NEW RUNWAY - NEW BEGINNINGS
November 4 ,1996 marked a new dawn in Canadian Aviation history, with the opening of a new Runway (08L-26R) at Vancouver International Airport. The opening of the new runway not only relieved air traffic congestion at the airport, but also allows flights in and out of Vancouver in weather conditions which previously shut down the airport, causing flight delays and cancellations, which affected the entire Canadian aviation system.

This significant step forward is due to the installation of the latest generation of electronic landing guidance and lighting systems on the new runway to Category IIIA standards, which allows aircraft to land in visibility conditions as low as 200 m (600 ft). Previously, visibility less than 400 m (1400 ft) would shut down the airport for landings.

Vancouver International Airport (YVR) is located on Sea Island in Richmond B.C., which is a suburb of Vancouver B.C. The airport is the second busiest facility in Canada, serving 14 million passenger per year, and over 500 flights a day. In 1992, the Vancouver International Airport Authority took over responsibility for the operation of the airport from Transport Canada, and immediately began planning an expansion program which included a new International Terminal Building and the 3030 m (9941 ft) long runway, 12 new interconnecting taxiways, 3 extensions to existing taxiways and an expanded terminal apron.

DESIGN STANDARDS
The lighting systems installed meet international standards for airfield lighting established by ICAO (International Civil Aviation Organization), modified to suit Canadian requirements by Transport Canada. The requirements are published in Transport Canada document TP312 Aerodrome Standards and Recommended Practices. The lighting systems required include:

• Category III Precision Approach lights (CAT III) which also incorporate the lighting requirements for Category I (CAT I) and Category II (CAT II) and Visual Flight Rules (VFR).
• Precision Approach Path Indicator (PAPI) Systems,
• Runway Lighting Systems including elevated edge lights, and in pavement centerline and touchdown zone lights
• In pavement taxiway centerline lighting to guide aircraft from the runway to the taxiways and onto the apron for final docking at the terminal building.

ICAO standards stipulate the Isocandela requirements for the various types of luminaries used at airports, to which lighting equipment must comply.

LUMINAIRE SELECTION
Prior to 1992 Vancouver International Airport as with all Canadian International Airports was owned, and operated by the Canadian Government through it Transport Canada Ministry. In order to maintain national standards and for ease of maintenance and spare parts stock, Transport Canada had over the years adopted very specific lighting equipment for use at its facilities.

When YVR was privatized in 1992, the Airport Authority was no longer restricted to using only equipment listed on Transport Canada approval list. The only requirements which had to be met were the photometric requirements, and certain physical characteristics such as loading and temperature. This opened up a vast array of lighting equipment from around the world to be examined and chosen from.

The design team assembled product data and samples from suppliers in Canada, USA, England, France, Belgium and Germany, and evaluated the equipment based on photometric performance, physical characteristics, environmental suitability, completeness of product line, maintainability and availability of spare parts. The end users of the products ie the airport maintenance staff, were given the samples and were asked to comment on the various aspects of each luminaire. They in turn disassembled and reassembled the units, subjected the luminaries to various load tests, installed the units in the existing runway and tested their suitability for snowplowing etc, and provided the design team with their preferences.

The selection was narrowed to three suppliers, and Requests for Quotations were prepared. The selectees were from Canada and England, and represented products from Canada, USA, England and Belgium. When the quotations were received, each proponent was interviewed, and Siemens Electric Ltd. was selected to supply all the luminaries for the project, some 2600 light units. The in pavement luminaries selected are manufactured in Belgium by ADB and are a new generation of luminaire made of an aluminum alloy, and consist of an 200 mm (8") dia. light pod, and an adaptor ring. The light pod weighs approximately 3 kg (7 lbs), rather than the more traditional style luminaire which weighs approximately 15 kg (30 lbs), and was an important consideration to the maintenance department, for changing out and refurbishing the units.

All the luminaires selected employ halogen lamps with wattages ranging from 45 W to 200 W.

Another important consideration in selecting the luminaires, was power consumption. The Airport Authority, has made a strong environmental commitment, and the design team looked at ways to save electrical energy. The majority of the luminaires selected, because of the optical design use 48 W halogen lamps, whereas the more traditional luminaires previously used required 62 W lamps. This saving coupled with unique taxiway lighting selection options makes for less lamps being energized at any time. This saving in energy was recognized by the local power authority B.C. Hydro, who commended the Airport Authority, and rewarded them with a financial contribution toward the cost of the lighting.

AIRFIELD LIGHTING POWER SYSTEMS
Airfield Lighting systems for large airports traditionally operate on a 6.6 Ampere constant current series power system, which allows the lights to be operated at various intensity (percentage of required effective candela) levels, by imposing a constant current on the circuit, which is adjustable to suit the prevailing visibility conditions.

The standards for the intensity of lighting systems use 5 settings which equate to:

Special rated high voltage lighting cable designated in Canada as ASLC (Airport Series Lighting Cable) has been designed to account for the special requirements for Airfield Lighting systems, which employ high voltages, but relatively low current. This cable is insulated to 5000 Volts, and employs a 7 strand No. 8 AWG copper conductor. The overall thickness of this cable type is much smaller than the standard 5000 Volt No. 8 cable because of the need to only carry 6.6 Ampere rather than the normal current rating of 45 Ampere. These cables are also suitable for direct burial.

Main Ductbank

There are approximately 350 km (218 miles) of primary cable used for the new lighting systems. The cables run from the Regulator Switchboard which is located in the North Field Electric Centre (FEC) located in the new terminal building to each end of the new runway, in a T- formation. The power ductbank employs 30-100 mm ducts, to the " T" and then reduces to 16 ducts each way paralleling the new runway. The ductbanks are concrete encased where they pass under aircraft surfaces, and are direct buried in sand bedding in non-vehicular areas.

The lighting system is backed up by a dedicated 400 KW Diesel generator. Standards require that the standby power source operate with a maximum 15 second switch over time in visibility conditions above 800 m (2600 ft) and within 1 second when conditions are less than 800 m. In order to accomplish this requirement, when weather conditions deteriorate to 800 m, the standby power source is started, and the airfield lighting load is switched over to the generator. The generator them becomes primary power source, with Utility Power becoming the standby source. In this way if the generator fails, the hydro power is available instantaneously, with no lose of lighting to approaching aircraft.

Field lighting series circuits are designed as loops, with the primary conductors leaving the constant current regulator, traveling to each luminaire in the circuit where a suitably sized series isolating transformer is located. The primary conductor is attached to the transformer primary leads via specially designed watertight high voltage connectors, and then proceeds to the next luminaire until the load is complete, and then returns to the regulator. A bare copper ground counterpoise wire is also buried along with the primary conductor, and is attached to each transformer and luminaire. The counterpoise provides both ground return, and lightning protection for the circuit.

The isolating transformer provides the means to isolate the high operating voltage (+- 3030 Volts) from the low voltage (+- 35 Volts) required by the lamps, while allowing the full current (6.6 Amp) to the lamp. The transformer also allows for circuit continuity in the event of a lamp failure. Secondary power from the isolating transformers is distributed to the in-pavement lights using No. 10 RW90 wiring, which reduced the voltage drop to the lamps. There was approximately 500 km (300 m) of secondary wiring installed on the project.

Circuit design is such that all lighting is interleaved, so the failure of a circuit will not result in the complete lose of visual guidance to a pilot using the system.

PRECISION APPROACH LIGHTING SYSTEM

Runway Threshold Lights

The approach lighting system installed at YVR is a Precision Category II/lII system, and is referred to by the acronym of ALSF-2, which is short for Approach Light system with Sequenced Flashers. These lights are used when visibility is less than 800 m (2600 ft). The system is also designed to operate as a Category l approach system when visibility permits. This system is know as SSALR or Simplified Short Approach Light system with Runway Alignment Lights and Sequenced Flashers. This system is used when visibility is above 800 m (2600 ft). The intensity of the lights is varied to suit day or night conditions and in the case of ALSF-2, the intensity is varied to suit Category II (visibility to 400 m (1400 ft)) or Category III conditions.

approach lights at light station 10

The ALSF-2 system consists of 24 light stations extending 720 m (3000 ft) beyond the threshold of the runway, with each station located 30 m (100 ft) apart. The first 14 light stations consists of a barrette of 5- 200 W uni-directional white lights centered on the extended runway centerline. The 15th light station located 300 m (1000 ft) from the threshold has the centerline barrette as well as a additional barrette of nine lights on either side of the centerline extending 16.5 m (55 ft) from the centerline. Each of the first 15 light stations also has a 20,000 candela sequenced flashing capacitor discharge light located on the extended runway centerline. Light stations 16 through 24 are again outfitted with the 5 white centerline barrettes previously described as well as side row barrettes consisting of 3-200 W red uni-directional lights located to align with the runway touchdown zone lights at approximately 11 m (36 ft) either side of the centerline. Light station 20 which is located 150 m (500 ft) from the threshold is also outfitted with an additional 4-200 W white lights located adjacent to the centerline barrette. The threshold of the runway is marked with 59-200 W green lights, for a total of 274 luminaries for each runway.

Pullpit with primary wiring and isolating transformer

When visibility conditions prevail which require the SSALR system only, the white centerline barrettes at light stations

approach lighting pier

1 through 14, 16, 18, 20, 22, 24 and the red side row barrettes are off. In addition B of the lights marking the 300 m (1000 ft) mark are off, and only 22 of the green threshold lights at illuminated. The SSALR system also only operates the sequenced flashing lights at light stations 1, 3, 5, 7 and 9. The SSALR system uses 67 of the 274 luminaries approach light units for each runway.

The approach lighting system for Runway 08L projects into Georgia Straight, off the west end of Sea Island, and required the construction of a precast concrete pier into the environmentally sensitive foreshore area. The lighting pier is approximately 500 m (l640 ft) long, and provides for vehicle access for maintenance and operations personnel.

The white 200 W luminaries, produce a minimum average of 20,000 cd, the red side row luminaries produce 5000 cd and the green threshold units produce 10,000 cd.

PRECISION APPROACH PATH INDICATOR SYSTEM
Each runway is served with a precision approach path indicator system known by the acronym of PAPI. These system provides the pilot of an approaching aircraft with the visual glide slope indication, which when flown will ensure adequate clearance of the aircraft over any obstacles in the approach, and will provide for the aircraft to cross the threshold at an appropriate height.

The system consists of 4 units or light boxes. Each unit contains 3-200 W halogen lamps. The light boxes are located at a distance from the threshold which is calculated to provide the proper wheel clearance over the threshold, and adjusted to coincide with the electronic glide path equipment. The light boxes are set perpendicular to the runway centerline, with the first unit situated 15 m (50 ft) from the edge of the runway. Adjacent units are located 9 m (30 ft) from each other. The units are aimed to provide for an approach angle of 3 deg., and as a result the innermost unit is set at 2 deg. 30 min, the next unit at 2 deg 50 min, the third unit at 3 deg 10 min and the outermost unit at 3 deg 30 min.

When descending at the appropriate slope, the two inner light boxes will project a red beam of light, while the 2 outer boxes will project a white beam. If slightly high, the 3 outer boxes will project white while the innermost box will be red, and if the pilot is too high on his approach angle, all 4 boxes will be white. Conversely if slightly low, the three inner boxes will be red, with the outer box showing white, and if too low, all four boxes will project a red beam.

T h e p h o t o m e t r i c s of the PAPI units selected are such that the PAPI's main light beam can be acquired at anywhere between 6 and 13 km during cloudy daylight, and 15 to 30 km during clear nights. Colour interpretation (red/white) begins between 3 and 6 km during clear daylight and 23 km during clear nights.

RUNWAY LIGHTING SYSTEMS
The runway is served by three different lighting system: Elevated Edge lights, in-pavement centerline lights and in-pavement touchdown zone lights.

Elevated Edge Lights
The elevated edge lights are located along the length of the runway, 1.5 m (5 ft) from the edge of the runway, and are spaced at 60 m (200 ft) intervals. The luminaries are mounted on frangible columns, which place the top of the light unit 350 mm (14 in) above the runway edge. The units use a 150 W halogen lamp, and employ an inner lens and an outer lens which produce a white light with a minimum average intensity of 10,000 cd. The edge lights are fed from two regulators, and are alternated so the failure of one regulator will not extinguish more than one light in a row. Each light unit is connected to the series circuit loop with a 200 Watt isolating transformer. The elevated light units are mounted on 50 mm dia frangible couplings which are designed to break off when hit, in order to minimize damage to an aircraft. The couplings and the lights are made of non ferrous materials in order to reduce the chances of sparking in the event of an incident. There are a total of 102 elevated runway edge lights.

Runway Centerline Lights
The runway centerline luminaries are in-pavement units, and are placed at 15 m (50 ft) spacing. These units are bi directional, employing 2- 48 W halogen reflector lamps. The lamps are connected in series internally, and are powered via a single 100 W series isolating transformer. The runway centerline lights produce an minimum average intensity of 5000 cd for white and 750 cd in red. The lights are arranged to show white in the direction of travel from the threshold to a point 900 m (2950 ft) from the end of the runway, the lights then alternate red and white to 300 m (1000 ft) from the runway end where the lights change to red to the end of the runway. This lighting pattern provides visual guidance to pilots as to the length of runway remaining. The end of the runway is marked with 4 red lights placed symmetrically on either side of the centerline beginning in line with the elevated edge lights and spaced 3 m (10 ft) apart.

The runway centerline lights are powered from three regulators with adjacent lights connected to different regulators. There are a total of 201 runway centerline lights.

Runway centreline and touch down zone lights - typical in-pavement luminarire at right

Runway Touchdown Zone Lights
Each runway is served with in-pavement touchdown zone lights, which are located symmetrically about the runway centerline. The luminaries begin at the runway threshold, and extend 300 m (1000 ft) down the runway. The lights are used to assist approaching aircraft during lower visibility conditions to identify the ideal landing area of the runway. These luminaries are uni-directional units with a single 48 W halogen reflector lamp, and are connected to 45 Watt isolating transformers. The touchdown zone lights produce a minimum intensity of 5000 cd, and are a white light.

The touchdown zone lights for each runway are powered by 3 regulators, and the circuits are interleaved both longitudinally and transversely.

TAXIWAY LIGHTING SYSTEMS
The taxiways are served with in-pavement centerline lights, and are used to guide aircraft from the runway to the apron. Three different lighting systems were employed on the taxiways depending the purpose of the taxiway. Taxiways which are used for transiting aircraft around the airport, ie taxiways which do not directly access the runway, are served with green bi- directional 1 circuit luminaries, with 65 W halogen lamps. The taxiways which provide access or egress from the runway are provided with bi - directional dual circuit luminaries, which allows the taxiway to be operated as either an entry or exit taxiway. If selected as an exit taxiway, the luminaries are only illuminated in the direction of travel off the runway, the other side of the luminaire is extinguished, so there is no guidance along the taxiway onto the runway. This configuration also allows for a substantial saving in power costs. The third configuration is on the two taxiways which are located toward the centre of the runway, which are designated for runway exit only, and therefore are only provided with uni-directional luminaries, which direct aircraft off the runway, but provide no guidance onto the Runway.

Runway guard lights and elevated stop bar luminaries

The lighting used to direct aircraft off the runway alternate green and yellow, and begin approximately 60 m (200 ft) from the runway taxiway intersection, to provide for advance indication of the exit. The green yellow alternation ends at the point on the taxiway where the aircraft is considered clear of the runway, (approximately 90 m (300 ft) ) from the Runway centerline. from the clearance point on, the lights change to green. The lighting provided on the entry side of the luminaries are all green to guide pilots onto the runway, where the runway lighting systems provide guidance for takeoff roll.

The intersection of two taxiways is indicated with a three light barrette of yellow lights placed across the taxiway at 60 m (200 ft) from an intersection. This provides pilots with a hold point at a safe position to allow intersecting aircraft to manoeuvre.

Runway Incursion Protection
The most important features of a Category III lighting system is the requirement to protect the runway from unauthorized entry in low visibility conditions. When the visibility is down to 600 m, the control tower can no longer see the runway or taxiways, and the ground traffic controllers must rely on ground radar, and lighting enhancements to keep track of aircraft maneuvering on the airfield. To this end, each entry taxiway is provided with lighting systems at the hold points on the entry taxiways. The hold point is approximately 90 m from the runway centerline, and is indicated with Runway Guard Lights and Stop bars.

The runway guard lights are elevated dual alternating flashing lights located on either side of the taxiway. These units are operated at all times under all visibility conditions to provide conspicuity of the hold line. During low visibility conditions, the Runway is further protected with Stop Bars lights. These units are uni directional in-pavement red lights set across the entire width of the entry taxiways at the hold line. The lights are visible from the entry direction.

LOW VISIBILITY OPERATIONS
During low visibility conditions, Vancouver International Airport only permits access to the runway for takeoffs from the four entry taxiways located at the ends of the runway. These taxiways are outfitted with dynamic Stopbars, which are controllable from the lighting control touch screen panel in the control tower. The other entry taxiways are not used for runway access during low visibility conditions, and therefore are outfitted with static Stopbars, which are not independently controllable from the tower.

When low visibility conditions are declared, the stop bar lights are illuminated, and remain on until low visibility conditions are canceled. When the stop bars are illuminated, the taxiway centerline lighting beyond the stop bar are extinguished, creating a "black hole" effect between the stop bar and the runway. These centerline lights are wired into two control groups, which permits them to be switched of or on as a unit. When a traffic controller authorizes a pilot to proceed to the runway for takeoff, the stop bar is extinguished, and the two green centerline light groups beyond are energized, creating a light path to follow. When the aircraft crosses the hold line, a microwave motion detector switches the stop bar back on to prevent other aircraft from proceeding across the stop bar. When the aircraft reaches a second set of microwave detectors, the first centerline light group is switched off thereby recreating the black hole. When the aircraft passes a third set of microwave detectors located on the runway, the entire system is reset, and made ready for the controller to allow the next aircraft to proceed. The first set of microwave detectors also double as an incursion alarm, in that if a vehicle or aircraft crosses the hold line without authorization, an alarm sounds in the control tower to warn of unauthorized entry.

FIBRE OPTIC AIRFIELD GUIDANCE SIGNS
With the opening of the new runway and taxiways systems, the airport became much more complicated to manoeuvre around, particularly for pilots unfamiliar with the airport. The new low visibility operations capability of the airport further compounds the ability to manoeuvre around the airport and know exactly where you are.

Taxiways traditionally have been identified with alpha designators, however this restricted airports to 26 taxiways. Transport Canada has adopted a system of alpha and alpha numeric designators for the naming of taxiways, which Vancouver International Airport adopted, as the airport had reached its alpha designator limit.

As a parallel project to the construction of the new runway and taxiways, all the existing taxiways were renamed, which required the installation of new signage to indicate the new designators. This project involved the installation of approximately 200 new signs, which had to be in place and made operational during a single night switch over. This switch over night coincided with the publication of international airport charts.

Transport Canada requires that airfield guidance signs for use in low visibility situations (less than 400 m (1300 ft)) be visible at a distance of 250 m (800 ft) and be legible at a distance of 180 m (600 ft). In order to meet these conditions, Canada has accepted the use of fibre optic signage. Vancouver International has chosen to use fibre optic signage. Each sign is illuminated with a minimum of two 50 W MR16 lamps, in order to meet the requirement that the failure of a lamp will not reduce the illuminance of the sign by more than 50 %. The fibre optic elements are also arranged in an interleaved fashion as well to meet the 50% requirement.

Signs are located at all taxiway intersections with other taxiways as well as with the runway. Signs are also located at the hold points on the taxiways, at the same location as the stop bars and runway guard lights. Signs are located at set distances from the intersection to allow safe maneuvering of intersecting aircraft, and are co located with the taxiway intersection barrette lights previously described.

INSTALLATION METHODS
The aircraft surface structures are designed to accept an unlimited number of loadings of a fully loaded Boeing 747-400 aircraft, without failure. The runway and taxiways are built of concrete, while non load areas (shoulders etc) are finished with Hot Mix Asphaltic Concrete. The concrete surfaces are 380 mm (15 in.) thick, and were slipformed paved. The concrete was placed on a 200 mm (8") thick bed of Cement Stabilized Base (CSB), which was placed on 250 mm (10") of compacted Crushed Granular Rock. This rock was placed on a layer of sand which varies from 300 mm to 2000 mm, depending on the amount of settlement experienced during the preloading phase of the project. Over 2.2 million cubic meters of sand was imported and placed along the runway and taxiway foot print.

The installation of the lighting equipment support structures was an integral part of the paving process, and had to be carefully coordinated in order to keep the paving moving at a pace which would allow the runway to open on time.

Each in-pavement luminaire is mounted in an inset light base (ILB), which has a nominal diameter of 340 mm (13.5"). Ducting is run between the ILB's for the isolating transformer secondary wiring, and then ducted to polyethylene pullpits located outside the concrete paved surfaces.

Typically the installation progressed as follows: When the CSB was placed, and sufficiently cured, the layout survey crews identified with paint markings and tack blockslocations for all ILB's, and duct trenches. A small "Bobcat" outfitted with a 1m dia auger bit moved in and drilled into the CSB at each ILB location. The diggings were removed, and the Bobcat, was then fitted with a trenching wheel, and the duct trenches were cut. The timing of the auguring and trenching was critical as waiting too long would allow the CSB to harden too much, and the auger could no longer cut into the material, and not waiting long enough would cause the trenches and holes to collapse in on themselves. The next crew would then move in and place the ILB's into the holes, secure them to jigs, which served to suspend the can off the bottom of the hole, as well as to provide for the fine alignment required to suit the rotation and elevation of each ILB. The contractor dedicated one quality control surveyor to the placement of the ILB's. The specifications provided for elevation control to within 2 mm and luminaire rotation to be within one half degree of azimuth. After the ILB's were set, the ducting was connected to the cans, and run over to the edge of the pavement structures. As the ILB's were set in place, a reinforcing steel cage was also secured to the jig in order to aide in crack control of the concrete pavement. The ILB's , rebar cages and ducts were then anchored in place with a cementitious grout, which was supplied in 3000 lb. bags and mixed on site in a grout plant. The grout was then placed with a hose, as the mixture was to be flowable in order to surround the ducts and ILB's fully. The grout was always placed in the augured holes from one side only, and allowed to run under the ILB, in order to assure no air pockets were trapped under the can. The setting jigs were left in place for approximately three days, until the grout was fully set. The jigs were then removed, cleaned and the process repeated in the next areas, as CSB placement and auguring was completed. After the jigs were removed, each ILB was opened, the ducting was mandrilled to ensure soundness and the top flange of the ILB was greased, and a steel lid was fastened onto the ILB. The grease was used to prevent the PCC grout from setting onto the ILB mounting flanges, during the paving operation. A latticework of rebar was then secured to the rebar cage, and the units were ready for the placement of PCC. All the PCC concrete used on site was mixed on site, using both sand and aggregate which had previously been used for preload materials. The PCC was mixed in 10 cu m batches, and placed into large off road dump trucks, and delivered to the actual paving site, where it was dumped in front of the slipform paver, and pushed into the paver augers with front end loaders. The paver them vibrated the PCC in place, and concrete finishers, touched up the finished product at the back of the paver, ensuring that straight edging requirements were met. The PCC was then given a broomed finish, and coated with curing compound. Three days after the PCC was placed, the survey crews again the locations for each ILB, now buried in the concrete, and marked its location in paint on the PCC. When the PCC was completely set, a concrete coring crew moved in and cut a thirteen in. dia hole at each ILB location, to expose the steel ILB cover. Typically the ILB cover was 46 mm below the PCC surface. The ILB cover was removed, and any slurry from the paving and coring process was cleaned up, and the grease was removed from the flange.

At this point, each ILB was measured to establish the exact distance between the ILB and the concrete surface, and a custom sized Y flange ring was ordered. These rings provide the elevation correction needed to ensure the luminaire optics are at the correct position, as well as to interface between the luminaire and the concrete core. The rings are fitted with a steel dam, which prevents the sealant used to seal the concrete core from adhering to the luminaire. The final step in the civil electrical installation was to install the isolating transformer pulpits, which are located 1.5 m (5 ft) from the concrete edge, and the interconnecting ducting. These pullpits are set on a base of compacted sand, and were provided with a steel collar which was securely fastened to the pullpit top flange. The steel collar was used to prevent the plastic pullpit from softening and going out of round when the asphalt shoulder was placed.

When the pullpit system was completed, the electrical contractor, then began installing the wiring, splicing the isolating transformers into the system, and installing the luminaires. The final step to complete the installation was to seal the space between the concrete cores and the Y flange ring, and energize the system.

THE GATEWAY TO ASIA PACIFIC - THE REALITY
On November 4, 1996 the newest large commercial aircraft in the world the Boeing 777 became the first aircraft to land on the newest Category lll runway in the world, completing the objective of the Vancouver International Airport Authority to become the all weather Gateway to the Orient.

This paper has been prepared by the author for consideration for publication by the Illuminating Engineers Society of North America (IES), and for presentation by the author at the IES Annual Conference to be held in Seattle Washington August 18-21 1997. As such no part of this paper may be reproduced or distributed without the written permission of the author, and the IES.

All photos in this paper are by the author, except for the cover photo and the photo identified as "Approach Lights In Full Category III Configuration". These photos are by Mr. Jim Jorgenson.