ANTI-COLLISION/STROBE LIGHTING - DESCRIPTION AND OPERATION

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1. General

A. The aircraft recognition lighting system is used as a visual aid to other aircraft and thus prevent a possible collision.
The system has:

One anti-collision light installed on the top and one on the bottom of the aircraft fuselage. Each anti-collision light gives a red high-intensity light that flashes.
One strobe light installed on each wing tip. Each strobe light gives a white high-intensity light that flashes.
One strobe light installed on the tail cone, below the APU exhaust. The strobe light gives a white high-intensity light that flashes.

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2. Component Location

Anti-Collision and Strobe Lighting - Component Location ** ON A/C NOT FOR ALL

FIN	FUNCTIONAL DESIGNATION	PANEL	ZONE	ATA REF
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16LA	LIGHT ASSY-NAV AND STROBE, REAR		317	33-41-17
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3LV	PSU		244	33-48-36
4LV	PSU		140	33-48-37
6LV	ANTI COLLISION LIGHT		140	33-48-12
7LV	ANTI COLLISION LIGHT		244	33-48-11
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14LV	PSU	634AB	634	33-48-38
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14LV	PSU		634	33-48-38
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15LV	PSU	534AB	534	33-48-38
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15LV	PSU		534	33-48-38
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16LV	STROBE LIGHT		634	33-48-14
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17LV	LIGHT-STROBE, L WING TIP		534	33-48-14
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17LV	STROBE LIGHT		534	33-48-14
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18LV	PSU		312	33-48-39
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19LV	STROBE LIGHT		317	33-48-13

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3. System Description
The aircraft recognition lighting system has two independent systems which operate alternately in synchronization:

The anti-collision light system, and
The strobe light system.

The both systems operate independently:

The anti-collision light system is controlled by the BEACON control switch (2LV), located on the overhead panel 25VU.
The strobe light system is controlled by the STROBE control switch (11LV), located on the overhead panel 25VU.

A. Anti-Collision Lights
Two anti-collision lights (6LV and 7LV), which do not turn, flash at a rate of 55 plus or minus five flashes per minute. Each light gives 360 degrees of horizontal diffusion and 75 degrees of vertical diffusion.
The LED anti-collision lights (6LV and 7LV), which do not turn, flash at a rate of 45 plus or minus two flashes per minute or 55 plus or minus five flashes per minute in relation to the power supply unit. Each light gives 360 degrees of horizontal diffusion and 75 degrees of vertical diffusion.

B. Strobe Lights
Two strobe lights (16LV and 17LV), installed on the wing tips, have two flash tubes. The flash tubes flash at the same time at a rate of 55 plus or minus five flashes in one minute.

The strobe light (19LV), on the tail cone, flashes at a rate of 55 plus or minus five flashes in one minute.
Two forward pointing LED strobe lights flash at the same time at a rate of 60 +/- 5 flashes per minute.

A forward-facing LED strobe light with Near End-Of-Life (NEOL) indication is installed at the leading edge of each sharklet. The NEOL indication is a blue LED light that flashes when the LED light is near degradation and you must replace it by a serviceable light before 1000 flight hours. When the NEOL indication comes on, the LED light will not be extinguished after 1000 flight hours but its performance can decrease to less than the certification requirements.

Rearward pointing tail strobe light flashes at a rate of 60 +/- 10 flashes per minute. This gives 120 +/- 10 flashes per minute in the forward direction and 60 +/- 10 flashes per minute in the rearward direction.

Two LED strobe lights (16LV and 17LV), installed on the sharklets, have a LED light assembly and flash at a rate of 60 plus or minus five flashes per minute.

A forward-facing LED strobe light with Near End-Of-Life (NEOL) indication is installed at the leading edge of each sharklet. The NEOL indication is a blue LED light that flashes when the LED light is near degradation and you must replace it by a serviceable light before 1000 flight hours. When the NEOL indication comes on, the LED light will not be extinguished after 1000 flight hours but its performance can decrease to less than the certification requirements.

The LED rear navigation and strobe light assembly (16LA), installed on the tail cone, has a LED light assembly and flashes at a rate of 60 plus or minus five flashes per minute.
The Near End Of Life (NEOL) indicator starts to flash when the light assembly is in the last 1000FH of its pre-programmed life. The light assembly will become unserviceable after its pre-programmed life.

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4. Power Supply
The 115VAC 101XP and 202XP are three phase busbars which supply power through the circuit breakers 1LV and 5LV to the Power Supply Units (PSU) 3LV and 4LV. The PSUs, which control the flash rate, supply the power to each anti-collision light.
The 115VAC three phase busbar 202XP supplies power through the circuit breaker 10LV to the Power Supply Units (PSU) 14LV,15LV and 18LV. The PSUs, which control the flash rate, supply power to each strobe light. The landing gear computer supplies 28VDC to the coil of the relay 13LV when the landing gear struts are compressed.
The 115VAC 101XP and 202XP are three phase busbars which supply power through circuit breakers 1LV and 5LV to Power Supply Units (PSU) 3LV and 4LV. The PSUs, which control the flash rate, supply the power to each anti-collision light.
The 115VAC three phase busbar 202XP supplies power through circuit breaker 10LV to LED Power Supply Units (PSU) 14LV and 15LV and power unit 18LV. The LED PSUs and PSU, which control the flash rate, supply power to each LED strobe light and tail strobe light. The landing gear computer supplies 28VDC to the coil of relay 13LV when the landing gear struts are compressed.
For the anti-collision lights:

Busbars 101XP and 202XP supply 115VAC to Power Supply Units (PSUs) 3LV and 4LV through the circuit breakers 1LV and 5LV. The PSUs, which control the flash rate, supply the power to each anti-collision light.

For the sharklet strobe lights:
Busbar 202XP supplies 115VAC to LED PSUs 14LV, 15LV and 18LV through circuit breaker 10LV. The LED PSUs, which control the flash rate, supply power to each LED strobe light. The landing gear computer supplies 28VDC to the coil of relay 13LV when the landing gear struts are compressed.

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5. Component Description

Strobe Lights-Wings ** ON A/C NOT FOR ALL

A. Anti-Collision Light FIN: 6-LV FIN: 7-LV

Anti-Collision Light ** ON A/C NOT FOR ALL

Each anti-collision light has a flash tube installed on a reflector. The tube is in a Faraday cage, and has a red glass lens.

LED Anti-Collision Light ** ON A/C NOT FOR ALL

The LED control circuit:

Decreases the DC power to the required output voltage necessary to energize to the LEDs, and
Controls the LED current. The light sensor output is given as a feedback to the LED control circuit to keep the LED color constant.
The lens assembly is used to make sure that there are no vibrations.

(1) Flash-tube technology power-supply:

A transformer is installed in the base of the light. The housing of the anti-collision transformer has cooling fins.
A start electrode is used to start the flash tube.
The PSU supplies the anode/cathode with a 400 to 500VDC. It also supplies a start pulse for the anti-collision and the strobe lights.

(2) LED technology power-supply:

An PSU is installed in the base of the light.
It supplies power to the LED anti-collision light. The LED control circuit supplied the current for the LED light assembly.

B. Strobe Light FIN: 16-LA FIN: 16-LV FIN: 17-LV FIN: 19-LV

Strobe Lights-Wings ** ON A/C NOT FOR ALL

Strobe Light-Rear ** ON A/C NOT FOR ALL

The strobe light, on the tail cone, has a flash tube installed on a reflector. The tube is installed in a Faraday cage and has a white lens.

Each LED strobe light, on the sharklets, has a control unit and an LED light assembly.

Strobe Lights-Wings ** ON A/C NOT FOR ALL

Strobe Light-Rear ** ON A/C NOT FOR ALL

Each strobe light, on the wing tips, has a flash tube installed on a reflector. The tube is installed in a Faraday cage and has a white lens.

The strobe light, on the tail cone, has a flash tube installed on a reflector. The tube is installed in a Faraday cage and has a white lens.

Strobe Lights-Wings ** ON A/C NOT FOR ALL

Strobe Light-Rear ** ON A/C NOT FOR ALL

The LED strobe light, on the tail cone, has a control unit and a LED light assembly. It combines the navigation and strobe light.
Each LED strobe light, on the sharklets, has a control unit and a LED light assembly.

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6. Operation

Anti-Collision and Strobe Lighting - Schematic ** ON A/C NOT FOR ALL

A. Anti-Collision Lights
When the control switch 2LV is in the ON position:

The busbar 101XP 115VAC BUS1 supplies the PSU 3LV through the relay 8LV and the exterior-light beacon-upper circuit-breaker 1LV. The PSU 3LV supplies the anti-collision light 7LV.
The busbar 202XP 115VAC BUS2 supplies the PSU 4LV through the relay 9LV and the exterior-light beacon-lower circuit-breaker 2LV. The PSU 3LV supplies the anti-collision light 6LV.

When the control switch 2LV is in the OFF position:
The relay 8LV and the PSU 3LV are not supplied with the 115VAC
The relay 9LV and the PSU 4LV are not supplied with the 115VAC
The anti-collision lights 6LV and 7LV go off.

B. Strobe Light
The strobe light system is supplied with three phase 115VAC/400Hz when the busbar 202XP is energized and circuit breaker 10LV is closed.

(1) With the switch STROBE 11LV set to AUTO, 115VAC is supplied to the power relay 12LV. 28VDC, from the landing gear computer, is removed when the landing gear struts are extended. This de-energizes the coil of the control relay 13LV and gives a ground signal for the power relay 12LV. The PSUs 14LV, 15LV and 18LV are supplied with 115VAC. From these PSUs an increased voltage is supplied to operate the strobe lights 16LV, 17LV and 19LV.
28VDC is supplied to the coil of relay 13LV when the landing gear struts are compressed. This energizes the coil of the control relay 13LV and removes the ground signal. The power relay 12LV is de-energized and the three-phase 115VAC/400Hz is removed from the PSUs 14LV, 15LV and 18LV.

(2) With the switch STROBE 11LV set to ON, 115VAC is supplied to the power relay 12LV. It also gives a ground signal for the coil of the power relay 12LV. The PSUs 14LV, 15LV and 18LV are supplied with three-phase 115VAC/400Hz from the power relay 12LV. The strobe lights flash as described.

(3) When the switch STROBE 11LV is set to OFF:

The 115VAC is removed from the coil of power relay 12LV
The ground signal is removed from the coil of power relay 12LV
The strobe lights go off.

(4) With switch STROBE 11LV set to AUTO, 115VAC is supplied to power relay 12LV. 28VDC, from the landing gear computer, is removed when the landing gear struts are extended. This de-energizes the coil of control relay 13LV and gives a ground signal for power relay 12LV. LED power units 14LV and 15LV and power unit 18LV are supplied with 115VAC. From these power units an increased voltage is supplied to operate LED strobe lights 16LV and 17LV and tail strobe light 19LV.
28VDC is supplied to the coil of relay 13LV when the landing gear struts are compressed. This energizes the coil of control relay 13LV and removes the ground signal. Power relay 12LV is de-energized and the three-phase 115VAC/400Hz is removed from LED power units 14LV and 15LV and power unit 18LV.

(5) With switch STROBE 11LV set to ON, 115VAC is supplied to power relay 12LV. It also gives a ground signal for the coil of power relay 12LV. LED power units 14LV and 15LV and power unit 18LV are supplied with three-phase 115VAC/400Hz from power relay 12LV. The LED strobe lights and tail strobe light operate.

(6) When switch STROBE 11LV is set to OFF:

The 115VAC is removed from the coil of power relay 12LV
The ground signal is removed from the coil of power relay 12LV
The LED strobe lights and tail strobe light go off.

(7) With switch STROBE 11LV set to AUTO position:

The 115VAC is supplied to power relay 12LV.

(a) When the landing gear struts are extended, the 28VDC power supply from the landing gear computer is not available. The coil of the flight/ground relay 13LV is no longer supplied. The flight/ground relay 13LV gives a ground signal for the power-up relay 12LV.

The LED PSUs 14LV, 15LV and 18LV are supplied with 115VAC. From these PSUs an increased voltage is supplied to operate LED strobe lights 16LV and 17LV, and the LED strobe light of the rear navigation and strobe light assembly 16LA.

(b) When the landing gear struts are compressed, the 28VDC power supply from the landing gear computer supplies the coil of the flight/ground relay 13LV. This removes the ground signal to the power-up relay 12LV. The power-up relay 12LV is de-energized and the 115VAC is not supplied from the LED PSUs 14LV, 15LV and 18LV. The LED strobe lights 16LV and 17LV, and the LED strobe light of the rear navigation and strobe light assembly 16LA do no operate.

(8) When the STROBE switch 11LV is set to the ON position:

The 115VAC is supplied to the power-up relay 12LV. It also gives a ground signal for the coil of power-up relay 12LV. The LED PSUs 14LV, 15LV and 18LV are supplied with 115VAC from power-up relay 12LV. The LED strobe lights 16LV and 17LV, and the LED strobe light of the rear navigation and strobe light assembly 16LA operate.

(9) When the STROBE switch 11LV is set to the OFF position:

The 115VAC is removed from the coil of power-up relay 12LV
The ground signal is removed from the coil of power-up relay 12LV
The LED strobe lights 16LV and 17LV do no operate.
The LED strobe light of the rear navigation and strobe light assembly 16LA do not operate.

[Rev.10 from 2021] 2026.04.01 12:33:40 UTC