Assignment 2: Runway Length Analysis

CEE 4674: Airport Planning and Design Spring 2010
Date Due:
Problem 1
Assignment 2: Runway Length Analysis
Instructor: Trani
Use the basic equation of motion representing the aircraft acceleration described in the class notes and briefly answer the
following questions. In your answers, point out the terms in the equation that are affected by the environmental parameters
mentioned in each question.
a. What is the effect of mass in the takeoff roll distance?
Mass is a term in the denominator of the acceleration equation of motion. The larger the mass, the smaller the resulting
acceleration. This results in longer takeoff distance.
b. What is the effect of altitude in the takeoff roll distance?
Altitude reduces air density. Air density is a factor that affects engine performance and the aerodynamic forces in the
equation of motion. The net effect is that lower thrust is produced and this produces longer takeoff distances.
c. What is the effect of flap setting in the takeoff roll distance?
Flaps are designed to increase the generation of lift during takeoff and landing. Moderate flaps settings allow a
reduction in takeoff speeds and thus reduce takeoff distance compared to a no flap takeoff. The effect of flaps in the
equation of motion is the changes to Cd and Cl (aerodynamic coefficients).
Problem 2
Investigate the effect of air temperature on runway length performance for small aircraft with reciprocating engines and fewer
than 10 seats. Suppose that we want to design the runway length for an airport that serves 100% of the small fleet population.
a) Find the runway length difference between ISA conditions and ISA + 40 degrees (Farenheit) both at sea level
Use Table 2.1 in AC 5325-4B. 3,200 feet for 100% of aircraft with fewer than 10 seats at ISA conditions (59 deg. F).
Increase to 3800 feet for ISA + 40 deg. F.
b) Repeat part (a) but at 5,000 feet elevation.
Use Table 2.1 in AC 5325-4B. 5,400 feet for 100% of aircraft with fewer than 10 seats at ISA conditions (59 deg. F).
Increase to 6,600 feet for ISA + 40 deg. F.
c) Comment on the results obtained and state a possible rule of thumb to estimate the runway length without using the FAA
charts.
Problem 3
Calculate the runway length for a new airport to serve corporate jets near a metropolitan area. The airport manager expects to
attract aircraft such as the Cessna Citation X (model 750). The airport site is to be located 40 miles from Wichita Mid Continent
airport (KICT) in a land 1,400 feet above mean sea level. Use the historical data available at www.weather.com to derive an
appropriate temperature in the design of the airport. Use the 90% useful load curves and apply all necessary corrections. Use
Table 3.2 in AC 5325-4B provides guidance for this analysis. 92 deg. F is the temperature to be used. 9,000 feet is the
approximate runway length needed. No correction for wet runway is needed.
Problem 4
A new runway is planned for Portland International Airport (Oregon). The runway should be enough to satisfy a Boeing 777-300ER.
The Boeing 777-300ER (with GE90-115B1 engines) in question has a maximum takeoff weight of 775,000 lbs. (MTOW). See the
specifications of the Boeing 777-300ER in the appropriate Boeing documents. No critical stage length has been provided so
assume the aircraft will operate at its maximum takeoff weight. Obtain the temperature profile for the airport using
www.weather.com or NOAA historical data. Assume the airline operates the Boeing 777-300ER in a three-class cabin
configuration with 370 seats.
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a) Find the runway length needed to operate this aircraft at MTOW conditions out of Portland. Clearly state all your
assumptions regarding temperature, field elevation and others. Comment and compare your solution to the existing
runways at PDX. In your calculations assume no grade correction.
b)
Consult the Boeing 777 documents on the web. Use STD dat + 27 deg. F for the analysis. Check the correct figure for
the aircraft with GE90-115B engines. Runway length is 10,400 feet. Correct for gradient (20 feet difference) we get 10,600
feet.
c) If one day runway 10L/28R is used for all departures due to a closure of runway 10R/28L for maintenance estimate the
maximum range the aircraft could travel with a full complement of passengers (no cargo).
Runway 10L/28R is 8,000 feet. The aircraft could takeoff at a DTW of 680,000 lb (see Figure 2). Work backwards to get an
approximate range (from Payload Range diagram) of 5,700 miles.
Figure 1. Boeing 777-300ER Specifications. Source: Boeing.
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Figure 2. Takeoff Performance for Boeing 777-300ER. Source: Boeing.
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