U.S. Departmentof TransportationFederal AviationAdministrationSubject: RUNWAY LENGTHREQUIREMENTS FOR

U.S. Departmentof TransportationFederal AviationAdministrationSubject: RUNWAY LENGTHREQUIREMENTS FOR AIRPORT DESIGNAdvisoryCircularDate: 7/1/2005Initiated by: AAS-100AC No: 150/5325-4BChange:1. PURPOSE. This Advisory Circular (AC) provides guidelines for airport designers and planners to determinerecommended runway lengths for new runways or extensions to existing runways.2.CANCELLATION. This AC cancels AC 150/5325-4A.3. APPLICATION. The standards and guidelines contained in this AC are recommended by the Federal AviationAdministration strictly for use in the design of civil airports. The guidelines, the airplane performance data curvesand tables, and the referenced airplane manufacturer manuals are not to be used as a substitute for flight planningcalculations as required by airplane operating rules. For airport projects receiving Federal funding, the use of thisAC is mandatory.David L. BennettDirector, Office of Airport Safety and StandardsPage intentionally blank7/1/2005AC 150/5325-4BCONTENTSSectionsPageChapter 1101102103104105106107IntroductionBackgroundDetermining Recommended Runway LengthsPrimary RunwaysCrosswind RunwaysRunway Length Based on Declared Distances ConceptComputer ProgramSelected 14 Code of Federal Regulations Concerning Runway Length RequirementsChapter 2Runway Lengths for Small Airplanes with Maximum Certificated Takeoff Weight of 12,500 Pounds(5,670 Kg) or LessDesign GuidelinesDesign ApproachSmall Airplanes With Approach Speeds of Less than 30 KnotsSmall Airplanes With Approach Speeds of 30 Knots or More but Less than 50 KnotsSmall Airplanes With Approach Speeds of 50 Knots or More with Maximum Certificated TakeoffWeight of 12,500 Pounds (5,670 Kg) or LessDevelopment of the Runway Length Curves201202203204205206Chapter 3301302303304305306Chapter 4401402403404Chapter 5501502503504505506507508509111334445555556Runway Lengths for Airplanes within a Maximum Certificated Takeoff Weight of More than 12,500Pounds (5,670 Kg) UpTo and Including 60,000 Pounds (27,200 Kg)9Design Guidelines9Design Approach9Percentage of Fleet and Useful Load Factor9Runway Length Adjustments10Precaution for Airports Located at High Altitudes10General Aviation Airports11Runway Lengths for Regional Jets and those Airplanes with a Maximum Certificated Takeoff Weightof More than 60,000 Pounds (27,200 Kg)17Design Guidelines17Design Approach17Procedures For Determining Recommended Runway Length17Examples20Design RationaleIntroductionAirplanesLanding Flap SettingsAirplane Operating WeightsAirport ElevationTemperatureWindRunway Surface ConditionsMaximum Differences of Runway Centerline Elevation21212121212222222223Small Airplanes with Fewer than 10 Passenger Seats (Excludes Pilot and Co-pilot)Small Airplanes Having 10 or More Passenger Seats (Excludes Pilot and Co-pilot)75 Percent of Fleet at 60 or 90 Percent Useful Load7812Figures2-12-23-1iAC 150/5325-4B3-24-1A3-1-1A3-1-2A3-2-1A3-2-27/1/2005100 Percent of Fleet at 60 or 90 Percent Useful LoadGeneric Payload-Range ChartLanding Runway Length for Boeing 737-900 (CFM56-7B27 Engines)Takeoff Runway Length for Boeing 737-900 (CFM56-7B27 Engines)Landing Runway Length for SAAB 340B (CT7-9B Engines)Takeoff Runway Length for SAAB 340B (CT7-9B Engines)131932333637Airplane Weight Categorization for Runway Length RequirementsRunway Length for Additional Primary RunwaysRunway Length for Crosswind RunwayAirplanes that Make Up 75 Percent of the FleetRemaining 25 Percent of Airplanes that Make Up 100 Percent of FleetRelationship Between Airport Elevation and Standard Day TemperatureRationale Behind Recommendations for Calculating Recommended Runway LengthsBoeing 737-900 General Airplane CharacteristicsSAAB 340 Airplane Characteristics344141518243135Tables1-11-21-33-13-24-15-1A3-1-1A3-2-1AppendicesAppendix 1 Websites for Manufacturers of Airplanes Over 60,000 Pounds (27,200 Kg)Appendix 2 Selected Federal Aviation Regulations Concerning Runway length requirementsAppendix 3 Examples Using Airplane Planning Manualsii2527297/1/2005AC 150/5325-4BCHAPTER 1. INTRODUCTION101.BACKGROUND. Airplanes today operate on a wide range of available runway lengths. Various factors,in turn, govern the suitability of those available runway lengths, most notably airport elevation above mean sealevel, temperature, wind velocity, airplane operating weights, takeoff and landing flap settings, runway surfacecondition (dry or wet), effective runway gradient, presence of obstructions in the vicinity of the airport, and, if any,locally imposed noise abatement restrictions or other prohibitions. Of these factors, certain ones have an operationalimpact on available runway lengths. That is, for a given runway the usable length made available by the airportauthority may not be entirely suitable for all types of airplane operations. Fortunately, airport authorities, airportdesigners, and planners are able to mitigate some of these factors. For example, runways designed with longitudinalprofiles equaling zero slope avoid required runway length adjustments. Independently, airport authorities workingwith their local lawmakers can establish zoning laws to prohibit the introduction of natural growth and man-madestructural obstructions that penetrate existing or planned runway approach and departure surfaces. Effective zoninglaws avoid the displacement of runway thresholds or reduction of takeoff runway lengths thereby providingairplanes with sufficient clearances over obstructions during climb outs. Airport authorities working with airportdesigners and planners should validate future runway demand by identifying the critical design airplanes. Inparticular, it is recommended that the evaluation process assess and verify the airport’s ultimate development planfor realistic changes that could result in future operational limitations to customers. In summary, the goal is toconstruct an available runway length for new runways or extensions to existing runways that is suitable for theforecasted critical design airplanes.102.DETERMINING RECOMMENDED RUNWAY LENGTHS.a.Assumptions and Definitions.(1)Design Assumptions. The assumptions used by this AC are approaches and departureswith no obstructions, zero wind, dry runway surfaces, and zero effective runway gradient. Assumptions relative toairplane characteristics are described within the applicable chapter of this AC.(2)Critical Design Airplanes. The listing of airplanes (or a single airplane) that results inthe longest recommended runway length. The listed airplanes will be evaluated either individually or as a singlefamily grouping to obtain a recommended runway length.(3)Small Airplane. An airplane of 12,500 pounds (5,670 kg) or less maximum certificatedtakeoff weight.(4)Large Airplane. An airplane of more than 12,500 pounds (5,670 kg) maximumcertificated takeoff weight.(5)Maximum Certificated Takeoff Weight (MTOW). The maximum certificated weightfor the airplane at takeoff, i.e., the airplane’s weight at the start of the takeoff run.(6)Regional Jets. Although there is no regulatory definition for a regional jet (RJ), an RJfor this advisory circular is a commercial jet airplane that carries fewer than 100 passengers.(7)Crosswind Runway. An additional runway built to compensate primary runways thatprovide less than the recommended 95 percent wind coverage for the airplanes forecasted to use the airport.(8)Substantial Use Threshold. Federally funded projects require that critical designairplanes have at least 500 or more annual itinerant operations at the airport (landings and takeoffs are considered asseparate operations) for an individual airplane or a family grouping of airplanes. Under unusual circumstances,adjustments may be made to the 500 total annual itinerant operations threshold after considering the circumstances ofa particular airport. Two examples are airports with demonstrated seasonal traffic variations, or airports situated inisolated or remote areas that have special needs.1AC 150/5325-4B7/1/2005(9)Itinerant Operation. Takeoff or landing operations of airplanes going from one airportto another airport that involves a trip of at least 20 miles. Local operations are excluded.(10)Effective Runway Gradient. The difference between the highest and lowest elevationsof the runway centerline divided by the runway length.b.Procedure and Rationale for Determining Recommended Runway Lengths. This AC uses afive-step procedure to determine recommended runway lengths for a selected list of critical design airplanes. Aspreviously stated, the information derived from this five-step procedure is for airport design and is not to be used forflight operations. Flight operations must be conducted per the applicable flight manual. The five steps and theirrationale are as follows:(1)Step #1. Identify the list of critical design airplanes that will make regular use of theproposed runway for an established planning period of at least five years. For Federally funded projects, thedefinition of the term “substantial use†quantifies the term “regular use†(see paragraph 102a(8).)(2)Step #2. Identify the airplanes that will require the longest runway lengths at maximumcertificated takeoff weight (MTOW). This will be used to determine the method for establishing the recommendedrunway length. Except for regional jets, when the MTOW of listed airplanes is 60,000 pounds (27,200 kg) or less,the recommended runway length is determined according to a family grouping of airplanes having similarperformance characteristics and operating weights. Although a number of regional jets have an MTOW less than60,000 pounds (27,200 kg), the exception acknowledges the long range capability of the regional jets and thenecessity to offer regional jet operators the flexibility to interchange regional jet models according to passengerdemand without suffering operating weight restrictions. When the MTOW of listed airplanes is over 60,000 pounds(27,200 kg), the recommended runway length is determined according to individual airplanes. The recommendedrunway length in the latter case is a function of the most critical individual airplane’s takeoff and landing operatingweights, which depend on wing flap settings, airport elevation and temperature, runway surface conditions (dry orwet), and effective runway gradient. The procedure assumes that there are no obstructions that would preclude theuse of the full length of the runway.(3)Step #3. Use table 1-1 and the airplanes identified in step #2 to determine the methodthat will be used for establishing the recommended runway length. Table 1-1 categorizes potential design airplanesaccording to their MTOWs. MTOW is used because of the significant role played by airplane operating weights indetermining runway lengths. As seen from table 1-1, the first column separates the various airplanes into one ofthree weight categories. Small airplanes, defined as airplanes with MTOW of 12,500 pounds (5,670 kg) or less, arefurther subdivided according to approach speeds and passenger seating as explained in chapter 2. Regional jets areassigned to the same category as airplanes with a MTOW over 60,000 pounds (27,200 kg). The second columnidentifies the applicable airport design approach (by airplane family group or by individual airplanes) as notedpreviously in step #2. The third column directs the airport designer to the appropriate chapter for design guidelinesand whether to use the referenced tables contained in the AC or to obtain airplane manufacturers’ airport planningmanuals (APM) for each individual airplane under evaluation. In the later case, APMs provide the takeoff andlanding runway lengths that an airport designer will in turn apply to the associated guidelines set forth by this AC toobtain runway lengths. The airport designer should be aware that APMs go by a variety of names. For example,Airbus, the Boeing Company, and Bombardier respectively title their APMs as “Airplane Characteristics for AirportPlanning,†“Airplane Characteristics for Airport Planning,†and “Airport Planning Manuals.†For the purpose ofthis AC, the variously titled documents will be referred to as APM. Appendix 1 lists the websites of the variousairplane manufacturers to provide individuals a starting point to retrieve an APM or a point of contact for furtherconsultation.(4)Step #4. Select the recommended runway length from among the various runwaylengths generated by step #3 per the process identified in chapters 2, 3, or 4, as applicable.(5)Step #5. Apply any necessary adjustment to the obtained runway length, wheninstructed by the applicable chapter of this AC, to the runway length generated by step #4 to obtain a finalrecommended runway length. For instance, an adjustment to the length may be necessary for runways with nonzero effective gradients. Chapter 5 provides the rationale for these length adjustments.27/1/2005AC 150/5325-4BTable 1-1. Airplane Weight Categorization for Runway Length RequirementsAirplane Weight CategoryMaximum Certificated Takeoff Weight (MTOW)12,500 pounds (5,670 kg)Approach Speeds less thanor less30 knotsApproach Speeds of at least30 knots but less than 50knotsApproachWithSpeeds ofLess than 1050 knots orPassengersmoreWith10 or morePassengersOver 12,500 pounds (5,670 kg) but less than 60,000pounds (27,200 kg)60,000 pounds (27,200 kg) or more or Regional Jets2Family grouping ofsmall airplanesLocation of DesignGuidelinesChapter 2;Paragraph 203Family grouping ofsmall airplanesChapter 2;Paragraph 204Family grouping ofsmall airplanesChapter 2;Paragraph 205Figure 2-1Chapter 2;Paragraph 205Figure 2-2Chapter 3;1Figures 3-1 or 3-2and Tables 3-1 or 3-2Chapter 4; AirplaneManufacturer Websites(Appendix 1)Design ApproachFamily grouping ofsmall airplanesFamily grouping of largeairplanesIndividual large airplaneNote 1: When the design airplane’s APM shows a longer runway length than what is shown in figure 3-2, use the airplane manufacturer’s APM.However, users of an APM are to adhere to the design guidelines found in Chapter 4.Note 2: All regional jets regardless of their MTOW are assigned to the 60,000 pounds (27,200 kg) or more weight category.PRIMARY RUNWAYS. The majority of airports provide a single primary runway. Airport authorities,103.in certain cases, require two or more primary runways as a means of achieving specific airport operationalobjectives. The most common operational objectives are to (1) better manage the existing traffic volume that exceedthe capacity capabilities of the existing primary runway, (2) accommodate forecasted growth that will exceed thecurrent capacity capabilities of the existing primary runway, and (3) mitigate noise impacts associated with theexisting primary runway. Additional primary runways for capacity justification are parallel to and equal in length tothe existing primary runway, unless they are intended for smaller airplanes. Refer to AC 150/5060-5, AirportCapacity and Delay, for additional discussion on runway usage for capacity gains. Another common practice is toassign individual primary runways to different airplane classes, such as, separating general aviation from nongeneral aviation customers, as a means to increase the airport’s efficiency. The design objective for the mainprimary runway is to provide a runway length for all airplanes that will regularly use it without causing operationalweight restrictions. For Federally funded projects, the criterion for substantial use applies (see paragraph 102a(8).)The design objective for additional primary runways is shown in table 1-2. The table takes into account theseparation of airplane classes into distinct airplane groups to achieve greater airport utilization. Procedurally, followthe guidelines found in subparagraph 102(b) for determining recommended runway lengths for primary runways,and, for additional primary runways, apply table 1-2.104.CROSSWIND RUNWAYS. The design objective to orient primary runways to capture 95 percent of thecrosswind component perpendicular to the runway centerline for any airplane forecast to use the airport is notalways achievable. In cases where this cannot be done, a crosswind runway is recommended to achieve the designstandard provided in AC 150/5300-13, Airport Design, for allowable crosswind components according to airplanedesign groups. Even when the 95-percentage crosswind coverage standard is achieved for the design airplane orairplane design group, cases arise where certain airplanes with lower crosswind capabilities are unable to utilize theprimary runway. For airplanes with lesser crosswind capabilities, a crosswind runway may be built, provided thereis regular usage. For Federally funded projects, the criterion for substantial use applies to the airplane used as thedesign airplane needing the crosswind runway (see paragraph 102a(8).) The design objective for the length ofcrosswind runways is shown in table 1-3. Procedurally, follow the guidelines found in subparagraph 102(b) fordetermining recommended runway lengths for crosswind runways, and, for additional crosswind runways, applytable 1-3.3AC 150/5325-4B7/1/2005Table 1-2. Runway Length for Additional Primary RunwaysRunway Service Type, UserCapacity Justification, Noise Mitigation,Regional Jet ServiceSeparating Airplane Classes – Commuter,Turboprop, General Aviation, Air TaxisRunway Length for Additional PrimaryRunway Equals100 % of the primary runwayRecommended runway length for the lessdemanding airplane design group orindividual design airplaneTable 1-3. Runway Length for Crosswind RunwayRunway Service1ScheduledSuch as Commercial Service Airports2Non-ScheduledSuch as General Aviation AirportsRunway Length for Crosswind Runway Equals100 % of primary runway lengthwhen built for the same individual design airplane orairplane design groupthat uses the primary runway100% of the recommended runway length determinedfor the lower crosswind capable airplanesusing the primary runway100% of the recommended runway length determinedfor the lower crosswind capable airplanesusing the primary runwayNote 1: Transport service operated over routes pursuant to published flight schedules that are openly advertised with dates or times (orboth) or otherwise made readily available to the general public or pursuant to mail contracts with the U.S. Postal Service (Bureau ofTransportation Statistics, Department of Transportation (DOT)).Note 2: Revenue flights, such as charter flights that are not operated in regular scheduled service, and all non-revenue flights incident tosuch flights (Bureau of Transportation Statistics, DOT). For Federally funded programs, such as AIP, there must be at least 500 annualitinerant operations and 100% of the class.105.RUNWAY LENGTH BASED ON DECLARED DISTANCES CONCEPT. The application of thedeclared distances concept to overcome safety deficiencies is not intended for new runways. New runways mustmeet design standards when constructed. See AC 150/5300-13, appendix 14, for information related to declareddistances.106.COMPUTER PROGRAM. The airport design software cited in Appendix 11 of AC 150/5300-13,Airport Design for Microcomputers (AD42D.EXE), was developed for airport planners to facilitate in the planningof airport layouts. The computer program only provides estimates instead of actual length requirements. The designsoftware is available at http://www.faa.gov/airports_airtraffic/airports/construction/.107.SELECTED 14 CODE OF FEDERAL REGULATIONS CONCERNING RUNWAY LENGTHREQUIREMENTS. Appendix 2 provides a list of selected 14 Code of Federal Regulations that address theairworthiness certification and operational requirements of airplanes associated with runway length.47/1/2005AC 150/5325-4BCHAPTER 2. RUNWAY LENGTHS FOR SMALL AIRPLANES WITH MAXIMUM CERTIFICATEDTAKEOFF WEIGHT OF 12,500 POUNDS (5,670 KG) OR LESS201.DESIGN GUIDELINES. The design procedure for small airplanes requires the following information: thecritical design airplanes under evaluation, approach speed in knots (1.3 x stall speed), number of passenger seats,airport elevation above mean sea level, and the mean daily maximum temperature of the hottest month at the airport.Once obtained, apply the guidance from the appropriate paragraph below to obtain the recommended runway length.For this airplane weight category, no further adjustment to the obtained length from the figures 2.1 or 2.2 isnecessary. For example, there is no operational requirement to take into account the effect of effective runwaygradient for takeoff or landing performance.202.DESIGN APPROACH. For purposes of design, this AC provides a design concept for airports that serveonly airplanes with a maximum certificated takeoff weight of 12,500 pounds (5,670 kg) or less. The design conceptstarts by grouping all small airplanes, that is, the critical design airplanes, according to approach speed. The highestapproach speed group is divided on the basis of passenger seats, namely, “airplanes having fewer than 10 passengerseats†as compared to “airplanes having 10 or more passenger seats.†The less than 10 passenger seats category isfurther based on two percentages of fleet, namely, “95 percent of the fleet†or “100 percent of the fleet†categories,as explained in paragraph 205. For these airplanes, figures 2-1 and 2-2 show only a single curve that takes intoaccount the most demanding operations to obtain the recommended runway length. Although both figures pertainmainly to small propeller driven airplanes, figure 2-2 does include small turbo-powered airplanes. Airport designerscan, instead of applying the small airplane design concept, determine the recommended runway length from airplaneflight manuals for the airplanes to be accommodated by the airport in lieu of the runway length curves depicted infigures 2-1 or 2-2. For example, owners of multi-engine airplanes may require that their pilots use the airplane’saccelerate-stop distance in determining the length of runway available for takeoff.203.SMALL AIRPLANES WITH APPROACH SPEEDS OF LESS THAN 30 KNOTS. Airplanes withapproach speeds of less than 30 knots are considered to be short takeoff and landing or ultra light airplanes. Theirrecommended runway length is 300 feet (92 meters) at mean sea level. Runways located above mean sea levelshould be increased at the rate of 0.03 x airport elevation above mean sea level to obtain the recommended runwaylength at that elevation.204.SMALL AIRPLANES WITH APPROACH SPEEDS OF 30 KNOTS OR MORE BUT LESS THAN50 KNOTS. The recommended runway length is 800 feet (244 meters) at mean sea level. Runway lengths abovemean sea level should be increased at the rate of 0.08 x airport elevation above mean sea level to obtain therecommended runway length at that elevation.205.SMALL AIRPLANES WITH APPROACH SPEEDS OF 50 KNOTS OR MORE WITH MAXIMUMCERTIFICATED TAKEOFF WEIGHT OF 12,500 POUNDS (5,670 KG) OR LESS. Figures 2-1 and 2-2provide the recommended runway lengths based on the seating capacity and the mean daily maximum temperatureof the hottest month of the year at the airport. The fleet used in the development of the figures consisted of smallairplanes certificated in the United States. Figure 2-1 categorizes small airplanes with less than 10 passenger seats(excludes pilot and co-pilot) into two family groupings according to “percent of fleet,†namely, 95 and 100 percentof the fleet. Figure 2-2 categorizes all small airplanes with 10 or more passenger seats into one family grouping.Figure 2-2 further alerts the airport designer that for airport elevations above 3,000 feet (914 m), that the airportdesigner must use the 100 percent of fleet chart of figure 2-1 instead of using figure 2-2. As shown, both figuresprovide examples that start with the horizontal temperature axis then, proceed vertically to the applicable airportelevation curve, followed by proceeding horizontally to the vertical axis to read the recommended runway length.a.Selecting Percentage of Fleet for Figure 2-1. The differences between the two percentagecategories are based on the airport’s location and the amount of existing or planned aviation activities. The airportdesigner should make the selection based on the following criteria.(1)95 Percent of Fleet. This category applies to airports that are primarily intended to servemedium size population communities with a diversity of usage and a greater potential for increased aviationactivities….