Summer Weather Returns to MSPPosted on June 14, 2018
Summer has arrived in the Twin Cities. At Minneapolis-St. Paul International Airport (MSP) summer means vacations, more travelers and more aircraft takeoffs and landings. Neighbors near the airport may be noticing some of the effects of these changing weather conditions.
Warmer temperatures and humidity cause aircraft to use longer distances to takeoff and, once airborne, climb slower. To find out more, check out our FAQ #2 titled “Can airplanes climb/fly higher to reduce noise?”
Another way that summer affects MSP is the use of its runways. Aircraft must take off and land into the wind as much as possible. In the summer, south winds are more prevalent. To provide the highest level of safety, the Federal Aviation Administration (FAA) will choose runways that provide aircraft with the highest degree of headwind. When the winds are from the south or the east, aircraft will typically arrive over Minneapolis on Runways 12L and 12R and depart over Mendota Heights, Eagan and Bloomington on Runways 12L, 12R and 17. These wind conditions were especially common in May and have continued into June.
To help explain how wind conditions affect runway use, the MAC created an aircraft noise basics video called “How Are Runway Decisions Made?:” www.macnoise.com/aircraft-noise-basics/aircraft-noise-basics-part-4-how-are-runway-decisions-made.
There are noise-abatement-departure procedures in place on all three of the runways mentioned. Compliance with these procedures is monitored and reported by the MAC at www.macenvironment.org/reports/.
For Runway 12L and 12R, the FAA instructs carrier jets to remain in the Eagan-Mendota Heights Corridor after departure. The cities of Eagan and Mendota Heights zoned this corridor to mainly have land uses compatible with aircraft overflights. Monthly adherence to the procedure is typically above 90 percent.
The Runway 17 noise-abatement-departure procedure predates the construction of the runway. When Runway 17/35 was planned, a federal Environmental Impact Statement (EIS) was completed to study the effect of this runway on the environment. In the EIS, the MAC made a commitment to evaluate a departure procedure to reduce noise impacts to residential areas immediately south of the airport. After the runway was approved and designed, a federal Environmental Assessment (EA) was completed to study a range of departure procedures from Runway 17. The EA document concluded that a 2.5-mile turn point for Runway 17 departures going west would be the most suitable flight route for noise reduction. This procedure specifies that "Runway 17 jet departures bound for destinations requiring headings west of runway heading would fly runway heading until reaching a point 2.5 nautical miles from the start of take-off roll as defined by distance measure equipment (DME). At the 2.5 nautical mile point, aircraft would turn to their assigned westbound departure heading." The purpose for this procedure is to keep westbound aircraft over the Minnesota River Valley instead of over residential neighborhoods immediately after departure. The EA also concluded that eastbound aircraft should turn to their initial departure headings as soon as possible after departure, as areas east of runway heading are almost uniformly residential and there is not one area that is better than another for aircraft overflights. The westbound Runway 17 Departure Procedure is used daily and its compliance is monitored by the MAC. Monthly adherence to the procedure is typically over 99 percent.
For more detail about noise abatement efforts at MSP, please visit: www.macnoise.com/our-neighbors/msp-noise-abatement-efforts.
The MAC hosts quarterly Listening Sessions for members of the public to learn more about MSP air traffic and discuss aircraft noise matters of interest. The next session will be held on July 17, 2018 in the City of Richfield. Please visit the MAC Noise Program Office calendar for meeting details: https://www.macnoise.com/calendar.