Caution Lights Are Always Which Color Aviation
All NEW – Completely revised with even more lights!
Airliners have a lot of exterior lights. Bulb locations vary with different models and manufacturers, but most airliners have the same types of lights.
Find out why airplanes have so many exterior lights and how pilots use them!
Lights That Help Pilots See Outside
Lighting the way so pilots can see where they're going.
Taxi Lights
Taxi lights are usually installed on the nose gear strut and/or wings. Their purpose is similar to that of automobile headlights.
Taxi lights illuminate the taxiway several feet in front of the aircraft so pilots can safely drive to the gate or runway. The Boeing 757 and 767 have two taxi lights on the nose gear strut.
Runway Turnoff Lights
Two special taxi lights, called runway turnoff lights are installed on the nose gear strut or wing roots. Turnoff lights are aimed to the left and right of the nose.
Runway turnoff lights illuminate high-speed runway exits as the aircraft decelerates during the landing roll out. The lights are also useful when making tight turns on taxiways.
Landing Lights
Landing lights are the largest, brightest lights on an aircraft. They are typically mounted somewhere on the wings, landing gear, or beneath the fuselage.
Landing lights have a very narrow beam (think spot light instead of flood light) and are pointed slightly down so they illuminate the runway during takeoff and landing.
When landing, the lights begin to illuminate the runway when the aircraft is about 200 feet above the ground.
Landing and taxi lights are extremely bright. They use 600 watt bulbs (automotive headlights are around 65 watts). Pilots and maintenance crews are very careful when using or testing these lights, especially at night. Turning on landing lights when ground personnel are nearby can cause severe eye damage.
Landing & Taxi Light Bulbs
Landing and taxi lights use several types of bulbs. Just like cars, different aircraft types use different bulbs.
Landing Light Bulb
The General Electric Q4559X (or incandescent 4559) bulb is used as a landing light on several Boeing, Airbus, and regional jet aircraft. The bulb is also used in the entertainment industry as a spot light because it's ridiculously bright.
The Q4559X is an 8 inch diameter, halogen, PAR 64, 28 volt, 600 watt bulb. It produces 765,000 candlepower and is classified as aVery Narrow Spot (VNSP) with 11° horizontal beam spread.
The halogen Q4559X costs around $50USD retail. The incandescent version costs less but has a shorter lifespan.
Taxi Light Bulb
The Boeing 757 and 767 use the GE 4554 lamp for taxi lights. The 4554 is a PAR 46, 28 volt, 450 watt lamp that provides 90,000 candlepower. It has a wide 50° horizontal beam spread.
Wing Inspection Lights
Wing inspection lights are mounted on the side of the aircraft fuselage, just forward of the wing root. They are aimed rearward to illuminate the leading edge and top of the wing. Their primary function is to help the crew and maintenance personnel inspect the wings for ice, snow, or damage. The lights are also effective for collision avoidance.
Collision Avoidance: Flashy and Colorful!
There are a lot of airplanes in the sky; especially near busy airports. It's important for pilots to see other aircraft in the sky and on the ground. Anti-collision lights help make airplanes easy to spot, even several miles away.
Colorful Position Lights
All aircraft have red and green lights on the wingtips. Red● is always on the left wing, green● on the right. White position lights are mounted on wingtips and/or the tail and face aft.
Position lights are often called "navigation" or "nav" lights, although they have nothing to do with navigation.
Red and green position lights were first used on ships in the 1800's. Collisions were far too common in busy shipping lanes, so the industry began experimenting with position lights. The lights reduced nautical collisions so well, that they were eventually adopted for aircraft use.
Pilots must use position lights from sunset to sunrise. Airlines usually require crews to use them all the time.
Position Lights on Spacecraft 🔴🟢
Position lights are standard on water vessels and aircraft. What about spacecraft?
Orbital ATK's Cygnus cargo spacecraft and the reusable SpaceX Dragon both have position lights. The lights enable International Space Station personnel to quickly confirm vehicle alignment during approach and docking.
No Lights for the Space Shuttle
The Space Shuttle had no position lights, anti-collision, or landing lights. Engineers were careful to save every ounce of weight possible. The Shuttle had a FAA waiver to fly without position lights. It operated in airspace that was cleared of traffic. For the orbiter's 26 night landings, bright floodlights illuminated the runways to compensate for the lack of landing lights.
When pilots see another aircraft's white position lights, they know the aircraft is flying away from them. Seeing red and green lights indicates the aircraft is approaching. The lights help pilots, tower, ground controllers, and ground support personnel determine aircraft position and direction – thus the name "position lights." 🙂
Problems with Red and Green Lights
Red and green are probably not the best colors to use in aviation (or automobile traffic lights). Red-green color blindness is the most common form of color vision deficiency. 8% of all men and 0.5% of all women suffer from some form of it.
Red-green color blindness may disqualify a person from becoming a pilot. Waivers are available and depend on the type and severity of the problem. If you want to fly and think you have a color vision deficiency, check with an aviation medical examiner. The examiner can determine if you can fly.
Anti-Collision Lights: Red
Nothing attracts attention better than a super bright, red flashing light.
Red anti-collision lights are located on the top and bottom of aircraft so a light can be seen from any angle.
Watch aircraft as they arrive and depart airport gates. Crews turn on the red flashing lights just before aircraft movement and engine start. The crew turns off the lights after they shut down the engines and set the parking brake.
Red anti-collision lights are also turned on by maintenance personnel when testing hazardous components like landing gear doors or flaps.
Walking near an operating jet engine or turboprop is more dangerous than juggling chain saws. When ground personnel see the red lights flashing, they know the area is unsafe.
Red anti-collision lights are often called "rotating beacons." Years ago, the lights used a motorized rotating reflector to create the flashing effect. Xenon arc lamps (like a camera flash) replaced the rotating reflectors a few decades ago. Anti-collision lights on new aircraft like the Boeing 787 and Airbus A350 use super bright LEDs to create the required burst of red light. You can tell when an aircraft has the new LED anti-collision lights: the lights stay on longer than the old xenon flash bulbs. It looks more like ON/OFF than a flash; they're easy to spot.
Anti-Collision Lights: White
Installed on the wingtips are blinding white, flashing anti-collision lights. They are often called "strobes" and can be seen for miles. It's easy to spot the white flashing lights on airplanes flying high overhead at night.
White anti-collision lights are too bright to be used while taxiing or waiting in line at a runway. They are distracting (and blinding) to other pilots. Crews turn the lights on just before takeoff, and off immediately after landing.
Some Airbus aircraft have an automatic setting for anti-collision lights that uses a "weight-on-wheels" switch. When the wheels leave the runway, the lights turn on. When the aircraft lands, the lights turn off.
Like their flashing red counterparts, white anti-collision lights have historically used xenon lamps. Newer aircraft use LED systems.
Landing Lights as Anti-Collision Lights
Pulsing landing lights were introduced several years ago to enhance aircraft visibility. The system alternately pulses the left and right landing lights to create an attention-getting display that is effective both day and night.
Southwest, Alaska, Qantas, and Horizon airlines operate aircraft with the Precise Flight Pulselite® system. Similar systems are found at other airlines and on many general aviation aircraft, including helicopters. Southwest refers to the lights as theAlternating Landing Light System (ALLS).
A pilot operates pulsing landing lights with a three position switch. The lights are off during cruise. When descending, the lights are switched to PULSE to increase aircraft visibility in congested airspace. The pilot positions the switch to ON a few hundred feet before touchdown so all lights are on, at full brightness for landing.
Benefits of Pulsing Lights (according to Precise Flight):
- Increases aircraft visibility
- Reduces ground collisions
- Reduces possibility of bird strikes
- Increases life of incandescent bulbs (the system modulates bulbs, allowing filaments to run at lower temperatures)
Drawbacks
Pulsing lights can be distracting to pilots when flying in the clouds. It would be like driving a car in dense fog with your headlights flashing back and forth. Crews typically use the ON setting when descending through clouds, then switch to PULSE when clear of clouds.
To see a pulsing landing light system in action, here's the promo from Precise Flight:
Thank you to Capt. Herb Jackson Jr. for providing information and insight about pulsing landing lights. Follow Herb on Twitter!
Logo Lights
Logo lights are usually mounted on the horizontal stabilizer and light up the vertical fin. Older aircraft, like the DC-8, DC-9, and MD-80/90 variants have logo lights mounted on the wingtips. Airlines love to show off their logos at night – that's exactly what logo lights are for.
Logo lights are not required, but commonly used for the advertising benefits. The lights are also effective for collision avoidance. They make it easy for pilots to spot aircraft on the ground and in flight. Logo lights also help ground controllers identify aircraft on taxiways.
Light Controls
Eleven switches control millions of candlepower on a Boeing 767. The external lighting controls are on the overhead panel within easy reach of either pilot. The taxi and runway turnoff lights are on the left. Three big toggle switches on the bottom control the landing lights. The row of four push switches control position, anti-collision and wing inspection lights. Logo light control is on the right.
Exterior Lighting Management
Each phase of flight has its own lighting requirements. Airlines provide pilots with specific guidance for lighting management. The following is general information.
Ground Operations and Taxi
- Position lights are on anytime an aircraft has electric power available.
- Logo lights are switched on during preflight inspection.
- Aircraft maintenance: Technicians will turn on red anti-collision lights when working with hazardous components (gear doors, flaps).
- Push back and engine start: Red anti-collision lights are turned on just before push-back from the gate and engine start. They are turned off after engines are shut down at the gate.
- Taxi and runway turn-off lights are used at the captain's discretion while taxiing. Pro tip: pilots will turn off taxi lights when pointed toward another aircraft cockpit to avoid blinding the crew.
Runway Operations
- White anti-collision lights are turned on when cleared onto a runway, turned off when exiting a runway.
- Taxi lights and wing inspection lights are turned on when cleared onto the runway.
- Landing lights are turned on when cleared for takeoff, turned off when exiting runway.
- During takeoff and landing every exterior light on the aircraft is used to maximize aircraft visibility.
In-Flight
- During initial climb: landing, taxi, wing inspection, and logo lights are on until above 18,000 feet to maximize visibility in busy airspace. They are turned off above 18,000.
- Only red and white anti-collision lights are used during cruise.
- If a crew spots an aircraft flying toward them, they will sometimes flash the landing lights to say "Hello, we see you!"
- During descent: Landing, wing inspection, and logo lights are turned on below 18,000 feet to maximize visibility in busy airspace.
- Technique: Pilots often form a habit of leaving taxi lights turned off until the tower clears them to land. When the crew receives landing clearance, the captain will turn the taxi lights on. If things get busy, a taxi light switch that's off reminds the crew they need a landing clearance.
LED Lights Are Now on Airliners!
As LED technology advances, the aviation industry is quickly changing its light bulbs. Airports all over the world are changing runway and taxiway lights to LED.
New, super bright LEDs are now being installed on airplanes. The lights appear brighter than the old incandescent bulbs. The color of the LED taxi and landing lights is a little "cooler" or whiter than the yellowish color of incandescent bulbs. They look great!
Why change to more expensive LEDs?
Airlines are switching to LED lights for the same reasons as consumers. The new lights consume far less energy than older bulbs (for an aircraft, that means less demand on the electric generators and less fuel burn). The biggest reason is that LEDs last far longer than incandescent bulbs. This corresponds to lower replacement and maintenance costs – it's a huge annual savings.
Airports Have Pretty Lights, Too!
Be sure to read the companion article: Savvy Passenger Guide to Airport Lights.
Everything you ever wanted to know about colorful airport lights!
Caution Lights Are Always Which Color Aviation
Source: https://aerosavvy.com/airplane-lights/