway starts HERE!

Correct answer: C. Landing, take-off and taxiing are permitted exclusively on the designated runway or taxiway

Ground signals are like traffic signs for aircraft. The white dumbbell with a black bar means the aerodrome has both paved and unpaved areas, but all operations — landing, take-off, and taxiing — must only happen on the hard paved runways and taxiways. Stay on the pavement!

Correct answer: A. Runway EDGE lights

Simple one! The lights that run along both sides of the runway to show its edges are called Runway Edge Lights. They are white and yellow in the last 2000 ft to warn you are near the end). They are like the lane markings on a road, but made of light!

Correct answer: C. At least 15 minutes before the expected arrival of an aircraft

Aerodrome lights can be switched off to save energy when no flights are expected, but they must be ready to turn back on at least 15 minutes before any arriving aircraft. This gives enough time to power up all the lights and ensure the runway is fully lit and safe for the pilot to see during approach and landing.

Correct answer: B. White paired, flash lights at 150 mtr longitudinal.

TDZL stands for Touchdown Zone Lights. These are the lights on the runway that help pilots identify the touchdown zone — the area where they should land. They are white paired lights arranged in rows along both sides of the centreline, flashing, spaced at 150 metre longitudinal intervals. They give the pilot a clear visual reference for where to put the wheels down during low visibility approaches.

Correct answer: D. 4 identifications in the same tone

When a VOR and DME are CO-LOCATED and frequency-paired, every 30 seconds 4 Morse code identifications are transmitted, all at the SAME tone — because both share the same ident signal. This confirms both are serviceable together. Same tone, 4 times = co-located VOR/DME confirmation.

Correct answer: D. Multiple lobes in the radiation pattern

The ILS glideslope antenna radiates its signal in multiple lobes at different angles above the horizon. The main lobe creates the true glidepath typically 3°), but the radiation pattern naturally produces additional false lobes at angles above and below. These false glidepaths can appear as valid ILS signals. They are steeper than the true glidepath, so pilots intercepting from above may lock onto a false glideslope.

Correct answer: C. The proximity of a runway

When taxiway centreline lights change from all-green to alternating yellow and green, it is a warning that you are getting CLOSE TO A RUNWAY. Think of it like a yellow warning zone on the ground — Hey! Runway ahead! Be careful! It gives the pilot time to check for landing traffic before crossing.

Correct answer: C. Aerodrome is unsafe, landing is prohibited

A FLASHING RED light from the tower to an aircraft IN FLIGHT means the aerodrome is unsafe and landing is PROHIBITED. Red = danger and stop. Flashing = this is urgent and directed at you. Think of it as a big red stop sign — the aerodrome has a problem runway obstruction, emergency, etc.) and you absolutely must not land. Go elsewhere.