Draft _FAA_E_3007_Rev_C (002).pdf

i

FAA-E-3007C

June 9, 2022

SUPERSEDNG

FAA-E-3007B

November 28, DEPARTMENT OF

TRANSPORTATION FEDERAL

AVIATION ADMINISTRATION

PERFORMANCE SPECIFICATION

FOUR BOX, Light Emitting Diode

PRECISION APPROACH PATH INDICATOR

(PAPI)

Revision C

DRAFT

June 9, 2022 ii

TABLE OF CONTENTS

1.0 SCOPE

1.1 Specification Scope

2.0 APPLICABLE DOCUMENTS

2.1 FAA Documents

2.1.1 FAA Specifications

2.1.2 FAA Standards

2.1.3 FAA Drawings

2.1.4 FAA Management Documents

2.1.5 FAA Advisory Circulars

2.2 Military and Federal Publications

2.2.1 Military Specifications

2.2.2 Military Standards

2.2.3 Federal Specifications

2.2.4 Federal Standards

2.2.5 Federal Communications Commission Rules and Regulations

2.3 Other Publications

2.3.1 National Electrical Manufacturers Association (NEMA) standards

2.3.2 American National Standards Institute

2.3.3 National Fire Protection Association Publications

2.3.4 Masters Painters Institute (MPI)

2.3.5 American Society for Testing and Materials (ASTM)

2.3.6 Institute for Printed Circuits: IPC-2221 Generic Standard on Printed Board Design

2.3.7 Society of Automotive Engineers

2.3.8 Underwriters Laboratories Inc

3. REQUIREMENTS

3.1 General Functional Requirements

3.2 Photometric Requirements

3.2.1 Light Beam

3.2.3 Light Colors

3.2.4 Light Beam Aiming Tolerance

3.3 Sub-assemblies

3.3.1 Lamp Housing Assembly

3.3.2 Power and Control Assembly

3.3.3 Aiming Instrument Set and Calibration Bar

3.4 Monitored Points and Controls

3.4.1 External signal

3.5 Electrical Components

iii

3.5.1 Electrical Connectors

3.5.2 Printed Wiring Boards

3.5.3 Component Ratings

3.5.4 Fiber Optics

3.6 Materials and parts

3.6.1 Metals

3.6.2 Aluminum

3.6.3 Optical covers

3.6.4 Gaskets

3.6.5 Nameplates

3.7 Interchangeability

3.8 Finishes

3.8.1 Paint

3.9 Environmental Requirements

3.9.1 Temperature

3.9.2 Altitude

3.9.3 Temperature Shock (Thermal Shock)

3.9.4 Humidity

3.9.5 Sand and Dust

3.9.6 Rain

3.9.7 Salt Spray

3.9.8 Solar Radiation (Sunshine)

3.9.9 Vibration

3.9.10 Ice Accumulation

3.10 Transient Suppression

3.10.1 Transient waveforms

3.10.2 Parameters

3.11 Electromagnetic Interference Control

3.11.1 Conducted Emissions

3.11.2 Radiated Emissions

3.11.3 Conducted Susceptibility

3.11.4 Radiated Susceptibility

3.12 Electrical Safety

3.12.1 Dielectric Strength

3.12.2 Ground Bonding

3.13 Assembly, Wiring, and Marking

3.13.1 Assembly

3.13.2 Wiring

iv

3.13.3 Marking

3.14 Workmanship

3.15 Brazing

3.16 Soldering

3.17 Maintainability

3.17.1 Maintainability Design Criteria

3.18 Reliability Design Criteria

3.18.1 System Reliability Parameters

3.19 Expected Life of Product

3.20 Software

4 VERIFICATION

4.1 VRTM

4.2 Test Articles

4.3 PAPI Requirements Testing Discussion

4.4 Test Methods

4.4.1 Design Qualification Test (DQT)

4.4.2 Production Acceptance Tests

4.4.3 Type Tests

4.5 Test Procedures

4.5.1 Visual Inspection

4.5.2 Altitude Test

4.5.3 Temperature Test

4.5.4 Sand and Dust Test

4.5.5 Salt Fog Test

4.5.6 Rain Test

4.5.7 Humidity Test

4.5.8 Thermal Shock Test

4.5.9 Solar Radiation (Sunshine) Test

4.5.10 Vibration Test

4.5.11 Electrical Safety

4.5.12 Transient Suppression Test

4.5.13 Electromagnetic Interference Test

4.5.14 Lamp Housing Assembly Aiming Test

4.5.15 First Article Photometric Test

4.5.16 Production Unit Photometric Test

4.5.17 Clinometer Test

4.5.18 Power and Control Assembly Performance Test

4.5.19 1000-Hour Operational Test v

4.5.20 Two-hour Operational Test

4.5.21 Tilt Fault Detection System Performance Test

4.5.22 Ice Accumulation Performance Test

4.5.23 LHA Tilt Detection Test

4.5.24 Input Power Test

4.5.25 Rigidity Test

4.6 Test Performance

5. PACKAGING

6. NOTES

6.1 Cross-reference with NAS-SS-1000

6.2 Mounting hardware not furnished under this contract

6.3 Flashing PAPI

TABLE OF TABLES

Table 1. PAPI monitored points, LHA origin (monitored at PCA)

Table 2. PAPI monitored points, PCA origin

Table 3. Design Qualification Tests

Table 4. Production Acceptance Tests

Table 5. Type Tests

Table 6. Vibration Test Data

Table 7. Test Performance

TABLE OF FIGURES

Figure 1. PAPI Signal Presentation

Figure 2. PAPI Approach Path (Side View)

Figure 3. Light Intensity Requirements for PAPI

Figure 4. Lamp Housing Assembly Side View (Typical – For illustration only)

Figure 5. LHA mounting pad

Figure 6. Functional Relationship of PAPI Units. Electrical interconnections between the PCA and the four

LHAs is dependent on the design (for illustration only)

TABLE OF APPENDICES

APPENDIX A. Verification of Requirements Traceability Matrix (VRTM)

APPENDIX B NAS-SS-1000 and NAS-RD-2013 Requirements Traceability vi

Summary of Changes to FAA-E-3007

Version Description Date Description of Change

FAA-E-3007 Original September 30, 2008

FAA-E-

3007A

Revision A to Original

Specification

June 22, Changes the color temperature range in paragraph 3.2.3 on page 7 and in Item # 9 on page 37. Change approved by FAA NAS Configuration Control Board, CCD # 32522

FAA-E-3007B Revision B November

28, 2011

Identifies the requirement for a transverse leveling pad to be an integral part of the LHA.

Adds the firm requirement for an aiming instrument set. Identifies the requirement for the PCA to operate when located up to 1000’ from the farthest LHA. Clarifies the Light-out feature requirement in section 3.3.1.2.4.

Changes the grounding wire size to 4 AWG.

Clarifies statements in several locations and corrects some misspelled words.

FAA-E-3007C Revision C March 4, Included stakeholder feedback as well as requirement 3.2.1.1 to allow for an internal mechanical, electrical or software baffle mechanism for the LED PAPI System.

Additional updates were included to further clarify current requirements and correct misspellings and standardize language and formatting.

FAA-E-3007C Revision C June 9, Updated the specification based on comments received during the Requirements Management Board (RqMB) review process.

06/09/2022 FAA-E-3007C

1.0 SCOPE

1.1 Specification Scope. This specification sets forth the requirements for a Precision

Approach Path Indicator (PAPI) that is used to provide accurate approach path guidance to pilots of landing aircraft. The PAPI consists of four Lamp Housing Assemblies (LHA), a

Power and Control Assembly (PCA), and an aiming instrument set (AIS). This specification specifically addresses the use of light emitting diode (LED) illumination sources that will replace incandescent bulb technology. The use of LED illumination sources in lieu of incandescent bulbs shall meet all PAPI operation requirements, provide much improved reliability and maintainability characteristics, and will significantly reduce life-cycle system operational costs.

2.0 APPLICABLE DOCUMENTS

2.1 FAA Documents. The following FAA specifications, standards, and drawings form a part of this specification and are applicable to the extent specified herein. Applicable revision levels are as shown here.

2.1.1 FAA Specifications.

FAA-D-2494B Technical Instruction Book Manuscripts: Electronic, Electrical and Mechanical Equipment, Requirement for Preparation of

Manuscript and Production of Books.

FAA-G-2100H Electronic Equipment, General Requirements

2.1.2 FAA Standards.

FAA-STD-019H Lightning and Surge Protection, Grounding, Bonding and

Shielding Requirements for Facilities and Electronic

Equipment

FAA-STD-026A NAS Software Development

FAA-STD-049- Fiber Optics Standard for Telecommunications Systems and

Equipment

2.1.3 FAA Drawings.

C-6046- Frangible Coupling, Types 1 and 1A, Details

2.1.4 FAA Management Documents. (Not Used)

2.1.5 FAA Advisory Circulars.

150/5345-28F. Precision Approach Path Indicator (PAPI) Systems.

2.2 Military and Federal Publications. The following military and federal publications, of the issues specified, form a part of this specification and are applicable to the extent specified herein.

2.2.1 Military Specifications.

MIL-A-8625F Anodic Coatings, for Aluminum and Aluminum Alloys

MIL-C-5541E Chemical Conversion Coatings on Aluminum and Aluminum

Alloys

2.2.1.1 Military Publications.

MIL-HDBK-454A Standard General Requirements for Electronic Equipment

MIL-HDBK-472- Maintainability Predictions

2.2.2 Military Standards.

MIL-STD-202G Electronic and Electrical Component Parts

MIL-STD-276A Impregnation of Porous Nonferrous Metal Castings

MIL-STD-461E Electromagnetic Emission and Susceptibility Requirements for the Control of Electromagnetic Interference

MIL-STD-810F Environmental Test Methods

MIL-STD-889B Dissimilar Metals

MIL-STD-961E Department of Defense Standard Practice for Defense

Specifications

MIL-STD-1472F Department of Defense Design Criteria Standard

2.2.3 Federal Specifications.

TT-P-1757B Primer Coating, Zinc Chromate, Low Moisture Sensitivity

2.2.4 Federal Standards.

FED-STD-595C Color

2.2.5 Federal Communications Commission Rules and Regulations.

Part 15 Radio Frequency Devices, Equipment Authorization

Subpart J Procedures

2.3 Other Publications. The following publications, of the issues in effect on the date of the invitation for bids or RFPs, form a part of this specification and are applicable to the extent specified herein.

2.3.1 National Electrical Manufacturers Association (NEMA) standards.

NEMA 4 Watertight and Dust Tight Indoors and Outdoors (Enclosure)

2.3.2 American National Standards Institute.

ANSI C61.1 Quantities and Units Used in Electricity

2.3.3 National Fire Protection Association Publications.

NFPA No. 70 National Electrical Code

2.3.4 Masters Painters Institute (MPI).

QPL-TT-E-489-48, MPI # 48 Interior Alkyd, Gloss

MPI # 49 Interior Alkyd, Flat

2.3.5 American Society for Testing and Materials (ASTM).

B26 Aluminum-Alloy Sand Castings

B85 Aluminum-Alloy Die Castings

B108 Aluminum-Alloy Permanent Mold Castings

B209 Aluminum and Aluminum-Alloy Sheet and Plate

B211 Aluminum and Aluminum-Alloy, Bar, Rod, and Wire

B221 Aluminum and Aluminum Alloy Extruded Bars, Rods, Shapes and Tubes

B241 Pipe, Seamless, and Seamless Extruded Tube, Aluminum and Aluminum-Alloy

2.3.6 Institute for Printed Circuits: IPC-2221 Generic Standard on Printed Board

Design.

2.3.7 Society of Automotive Engineers.

SAE-AS25050 Colors, Aeronautical Lights and Lighting Equipment, General

Requirements For

2.3.8 Underwriters Laboratories Inc.

UL 1059 Terminal Blocks

UL 489 Molded case circuit breakers and circuit-breaker enclosures.

(Copies of applicable FAA specifications, standards, and drawings may be obtained from the

Contracting Officer in the Federal Aviation Administration office issuing the SIR, IFB, or contract involved, or other use to be made of the requested material.)

(Single copies of military specifications and standards may be obtained from the Federal

Aviation Administration, Washington, D.C. 20590, ATTN: Contracting Officer. Requests should cite the invitation for bids, RFPs, or contract for which the material is needed. Mail requests, if found acceptable, will be forwarded to a military source of supply for filling;

hence, ample time should be allowed. Single copies of military specifications, standards, and publications may also be obtained directly from the Commanding Officer, Naval Publications and Forms Center, 5801 Tabor Avenue, Philadelphia, PA 19120.)

(Information on obtaining Federal specifications and standards may be obtained from

General Services Administration offices in Washington, D.C.; Atlanta; Boston; Chicago;

Denver; Kansas City, Missouri; New York; San Francisco; and Seattle.)

(Information on obtaining NEMA standards may be obtained from the National Electrical

Manufacturers Association, 155 East 44th Street, New York, NY 10017.)

(Copies of ANSI standards may be obtained from the American National Standards Institute, 70 East 45th Street, New York, NY 10017.)

(Information on obtaining the National Electrical Code may be obtained from the National

Fire Protection Association, Battery March Park, Quincy, MA 02269.)

(Information on American Society for Testing and Materials Specifications may be obtained from ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA, 19428-2959)

(Information on Institute for Printed Circuits Specifications may be obtained from IPC-

Association Connecting Electronics Industries, 3000 Lakeside Drive, 309S, Bannockburn, IL, 60015.)

(Information on Society of Automotive Engineers Standards may be obtained from SAE

Customer Service, 400 Commonwealth Drive, Warrendale, PA, 15096-001.)

(Information on Underwriter’s Laboratories Standards can be obtained from COMM2000, 1414 Brook Drive, Downers Grove, IL, 60515.)

3. REQUIREMENTS.

3.1 General Functional Requirements. The PAPI will be installed alongside a runway to provide accurate visual approach path information to pilots of landing aircraft, either day or night. The PAPI shall meet the requirements specified herein, and shall consist of:

a) Four LHAs, with integral mounting and adjustment hardware

b) One PCA

c) One aiming instrument set.

The PAPI signal presentations are shown in Figure 1 and a typical PAPI approach path (side view) is shown in Figure 2.

Figure 1. PAPI Signal Presentation

Figure 2. PAPI Approach Path (Side View)

3.2 Photometric Requirements.

3.2.1 Light Beam. Each PAPI LHA shall provide a split beam of light consisting of white light in the top sector and red light in the bottom sector as viewed from the front.

The transition from red light to white light shall occur within an angle of 3 minutes of arc at the beam center and within an angle of 5 minutes of arc at the beam edges. The transition band shall be flat to within 3 minutes of arc. The PAPI shall provide usable visual approach guidance out to 10 degrees either side of the extended runway centerline.

3.2.1.1 Baffling. The LHA shall be capable of varying the horizontal angle of the

Light Beam by adjusting an internal mechanical, electrical or software baffle within the LHA that controls the horizontal light field in increments of 0.5 degrees within the range from ten degrees to three degrees.

3.2.2 Light Intensity. The PAPI shall provide guidance at two light intensity steps:

Day mode and Night mode. The minimum values for Day mode intensity shall be as specified in Figure 3. Minimum values for Night mode intensity shall be 10 percent ±

1 percent of the Day mode values. The maximum value for Day mode intensity shall be 61,000 candela and the Night mode intensity maximum value shall be 6,100 candela.

Figure 3. Light Intensity Requirements for PAPI

3.2.3 Light Colors. The white light shall be generated by LEDs having a color temperature of 4,500K to 6,500K. The red light shall be generated by LEDs having a spectral output between 620.5nM and 645nM.

3.2.4 Light Beam Aiming Tolerance. The centerline of the transition zone (i.e., the vertical area of change from red light to white light) of each LHA projected light signal shall be parallel to the zero aiming angle projection within ±5 minutes of arc. The LHA transition from red to white light must occur within 1.05 inches (3 minutes of angle at

100 feet) at the beam center. This means that the projected vertical transition zone signal angle will be coincident with the LHA aiming angle, whether measured by internal or external means, to the tolerance stated, and is a measure of the aiming accuracy of the LHA/aiming device combination.

3.3 Sub-assemblies.

3.3.1 Lamp Housing Assembly.

3.3.1.1 Lamp Housing Assembly General. The LHA shall use LEDs as the light-producing elements. An example of an LHA that uses three projection lenses and aiming pad for a clinometer is shown in Figure 4. The LHA shall consist of:

a) An optical bench that will permit the mounting LEDs, projection lenses, and the required adjustment hardware.

b) A removable housing shell, integral with a deflection plate (Figure 4)

c) A tilt fault detection system consisting of either a tilt switch assembly or built-in solid-state clinometer to supply tilt readings to indicate a deviation from the proper leveling and therefore not providing the proper glide slope guidance. More detail is provided in 3.3.1.4.4.

d) An aiming pad and a transverse leveling pad since the LHA is leveled and aimed using an external clinometer. The aiming pad and leveling pad are to be an integral part of the optical bench, made in such a manner that the clinometer may be placed on the aiming pad and leveling pad without opening or removing the LHA housing shell.

They are to meet the requirements of 3.2.4.

e) A thermostatically controlled heater to prevent ice formation on the lenses.

Figure 4. Lamp Housing Assembly Side View (Typical – For illustration only)

Figure 5. LHA mounting pad.

3.3.1.2 Lamp Housing Assembly Operational Requirements.

3.3.1.2.1 Optical. The LHA shall be designed to maintain the required light beam orientation and photometric requirements in accordance with section 3.2 performing under the environmental conditions specified in section 3.9.

3.3.1.2.2 Control and Status. Upon receiving the appropriate command from the

PCA, the LHA shall operate in either night mode or day mode. The default mode for an LHA absent of any LHA command, shall be off (non-illuminated). The

LHA shall report status information back to the PCA. As a minimum this information shall include: the mode that it is in (Day/Night); whether the light output is low or in tolerance for the selected mode; and whether a tilt fault condition exists (or angle information from a solid-state clinometer for interpretation by the PCA). The control and status signals shall be implemented by discrete signals, a serial wire link, or a fiber-optic link. Use of a wireless communication link between the PCA and the LHAs is not permitted.

3.3.1.2.3 Weight. The weight of the LHA, excluding mounting legs, shall not be greater than 100 pounds (45.5 kilograms (kg)).

3.3.1.2.4 LED-out Feature. An alert shall be given if the light output at zero degrees horizontal (azimuth) is less than the value stated in Section 3.2.2. The LHA shall be considered to be unserviceable if the light output at zero degrees horizontal exceeds 25 percent below the minimum value stated in Section 3.2.2 for that horizontal angle. If this condition is present, a signal shall be generated and sent to the PCA reporting the condition such that the PCA can turn off the LEDs in all the LHAs.

3.3.1.3 Lamp Housing Assembly Enclosure.

3.3.1.3.1 Optical Bench.

3.3.1.3.1.1 The optical bench shall be constructed of corrosion resistant metal. The LHA’s structural design, shall provide rigidity to maintain the required optical alignment tolerance of 3 minutes at 100ft when subjected to a bending load of 1000 Newton Meters (Nm), torsional load of 1000 Newton Meters (Nm) per degree. The LHA shall maintain the required optical alignment of 3 minutes at 100ft while withstanding a uniformly distributed load of 15 lbs. per square foot (73 kilograms per square meter). The mounting base is that part of the

LHA to which the subassemblies attach to. Wiring entrances to the mounting base shall accommodate a 1/2 inch NEMA conduit fitting. The mounting base and optical bench may be combined as a single integrated unit.

3.3.1.3.1.2 The maximum dimension of any drain hole (if required) shall be not greater than 1/16 inch (1.57 millimeters (mm)) in diameter to prevent intrusion of foreign objects.

3.3.1.3.1.3 A transverse leveling pad and aiming pad compatible with the clinometer specified in section 3.3.3 shall be an integral part of the LHA and accessible on the outside of the LHA without opening any LHA covers or the housing shell. The clinometer shelf shall be located on the left side when facing the approach direction and shall be in the same plane as the optical bench and will allow the LHA to meet the requirements in paragraph 3.2.4. The tolerance for the flatness of the pads shall be ≤.005 inches. The aiming pads need to be parallel to the optical axis of the light beams within 1 minute of angle.

3.3.1.3.1.4 If an internal clinometer is included, in addition to the external clinometer shelf and aiming set, a means must be provided to read it without opening any LHA covers or the housing shell.

3.3.1.3.2 Housing Shell.

3.3.1.3.2.1 The optical bench shall be enclosed by a housing shell made of inherently corrosion resistant material. Removal or pivoting of the housing shell shall permit easy access to the internal components mounted on the optical bench and should have a method of securing the lid in the open position sufficient to allow access to all components. The housing shell shall be installed on the mounting base (see Figure 4) by means of threaded fasteners. The housing shell shall overlap the sides of the unit and be fastened in such a manner that rain will not enter the unit if the gaskets fail or if fasteners are lost. The housing shell shall include an integral deflection plate on the top front edge to prevent the pilot from seeing light reflected off the back of the LHAs. The integral deflection plate shall have a minimum height of 7 percent of the length of the housing shell (adequate protection up to 4 degrees above flight path).

3.3.1.3.2.2 All points that have electrical potentials in excess of 70 VDC or 50 VAC shall be shielded by guards or barriers to prevent accidental contact by a service technician. The

LHA shall be provided with an interlock to disable power when the housing shell is opened.

Interlocks, if used, shall include a mechanical override. In addition, closure of the housing shall either reset the override or shall be prohibited if the override is active.

3.3.1.3.3 Power Input Cable and Signal Cable Entrance.

3.3.1.3.3.1 Space shall be reserved in the rear of the LHA to permit connection of the incoming cables to the terminal blocks. The power cables shall enter through one hole located in the bottom rear of the housing. The control and status signals cable (or fiber) shall enter through another hole located in the bottom rear of the housing. The earth ground wire shall be brought in through a separate hole from the power or signal wires. The holes shall be sized to allow the installation of strain relief connectors for liquid tight flexible conduit of 1 inch (30.2mm).

3.3.1.3.3.2 A separate ground lug shall be provided for earth ground. The ground lug shall have a slotted, green-colored head suitable for a No. 4 American Wire Gauge bare copper ground wire. A hole of up to ½ inch (12.7 mm) diameter shall be provided in the bottom of the LHA near the wire entrance holes.

3.3.1.3.4 Mounting Provisions.

3.3.1.3.4.1 The LHA shall be designed for installation on a concrete foundation using the footprint shown in Figure 5. The mounting base shall have three adjustable legs to permit aiming of the light beam to any vertical angle from 0 degrees to 6 degrees above horizontal.

Also, the mounting and adjustment hardware shall permit transverse leveling where any mounting leg may be up to 1 inch (2.54 cm) higher or lower than any other leg after installation.

3.3.1.3.4.2 The legs will consist of mounting and adjusting hardware, 2-inch Electrical

Metallic Tubing (EMT), frangible couplings conforming to FAA Drawing C-6046, and aluminum flange; these components are supplied separately by the FAA and are not part of this PAPI specification.

3.3.1.3.4.3 The attachments to the mounting base shall be designed in such a way that aiming may be accomplished without opening the LHA. The leg attachments to the mounting base shall not create any stress on the mounting base at any angle from 0 to 6 degrees above horizontal. In addition, the leg attachments shall be designed to bend or fold over without damaging the mounting base if the unit is forcibly dislodged from the frangible couplings.

3.3.1.4 LHA Components.

3.3.1.4.1 LEDs.

3.3.1.4.1.1 LEDs shall be used to produce the white and red portions of the beam without a filter element. The LEDs shall have a rated life of 50,000 hours or more when operated at day mode intensity. The LED drivers shall have enough range to produce the light levels required in 3.2.2 over the entire lifespan of the LEDs. The LEDs shall maintain the minimum light level specified in Section 3.2.2 for the 50,000 hours.

3.3.1.4.1.2 The LHA shall use LED modules or individual LEDs that can be replaced within the required Mean Time to Repair (MTTR) at the field level to restore the LHA to normal operation. An array may be repairable at either a field or depot level. If an array is used, the LEDs shall be connected such that a single LED failure shall not produce a condition that causes other LEDs in the module to fail.

3.3.1.4.1.3 The LED mounting shall permit firm and positive positioning of the LEDs.

The mounting shall be designed to facilitate removal and replacement to meet the required

Mean Time To Repair (MTTR) in accordance with section 3.17.1(a). Replacing LEDs or

LED modules shall not require optical realignment.

3.3.1.4.1.4 The method of controlling the intensity shall not decrease the life expectancy of the LEDs. Any method used to modulate the intensity of the LEDs shall not produce any visible “strobe effects” (i.e., modulated at a rate <120Hz) when viewed at a distance greater than 100 feet (30.3 meters).

3.3.1.4.2 Projection Lens. The glass projection lenses shall be mounted in a vertical frame or frames made of inherently corrosion resistant material, which may be an integral part of the optical bench. The LHA lenses shall have UV protection so that light, including direct sunlight, entering the LHA through the lenses does not cause any damage to the LHA.

The lenses shall be recessed under an overhang to minimize the direct impingement or splash-back of rain or snow on the lenses, and the overhang shall protrude beyond the front of the unit by a distance equal to or greater than the height of the housing shell.

3.3.1.4.3 Terminal Blocks

3.3.1.4.3.1 Terminal blocks shall be provided in the rear of the LHA for all electrical interfaces to the LHA. Power connections and control and status signals shall be on different terminal blocks that are clearly labeled for each purpose.

3.3.1.4.3.2 Either enclosed base type or DIN rail type terminal blocks shall be used.

Terminal blocks shall provide inherently corrosion resistant terminals rated to carry 150% of expected current at 250 VAC. In addition, the terminal blocks shall satisfy the dielectric strength requirements of 3.12.

3.3.1.4.3.3 Electrical contact surfaces of terminals shall be brass, bronze, copper, or stainless steel which satisfies UL 1059 Standard. Pressure screws of the electrical terminals shall be brass, bronze, or stainless steel that satisfy UL 1059 standard. Each pressure-type terminal shall be equipped with a pressure plate to prevent the tip of the screw from turning directly on the wire. The separators shall prevent current leakage under the environmental conditions specified in 3.9.

3.3.1.4.3.4 The terminal blocks shall accommodate all internal connections and external cable connections using a dedicated terminal for each conductor. External connections will be made using conductors ranging in size from No. 12 AWG to No. 8 AWG for power wiring and No. 18 or No. 20 AWG for signal wiring. Markings shall be provided in accordance with

3.13.3.

3.3.1.4.4 Tilt Switch or Tilt Indicator.

3.3.1.4.4.1 Each LHA unit shall have a tilt detection system that may consist of either a tilt switch or a built-in solid-state clinometer to determine if the LHA has deviated from its set aiming angle. If a tilt switch is used, it shall be of a non-mechanical design that will meet the vibration requirements in accordance with section 4.5.10. A solid-state clinometer may also be used to measure the aiming angle and transverse level of the LHA in order to determine if a tilt condition has occurred. If a solid-state clinometer is used, there shall be a display internal to the LHA to display the aiming angle and transverse level in minutes. In addition, if a solid state clinometer is used to measure and display aiming and transverse angle, a means shall be provided to calibrate the device at the depot level.

3.3.1.4.4.2 The tilt fault detection system shall de-energize the LEDs, in all LHAs, when the optical pattern is lowered 1/4 degree or more or raised 1/2 degree or more with respect to the preset aiming angle. The tilt fault detection system shall have a time delay of at least 10 seconds to no more than 30 seconds that will prevent intermittent tilt indication due to vibration. The tilt fault detection system shall have failsafe operation so that any malfunction of the tilt switch or solid-state clinometer, including loss of input power, shall de-energize the LEDs in all LHAs.

3.3.1.4.5 Power supplies. Power supplies for the LEDs shall drive the LEDs at the levels specified in 3.2.2. The power supply and all associated wiring shall be designed to withstand the dielectric requirement in accordance with 3.12.

3.3.1.4.6 Heater. The LHA shall be provided with a thermostatically controller heater to prevent the formation of ice on the lenses in accordance with 3.9.10.

3.3.1.5 LHA Finish.

3.3.1.5.1 Housing Shell Finish. All exterior and interior surfaces of the lamp housing shell shall be finished in accordance with 3.8.1 using the colors specified in this section.

3.3.1.5.2 Interior Finish. The deflection plate front surface and all interior surfaces of the housing shell, including the interior surface of the overhang, shall be finished with black, color No. 37038 of FED-STD-595.

3.3.1.5.3 Exterior Finish. All exterior surfaces of the housing shell including the back surface of the deflection plate, shall be painted International Orange, color No. 12197 of

FED-STD-595.

3.3.1.5.4 Optical Bench Finish. The optical bench including the projector mounting frames, shall be painted in accordance with 3.8.1, with black, color No. 37038 of

FED-STD-595, or as an alternative, black anodized per MIL-A-8625 in lieu of painting.

3.3.1.5.5 Mounting Base Finish. The LHA mounting base shall be painted in accordance with 3.8.1, with black, Color No. 37038 of FED-STD-595, or alternatively, black anodized per MIL-A-8625 in lieu of painting.

3.3.2 Power and Control Assembly.

3.3.2.1 Power and Control Assembly General. The PCA shall control the power to the LHAs. The PCA shall issue commands to the LHAs to go to night mode or day mode.

The PCA shall receive status back from the LHAs, as a minimum the mode that it is in; “light output low” for the selected mode; and tilt angle information or tilt fault status. The control and status signals may be implemented by discrete signals or a non-proprietary data link. The

PCA shall form one unit that is intended to be installed adjacent to the LHA furthest from the runway. The Power and Control Assembly (PCA) shall operate satisfactorily with all four

Light Housing Assemblies (LHA’s) when located up to 1000 feet from the farthest LHA to produce the required photometric output. The weight of the PCA shall not exceed 50 pounds

(22.67 kg). No external cooling shall be required.

Figure 6. Functional Relationship of PAPI Units. Electrical interconnections between the PCA and the four LHAs is dependent on the design (for illustration only)

3.3.2.2 PCA Operational Requirements.

3.3.2.2.1 Purpose. The PCA shall supply power for operation of the PAPI. When the system is powered up, the PCA shall command the LHAs to illuminate at night intensity, and then if sufficient light is present, command the LHAs to illuminate at day intensity.

3.3.2.2.2 Modes. The ON/OFF operation of the PAPI shall be controlled by a three position switch: REMOTE, LOCAL, or OFF. The switch shall select an operation as follows:

REMOTE allows the remote control input signal (120 VAC, 60Hz) to turn the LHA LEDs on or off; LOCAL turns the LHA LEDs on; and OFF turn the LHA LEDs off. In both the

Remote and the LOCAL positions, the PAPI shall illuminate the LHAs if no fault conditions are detected or shut down the system if faults are detected.

3.3.2.2.3 Input Power. The 120/240 volt, 60 Hz input power lines (with Neutral grounded in accordance with the latest version of National Electric Code) shall terminate at the power terminal block (3.3.2.4.1), and shall be connected to internal circuitry of the PCA through a two-pole main circuit breaker (3.3.2.4.2). The system shall have a maximum power consumption of The system shall have a maximum power consumption of 1.5 KW including any heaters. Circuit breakers shall be used to protect any power feeds from the

PCA to the LHAs.

The Total current harmonic distortion for equipment or subsystems requiring power of 40 kilowatts or more shall be limited to 10 percent. The system shall recover automatically (or continue to operate) from momentary power interruptions and brownout conditions where the input voltage dips more than 10 percent below or surges 15 percent above nominal. The

PCA shall include a 120 VAC Ground Fault Interrupt duplex outlet for connecting maintenance and service equipment. The PCA shall include a shatterproof service lamp controlled by an on/off switch, protected by a fuse or circuit breaker, for illuminating the interior of the PCA cabinet during service operations.

3.3.2.2.4 Fault Conditions. The PCA shall shut down the power to the LEDs in all 4

LHAs if any of the following events are present for at least 10 seconds: any LHA stays in day mode when night mode is selected, an LED-Out condition as defined in 3.3.1.2.4 occurs, or a tilt fault condition as described in 3.3.1.4.4.2 is detected in an LHA. Loss of communication from any LHA for more than 10 seconds or an LHA not responding to a command to shut down (neither night or day mode active) shall cause the PCA to shut down power to the LEDs in all 4

LHAs. LED indicators or a display inside the PCA shall indicate the initial cause of a system shutdown.

If a microprocessor or microcontroller is utilized, a watchdog timer circuit shall be employed to detect a software lockup condition and cause a hardware reset to be issued to the system.

3.3.2.2.5 Remote Monitoring System (RMS). External signals shall be provided for use by an optional RMS in accordance with section 3.4.1.

3.3.2.2.6 Remote Control Input. A Remote Control Input shall be provided to control the PAPI when the system is set to the Remote mode, 120 VAC ±10 percent applied to the input shall turn the system on and lack of input shall turn the system OFF. The Remote

Control Input connections shall withstand the dielectric requirements in accordance with

3.12.

3.3.2.3 Power and Control Assembly Cabinet.

3.3.2.3.1 Cabinet Configuration. The PCA cabinet shall contain all the PCA components (3.3.2.4) in one single enclosure, including a main switch, terminal blocks, cable clamps, grounding lugs, and protective devices. The cabinet shall be an outdoor, liquid-tight, National Electrical Manufacturers Association (NEMA-4X) type enclosure. All plane surfaces of the control cabinet shall intersect at 90 degrees. Access to the interior of the cabinet shall be provided through one hinged door with gasket with provision for padlocking.

The padlock hasp shall have a 7/16 inch (11.1 mm) hole. The door shall open a minimum of

110 degrees and shall be equipped with a latching mechanism to hold the door in the open position. The internal face portion of the door shall display a system wiring diagram. The door of the cabinet shall be bonded to the body of the cabinet in accordance with National

Electric Code (NEC) Article 250-90 (2002).

3.3.2.3.2 Internal Components. All components except the photo sensing device

(3.3.2.4.4) and the transient suppressors (3.10) shall be contained inside the cabinet. There shall be no other devices protruding through the walls of the cabinet. Electronic components shall be mounted on plug-in printed wiring boards or flat mounted printed wiring boards with pluggable connectors in accordance with 3.5.2. All adjustments located on printed wiring boards shall be readily accessible to the operator. Adjustments shall be made without the need to use extender cards or cables.

3.3.2.3.3 Internal Wiring. Proper high-temperature wire in accordance with the latest version of National Electric Code Article 310 (see Tables 310-13 and 310-61) shall be used throughout the cabinet. Space shall be provided in the bottom of the cabinet for all wiring

(input, output, and internal) and for all terminal blocks. An internal ground lug shall be provided in the cabinet for grounding purposes. The ground lug shall have a slotted, green-colored head suitable for a No. 4 American Wire Gauge bare copper ground wire.

3.3.2.3.4 High Voltages. All points that have electrical potentials in excess of 70 VDC or 50 VAC shall be shielded by guards or barriers to prevent accidental contact by a service technician. The PCA shall be provided with an interlock to disable power when the door is opened. Interlocks shall include a mechanical override. In addition, closure of the door shall either reset the override or shall be prohibited if the override is active.

3.3.2.4 PCA Components.

3.3.2.4.1 Terminal Blocks. One input terminal block of the enclosed base type or DIN rail type, with three screw-pressure terminals, shall be provided for the primary power. For the LHA connections, power connections shall be located on one or more terminal blocks and control and status signals shall be located on different terminal blocks of the enclosed base type or DIN rail type. Terminal blocks shall provide inherently corrosion resistant terminals rated to carry 150% of expected current at 250 VAC. Electrical contact surfaces of terminals shall be brass, bronze, copper, or stainless steel that satisfy UL 1059 standard. Pressure screws of the electrical terminals shall be brass, bronze, or stainless steel that satisfy UL 1059 standard. Each pressure-type terminal shall be equipped with a pressure plate to prevent the tip of the screw from turning directly on the wire. The separators shall prevent current leakage under the environmental conditions specified in 3.9. The terminal blocks shall have a dedicated terminal for each conductor, for all internal connections, plus connection of external power cables. External connections shall be made using conductors ranging in size from No. 12 AWG to No. 8 AWG for power wiring and No. 18 or No. 20 AWG for signal wiring. Marking shall be provided in accordance with 3.13.3.

3.3.2.4.2 Circuit Breaker. A two-pole, hydraulic-magnetic circuit breaker or electronic solid state type shall be provided as a main circuit breaker and power switch. The circuit breaker shall have an arc quenching chamber and shall have a minimum rating of

Asymmetrical interrupting capacity (AIC) of 5,000 A (5KA) at 120/240V, 60Hz as rated by

Underwriters Laboratories Standard UL 489.

3.3.2.4.3 Photoelectric Switching Circuitry. A photoelectric switching circuit shall be provided to automatically change the intensity of the lights in two steps as described below.

All operating components of the switching circuitry, except the photo sensing device

(3.3.2.4.4) and any associated signal conditioning circuitry, shall be mounted on a printed wiring board mounted within the cabinet. The photoelectric switching circuit shall cause the

PCA to set the LHA output to high when the illumination on a vertical surface facing north reaches 58±2 foot-candles (624±21.5 lux), and shall set the LHA output to LOW when the illumination falls to 35±2 foot-candles (377 ±21.5 lux). The on-off points shall vary not greater than ±2 foot-candles (±21.5 lux), at any ambient temperature in the range specified in

3.9.1 with line-to-line voltage variations from 230V to 250V. Similarly, the on-off points shall vary not greater than 3 foot-candles (32.28 lux) with line-to-line voltage variations from

216V to 230V and from 250V to 264V. A symmetrical time delay of 10 seconds shall be provided to prevent the output current from changing due to transient light conditions. A fail-safe feature shall set the output level to the low (night) setting in the event the photo sensing device fails.

3.3.2.4.4 Photo sensing Device. The photo sensing device shall be mounted on the top surface of the PCA cabinet and shall be able to be rotated in any direction so as to point to

North and to lock in that position. The photo sensing device shall be equipped with a thermostatically controlled heater to prevent the formation of ice on the lens under all temperature conditions specified for the system. The photo sensing device shall be mounted in such a way that it will remain clear of up to 6 inches (15.25 cm) of snow accumulated on top of the PCA cabinet. The device itself shall be hermetically sealed, and shall have a spectral response that peaks in the 5500 - 6000 angstroms (0.021 - 0.023 mil) region. The device shall meet the temperature requirements of the photoelectric switching circuitry

(3.3.2.4.3). The device shall activate the photoelectric switching circuitry (3.3.2.4.3).

3.3.2.4.5 Power Supply. A power supply shall be provided to supply the proper voltages and currents necessary to operate the PCA circuits within the tolerances and conditions set forth in this specification. Wherever practicable, all electronic components shall be mounted on a plug-in printed wiring board mounted within the cabinet. The power supply and all associated wiring shall be designed to withstand the dielectric requirements in accordance with 3.12.

3.3.2.4.6 Elapsed Time Indicator. An elapsed time indicator shall be provided to register the number of hours of operation during all intensity settings. The meter shall indicate total time in hours and tenths of hours. The meter shall be recyclable and shall have a minimum indicator range of 60,000 hours. The meter shall be mounted within the cabinet. All displays shall be capable of providing information in all areas. All display shall be capable of producing a minimum luminance of 1000 cd/m2.

3.3.2.5 Power and Control Assembly Finish. All exterior and interior surfaces of the

PCA shall be finished as described in 3.8.1, with Aviation White, Color No. 17875 (in accordance with FED-STD-595) except that aluminum surfaces that are clear anodized in accordance with MIL-A-8625,Type II do not require painting.

3.3.3 Aiming Instrument Set and Calibration Bar. An aiming instrument set is required for a PAPI that is aimed by external means. The Aiming Instrument Set shall consist of a clinometer, a calibration bar, and a portable storage case.

3.3.3.1 Clinometer. The clinometer shall be used to accurately adjust the LHA during cross-leveling (lateral), longitudinal leveling, and elevation setting.

3.3.3.1.1 Construction. The base of the clinometer shall be rustproof. The clinometer shall be constructed of inherently corrosion resistant metal. The aiming device shall not exceed 10 lbs. (4.5 kg) in weight. Aluminum and other soft metals shall not be used where subject to metal-to-metal rubbing. Design and construction of the clinometer shall be such that deviation from true position due to its own weight shall be not greater than or less than 2 minutes of arc when the clinometer is placed on the optical bench (3.3.1.3.1.3). The clinometer shall be designed so that repeated changing of the dial setting will not cause excessive wear that could deteriorate the accuracy of the instrument.

3.3.3.1.2 Level. The clinometer shall utilize a 6-inch (15.24 cm) (maximum) level having an accuracy of ±2 minutes. The level shall be permanently attached to the clinometer to permit fine adjustments to calibrate the instrument. The level shall have a protective device to minimize possible damage.

3.3.3.1.3 Dial for Mechanical Clinometer. An accurate direct-reading dial or micrometer type indicator shall be provided for setting the LHA to the desired angle. The reading dial shall indicate at minimum, angles from 1.5 degrees to 6 degrees in graduated increments of minutes of arc. The spacing between each degree mark shall be at least 1/2 inch (12.7 mm).

A 0.00 degree setting shall be provided on the dial for calibration purposes and shall have an accuracy of ±2 minutes of arc and a repeatability of ±1 minute of arc while on the calibration bar. Alternate designs using a Vernier dial may be used, so long as the Vernier dial is provided with equivalent graduations as specified for the direct reading dial.

The clinometer shall have provisions for firmly securing the dial setting after factory calibration, but shall permit field adjustment to the 0.00 degree position by the user.

3.3.3.2 Calibration Bar. A calibration bar shall be provided with each clinometer to permit field checking and calibration. The calibration bar shall be designed for laying on a flat surface or in the carrying case (see 3.3.3.3) and shall have adjustment features to permit it being leveled to a horizontal plane. The tolerance for the flatness of the calibration bar shall be ≤0.005 inches. A portable level, not attached to the bar, shall be provided with each calibration bar to permit leveling. The level shall have a metal base meeting the requirements of 3.6.1. The level shall be used to set up the calibration bar and verify the calibration of the clinometer.

3.3.3.3 Carrying and Storage Case. A rigid portable inherently corrosion resistant metal, fiberglass, or shatterproof plastic case shall be provided for carrying and storing the clinometer. The case shall have a carrying handle and shall have a suitable latch for securing the cover in the closed position. The interior shall be designed to accommodate the calibration bar and clinometer so that it will be held and cushioned firmly in place. The case shall also carry and store the calibration bar and portable level. The aiming instrument set carrying case shall have an instruction plate installed on the inside of the cover in a location easily viewed by the user and shall contain all necessary instructions for calibration and use of the aiming instrument set. The instruction plate shall be made of aluminum. The plate shall conform to the requirements of 3.6.5.

3.4 Monitored Points and Controls. Test points shall be provided on all signals required to be monitored during checkouts, alignment, and calibration, or during preventive maintenance procedures. Test points shall not be located in compartments with voltage points of 500 volts or more, and all test points shall be located so as to preclude accidental shock to personnel engaged in normal operating or maintenance activities. The removal of components, modules, or circuit cards shall not be required to gain access to test points or adjustments. Test point controls and indicators mounted on printed wiring boards installed in a card cage shall be accessible from the front of the circuit cage assembly without the use of extender boards.

3.4.1 External signal. Monitored items/test points shall be brought out to a port on the

PCA card or backplane for possible connection to a future Remote Monitoring System

(RMS). Tables I and II below give examples of signals that may be found on a PAPI system.

These signals are not subject to the dielectric requirements in accordance with 3.12.

Table 1. PAPI monitored points, LHA origin (monitored at PCA)

SIGNAL DEFINITION SIGNAL TYPE

1TLT TILT FAULT OUTPUT ON LHA 1 Status

1L01 LED-OUT OUTPUT ON LHA 1 Status

LHA #1 power

OK

Indicates that LHA 1 Power Supply is operating properly

Status

LHA 1 OUT

OF

TOLERANCE

Indicates that the LEDs are too dim for the selected mode

2TLT TILT SWITCH OUTPUT ON LHA 2 Status

2L01 LED FAULT OUTPUT ON LHA 2 Status

LHA #2 power

OK

Indicates that LHA 2 Power Supply is operating properly

Status

LHA 2 OUT

OF

TOLERANCE

Indicates that the LEDs are too dim for the selected

3TLT TILT SWITCH OUTPUT ON LHA 3 Status

3L01 LED FAULT OUTPUT ON LHA 3 Status

LHA #3 power

OK

Indicates that LHA Power Supply is operating properly

Status

LHA 3 OUT

OF

TOLERANCE

Indicates that the LEDs are too dim for the selected

4TLT TILT SWITCH OUTPUT ON LHA 4 Status

4L01 LED FAULT OUTPUT ON LHA 4 Status

LHA #4 power

OK

Indicates that LHA Power Supply is operating properly

Status

LHA 4 OUT

OF

TOLERANCE

Indicates that the LEDs are too dim for the selected

GND GROUND OUTPUT

Table 2. PAPI monitored points, PCA origin

SIGNAL DEFINITION SIGNAL TYPE

REMOTE ON REMOTE ON FOR NORMAL

MODE. This is a signal that is used to turn the PAPI on remotely

Status

PHOTORE SLO Output of the photocell. This may vary according to the design

Monitor point

DAY Indicates if the PAPI is in day or night mode

Status

TILT TILT CONDITION SHUTDOWN.

Indicates if the system is shut down due to a tilt condition

Status

OUT OF TOLERANCE Indicates that a shutdown has occurred due to the LEDs being too dim for the selected mode.

Status

POWER ON A DC signal that indicates the PAPI system is powered up

Status

LAMPS ON A DC signal that indicates that the

LHAs are illuminated

PS VOLTAGE One monitoring point for each power supply voltage present in the

PCA

Monitoring point

Generate Power On

Reset

Connecting this signal to power ground causes a power on reset condition

Control

ANLG GND ANALOG GROUND Reference point

PW GND POWER GROUND Reference point

3.5 Electrical Components. Electrical components must meet the requirements specified herein unless otherwise noted.

3.5.1 Electrical Connectors. Electrical connectors shall be in accordance with

FAA-G-2100 section 3.3.1.3.4.

3.5.2 Printed Wiring Boards. Printed wiring boards, assemblies and components mountings shall conform to FAA-G-2100, paragraphs 3.2.2.1 and 3.2.2.2, with the exception of paper base copper-clad laminates, which are prohibited. Conformal coating is required and shall be in accordance with FAA-G-2100 paragraph 3.3.1.4.7b.

3.5.3 Component Ratings. When component ratings are not specified, they shall be selected to ensure that the components are not operated in excess of 80 percent of their normally de-rated maximum values for the temperatures encountered under the specified equipment environmental conditions. De-rating of electronic components shall be in accordance with MIL-STD-454, Requirement 18.

3.5.4 Fiber Optics. Any fiber optics used in the PAPI shall conform to FAA-STD- 049.

3.6 Materials and parts. Materials and parts shall be as specified herein. Materials and parts not specifically designated by a standard or specification shall meet the requirements of

FAA-G-2100 section 3.3.1. All materials and parts shall be suitable for operation under the environmental conditions in accordance with 3.9 of the LED PAPI Specification.

3.6.1 Metals. Metals shall be inherently corrosion resistant.