Laurie Ferguson Craig, in her "My Turn" commentary (Empire, Sept. 30) suggests that the use of foamed concrete (EMAS, or engineered materials arresting system) in the runway safety area at Juneau International Airport could reduce or eliminate the need to acquire land in the Mendenhall Wetlands State Game Refuge. The material has been used elsewhere to reduce the length of runway safety area needed to safely stop a plane driving off the end of the runway.
EMAS is designed to safely slow and stop a plane that leaves the runway at 70 knots. The company that manufactures it recommends 379 feet of EMAS to stop an errant 737-400 (which may not be the most demanding plane using the airport). At the Juneau airport, this would require shortening the runway as now configured by 258 feet, leaving 8,198 feet for takeoff. According to Boeing, a fully loaded 737-400 requires a 9,500-foot runway for takeoff on a good day (dry, 59 degrees Fahrenheit, no wind), so a typical 737 that now carries reduced fuel or passengers for the existing Juneau runway would have to reduce its load even further with EMAS installed.
EMAS was designed for planes on the ground, but runway safety area is also required to protect planes in the air in landing configuration. Federal Aviation Administration policy calls for 1,000 feet of runway safety area in front of the threshold for this kind of airport. Since EMAS is not designed to safely stop planes traveling 135 knots and dropping from the sky, the required 1,000 feet would be taken from the available runway, reducing the landing distance available to 7,198 feet and messing with the approach lighting system. According to Boeing, on a good day, a 737-400 can land safely in about 5,500 feet.
Now recall the days of some of your more exciting landings at Juneau. Our pilots are exceptionally skilled, in my opinion, and elect to land at Juneau in weather I wouldn't drive in. But they are also prudent. With 1,258 feet less runway to work with at Juneau, the airlines will likely divert more legislators and other people to Anchorage, Yakutat, Sitka, Ketchikan or Seattle than is now the case.
Bottom line: If no wetlands are to be disturbed off the ends of the runway, there will be loss of service due to regulatory shortening of the runway no matter what you do.
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