Aircraft Lights Explained: Position, Anticollision and Landing Lights

Where each position light can be seen, using the dihedral angles in 14 CFR 25.1387. The three sectors together cover every direction around the airplane. Original diagram for PilotPassion, not to scale.

Source: eCFR, 14 CFR Part 25 and 91.209</> Embed this chart

The Main Aircraft Lights

Position Lights: Red, Green and White

The FAA's maintenance handbook says aircraft operating at night must be equipped with position lights that meet the minimum requirements in 14 CFR. A set consists of one red, one green and one white light. On the installations the handbook describes, the green unit is at the extreme tip of the right wing, the red unit is in a similar position on the left wing, and the white unit is usually on the vertical stabilizer, where it's visible through a wide angle from the rear. On some installations a switch in the flight deck gives steady or flashing operation. Traditional position lights use incandescent bulbs, and the handbook says LED lights have been introduced on modern aircraft because of their good visibility, high reliability and low power consumption.

14 CFR 25.1385 sets the layout for transport category airplanes. The forward lights are a red and a green light spaced as far apart as practicable, red on the left and green on the right. The rear light is white, mounted as far aft as practicable on the tail or on each wing tip.

14 CFR 25.1387 defines where each light must be visible. The red and green lights each show unbroken light across 110 degrees from dead ahead, one to each side. The white light covers 70 degrees either side of straight behind, a 140 degree arc. The three sectors fit together with no gaps, so from any direction around the airplane you can see at least one of the lights.

The minimum intensity in the horizontal plane is set in 25.1391 in candles: 40 candles within 10 degrees of dead ahead for the red and green lights, 30 from 10 to 20 degrees, and 5 from 20 to 110 degrees. The white rear light needs 20 candles. Other sections set the minimums above and below the horizontal plane. 25.1397 sets the colors by CIE chromaticity coordinates, called aviation red, aviation green and aviation white.

Smaller airplanes

Part 25 covers transport category airplanes, and many pilots fly something else. Airplanes certificated under the current 14 CFR Part 23 follow a performance-based rule, 23.2530. It requires position and anticollision lights, if required by Part 91, to have the intensities, flash rate, colors and fields of coverage to give another aircraft sufficient time to avoid a collision. Position lights must include a red light on the left, a green light on the right, spaced laterally as far apart as practicable, and a white light facing aft on an aft portion of the airplane or on the wing tips. It adds white riding lights for seaplanes and amphibians. Older airplanes were certificated to the standards in force at the time, so the numbers above are the transport category benchmark and not a universal specification.

How to Read Another Aircraft's Lights

Position lights show orientation, not distance or closure rate. The FAA's collision avoidance circular, AC 90-48D, says apparent movement is almost always the first perception of a collision threat, and that if another aircraft appears to have no relative motion, it's likely to be on a collision course with you. If it shows no lateral or vertical motion but is increasing in size, take immediate evasive action. The same circular says visual search at night depends almost entirely on peripheral vision, because of a night blind spot 5 to 10 degrees wide in the center of the visual field, so it recommends looking about 10 degrees above, below or to either side of a dim light, not straight at it.

Anticollision Lights: Beacons and Strobes

14 CFR 25.1401 describes the anticollision system for transport airplanes. It must light the vital areas around the airplane, with a field of coverage extending at least 75 degrees above and 75 degrees below the horizontal plane. Each light must be aviation red or aviation white. The system must flash at an effective rate of not less than 40 nor more than 100 cycles per minute, although overlaps between sectors may go up to 180. The minimum effective intensity is 400 candles within 5 degrees of the horizontal plane, decreasing to 20 candles from 30 to 75 degrees.

The AIM says an anticollision light system can use one or more rotating beacons or strobe lights, in red or white, and many aircraft have both. The maintenance handbook describes how each works:

• Rotating beacon. A rotating light, usually on top of the fuselage or tail where it doesn't affect the crew's vision or the visibility of the position lights. The unit usually has one or two lights operated by an electric motor. The light may be fixed under rotating mirrors inside a protruding red glass housing, and the flash rate is between 40 and 100 cycles per minute. Large transport aircraft use one light on top and one on the bottom.
• Strobe. An extremely bright intermittent flash of white light, usually mounted at the wing tips and possibly the tail. A dedicated power pack stores a high voltage in a capacitor and discharges it through a sealed xenon-filled tube, and the xenon ionizes with a flash.
• LED. Newer designs use LED-type anticollision lights.

The AIM says supplementary strobe lights should be off on the ground if they adversely affect ground personnel or other pilots, and in flight when they reflect off clouds. AC 90-48D recommends high-intensity anticollision white strobe lights visible from all directions, and pulse light systems for the aircraft landing lights, as collision avoidance equipment. It says many modern lighting and pulse systems, including LED bulbs, use less power, last longer and are brighter than minimum equipment.

Landing and Taxi Lights

14 CFR 25.1383 requires each landing light to be installed so the pilot sees no objectionable glare, and so that it gives enough light for a night landing. There must be a separate switch for each light, except that one switch may serve a multiple-light installation at one location, with a way to tell the pilots when retractable landing lights are extended.

The maintenance handbook says landing lights are high-intensity, directed by a parabolic reflector at the angle giving maximum range of illumination, and use a sealed beam, halogen or high-intensity xenon discharge lamp. On small aircraft they're usually in the middle of each wing's leading edge or built into the aircraft surface, and on large transports usually in the wing leading edge close to the fuselage. Taxi lights give illumination on the ground, but not the degree needed for landing. On tricycle gear they're often on the nonsteerable part of the nose gear, angled to light ahead and a little to each side, and some aircraft add wingtip clearance lights. Many small aircraft have no taxi light at all and rely on intermittent use of a landing light, and others use a dimming resistor in the landing light circuit for reduced illumination while taxiing.

The AIM recommends using lights to be seen. Landing lights go on when takeoff clearance is received or the takeoff roll begins. The FAA's voluntary Operation Lights On program encourages pilots to use landing lights below 10,000 feet, day or night, especially within 10 miles of an airport, in reduced visibility and where birds are expected, such as near the coast, lakes and refuse dumps. Taxi lights show intent: on when the aircraft is moving or about to move, off when stopped or yielding. The AIM adds that turning on lights improves see and avoid but pilots shouldn't become complacent, since not all aircraft have lights and some pilots may not have theirs on.

When the Lights Must Be On: 14 CFR 91.209

From sunset to sunrise, no person may operate an aircraft unless it has lighted position lights. In Alaska the period runs from when a prominent unlighted object can't be seen from 3 statute miles, or the sun is more than 6 degrees below the horizon. Nobody may park or move an aircraft in, or in dangerous proximity to, a night flight operations area of an airport unless the aircraft is clearly illuminated, has lighted position lights or is in an area marked by obstruction lights. An aircraft may not be anchored at night unless it shows anchor lights or is in an area where vessels need none.

Anticollision lights apply at all times, day or night. A person may not operate an aircraft equipped with an anticollision system unless the lights are on. The pilot in command may turn them off when conditions make that safer. The AIM gives the typical case: bad weather where the light output would be a hazard, such as reflections from cloud.

Lights Required for Night VFR

14 CFR 91.205(c) lists the equipment for VFR flight at night, on top of the day VFR equipment. For powered civil aircraft with standard U.S. airworthiness certificates, the lighting items are approved position lights, and an approved aviation red or aviation white anticollision light system. If the aircraft is operated for hire, it needs one electric landing light. It also needs an adequate source of electrical energy for all installed electrical and radio equipment and one spare set of fuses, or three spare fuses of each kind required, accessible to the pilot in flight. The rule adds that if any light of the anticollision system fails, operations may continue to a stop where repairs or replacement can be made. Our electrical systems guide covers the fuses and the source of power.

Lights on the Ground

The AIM advises turning on the navigation, position, anticollision and logo lights, where fitted, before taxi. At the pilot in command's discretion, all exterior lights should be on when taxiing on or across any runway. When entering the departure runway or lining up and waiting, all lights except landing lights should be lit, so that controllers and arriving pilots can see the aircraft. The landing light goes on when takeoff clearance arrives, or on the takeoff roll at an airport with no operating tower. The FAA also recommends that air carriers and commercial operators turn on their rotating beacons any time the engines are running, because jet and prop blast has overturned small aircraft behind large ones.

Wing Inspection and Interior Lights

Some aircraft have wing inspection lights that illuminate the leading edge of the wings so the crew can see ice forming at night, and they're usually controlled through a relay by an on/off toggle switch. 14 CFR 25.1403 requires transport category airplanes to have a means of illuminating or otherwise detecting ice on the critical parts of the wings, unless night operations in known or forecast icing are prohibited. Our icing guide explains why. Inside, the maintenance handbook says aircraft have interior lights for the cabin, often with white and red settings, and commercial aircraft have a main cabin system, an independent passenger reading light system and floor-level emergency lighting.

Airport Lights Are a Separate System

Runway edge lights, taxiway lights and approach lighting belong to the airport rather than the aircraft. See our guide to types of runway approach lighting systems.

Frequently Asked Questions

What color are aircraft navigation lights?

Red on the left, green on the right and white at the rear, usually at the wing tips and tail.

Why is the left light red and the right light green?

It's the standard layout the FAA sets for airplanes (14 CFR 25.1385, and 23.2530 for current small airplanes). The colors tell another pilot which side of the airplane they're looking at.

What does it mean if you see a green light?

You're looking at the right side of the aircraft. If you also see red, its nose is pointed toward you.

When do aircraft lights have to be on?

Position lights from sunset to sunrise (14 CFR 91.209). Anticollision lights must be on whenever the aircraft is operated, day or night, unless the pilot in command decides it's safer to turn them off.

What lights are required for night VFR flight?

For powered civil aircraft with standard U.S. airworthiness certificates, 14 CFR 91.205(c) requires approved position lights and an approved aviation red or white anticollision light system, one electric landing light if the aircraft is operated for hire, and an adequate source of electrical energy for all installed electrical and radio equipment.

What's the difference between a beacon and a strobe?

Both are anticollision lights. A beacon rotates, often with mirrors inside a red housing, to produce a flash. A strobe discharges a capacitor through a xenon tube to give a short bright flash. The AIM says a system can use one or more of either, red or white.

How fast should anticollision lights flash?

For transport airplanes, 14 CFR 25.1401 requires an effective flash frequency of at least 40 and no more than 100 cycles per minute, with overlaps between sectors allowed up to 180.

Why turn off strobes in cloud?

The AIM says strobes should be turned off in flight when adverse reflection from clouds is a problem, and 91.209 allows the pilot in command to turn off anticollision lights for safety.

When should pilots use landing lights?

The AIM recommends them at takeoff and below 10,000 feet, especially within 10 miles of an airport, in poor visibility and where birds are likely.

Can anticollision lights be white?

Yes. Under 14 CFR 25.1401 each anticollision light must be either aviation red or aviation white, and 91.205(c) allows either color.

Are airport runway lights the same as aircraft lights?

No. Runway and taxiway lights are airport equipment. Aircraft lights are on the aircraft.

What do wing inspection lights do?

They illuminate the leading edge of the wing so the crew can see ice forming at night. Transport category airplanes must have a means of detecting ice on critical wing areas unless night operations in icing are prohibited.