LED VS HALOGEN AGL Light
Electronic vs Filament — LED AGL lights use a semiconductor light source, while halogen AGL lights use a heated tungsten filament. LED technology generally offers energy and maintenance advantages, while halogen remains a simpler filament-and-optics system. In both cases, the final fixture must still meet the required photometric, electrical, mechanical, and operational requirements.
At a Glance
| Feature | LED AGL Light | Halogen AGL Light |
|---|---|---|
| Light source | Light-emitting diode | Tungsten-halogen filament |
| Energy efficiency | Generally higher | Generally lower |
| Power consumption | Usually lower | Usually higher |
| Operating life | Generally longer | Generally shorter |
| Warm-up | Very fast | Requires filament heating/stabilization |
| Heat generation | Lower at source, but needs thermal management | High |
| Lamp replacement | Usually no separate lamp replacement | Lamp replacement required |
| Failure mode | Often gradual degradation or electronic failure | Often sudden filament failure |
| Optical design | LED + lenses/secondary optics | Lamp + reflector/lens |
| Maintenance | Generally lower | Generally higher |
| Initial cost | Often higher | Often lower |
How Each Light Source Works
LED AGL Light
An LED produces light through a semiconductor device rather than by heating a filament. Electrical power passes through an LED driver, into the semiconductor, and is converted directly into light.
Halogen AGL Light
A halogen lamp produces light by heating a tungsten filament to a very high temperature. Electrical power heats the filament, which then glows to produce light.
Where the Electrical Energy Goes
For the same AGL application, an LED fixture will often require less electrical power than a comparable halogen fixture. The actual saving depends on the specific fixture design and operating conditions.
How Each Source Ages
LED
LED systems generally have a long operational life, although their light output can gradually decrease with operating hours.
Halogen
Halogen lamps generally require more frequent replacement because the filament ages and has a limited life, eventually failing.
Typical Maintenance Concerns
LED AGL Light
- Cleaning optical surfaces
- Checking electrical connections
- Monitoring light output
- Checking driver/electronic condition
- Replacing the fixture or module when required
Halogen AGL Light
- Cleaning optics
- Checking electrical connections
- Monitoring lamp condition
- Replacing failed lamps
- Checking reflector and optical components
Easy memory: LED → generally fewer source replacements. Halogen → periodic lamp replacement required.
How Each Technology Tends to Fail
Halogen
A common failure mechanism is the filament ageing and eventually breaking, which can result in a relatively sudden, complete failure of the lamp.
LED
An LED system may show gradual output change over operating hours, but LED fixtures can also fail suddenly due to problems in the electronics, drivers, power components, or electrical connections. It is incorrect to assume every LED failure is gradual.
Shaping the Beam
LED AGL Light
Because LEDs can be highly directional, fixture designers use lenses and secondary optics to shape the required beam directly at the source.
Halogen AGL Light
Halogen lamps emit light more broadly, so reflectors and optical systems are often heavily involved in directing the light into the required beam.
LED Is Not Heat-Free
Halogen systems generate significant heat, combining high thermal output with the light itself. LEDs are more efficient, but they still generate heat and require good thermal management — an LED fixture is not heat-free.
Excessive LED junction temperature can affect: light output, service life, colour characteristics, and reliability. Thermal design is still a real engineering concern for LED fixtures.
How Each Technology Produces Colour
LED
LED colour depends on its semiconductor and phosphor/light-generation system, which determines the spectral output and resulting colour characteristics.
Halogen
Halogen light is generated by a heated filament producing broad-spectrum light, with filters or optical systems used where specific AGL colours are required.
Both technologies must ultimately produce the required aviation colour characteristics for their application.
Technology Alone Doesn't Determine Compliance
Both LED and halogen fixtures must satisfy the same required fixture performance — intensity, beam distribution, and colour — to achieve compliance.
An LED fixture is not automatically photometrically superior to a halogen fixture. The comparison must be based on the actual measured performance of the complete fixture, not the light-source technology alone.
Series-Circuit Compatibility
This is particularly important in AGL series circuits, where each fixture connects through the CCR and an isolating transformer.
Halogen
Halogen AGL systems traditionally use filament lamps directly associated with the series-circuit supply system.
LED
LED AGL fixtures require appropriate internal electronics or drivers to operate the LEDs correctly from the available series-circuit supply.
When retrofitting an AGL system, electrical compatibility must be checked in addition to photometric performance.
LED Retrofit vs Halogen Replacement
Replacing a halogen fixture with an LED fixture may provide reduced energy consumption, reduced lamp replacement requirements, and longer operational life. However, compatibility should be evaluated across the whole system:
- CCR compatibility
- Isolation transformer compatibility
- Circuit operating characteristics
- Monitoring compatibility
- Photometric requirements
- Mechanical installation
LED retrofit is not simply a lamp replacement — it may involve system-level compatibility considerations across the whole AGL circuit.
Failure and Issue Comparison
| Failure / Issue | LED | Halogen |
|---|---|---|
| Light source ageing | Gradual degradation possible | Filament ageing |
| Sudden source failure | Possible | Common with filament break |
| Driver/electronics failure | Possible | Less applicable to basic lamp |
| Lamp replacement | Usually not routine | Routine requirement |
| Thermal problems | Heat-sink/thermal-management related | High filament/fixture temperature |
| Optical contamination | Possible | Possible |
| Connection failure | Possible | Possible |
Where Both Technologies Are Used
Both technologies can be used in applications such as runway edge lighting, taxiway edge lighting, taxiway centreline lighting, runway centreline lighting, stop bars, runway guard lights, and approach lighting. The selection depends on factors including:
- Photometric performance
- Energy consumption
- Maintenance strategy
- Existing infrastructure
- Electrical compatibility
- Initial cost
- Lifecycle cost
Full Engineering Parameters
| Parameter | LED AGL Light | Halogen AGL Light |
|---|---|---|
| Source technology | Semiconductor | Heated filament |
| Energy efficiency | Generally higher | Generally lower |
| Power consumption | Generally lower | Generally higher |
| Heat generation | Lower but requires thermal management | Higher |
| Operating life | Generally longer | Generally shorter |
| Source replacement | Less frequent | More frequent |
| Maintenance | Generally lower | Generally higher |
| Failure behaviour | Gradual degradation and/or electronic failure | Filament ageing and failure |
| Optical control | LED + secondary optics | Reflector/lens optics |
| Electrical complexity | Usually higher | Usually simpler |
| Initial equipment cost | Often higher | Often lower |
| Lifecycle cost | Often lower | Can be higher due to energy and lamp replacement |
LED vs Halogen AGL Light
LED and halogen are not simply interchangeable light sources. The fundamental difference is how each produces light — an electronic semiconductor process versus a heated filament.
LED technology generally offers energy efficiency, longer life, and lower routine maintenance, but depends more on electronics and thermal management. Halogen technology is a simpler filament-and-optics system, with higher power consumption, more heat, and more frequent lamp replacement. In both cases, the final fixture must still meet the required photometric, electrical, mechanical, and operational requirements.
For AGL retrofits: evaluate CCR, isolation transformer, and monitoring compatibility alongside photometric performance — LED retrofit is a system-level decision, not a simple lamp swap.
Engineering & Expert Notes
Treat the Change as an Electrical Review
RetrofitCheck CCR, transformer and circuit effects.
Verify Photometry After Installation
VerificationConfirm intensity and colour with instruments.
Check Thermal Design
ThermalHeat shortens life.
Update Spares
SparesReplace halogen spares with the new parts.
Frequently Asked Questions
LED → electronic, long-life, energy-efficient light source. Halogen → filament-based, replaceable lamp light source.
No. Photometric compliance depends on the actual measured performance of the complete fixture — intensity, beam distribution, and colour — not on the light-source technology alone.
Yes. While LEDs are often associated with gradual output degradation, sudden failures can still occur due to problems in the driver, electronics, power components, or electrical connections.
No. LEDs are more efficient than halogen sources but still generate heat and require good thermal management — excessive junction temperature can affect output, life, colour, and reliability.
Not necessarily. LED retrofit may involve system-level compatibility checks — CCR compatibility, isolation transformer compatibility, circuit operating characteristics, monitoring compatibility, photometric requirements, and mechanical installation.
Because LED AGL fixtures require internal electronics or drivers to operate correctly from the series-circuit supply, unlike halogen lamps which connect more directly to that supply through an isolating transformer.
LED airport lights use solid-state modules, so they last much longer, use less power and can give the required colour without filters. Halogen lights use a heated filament, which gives a shorter life and needs more frequent lamp changes. LED loads also behave differently on a series circuit, so the transformer and CCR compatibility should be checked before a changeover.
Governing Documents
For an actual project design, always verify the current edition of the applicable documents.
FAA AC 150/5345-46
Specification for Runway, Taxiway, Heliport, and Vertiport Light Fixtures — covers LED and other fixture technology requirements for airport lighting.
ICAO Annex 14, Volume I
Aerodrome Design and Operations — photometric, colour, and general fixture performance requirements independent of light-source technology.
CCR & Series-Circuit Documentation
Manufacturer and project-specific documentation on constant current regulator and isolating transformer compatibility with the fixture technology selected.
Final Engineering Note
Do not select a fixture technology on efficiency or lifecycle claims alone. Confirm measured photometric performance and full system-level electrical compatibility.
LED is not automatically superior to halogen — both must meet the same photometric, electrical, and mechanical requirements to be compliant AGL fixtures.
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