+--------------------------------------+-------------------------------+
| ![](media/image                      | **Advisory**                  |
| 1.wmf){width="0.38472222222222224in" |                               |
| height="0.36944444444444446in"}      | **Circular**                  |
|                                      |                               |
| **U.S. Department**                  |                               |
|                                      |                               |
| **of Transportation**                |                               |
|                                      |                               |
| Federal Aviation                     |                               |
|                                      |                               |
| Administration                       |                               |
+--------------------------------------+-------------------------------+

+-----------------------------+-----------------+---------------------+
| **Subject:** GENERIC VISUAL | **Date:**       | **AC No:** AC       |
| GLIDESLOPE INDICATORS       | 09/05/07        | 150/5345-52A        |
| (GVGI)                      |                 |                     |
|                             | **Initiated     | **Change:**         |
|                             | by:** AAS-100   |                     |
+-----------------------------+-----------------+---------------------+

1.  **PURPOSE.** This advisory circular (AC) contains the Federal
    Aviation Administration (FAA) standards for generic visual
    glideslope indicator (GVGI) systems. GVGI systems provide pilots
    with visual glideslope guidance during approaches for landing at
    general aviation airports.

2.  **APPLICATION.** The FAA recommends the guidelines and standards in
    this AC for generic visual glideslope indicator (GVGI) equipment for
    General Aviation airport applications. In general, this AC is not
    mandatory and does not constitute a regulation. However, use of
    these guidelines is mandatory for equipment that is funded under
    Federal grant assistance programs. Mandatory terms such as \"must\"
    used herein apply only to those who purchase GVGI equipment using
    Airport Improvement Program (AIP) or Passenger Facility Charge
    Program (PFC) funds.

3.  **EFFECTIVE DATE.** Effective 6 months after the date of this
    circular, only equipment qualified per this specification will be
    listed in AC 150/5345-53*, Airport Lighting Equipment Certification
    Program.*

4.  **CANCELLATION.** AC 150/5345-52, *Generic Visual Glideslope
    Indicators (GVGI),* dated June 21, 1988, is cancelled.

5.  **PRINCIPAL CHANGES.** The following principal changes are
    incorporated:

> **a.** The document format is updated for a 150/5345 series Advisory
> Circular.
>
> **b.** The horizontal and vertical beam patterns for Type L-883 units
> (single projector) is updated in paragraphs 3.3.3 and 3.3.4.

**c.** Paragraph 3.3 references Engineering Brief #67, *Light Sources
Other Than Incandescent or Xenon for Airport and Obstruction Lighting
Fixtures,* for GVGI units that may use alternative lighting devices
(ALDs) as the projector light source.

> **d.** GVGI intensity settings are clarified in paragraph 3.3.9.

**e.** GVGI lightning protection is updated to the requirements of
IEEE/ANSI C62.41 category C1 in paragraph 3.3.17. Requirements for
transient suppression testing per MIL-STD-461 are removed.

**f.** Paragraph 3.5b is updated to better define the equipment parts
list requirement.

**g.** Production testing is clarified and moved to section 5.

**h.** Lamp life testing is updated to the requirements of 150/5345-53,
*Airport Lighting Equipment Certification Program*, Appendix 5, *Lamp
Life Test Procedure*.

**i.** A new requirement prohibiting the accumulation of frost and
condensation (dew) on GVGI projector front lens surfaces is added in
paragraph 3.3.7.

6.  **METRIC UNITS.** To promote an orderly transition to metric units,
    this AC includes both English and metric dimensions. The metric
    conversions may not be exact equivalents, and until there is an
    official changeover to the metric system, the English dimensions
    will govern.

7.  **COPIES OF THIS AC.** The Office of Airport Safety and Standards
    makes this AC available online at www.faa.gov.

![](media/image2.png){width="2.3680555555555554in"
height="0.5493055555555556in"}

DAVID L. BENNETT

Director of Airport Safety and Standards

# 1. SCOPE AND CLASSIFICATION.

## 1.1 Scope. 

This specification covers the requirements for generic types of visual
glideslope indicators for general aviation airports; i.e., airports not
operating under Federal Aviation Regulation, Part 139, *Certification of
Airports*.

## 1.2 Classification. 

The generic visual glideslope indicator (GVGI) systems must be as
classified below:

### 1.2.1 Types.

a\. Type L-882 Systems - Multiple projector systems.

b\. Type L-883 Systems - Single projector systems.

### 1.2.2 Styles.

a\. Style A - Voltage powered systems.

b\. Style B - Current powered systems.

### 1.2.3 Classes.

a\. Class I - Systems that operate between +130 degrees Fahrenheit (F)
(+55 degrees Celsius (C)) and -30 degrees F (-35 degrees C).

b\. Class II - Systems that operate between +130 degrees F (+55 degrees
C) and -65 degrees F (-55 degrees C).

# 2. APPLICABLE DOCUMENTS. 

The following documents form part of this specification and are
applicable to the extent specified herein:

## 2.1 Federal Aviation Administration (FAA) Publications.

> a\. FAA Advisory Circulars (AC).
>
> AC 150/5345-10 *Specification for Constant Current Regulators and
> Regulator Monitors*
>
> AC 150/5345-26 *Specification for L-823 Plug and Receptacle, Cable
> Connectors*
>
> AC 150/5345-28 *Precision Approach Path Indicator (PAPI) Systems* (for
> information only)
>
> AC 150/5345-47 *Specification for Series to Series Isolation
> Transformers for Airport Lighting Systems*
>
> AC 150/5345-49 *Specification L-854, Radio Control Equipment*
>
> AC 150/5345-53 *Airport Lighting Equipment Certification Program*
>
> b\. FAA Drawings.
>
> Drawing C-6046 *Frangible Coupling, Type 1 and lA, Details*
>
> c\. FAA Engineering Briefs.
>
> Engineering Brief #67 *Light Sources Other Than Incandescent or Xenon
> for Airport and Obstruction Lighting Fixtures*

## **2.2 Military Specifications and Standards**.

> MIL-STD-810F *Department of Defense Test Method Standard For*
>
> 1 January 2000 *Environmental Engineering Considerations and
> Laboratory Tests*

## 2.3 Society of Automotive Engineers.

> SAE AS25050 *Colors, Aeronautical Lights and Lighting Equipment,
> General Requirements For*

## 2.4 Institute of Electrical and Electronics Engineers (IEEE).

> C62.41-1991 *IEEE Recommended Practice on Surge Voltages in
> Low-Voltage AC Power Circuits*
>
> C62.45 -1991 *IEEE Recommended Practice on Surge Testing for Equipment
> Connected to Low-Voltage (1000 V and Less) AC Power Circuits*

## 2.5 Document Sources. 

FAA ACs may be obtained from:

U.S. Department of Transportation

Subsequent Distribution Office

Ardmore East Business Center

3341 Q 75^th^ Ave.

Landover, MD 20785

Telephone: (301) 322-4961

FAX: (301) 386-5394

Website:
www.faa.gov/airports_airtraffic/airports/resources/advisory_circulars/

FAA Engineering Briefs may be obtained from:

Website:
www.faa.gov/airports_airtraffic/airports/construction/engineering_briefs/

Federal specifications and standards may be obtained from:

> Federal Supply Services

Specification Section

470 L\'Enfant Plaza East

SW Suite 8100

Washington, DC 20407

Telephone: (202) 619-8925

FAX: (202) 619-8985

Website: [www.dsp.dla.mil](http://www.dsp.dla.mil/)

Military specifications and standards publications may be obtained from:

> DAPS/DODSSP

Building 4, Section D

700 Robbins Avenue

Philadelphia, PA 19111-5094

Telephone: (215) 697-2179

FAX: (215) 697-1460

Website: www.dsp.dla.mil

SAE standards may be obtained from:

> SAE World Headquarters

400 Commonwealth Drive

Warrendale, PA 15096-0001

Telephone: (724) 776 4841

FAX: (248) 273 2494

Website: www.sae.org

IEEE Standards may be obtained from:

> Telephone: (800) 949 4333

Website: www.ieee.org

# 3. REQUIREMENTS.

## 3.1 Approval Process. 

The GVGI approval process consists of Phase 1, a signal concept flight
evaluation, and Phase 2, equipment performance testing. Proposed system
designs must complete and pass both phases in sequence before approval
is granted. Under Phase 1, a GVGI design installation will be flight
tested by the FAA. All flight performance data must be documented for
the purposes of a record and accurate information for later system
performance reviews. A flight pattern will be flown several times both
day and night. Glideslope sector signals will be observed and recorded.
Observed items will include but not be limited to: ease of
interpretation, possible signal conflict with airport equipment
(example: airport beacons, support equipment, fire and rescue vehicle
lighting), conspicuity, and color. Phase 2 tests consist of
environmental, photometric, mechanical, and operational tests. The
failure of the equipment to pass all tests will be cause for rejection.

### **3.1.1 Application for Approval**. 

Procedures for applying for qualification approval to this specification
are detailed in AC 150/5345-53, *Airport Lighting Equipment
Certification Program.* The application for approval must include at a
minimum: detailed drawings which indicate the principle of operation and
photometric data consisting of isocandela curves showing all glideslope
sector signals and data for horizontal and vertical beam spread. Under
Phase 1, the design will be evaluated using the design requirements in
paragraph 3.3 as a guide. If the review indicates the criteria can be
met, a Phase 1 evaluation will be scheduled.

### 3.1.2 Signal Concept Flight Evaluation. 

The FAA will select the test site. The equipment to be tested must be
supplied by the manufacturer. The FAA may install the equipment per the
manufacturer's instructions or the manufacturer (with the approval of
the FAA) will perform the installation. The flight test and evaluation
will be performed by the FAA. A copy of the flight test report and test
procedures must be given to the manufacturer upon conclusion of the
evaluation.

### 3.1.3 Approved Design Data.

The FAA may recommend changes or approve the proposed system design
contingent on incorporation of FAA recommendations during Phase 1 tests
and reviews. Photometric and signal characteristics of the revised
design must be submitted to the FAA prior to conducting Phase 2 tests.

### 3.1.4 Previous Approvals. 

Proposed systems employing signal concepts identical to signals
generated by FAA approved equipment per AC 150/5345-53, *Airport
Lighting Equipment Certification Program,* will not require Phase 1
testing. However, Phase 2 testing will be required. Precision Approach
Path Indicator (PAPI) systems listed in AC 150/5345-53 that are approved
per AC 150/5345-28, *Precision Approach Path Indicator (PAPI) Systems,*
are considered as meeting both the Phase 1 and 2 requirements of this
specification.

## 3.2 Environmental Requirements.

The equipment must be designed for outdoor installation and continuous
or intermittent operation (with routine maintenance) for a 20-year
service life under the following environmental conditions:

a\. Temperature. For Class I systems, any temperature from -30 degrees F
(-35 degrees C) to 130 degrees F (55 degrees C). For Class II systems,
any temperature from - 67 degrees F (-55 degrees C) to 130 degrees F (55
degrees C).

> b\. Humidity. Any relative humidity to 95 percent.
>
> c\. Wind-blown Rain. Exposure to wind-blown rain from any direction.

d\. Wind. Exposure to wind speeds up to 100 miles per hour (mph) (161
kilometers per hour (kp/h)) from any direction.

> e\. Sand and Dust. Exposure of the equipment to windblown dust.

**NOTE:** *Ingress of dust is not totally preventable, but dust must not
penetrate in a quantity to interfere with operation of the equipment or
to impair safe operation.*

> f\. Salt Spray. Exposure to a salt-laden atmosphere.
>
> g\. Sunshine. Exposure to solar radiation.

## 3.3 Design Requirements.

**NOTE:** *For manufacturers desiring to use alternative light devices
(ALDs) (devices other than incandescent or xenon: light emitting diodes,
cold cathode, or other light emitting devices) in GVGI systems, there
are additional requirements for both device design and testing. See FAA
Engineering Brief #67, Light Sources Other Than Incandescent and Xenon
for Airport and Obstruction Lighting Fixtures, for additional
information about ALD design and testing requirements.*

### 3.3.1 Visual Range. 

The glideslope signal must be conspicuous at a range of not less than 6
statute miles (10 kilometers (km)) on a bright clear day. Interpretation
of the signal (i.e., the ability to distinguish differences between each
sector of the signal) must occur at not less than 4 statute miles (9.6
km) from the signal source. For the purposes of this evaluation, the
term \"bright clear day\" is defined as a day where the visibility is 10
to 15 statute miles (16.1-24.1 km) with a clear sky and full sun. The
glideslope signal must be observed between 10:00 AM and 3:00 PM.

### 3.3.2 Overall Beam Pattern. 

a\. Type L-882. The overall beam pattern must consist of an oval shape
with the major axis parallel and the minor axis perpendicular to the
plane of the runway. Isocandela curves must be concentric ovals centered
about the intersection of the major and minor axes.

b\. Type L-883. The overall beam pattern must consist of a pattern shape
consistent with those listed in paragraphs 3.3.3 Vertical Beam Width and
3.3.4 Horizontal Beam Width.

### 3.3.3 Vertical Beam Width. 

a\. Type L-882. Guidance must be provided relative to the on-glideslope
signal over a vertical angle of not less than 4 degrees from the axis of
the on-glideslope signal. The on-glideslope signal must be distinct and
be between 0.33 and 0.5 degrees wide vertically and centered on the
glideslope signal axis.

b\. Type L-883. Guidance must be provided relative to the on-glideslope
signal over a vertical angle of not less than 2.6 degrees above, and 2.8
degrees below. The on-glideslope signal must be distinct and between
0.33 and 0.5 degrees wide vertically centered on the on-glideslope
signal axis.

###  3.3.4 Horizontal Beam Width. 

a\. Type L-882. The visual signal must provide guidance relative to the
approach angle over a horizontal angle of not less than ±10 degrees from
the center of the light beam.

b\. Type L-883. The visual signal must provide guidance relative to the
approach angle over a horizontal angle of not less than ±8 degrees from
the center of the light beam.

### 3.3.5 Visual Signal Colors. 

The visual signal must consist of not less than two and not more than
four horizontal color bands. Signal colors must be aviation colors red,
yellow, green, or white per chromaticity requirements in SAE AS-25050,
*Colors, Aeronautical Lights and Lighting Equipment, General
Requirements For*. Color sectors must be distinct and identifiable
throughout the horizontal beam width at all intensity settings. Only
aviation red must be used to indicate the lowest below-course sector of
the system. Transition zones between colors must be not more than 0.05
degree (3 minutes of arc) when used strictly for color separation.

### 3.3.6 Signal Interpretation. 

The signal must consist of multiple sectors. The sectors must be unique
and indicate at a minimum above-, on-, and below-glideslope conditions.

### 3.3.7 Condensation and Frost

GVGI system projector lens(es) must not allow an accumulation of frost
or condensation (dew) on the front surface that adversely affects the
signal presentation to pilots.

### 3.3.8 Failure Mode. 

The system must be designed to be fail-safe upon the occurrence of any
system failure that results in an incorrect glideslope signal being
transmitted from the system. The fail-safe mode is glideslope signal
turned off.

### 3.3.9 Intensity Settings. 

GVGI systems must be equipped with a photoelectric or manual control for
controlling day/night intensity settings. Style A systems using
photoelectric control must use one selectable night setting of
approximately 5 and 20 percent of full daylight intensity. Style B
systems must operate from a constant current regulator (CCR) with a
current range of 2.8 to 6.6 Amperes (five step CCR). The intensity of a
Style B GVGI is controlled by the tap settings on the CCR (manual
control) or via an automatic photoelectric control.

### 3.3.10 Light Pulse Frequency and Duration. 

If used, the manufacturer must specify the frequency and on/off ratio of
any pulsing lights.

### 3.3.11 Lamp Life. 

The lamps must be commercially available types using standard lamp
holders and have a minimum lamp useful life of 1000 hours when operated
at the high intensity setting (lamp useful life is defined as the life
of the lamp when installed in the projector and operated per the
manufacturer\'s design). Automatic lamp changing may be used to comply
with this requirement provided that the glideslope signal interruption
is not more than 2 seconds. Lamp life testing must be used to define
lamp life. See AC 150/5345-53, Appendix 5, *Lamp Life Test Procedure,*
for test procedures and a definition of lamp useful life.

### 3.3.12 Light Unit Construction. 

Each projector unit must be designed with the following characteristics:

a\. **Environmental Loads.** Dynamic and static environmental loads due
to wind, snow, and ice must not cause misalignment of the light signal.

b\. **Weight.** The weight of the complete unit must not exceed 150
pounds (lbs) (68 kilograms (kg)). If transformers are mounted
separately, this weight must be reduced to 100 lbs. (45.3 kg).

c\. **Height.** When installed in its minimum configuration, the
complete equipment installation must not exceed 40 inches (1 meter) from
ground level to the top of the unit.

d\. **Enclosure.** Equipment enclosures must be resistant to material
degradation caused by ultraviolet radiation. In addition, the enclosure
must prevent rain and snow from degrading the light signal photometric
characteristics.

e\. **Start up.** The visual signal must display correct color
characteristics and intensities within 5 seconds of turn on.

f\. **Filters and Lenses.** Filters and lenses must be stable and not
change their photometric characteristics under all operating conditions.

### 3.3.13 Mounting Provisions. 

The light units must provide for mounting on a maximum of three
frangible couplings (see FAA Drawing C 6046, *Frangible Coupling, Type 1
and lA, Details,* for coupling details and frangibility requirements)
and be suitable for mounting on a level concrete pad. Hardware must be
provided for leveling the unit and be designed to prevent displacement
of the optical system due to vibration. Alternate mounting systems may
be proposed which provide equivalent rigidity, frangibility, and
adjustment.

### 3.3.14 Aiming. 

The light unit(s) must be provided with integral adjustments to permit
vertical positioning of the "on-glideslope" signal axis at any elevation
between 1 and 12 degrees ± 0.08 degrees (5 minutes of arc). A separate
aiming device may be furnished with the equipment to set the signal axis
vertical angle.

### 3.3.15 Tilt Device. 

All systems must be provided with a device that de-energizes all
projector unit(s) when the on-glideslope signal axis is misaligned
between 0.25 and 0.5 degree below or between 0.5 and 1.0 degree above
the preset on-glideslope angle. A time delay of 10 to 30 seconds must be
included to prevent intermittent tilt device activation caused by
vibration. Adjustments must be provided to simulate excessive tilt
conditions for checking the proper operation of the tilt device.

### 3.3.16 System Control. 

System control must be designed as specified by the user for remote
manual, radio, or photoelectric control or any combination of these.

> a\. Remote Manual Control. The remote manual control may use either
> 120VAC or 48VDC.

b\. Radio Control. The radio control must be per AC 150/5345-49,
*Specification L-854, Radio Control Equipment*. The radio control must
activate the system and, if required, select the proper intensity
setting.

c\. Photoelectric Control. The photoelectric control unit must
automatically select the pre-set day or night intensity setting. The
control unit must select the day intensity as the illumination on the
photocell rises to 50-60 footcandles (538-646 lux) and the night
intensity as the illumination drops to 25-35 footcandles (269-377 lux).
A time delay of 45 to 75 seconds must be incorporated to prevent
switching caused by transient light and shadows. In the event of
photoelectric control failure, the system must revert to the low
intensity setting. Style A systems must select the low night intensity
setting for 3 seconds before switching to the day intensity setting.

### 3.3.17 Lightning Surge Protection.

Power units of Style A systems must withstand lightning transients per
IEEE C62.41 - 1991, *IEEE Recommended Practice on Surge Voltages in
Low-Voltage AC Power Circuits,* Category C1.

### 3.3.18 Style A Systems. 

Style A systems must operate from any standard utility single-phase
alternating current service voltage less than 600 volts.

### 3.3.19 Style B Systems. 

Style B systems must operate from a constant-current regulator with a
current range of 2.8 to 6.6 amperes per AC 150/5345-10, *Specification
for Constant Current Regulators and Regulator Monitors*. The system must
be compatible with series to series isolation transformers per AC
150/5345-47, *Specification for Series to Series Isolation Transformers
for Airport Lighting Systems*.

### 3.3.20 Grounding. 

Conductive materials enclosing electrical conductors, equipment, or
housing part of the equipment must be grounded to a common lug to allow
connection to a system ground conductor.

### 3.3.21 Power Cables. 

The equipment must be provided with power cables having factory molded
plugs. Style A systems may use any plug with adequate capacity and
electrical performance equivalent to that of an L-823 plug per AC
150/5345-26, *Specification for L-823 Plug and Receptacle, Cable
Connectors*. The length of cable must not be less than 1.5 feet (45.7
centimeters). Style B systems must have class A, style 1 or 6 plugs per
AC 150/5345-26, *FAA Specification for L-823 Plug and Receptacle, Cable
Connectors,* to mate with series to series isolation transformer
outputs.

### 3.3.22 Equipment Color.

The exterior color of all units must be either bright orange or yellow.

### 3.3.23 Identification Label. 

Each fixture or unit must be marked with a permanent label stating the
manufacturer's name and address, the equipment name, number, type,
style, class, and the electrical rating (worst case volt-amps).

### 3.3.24 Hardware.

All hardware must be selected to prevent corrosion and galling.

### 3.3.25 Maintenance. 

System components must be designed to allow replacement. The equipment
must be designed so that adjustments and repairs can be made with
standard tools.

## 3.4 Workmanship. 

Wiring must be neatly run and bundled. All wiring must be marked by
color coding or tagging. Wire marking must be consistent with the
instruction book schematics and troubleshooting diagrams. Sharp edges
and burrs must be removed. Painted surfaces must be free from runs,
blotches, and scratches.

## 3.5 Instruction Book. 

An instruction book containing the following information must be
furnished with each system:

a\. Complete schematic and wiring diagrams referencing wire markings and
showing all components cross-indexed to the manufacturer's parts list.
Wire markings on the schematic must be identical to the markings on the
equipment.

b\. Complete parts list with each circuit component keyed to the
designation assigned on schematics for wiring diagrams. Complete
information must be given for each part to permit ordering for
replacement purposes. This information must include the component's
rating, name of the manufacturer, and the manufacturer's part number.

c\. Installation instructions, including aiming, sighting criteria,
calibration of the aiming system, focusing, and adjustment of the tilt
device.

d\. Physical description, including photographs or drawings with
sufficient detail to identify the equipment components.

e\. Maintenance instructions, including re-lamping procedure, theory of
operation, and trouble-shooting charts.

f\. Equipment operating instructions.

# 4. QUALIFICATION TESTING.

# **4.1 Testing Phases.**

Testing must consist of signal concept flight evaluation (Phase 1 Tests)
and equipment performance testing (Phase 2 Tests). Phase 2 tests must be
conducted in the specified sequence on the same unit(s) used in the
Phase 1 tests. The test sequence is designed to simulate accelerated
environmental effects.

### **4.1.1 Phase 1 Tests**. 

Phase 1 tests consist of the signal concept flight evaluation tests and
must include the following documents and any revisions as required for
approval:

a\. Flight Evaluation Test Report.

b\. Approved design data package including detailed drawings.

c\. Signal characteristics.

d\. Photometric data package.

e\. Description of principles of operation.

f\. Lamp life test procedure.

These documents must be on file at the FAA Airport Engineering Division
(AAS-100, FAA Headquarters, Washington, DC) prior to the start of Phase
2 tests.

### **4.1.2 Phase 2 Tests**. 

The equipment to be subjected to Phase 2 tests must be the equipment
intended for production. Unless specifically directed in the test
procedures referenced by this specification, equipment may not be
disassembled or cleaned once the test sequence has begun.

**NOTE:** P*erform a photometric test prior to conducting any Phase 2
Tests to confirm that the visual glideslope equipment meets the same
criteria established in the photometric data package in paragraph
4.1.1d*.

### 4.1.3 Phase 2 Acceptance Criteria.

#### 4.1.3.1 Light Pulse Frequency and Duration. 

If used, the frequency and on/off ratio of the light pulses must be
within the manufacturer's specifications.

#### 4.1.3.2 Safety Features. 

Any deterioration or reduction in safety feature performance must be
cause for test failure.

#### 4.1.3.3 Loss of Signal. 

Loss of the glideslope signal must be cause for test failure.

#### 4.1.3.4 Visual Examination. 

The equipment must be inspected for compliance with the requirements for
size, weight, materials, finish, identification label, and quality of
workmanship. Failure to meet weight and size restrictions must be cause
for rejection.

#### 4.1.3.5 Light Color

Verify that signal colors are per paragraph 3.3.5

### 4.1.4 Phase 2 Tests.

#### 4.1.4.1 Solar Radiation Test. 

A sunshine test must be conducted per MIL-STD-810F, *Department of
Defense Test Method Standard for Environmental Engineering
Considerations and Laboratory Tests,* Method 505.4, Procedure II for
nonmetallic exterior parts. The material must be subjected to 56 cycles.
If plastic optical lenses or light emitting covers are used, their
photometric performance must be measured after this test. A certificate
of compliance from the plastic manufacturer attesting that the material
has previously passed the MIL-STD-810F requirements may be provided in
lieu of performing this test (subject to third party certification body
approval).

#### 4.1.4.2 Humidity Test. 

The humidity test must be per MIL-STD-810F, *Department of Defense Test
Method Standard for Environmental Engineering Considerations and
Laboratory Tests,* Method 507.4, Procedure, paragraph 4.5.2. The
equipment must be subjected to two complete cycles per Figure 507.4-1,
except the maximum temperature must be +130 degrees F (+55 degrees C).
At the conclusion of testing, inspect the equipment and components. Any
evidence of corrosion, discoloration, swelling, or cracking will be
cause for rejection.

#### 4.1.4.3 Low Temperature Test. 

A low temperature test must be conducted per MIL-STD-810F, *Department
of Defense Test Method Standard for Environmental Engineering
Considerations and Laboratory Tests,* Method 502.4, Procedure. The
equipment must be exposed to a minimum of -30 degrees F (-35 degrees C)
for Class I systems or -65 degrees F (-55 degrees C) for Class II
systems for 24 hours. Projector unit(s) must be initially de-energized
and then energized during the last 12 hours of the test. No accumulation
of dew or frost must be evident on any portion of the GVGI projector
lens(es) front surfaces per paragraph 3.3.7. Failure of the equipment to
operate will be cause for rejection.

#### 4.1.4.4 Salt-Fog Test. 

A salt-fog test must be conducted MIL-STD-810F, *Department of Defense
Test Method Standard for Environmental Engineering Considerations and
Laboratory Tests,* Method 509.4, Procedure I. The equipment must be
cycled for 48 hours exposure and 48 hours drying. At the conclusion of
testing, analyze any corrosion for its immediate and potential long-term
effects on the proper functioning and structural integrity of the
equipment.

#### 4.1.4.5 Wind Loading. 

Static force tests (an equivalent force derived from wind velocity in
paragraph 3.2d) must be conducted to ensure that the system will
withstand the specified wind load from any direction in azimuth without
displacing the optical pattern more than allowed in the snow and
ice-loading test per paragraph 4.1.4.6.

#### 4.1.4.6 Snow and Ice Loading Test. 

A uniformly distributed load of 15 pounds per square foot (73 kilograms
per square meter) must be applied over the entire top surface of the
projector unit(s). Before applying the load, the unit must be set up and
the light pattern displayed on a vertical surface 20 feet (6.1 meters)
from the front of the unit. The top, bottom, and the sides of the beam
pattern and any other characteristic features must be marked on the
wall. After loading the unit with the required amount of material, the
beam pattern must be checked for displacement from the markings, and the
load must be left in place for 5 hours. Upon removal of the load, the
beam pattern must again be checked against the original markings. The
beam pattern must remain within +l/4 inch (6.4 millimeters) of the
original markings.

#### 4.1.4.7 Photometric Tests. 

The light units must be tested after the tests in paragraph 4.1.4.1
through 4.1.4.6 are completed to ensure equipment compliance with the
photometric data in paragraph 4.1.2. A certificate of compliance from
the manufacturer of lenses and color filters may be used to meet the
chromaticity requirements of SAE AS 25050, *Colors, Aeronautical Lights
and Lighting Equipment, General Requirements for*. Photometric test
equipment must be calibrated and traceable to the National Bureau of
Standards.

##### 4.1.4.7.1 Computation of Effective Intensity. 

The effective intensity of flashing lights must be calculated per the
following formula. Intensities that are 90 percent or more of those
specified by the manufacturer are acceptable.

$$I_{e} = \int_{}^{}\text{Idt}(0\text{.}2 + (t_{2} - t_{1}))$$

> Where:
>
> *I*~e~ = Effective intensity (K candela)
>
> *I* = Instantaneous intensity (K candela)
>
> *t~1~*, *t~2~* = Integration limits (seconds)

The limits of integration must be selected so that the value of *I* is
maximized

#### 4.1.4.8 Frangibility Test. 

The manufacturer must demonstrate that the frangibility is not less than
that provided by an equal number (not to exceed three), 2-inch (50
millimeter) frangible couplings per FAA drawing C-6046. This may be
demonstrated by measuring the force required to break the coupling.

#### 4.1.4.9 Aiming Tests. 

The vertical and horizontal adjustment ranges of the light units must be
measured for compliance with the requirements of paragraph 3.3.14,
Aiming. The aiming device must be tested using a procedure submitted by
the manufacturer and approved by the third party certification body. It
must be demonstrated that when the light unit is moved via the
adjustment mechanism, the measuring device registers the change within
the allowable tolerance. The measuring device must be checked at one
degree intervals throughout the system's adjustment range.

#### 4.1.4.10 Lightning Surge Test. 

For Style A systems, the power input lines must be tested for resistance
to lightning transients per IEEE C62.41, Category C1. Apply 2 pulses of
a Category C1 combination wave at 15 second intervals to the power line
inputs per test methods described in IEEE C62.45*, IEEE Recommended
Practices on Surge Testing for Equipment Connected to Low-Voltage (1,000
volts and less) AC Power Circuits.* Failure of the equipment to operate
will be cause for rejection.

## 4.2 Operational Test. 

An operational test using the manufacturer\'s test procedure approved by
the third party certification body must be conducted to demonstrate
compliance with all equipment operating requirements. The procedure must
test the tilt device, power supply performance, photoelectric
controller, and any other operational features. If more than one lamp is
used in a projector, the system must be operated with one lamp out in
each projector to demonstrate that the proper voltage or current is
still applied at the terminals of the remaining operational lamps. The
manufacturer must demonstrate that the failure of a lamp will not
produce transients that could damage the remaining lamps. In addition,
it must be demonstrated that an automatic lamp changer (if part of the
equipment design) is functional and changes lamps per paragraph 3.3.11.

### 4.2.1 Lamp Life Testing. 

Lamp life testing must be performed per AC 150/5345-53, *Airport
Lighting Equipment Certification Program*, Appendix 5, *Lamp Life Test
Procedure*.

# 5. PRODUCTION TESTING. {#production-testing. .Style-Heading-1-+-Centered-Before:--0-pt-After:--12-pt}

**5.1 Production Tests.**

The manufacturer must use a test procedure to verify the light output
and aiming device accuracy for each production unit. After submission to
and approval by the third party certification body, the test procedures
must be used for all production units. The visual examination (paragraph
4.1.3.4), aiming test (paragraph 4.1.4.9), and the operational test
(paragraph 4.2) must also be performed for each visual glideslope
system.

**5.2 Production Test Records.**

Records showing actual test results of all tests required in paragraph
5.1 must be maintained for three years by the manufacturer. The records
must be traceable to the units tested by serial number.