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HomeMy WebLinkAboutDemand/Capacity . . tl n\1 i) '7 ;001; 1\"-' TI (~, .....(Jv Downstate New York General Aviation System Plan ~ Demand/Capacity . Interim Report DI!If.ARD/CAP AClTY MAL lSIS '!he purpose of this analysis is to determine the sdequacy of the existing network of airports to accommodate future demand. This determination is based upon the capacity of three primary functional airport areas: the airfield area, landside area, and surface access facilities. Airfield capacity is conceme:l with the operational aspects of aircraft activity in terms of annual and hourly indicators. Landside capacity involves the aircraft storage capability of the airpor~ Surface access capacity pertains to an airport's ability to accommodate vehicular traffic from local highway systems. In order to adequately address these subjects, this chapter was organized in the follOlling manner: Airfield Capacity Analysis Existing Iandside Capacity . Surface Access Capacity Comparison of Forecas t Demand to Capacity Each of these sections are dis cussed in the following pages. IV-l Airfield Capacity Analysis Critical to any aviation system is its ability to satisfy current and projected aviation demand. Airfield capacity, when compared to forecast levels of operational activity, provides the foundation from which facility deficiencies or excesses can be identified and, therefore, becomes the essence of formulating recommendations for future facilities. . This section of Chapter IV delineates the process by which airfield capacity was obtained and presents the results of the analysis. The di9cussion is organized as follows: Capacity Definitions and Methodology Airports with Published Airfield Capacities Airfield Capacity Calculation . Airfield Capacity Results CAP ACITY DEFDlITIOIlS AND MEntCDOLOG Y The FAA has recently published Advisory Circular 1 'JJ/ 'JJ60-5, "Airport Capacity and Delay." This Advisory Circular describes the latest methodologies available for calculating airfield capacity and delay. In addition, the advisory circular defines various capacity terms. There are three primary measures of airfield capacity: . Hourly Capacity Annual Service Volume (ASV) Annual Delay Hourly capacity is defined as the maximum number of aircraft operations that an airfield can accommodate in an hour. Annual service volume (ASV) is the level of annual aircraft operations that is used as a base for determining annual delay. As the annual aircraft operations approach the ASV, there is a rapid increase in delay. Successive hourly demands exceeding the hourly capacity result in unacceptable delays. When the hourly demand is less than the hourly capacity, aircraft delays will still occur if the demand within a portion of the time interval exceeds the capacity during the interval. An average delay of up to four minutes exists when ASV equals annual demand. Annual delay, which relates operational demand to annual service volume, expresses the total number of delay......inutes realized during a given year at a specific operational level. The specific methodologies used in this study include: FAA Advisory Circular 150/5060-5 Airport Capacity and Delay, U.S. Department of Transportation (WaShington, D. Co: September, 1983). IV-2 Airport Requirements Determination in Support of Texas Aviation System Plan. Texas Transportation Institute (College Station, Texas: July, 1972). The FAA methodology was adequate for all of the paved airports in the Downstate network. For the turf strips, the Texas Transportation Institute's capacity methodology was used, since these airports require special consideration. AIRPORTS 1ll11l PUB LISHED AIRFIElD CAP ACITlES There are nine airports in the Downstate region that already have published airfield capacities. '!hese are major airports with current master plans. Rather than create a redundant effort. the master plan capacities were used in this system plan. The following airports already have calculated airfield capacities: . Orange County Stewart Westchester County Flushing Brookhaven East Hampton L. 1. MacArthur Republic Suffolk County The specific hourly capacities and annual service volumes for these airports are presented later in the chapter in E>ehibit IV.3. AIRFIELD CAPACITY CALCULATlOO '!he following factors impact the availability of airport capacity in the Downstate region: . Airfield Layout and RUl1IIay Use Meteorological Conditions Aircraft Operational Fleet Mix Touch-and-Go Operations Navigational Aids The capacity methodologies used. required inputs for each of these factors. These factors are described below along with the inputs used for the network airports. Airfield Layout and RUl1IIay Use '!he airfield layout refers to the location and orientation of runways, taxiways, and terminal area. For airports with more than one runway, the airfield layout is important since simultaneous use of more than one runway affords greater arrival and departure capacity than the use of a single runway. Simultaneous use of a multi-runway airport is IV-3 possible only with a control tower. Thus, the runway usage of towered airports with more than one runway is significant to the capacity calculation. In the Downstate region, all of the airports with towers already have published airfield capacities. Therefore, this analysis is only concerned with airports having a single runway operating configuration. It should be noted that non-towered airports with more than one runway must operate using only one runway at a time for safety purposes. With a single runway, there are only two operating configurations. Depending upon the location of the exit taxiways the operating direction may or may not be significant. '!he operating direction is dictated primarily by the prevailing winds at the airport. Meteorological Conditions Weather conditions at an airport affect runway utilization due to variations in wind direction and velocity, together with changes in visibility. The prevailing wind and visibility conditions serve to determine the directions in which takeoffs and landings may be conducted, and the frequency of use for each operating configuration. The decision to use a particular runway is typically made by an air traffic controller at a towered airport, although the pilot has the option to request a different runway. At a non- towered airport the pilot will use a wind indicator to determine the direction of take-off or landing. The terms visual flight rules (VFR) and instrument flight rules (UR) are used as measures of ceiling and visibility. VFR conditions occur when the ceiling is at least 1,000 feet and visibili ty is three miles or greater. During these condi tions pilots fly on a see-and-be-seen basis. IFR conditions occur when the ceiling is less than 1,000 feet or visibility drops below three miles. In IFR weather, the air traffic control (ATe) system assllllles responsibility for the safe separation between aircraft. Wind conditions are of prime importance in determining runway use and orientation. Where prevailing winds are consistently from one direction, runways are oriented in that direction. In most areas, however, consistency of wind direction is not found. In such instances a multiple runway system may be required. '!he Federal /oriation Administration has established that an airport runway system should provide 95-percent usability for 12 or 15-mile per hour crosswind components, depending upon the characteristics of aircraft using the airport. For this study, a 12 mph crosswind canponent was used. Data necessary for conducting weather and wind analyses were obtained from the National Oceanic and Atmospheric Administration (NO~, National Climatic Center (NeC) in Asheville, North Carolina. NOAA maintains a networl< of weather observation stations that record meteorological conditions at many locations. For the Downstate region, weather observation stations at Poughkeepsie, White Plains, Islip, and Bridgeport, Ct. provided wind information necessary to conduct a wind-coverage analysis at each networl< airport. Exhibit IV.2, presented later, indicates total wind coverage for network airport runway orientations. This information was used as an input to the capacity calculation. IV-4 Aircraft Operational Fleet Mix Capacity analysis requires that total annual operations be converted to annual operations by aircraft classification category. Forecas ts of annual operations were developed for each network airport, exclusive of the Port-Authority airports, in an earlier chapter. Further, the necessary fleet mixes were also determined using an airport survey method. The capacity and delay model used for the analysis defines aircraft fleet mix in terms of four classes as presented in Exhibit IV.l. Significant to the analysis are the level of Class ''e'' and 'n" aircraft operating at each airport. Exhibit IV.2, presented later, indicates the percentage of operations involving ''e'' or 'n" at network airports to be analyzed. As shown, Dutchess County and Stormville are the only airports with a percentage of the fleet mix over l2,!D0 pounds. Thus, the remaining network airports without published airfield capacities are not affected by large aircraft or jet operations. Exhibit tV.1 - OPERATIONAL FLEET MIX-AIRCRAFT CLA~SIFICATION SYSTEM Class A: Small single-engine, gross weight l2,!D0 pounds or less Examples: Cessna l72/182 Beech Bonanza Mooney 201 Piper Cherokee/Warrior Class B: Small twin-engine, gross weight 12, SOO pounds or less Examples: Beech Baron Cessna 402 Cessna Citation I Beechcraft 99 Mitsubishi lIJ-2 Piper Navajo Rockwell Shrike Lear 25 Class C: Large aircraft, gross weight 12, !DO pounds to 300,000 pounds Examples: Beech King Air 200 Boeing 727 Convair 600 DeHavilland DH-7 Swearingen Metro Douglas DC-9 Fairchild FH-227 Gulfs tream I II Lear 35/55 E'mbraer Bandeirante Class D: Large aircraft, gross weight more than 300,000 pounds Examples: Airbus A-300/ A-3l0 Boeing 707 -300 Douglas DC-8-60/70 Lockheed L-10ll Touch-And-Go~erations A touch-and-go refers to an aircraft landing and immediate takeoff without an intermediate full stop. 'D:1ese operations are normally associated with training and tend to occur in higher percentages at smaller airports. Exhibit IV.2 indicates the estimated level of touch-and-go operations at network airports. Generally, a higher level of touch- and-go operations - all other factors remaining equal - will boost the O\1erall capacity of the airport, since a large number can be processed in a relatively short period of time. IV-5 Exhibit IV.2 - AIRPORT CAPACITY INPUTS AT NETWORK AIRPORTS Total Wind % Touch IFR % Fleet Mix County/ Airport Coverage % And Go Capabili ty Over 12.~O Ibs. Dutc:bea CouIlty Dutchess County 97.00 35:1: Yes 4% Sky Acres 94.27 40% Yes 0% Sky Park 94.64 40% Yes 0% Stormville 94.14 40% Yes 1% Oraage CouIlty Randall 98.67 40% Yes 0% Warwick 77.63 40% No 0% Pam- CouI1ty Mahopac 81.94 ~% No 0% ......1 sniI CouIlty Ramapo Valley 92.83 30% Yes 0% Sulli VlID CouIlty Monticello 96.74 40% Yes 0% Sullivan County International 94.42 25:1: Yes 0% Wurtsboro- Sullivan 94.12 30% Yes 0% Ulster County Kingston-lllster 79.80 40% No 0% UI.J &l.~ 40% No 0% Marlboro 79.80 ~% No 0% Sages 79.65 40% No 0% Stanton 79.80 40% No 0% Wallkill &l.~ 40% No 0% Suffolk County Bayport 64.38 50% No 0% Coram 63.94 ~% No 0% Ess t Moriches 64.20 40% No 0% Elizabeth Field 92.61 40% Yes 0% Mattituck 64.38 40% No 0% Montauk 81.98 30% Yes 0% Spadaro 64.1 5 40% No 0% IV-6 Navigational Aids Significant to the airfield capacity calculation is the exis tence of an instrument capability; that is, the airport's ability to operate during IFR weather conditions. Without this capability, the airport can only operate during VFR weather, and as a result, will have a lower annual service volume than a similar instrument-capable airport. Exhibit IV.2 indicates whether or not network airports have an instrument capability. AIRFIELD CAPACITY RESULTS The fOllowing section presents a summary of airfield capacities for airports in the Downstate study area. The summary is composed of existing capacities, published in previously accepted Master Plan studies, and capacities calculated through the use of both FAA and Texas Transportation Institute methodologie~ As a general rule, airports with air traffic control towers, paved runways, and parallel taxiways tend to have high capacities, since taxiway systems, in conjunction with air traffic control tOIlers, allow the efficient use of the runway system. All airports without air traffic control towers operate as if they had only one runway even if they have more. Thus, even multiple runway airports without tOIlers do not have significantly more capacity than do single runway airports. Turf airports, on the other hand, have seasonal operations, and therefore, indicate a lower ASV than the more developed airport~ Exhibit IV.J presents both previously published capacities and results of the airport capacity analysis conducted for this study. The airports are listed by county and indicate the Hourly Capacity and the Annual Service Volume. Later in this chapter, the capacity will be COIIIpared to expected demand, and potential ''trouble spots" will thereby be identified. IV-7 Exhibit IV..3 - HOURLY CAPACITIES AND ANNUAL SERVICE VOI1lMES FOR ALL NETWORK AIRPORTS Hourly Capacities Annual Master Plan Service County! Airport Source IFR VFR Weighted Vol\Jllle . Datc:heaa Couat:y Dutchess County No 30 127 116 232,100 Sky Acres No 6 128 78 152 , SOO Sky Park No 6 117 58 115,000 Stormville No 6 126 77 151 ,900 0raDge Couat:y Orange County Yes 34 72 168,000 Randall No 6 128 81 158,400 Stewart Yes SO 90 2SO,OOO Warwick No 72 46 109,900 l'ucDaa Couat:y Mahopac No 56 38,900 Jkt<:l< 1 ...d Couaty Ramapo Valley No 6 125 76 1 SO ,000 Sulli_ Couaty Monticello No 6 72 44 87 ,200 Sullivan County International No 6 117 71 140,100 Wurtsboro-Sullivan Co. No 6 112 68 134,600 Ulster Couat:y Kingston-Ulster No 72 46 113,000 LIIJ No 72 46 114,000 Marlboro No 56 38,000 Sages No 72 46 112,700 Stanton No 72 46 113,000 Wallkill No 72 46 114,000 Westc:heater Couat:y Westchester County Yes 56 88 210,000 IV-8 Exhibit IV.1 - HOURLY CAPACITIES AND ANNUAL SERVICE VOWMES FOR ALL NETWORK AIRPORTS Hourly Capacities Annual Master Plan Service County/ Airport Source IFR VFR Weighted Vol....e . Queeas Couaty Flushing Yes 76 149,000 John F. Kennedy Yes 53 82 NA La Guaniia Yes 60 62 NA Suffolk Couaty Bayport No 56 25,700 Brookhaven Yes 137 270,000 Coram No 56 25,700 East Hampton Yes 38 109 70 108,300 East Moriches No 72 46 90, 900 Elizabeth Field No 6 72 44 86,400 L. I. MacArthur Yes 53 183 144 303,000 Mattituck No 72 46 91,200 Montauk No 6 107 53 105,100 Repub lie Yes 20 106 270,000 Spadaro No 72 46 90 , 800 Suffolk CoUnty Yes 143 127 230,000 N.A. - Not Available IV-9 Ezistiug LaDdside Capacity This section assesses the landside espacity of the existing network of airports. Its purpose is to provide an indication of an airport's overall ability to accommodate facilities in four areas: . general aviation terminal space hangar and tie-down space general aviation apron area automobile parking area The information in this section will be used, along with information in the sections on Airside Capacity and Surface Access Capacity, to determine an airport's espacity to satisfy its foreesst demand, and then to determine the facilities necessary to meet the demand . The existing facilities at the airports are listed in the Airport Profiles section of the Inventory Chapter. ME11llDOLOGY The landside espacities as determined in this section are based upon the minimum land requirements of the Federal Aviation Administration Advisory Circular 1 '!f)/5300-4B, Utility Airports, atapeer 5. The Circular gives the recommended uiinimlllll acreage for Basic Utility (BU) and General Utility (GU) airports by dividing the airport into three areas - the landing, approach, and building areas. The landing area includes the runway, safety area, taxiways and lateral clearances to building restriction lines. The approach area includes the property within the runway clear zone, between the building restriction lines and land that may be required for airport hazard removal and approach protection. As a minimum, the airport should have under its control the land within the building restriction lines and that required for airport hazard removal and approach protection. The building area includes all areas beyond the building restriction line. that is, any fixed base operator facility, I-hangars, tie-downs, transient parking apron, automobile parking, access road, and utilities. The landside capacity is herein expressed in terms of the land which remains available for basing aircraft, either in hangars or by tie-downs after land has been set aside for the landing area, approach area and the remaining portions of the building area, and has been calculated as described. First, the landing area at each airport was determined. The entire recommended acreage was set aside even if the airport presently does not have a taxiway or have the recommended lateral clearances to the building restrictions lines. This method has been adopted to allow for the standards with respect to taxiways, safety areas and building restriction lines to be met at a future date; the approach areas were then estimated. The entire recommended acreage was set aside if the approach area is all on airport property. If not all the approach area is on airport property, the portion on the property was estimated. This was necessary to avoid IV-IO misleading estimates of the acreage rema1n1ng for basing aircraft. In the next step, the building area acreage allocated to the fixed base operator, transient parl<ing apron, automobile parking, access road, utilities, and administration building was assumed to be one-half of the recommended acreage. Then, the number of the acres of the landing area, the approach area on airport property, and the building area were then summed and compared to the airport property acreage. Any remaining acreage was assumed to be svailable for basing aircraft. It was assumed that each acre of available land could accommodate 16 based aircraft. This assumption allows for the 300 square yards per airplane recommended by the FAA for most based aircraft. Although this number would be somewhat lower for hangared aircraft and larger aircraft, it was felt that the use of 16 aircraft produced reasonably accurate results for determining overall airport capacity. Using this methodology means that the ability of the airport to meet the capacity standards in the areas of general aviation terminal space, automobile parking, and apron areas ia assured by the land in the building area set aside before the airport's ability to base aircraft is determined. LANDSmE CAPACITY DETERMINATIONS The majority of the airports in the existing network have sufficient landside capacity to accommodate at least the forecast demand. Others, however may not be able to accommodate the year 200 5 forecast demand or have limitations 011 how many aircraft can be based there. Those airports with capacity limitations are considered below. . Bayport - The airport has two runways and most of the approach area is beyond the airport property line. After calculating e land needed for the landing and building areas, and the portion of the approach area on airport property, the remaining land indicates about 96 aircraft can be based at the airport. Coram - The land area available for the airport is somewhat flexible; we have assumed 50 acres. Most of the approach area is not 011 airport property. Under these circumstances, we have estimated that approximately 128 aircraft could be based here. Flushing - The current master plan recommends a three runway configuration for the airport; it also recognizes that some buildings will violate the building restriction lines. The plan forecasts that 96 aircraft will be attracted to the airport if it is improved. Even being extremely conservative in calculating the land required for the runways and approach areas, there is very little land remaining for based aircraft. Therefore, we have assumed that the limits on based aircraft will be the 58 forecast in this study. . Mahopac - This airport, after allowing for the recommended acreage for necessary facilities, will be able to accommodate 32 aircraft, sauewhat fewer than its year 200 5 forecast of 42 aircraft. IV-ll Marlboro - The airport property consists of only 27 acres, far fewer than the recommended minimUID for a basic utility airport. Since only seven based aircraft are forecast for the year 2005, they can be accommodated at the airport. But the ability of the airport to be developed to FAA standards is questionable. Mattituck - This airport consists of even fewer acres than Marlboro, 18, and the 2005 forecast of based aircraft is much higher, 45. The airport currently has 23 based aircraft. If the recommended standards are applied, the airport will not be able to accommodate the forecast based aircraft. Montauk - The airport. property is only 40 acres, but has a runway of almost 3,500'. The recommended landing area for a runway that length is itself 36 acres. However, very little of the approach area is on airport property. It is possible that the airport will be able to accommodate its year 2005 forecast of 29 aircraft, but it will be at the expense of other building area recaDllll!nded facilities. Ramapo Valley - It is difficult to determine the extent of the airport property at this time. There are currently plans to remove the building area from north to south of the runway and to make the land north of the runway available for non-aviation land uses. When this occurs, the airport will not be able to accommodate its forecast based aircraft. For purposes of this study, we have assumed that the airport will accommodate about 160 aircraft. A master plan for the airport has just begun and it will more accurately determine the landside capaci ty cif the airport in the near future. Republic - This airport is owned by the State and operated by the New York Transportation Department through a contract with Lockheed Air Terminal of New York, Ine. A master plan update to take place in 1985 will address Republic's role. Preliminary indications are that the airport's capacity to accommodate based aircraft is limited to an estimated 750 aircraft. Spadaro - The airport property consists of only 15 acres and it had 17 based aircraft in 1982. The year 200 5 forecast is for 33 based aircraft. Given the deficiency of the airport property and its consequent inability to meet the recommended minimUID land requirements in the three categories, it is unlikely it will be able to accommodate the fore cas t demand. Stanton - The airport property is not adequate to meet the minimum land requirements recommended for a basic utility airport. It had 7 based aircraft in 1982 and is forecast to have 13 in the year 200 5. In view of the small number of based aircraft and of forecast operations, we have assUlDed the airport will be able to accommodate the based aircraft without meeting recommended landside facility requirements in terminal space, automobile parking and apron areas. . IV-12 Surface Access Capacity For the purposes of this study, the surface access capacity analysis was limited to on-airport access roads. On-airport access roads channel traffic from exterior roadways to airport facilities such as parking and terminals. If exterior highways are adequate, which is the case for most network airports, on-airport access roads are the limiting factor or cons':raint to vehicular flow to the airport. In this section, network airports are investigated for a preliminaty look at the adequacy and possible congestion problems of on-airport access roads. Access read capacity is the maximum number of vehicle movements possible, for a given time periOd, under a spec1fied set of environmental and traffic demand conditions. Capacity figures presented herein provide a conservative estimate of general access road traffic capacity. Specific road design and traffic conditions must be identified to determine definitive capacity figures for those airports with potential access road congestion problems. In general, network airports have access road systems consisting of single or multi- lane loops carrying traffic to the front of tbe terminal building with exits to parking areas, or collectors or narrow driveways leading to the airport parking lot. Three capacity categories have been designated for network airport access rozs (200, 400, or SOO vehicles per lane per hour). A description of these categories follows along with a list of the network airports included in each category. The two large commercial airports, JFK and LGA, are excluded because ot their low level of general aviation activity. 500 Vehicles/Lane/Bour (VUl):l Loop access roz to terminal Two one-way lanes Exits to parking, general aviation, and air cargo areas Moderate interference fran rozside Stable traffic flow Continuous passing No stopping except at terminal front Airports in the SOO VLB category include: Brookhaven, Dutchess County, Long Island MacArthur, and Westchester County. 1 American Association of State Bighway and Transportation Officials, A Policy on Design of Urban Highways aDd Arterial Streets, 1973 (Washington D.C.: AASHTO, 1973) . . IV-13 400 Vehicles/lane/HourI Single lane loop access road to terminal , Exits to parking, general aviation, and air cargo areas No stopping except at terminal front Moderate interference from roadside Stable traffic flow Airports in the 400 VLH category .include: Bayport, Stewart*, Suffolk County, and Sullivan County. 200 Vehicles/lane/HourI Single lane collector or "driveway" to and from parking area About 10-..ph speed limi t Parking on either side of road All remaining network airports are included in this 200 VLH category. * A new on-airport access road is planned for Stewart as well as Flushing Airport. 1 American AssoC1ation of State Highway and Transportation Officials, A Policy on Design of lkban Highways and Arterial Streets, 1973 (Washington D.C.: AASHTO, 1973). . IV-14 CaDpariSClIl of Forecast n.......I to Capacity . In order to determine where potential capacity overruns are likely to occur, forecast demand was compared to the capacities established in this chapter. Exhibit IV.4 presents a comparison of airfield capacity and forecast operational demand. . Emibit IV.4 - COMPARISON OF OPERATIONAL CAPACITY AND FORECAST DEMAND Operational 2005 Airfield Airfield surplusl County I Airport Capaci ty Operations (Deficit) Dutc:bess ~ Dutchess County 231,100 192,300 39,800 Sky Acres 152,3>0 64,640 frI,860 Sky Park 11 5,000 17,340 97 ,660 Stcn:mville 151,900 74,000 77,900 Onage CooIItty Orange County 168,000 151,080 16,920 Randall 158,400 41 ,300 117,100 Stewart 23>,000 185,560 64,440 Warwick 109,900 20,800 89,100 l'at:Iwa CooIItty Hahopac 38,900 20,160 18,740 ~1....d County llamapo Valley 13>,000 262,260 (112,260) Sullivan County Monticello 87 ,200 2,100 85,100 Sullivan County Int'l 140 ,100 32,640 107,460 Wurtsboro-Sullivan Co. 134,600 130,240 4,360 Ulster ~ Kings ton-Uls ter 113,000 25,63> 87,3 3> UIJ 114,000 7,130 106,frlO Marlboro 38,000 33> 37,63> Sages 112,700 Stanton 113 ,000 4,420 108,580 Wallkill 114,000 4,400 109,600 - IV-15 I;xhibit IV.4 - COMPARISON OF OPERATIONAL CAPACITY AND FORECAST DEMAND (Con't.) Operational 2005 Airfield Airfield Surp lust County/ Airport Capacity Operations ( Deficit) . Westdleater Colmty Westchester County 210,000 317,530 (107,530) Queeas Colmty Flushing 149,000 58,000 91,000 John F. Kennedy N/A N/A N/A La Guardia N/A N/A N/A Suffolk CoaIlty Bayport 25,700 20,710 4,990 Brookhaven 270,000 254,810 15,190 Coram 25,700 400 25,300 East Hampton 108,300 97,870 10,430 East Moriches 90,900 8,125 82,775 Elizabeth Field 86,400 29,200 57,200 L. I. MacArthur 303,000 43 5, 770 (132,770) Matti tuck 91 ,200 31,9!C 59,2!C Montauk 105,100 17,400 87 , 700 Republic 270,000 386 ,320 (116,320) Spadaro 90,800 2,310 88,490 Suffolk County 230,000 232,480 (2,480) In the exhibit, operational deficits for the year 200 5, if not allocated to another nearby airport with surplus capacity, are simply considered ''unserved demand". Thus, if capacity relief is not a part of an airport's future development plans, this unserved demand can be used to identify areas with high demand potential. Exhibit IV.5 presents a summary of lands ide capacity constraints. In this exhibit, only airports that are constrained with respect to year 200 5 forecast demand are included. IV-l 6 Exhibit IV. '5 - COMPARISON OF T.ANDSIDE CAPACITY AND BASED AIRCRAFT DEMAND 2005 County / Landside Based Based Surplus/ Airport Name Aircraft Capacity Aircraft (Deficit) Bayport 96 109 ( 13) Coram 128 8 120 Flushing 58 58 0 Mahopac 32 42 ( 10) Marlboro 7 7 0 Mattituck 30 45 ( 15) Mol1tauk 29 29 0 Ramapo Valley 160 282 (122) Republic 750 1,014 (264) Spadaro 30 33 ( 3) Stanton 13 13 0 Based upon the exhibit presented above, along with Exhibit IV.4, a set of preliminary findings can be discussed. First, assUllling no capacity improvements in either the airs ide or lands ide areas, the constraining factor is that which limits the airport the greates t. In other words, if airfield capacity can accommodate more activity than the 1.andside can handle, the landside capacity is then used to describe that airport's overall capacity. '!he converse of this situation is treated the same way. Assuming no airfield or landside improvements, and assUllling no changes existing aircraft basing patterns, unaccommodated demand can be expected to occur, by the year 2005, in the service areas of the following airports: . Bayport Republic L. I. MacArthur . Spadaro . Mahopac . Suffolk County . Mattituck . Westchester County . Ramapo Valley Capacity shortfalls at these airports will be considered in the Alternatives Analysis chapter. If nothing can be done to improve capacity in the alternatives analysis, it will simply be sham as unserved demand. , IV-17