---------------------------------------------------------------------------------------------------------------------Module title: 6 Runway Design - Runway Length---------------------------------------------------------------------------------------------------------------------Overview

-Part 1 Runway length – pilot’s perspective-Part 2 Runway length – airport designer’s perspective-Summary-Review questions

Assignment-Browse the online references listed below.-Read and study this lesson plan provided by your professor.-Answer the lesson plan review questions in writing.-Create a document containing only the review questions with answers, preferably in MS Word.-Save the document with the file name “YourLastName LessonNumber LessonTitle”, e.g., Cain 6 runway design – runway length.-Upload the document into the ePortfolio Assignment Digital Dropbox.

Outcomes: After completing this module, students will be able to:-----------------------------------------------------------------------------------------------------------Part 1 Runway length – pilot’s perspective -----------------------------------------------------------------------------------------------------------1. Name and define the following takeoff V speeds:

a. V1.b. VR.c. VLOF.d. V2.

2. Define accelerate-stop distance and accelerate-go distance for a commercial airplane operating under 14 CFR Part 121.

3. Given accelerate-stop distance, accelerate-go distance, and all-engine takeoff distance plus 15%, determine the minimum takeoff runway length required for a commercial airplane operating under 14 CFR Part 121.

4. Given the normal landing distance as defined by 14 CFR Part 121, determine the landing runway minimum length requirement.

-----------------------------------------------------------------------------------------------------------Part 2 Runway length – airport designer’s perspective-----------------------------------------------------------------------------------------------------------5. Define “Substantial Use Threshold” and “itinerant operations” when identifying a

runway design critical aircraft.6. Given an aircraft and airport characteristics, determine the FAA required runway

length using AC 150/5325-4B Runway Length Requirements methodology and manufacturers’ airport planning manual.

7. Given two or more aircraft expected to utilize an airport’s runway, determine the runway critical design aircraft.

ReferencesAC 150/5300-13

-302a Runway length 43

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-304a Runway length 54Other

-AC 150/5325-4B Runway Length Requirements Website (I-pdf) (I-doc) --Chapter 1. Introduction

---Para. 101 And 102 Only--Chapter 4. Runway Lengths For Regional Jets And Those Airplanes With A Maximum Certificated Takeoff Weight Of More Than 60,000 Pounds (27,200 Kg)--Chapter 5. Design Rationale

-14 CFR Part 25--§25.105, 107, 109

-14 CFR Part 121.189--§121.189

-AC 150/5300-13A chg 1 Airport Design ( Website ) (I-pdf) --Para, 304a, Runway geometry

---------------------------------------------------------------------------------------------------------------------Part 1 - Runway Length – Pilot’s Perspective ---------------------------------------------------------------------------------------------------------------------Overview-Introduction-Takeoff Runway Length Requirements -Landing Runway Length Requirements Introduction-In the AC 150/5300-13A Airport Design runway design standards matrix, runway length is the first runway design determination.-Runway length is one of the most visually obvious runway characteristics.

-Threshold (TH). The beginning of that portion of the runway available for landing. “Threshold” always refers to the start of the landing area, not the start of takeoff area.-Departure End of Runway (DER). The end of the runway that is opposite the landing threshold. It is sometimes referred to as the stop end of runway.

-Runways are very expensive to construct, so new runway length or runway extension determinations need to be very precise, typically to the nearest 100 feet.-There are two perspectives from which to determine required runway lengths:

--Airport designers designing a new runway:---Determined runway length one time for the runway design airplane at MTOW

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and one set of annual average environmental conditions.---Build the runway to this length.

--Pilots (and dispatchers)---Determined runway length required for every takeoff and landing at every airport using dynamic aircraft weight and environmental conditions.---Insure the runway length available (today) is equal to or greater than the runway required.

-It will be advantageous for the airport designer to understand how the pilot determines required takeoff and landing distance.-The pilot’s perspective will be addressed first, followed by the airport designer’s perspective.Takeoff Runway Length Requirements-14 CFR part 121 Code of Federal Aviation Regulations (FARs) prescribes minimum takeoff runway length requirements.-From an operational perspective, pilots must determine/insure if a runway is long enough for takeoff.-Some takeoff V-speed definitions are required here.

--V1 critical engine failure speed or decision speed. Engine failure below this speed shall result in an aborted/rejected takeoff; above this speed the takeoff run should be continued.--VR rotation speed is the speed at which the rotation of the aircraft is initiated to takeoff attitude. With an engine failure, VR must be fast enough (reduced induced drag) to allow for the acceleration to V2 at a 35-foot height above the runway elevation at the end of the runway (or clearway as will be seen in lessons 18 Declared Distances and 19 Takeoff Flight Path). 18 19 --VLOF lift-off speed. The speed at which the aircraft first becomes airborne.--V2 the takeoff safety speed which must be attained at the 35-foot height above the runway elevation at the end of the required runway distance.

-14 CFR part 121 requires that the takeoff runway must be at least the longest of the following three distances:

--1. Accelerate-go distance--2. Accelerate-stop distance--3. All engine takeoff distance plus 15% safety margin*--1. Accelerate-go distance—the distance required to accelerate to V1 with all engines at takeoff power, experience an engine failure at V1 and continue the takeoff on the remaining engine(s). The runway required includes the distance required to climb to 35 feet above the runway end elevation by which time V2 speed must be attained.

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Pilot’s Handbook of Aeronautical Knowledge, figure 10.34.

*--2. Accelerate-stop distance—the distance required to accelerate to V1 with all engines at takeoff power, experience an engine failure at V1, and abort the takeoff and bring the aircraft to a stop using braking action only (use of thrust reversing is not considered).

Pilot’s Handbook of Aeronautical Knowledge, figure 10.34.

--3. All engine takeoff distance plus 15%—the distance required to complete an all-engines operative takeoff to 35 feet above ground level (AGL).

Pilot’s Handbook of Aeronautical Knowledge, figure 10.34.

--Commercial aircraft must not takeoff if minimum runway length requirements are not met.*--Example:

--- Accelerate-go-distance 9,000 feet---Accelerate-stop-distance 9,500 feet ---All-engine takeoff distance+15% 8,000 feet---Takeoff runway required 9,500 feet minimum

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--One should remember that these distances are heavily dependent on aircraft MTOW, among other variables to be discussed.--For most commercial aircraft, the takeoff distance at MTOW exceeds the landing distance at maximum landing weight (MLW).

--However, both takeoff and landing distances will need to be determined to insure the longest is selected.

Landing Runway Length Requirements-Similar to takeoff runway length requirements, 14 CFR part 121 specifies minimum landing runway length requirements.*-Required landing distance for air carriers and other commercial operators is 1.4 times that distance needed to land and come to a complete stop from a point 50 feet above the threshold end of the runway.

--Threshold (TH). The beginning of that portion of the runway available for landing. In some instances, the threshold may be displaced. “Threshold” always refers to landing, not the start of takeoff.--In other words, the runway must be 40% longer than the expected landing distance.

Pilot’s Handbook of Aeronautical Knowledge, figure 10.38.

-Recall from a previous module that VREF =1.3 VSO.Summary-V1 critical engine failure speed or decision speed. Engine failure below this speed shall result in an aborted/rejected takeoff; above this speed the takeoff run should be continued.-VR rotation speed is the speed at which the rotation of the aircraft is initiated to takeoff attitude. With an engine failure, -VR must be fast enough (reduced induced drag) to allow for the acceleration to V2 at a 35-foot height at the end of the runway.-VLOF lift-off speed. The speed at which the aircraft first becomes airborne.-V2 the takeoff safety speed which must be attained at the 35-foot height at the end of the required runway distance.-Accelerate-go distance—the distance required to accelerate to V1 with all engines at takeoff power, experience an engine failure at V1 and continue the takeoff on the remaining engine(s). The runway required includes the distance required to climb to 35 feet by which time V2 speed must be attained.-Accelerate-stop distance—the distance required to accelerate to V1 with all engines at takeoff power, experience an engine failure at V1, and abort the takeoff and bring the aircraft to a stop using braking action only (use of thrust reversing is not considered).Given accelerate-stop

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distance, accelerate-go distance, and all-engine takeoff distance plus 15%, determine the minimum takeoff runway length required for a commercial airplane operating under 14 CFR Part 121.-The landing runway must be 40% longer than the expected landing distance.---------------------------------------------------------------------------------------------------------------------Part 2 - Runway Length – Airport Designer’s Perspective ---------------------------------------------------------------------------------------------------------------------Overview-Introduction-AC 150/5325-4B Runway Length Requirements Website (I-pdf) (I-doc) -Manufacturer runway length determinationsIntroduction-The runway length discussion in the Part 1 above was from a pilot’s operational perspective. The distance numbers are obtained on a per-flight from an aircraft’s performance manual considering various weights, environmental conditions, and airports.-The airport designers perspective is slightly different, but the designer’s perspective must necessarily agree with or exceed the pilot’s runway length operational requirements.*-The airport designer uses AC 150/5325-4B Runway Length Requirements prescribed methodology to determine runway length requirements for the runway critical design aircraft at MTOW.

*--Distances obtained from this methodology include all FAA required safety margins.*--Substantial Use Threshold. Federally funded projects require that critical design airplanes have at least 500 or more annual itinerant operations (takeoffs and/or landings to/from airports at least 20 miles apart.).

-*Aircraft manufacturers’ Airport Planning Manuals (APMs) insure runway lengths meet all 14 CFR Part 121 takeoff requirements that the pilots are using. One does not need to adjust APM numbers by 15% for example.-Ultimately, the airport designer will need to determine the longest runway required to accommodate the runway design aircraft that routinely utilizes its runways. The aircraft requiring the longest runway is the runway critical design aircraft or runway design aircraft.-AC 150/5325-4B prescribes the methodology for runway design aircraft over 60,000 pounds and all regional jets.

--While AC 150/5325-4B provides methodology for aircraft less than 60,000 pounds MTOW, we will focus on the methodology for aircraft over 60,000 pounds MTOW and all regional jets.--Both aircraft performance characteristics and airport conditions must be considered.--Aircraft performance characteristics:

---Use MTOW and MLW.--- Flap Settings. Use flap setting that produces the shortest runway length.

-Airport conditions:--Airport elevation above mean sea level--Temperature. Use the mean daily maximum temperature of the hottest month at the airport.

---If the mean daily maximum temperature of the hottest month is not included in the APM, then contact the airplane manufacturer directly for temperature corrections.

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--Wind velocity. Use zero wind velocity for both takeoff and landing operations.--Runway surface condition for landing (dry or wet)

---Wet conditions must be used for turbojet aircraft landings.*---If an APM provides only the dry runway condition, then increase the dry runway length by 15 percent to obtain wet conditions. Note: This is not the same 15 percent takeoff distance safety factor required for pilots by 14 CFR Part 121.

-Runway gradient for takeoff--For large airplane takeoff operations, increase takeoff distances by 10 feet per foot of difference in elevations between the high and low points of the runway centerline.

-Manufacturers’ Airport Planning Manuals--Using the AC 150/5325-4B guidance above, determine the takeoff and landing runway length requirements for the largest aircraft utilizing the runway from the airplane manufacturers’ APM.--Several aircraft may have to be examined to determine which aircraft produces the longest runway requirement and thus which aircraft is ultimately declared the runway critical design aircraft.--Round runway lengths exceeding xx,x30 feet and to the next 100-foot interval.

Example: Round 8,540 feet to 8,600 feet.-*It should be noted that the most important step in determining runway requirements is to find the correct APM chart! Carefully match exactly the aircraft name, number, engine type, and temperatures.

-Example -Determine the F.A.R takeoff and landing runway length requirements for the following airplane and airport conditions.

--Airplane conditions---Boeing 737-900 (CFM56-7B26 Engines at 24,000 lb. SL ST)---Maximum takeoff weight MTOW =174,200 pounds---Air conditioning OFF.---Takeoff flaps optimum (usually around 15 degrees)---Maximum landing weight MLW =146,300 pounds---Landing flaps 30 degrees (typically maximum flap deflection)

--Airport conditions---Airport elevation=1,000 feet---Mean daily maximum temperature of hottest month at the airport = 29.5º C

----Airport temperature must be converted to a standard day + format.----Standard day temperature at 1,000 feet AMSL is 15-2=13º C.----But if the actual temperature is 29.5º C, then that temperature is 16.5º C above standard, i.e., STD+16.5.

---Wet runway----Required for turbojet aircraft landing----Only considered for landing distance, not takeoff distance.

---Maximum difference in runway centerline elevations =+20 feet--Takeoff distance

-Step 1. Using the above airplane and airport conditions, find the appropriate takeoff chart in 737 Airplane Characteristics for Airport Planning in the course at

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http://www.boeing.com/boeing/commercial/airports/737.page.

pdf pg. 155--As long as the actual airport temperature is not more than 1.7° C above the selected chart temperature, then that chart may be used.--Substitute airport elevation above mean sea level for pressure altitude if necessary.

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--Step 2 – Adjust (increase) the takeoff distance for runway gradient (up slope).---Increase takeoff distance by 10 feet per foot of difference in elevations between the high and low points of the runway centerline.---20 feet upslope x 10 feet/foot = 200 feet---11,600 + 200 = 11,800 feet

--Landing distance---Using similar methodology, the landing distance for this problem is 7,000 feet.---MLW landing distance for most airplanes is less than MTOW takeoff distance.

---------------------------------------------------------------------------------------------------------------------Summary ----------------------------------------------------------------------------------------------------------------------The airport designer uses AC 150/5325-4B Runway Length Requirements prescribed methodology to determine runway length requirements for the runway critical design aircraft at MTOW.

--Distances obtained from this methodology already include all FAA required safety margins. No additional calculations are necessary.

-The runway critical design aircraft is that aircraft requiring the longest runway.--Substantial Use Threshold. Federally funded projects require that critical design airplanes have at least 500 or more annual itinerant operations (takeoffs and/or landings to/from airports at least 20 miles apart.).

-AC 150/5325-4B Runway Length Requirements methodology is used in conjunction with the manufacturers’ airport planning manual to determine runway length requirements.---------------------------------------------------------------------------------------------------------------------Review Questions – 6 Runway design – Runway length---------------------------------------------------------------------------------------------------------------------Name ________________________________________________________

Scoring rubric for 6 Runway design - Runway lengthQuestion Value Points lost

Part 11 102 103 204 20

Part 25 106 30

Total points lostFinal score

Part 11. Name and define the following takeoff V speeds:

a. V1.b. VR.

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c. VLOF.d. V2.

2. Define the following terms for a commercial airplane operating under 14CFR Part 121:a. accelerate-stop distanceb. accelerate-go distance.

3. Determine the minimum takeoff runway length required for a commercial airplane operating under 14 CFR Part 121 from the following information:

Accelerate-stop distance, 8,500 feetaccelerate-go distance 9,000 feetAll-engine takeoff distance plus 15%, 8,500 feetMinimum takeoff runway length requirement ____________ feet

4. Determine the landing runway minimum length requirement as defined by 14 CFR Part 121. Show work.

Normal landing distance as defined by 14 CFR Part 121 5,000 feetMinimum landing runway length requirement _________feet

Part 25. Define “Substantial Use Threshold” and “itinerant operations” when identifying a runway

design critical aircraft.6. Determine the FAR/JAR (a) takeoff and (b) landing runway length requirements for the

airplane and airport conditions shown below. (c) If this aircraft was the runway design critical aircraft, identify the required runway length. Record all answers in the spaces provided below.Note: + 100 feet accuracy, which is not good enough in the real world but will suffice for demonstration purposes.Use the Airbus A-340-500/600 Airplane Characteristics for Airport Planning from Airbus at https://www.dropbox.com/s/1a511iszy5h1fdr/A340-500_600_Jan11.pdf?dl=0 or http://www.aircraft.airbus.com/support-services/airport-operations/aircraft-characteristics/.Hint: Use the FAR/JAR Takeoff Weight Limitation and FAR/JAR Landing Field Length charts, entering with weight and pressure altitude to determine runway length requirements.--Airplane conditions

---Airbus A340-600WV001, RB 211 TRENT 556 engine---Maximum takeoff weight MTOW = 368,000 kg (811,301 pounds)---Maximum landing weight MLW = 259,000 kg (570,997 pounds)---Landing flaps unspecified

--Airport conditions---Airport pressure altitude=3,000 feet MSL---Mean daily maximum temperature of hottest month at the airport = 25º C

----Airport temperature must be converted to a “standard day +” format.----Standard day temperature at 3,000 feet MSL is 15-6 = 9º C.----But if the actual temperature is 25º C, then the that temperature is 16 º C above standard, i.e., STD+16.

-----Remember that a particular chart can be used as long as the actual temperature is not more than 1.7º C above the chart temperature.

---Wet runway

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----If an APM provides only the dry runway condition, as is the case with Airbus, then increase the dry runway length by 15 percent to obtain wet conditions.

---Maximum difference in runway centerline elevations =+10 feetRecord answers in this format.a. Takeoff (+ 100 feet accuracy, which is not good enough in the real world but will suffice for demonstration purposes.)

Identify the specific chart number and figure number used to determine the takeoff distance, e.g., 3-2-1, figure 1. __________________________________________.Takeoff distance uncorrected _____________ feetTakeoff distance correction for runway gradient _____________ feetTakeoff distance required _____________ feet

b. Landing (+ 100 feet accuracy, which is not good enough in the real world but will suffice for demonstration purposes.)

Identify the specific chart number and figure number used to determine the landing distance, e.g., 3-2-1, figure 1. __________________________________________.Landing distance uncorrected _____________ feetLanding distance wet runway correction _____________ feetLanding distance required _____________ feet

c. Required runway length _____________ feet

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