Ask the Expert

The Noise Program Office gets many questions from the public, and we want to provide answers. Here are Q&A’s based on some common questions you have asked.

Why was RNAV implemented for arrivals and not departures?

On March 6, 2014, a Resolution was passed by the MSP Noise Oversight Committee providing unanimous support from community members and airline representatives for the implementation of RNAV arrival procedures. In large part, the support from all stakeholders for these procedures was due to the fact that the procedures greatly improve efficiency and result in lower carbon emissions. With RNAV arrival procedures, arriving flights no longer follow a stair-step descent down to the airport. Instead, they fly a continuous descent, keeping the aircraft higher longer and reducing carbon emissions.

Additionally, the new arrival procedures did not change the areas over which arriving aircraft fly. Planes arriving at MSP must line up with the runway to ensure a safe touch-down. This path did not change due to RNAV arrival procedure implementation.

Are aircraft flying closer together and more frequently because of RNAV arrival procedures?

No, the Federal Aviation Administration mandates that arriving aircraft following the same path must maintain at least 3 miles of separation whether or not RNAV procedures are being used. Therefore, RNAV procedures have not reduced the distance between arriving aircraft or increased the frequency of arriving flights.

What are the peak hours of operations and how many flights are there during these hours?

During May 2016, the peak hour of operations for all flights occurred on May 25th from 8:00 to 9:00 p.m. with 112 arrivals and departures. This hour of the day regularly experiences the most arrivals and departures, with an average of 93 flights each day in May. In comparison, the peak hour of operations during the same month in 2009 had 123 arrivals and departures and in 2004 – before Runway 17/35 was built – had 131 arrivals and departures.

If you look only at arrivals, the peak hour in May 2016 occurred on May 20 from 6:00 to 7:00 p.m. with 77 arrivals. This hour regularly experiences the most arrivals at MSP with an average of 64 arrivals per day in May.

The peak hour of departures in May 2016 occurred on May 20 from 8:00 to 9:00 p.m. with 65 departures. This hour, along with the 7:00 to 8:00 a.m. hour, regularly experiences the most departures at MSP. On average, 54 flights departed MSP each day in May between 8:00 and 9:00 p.m. and 45 flights departed MSP each day in May between 7:00 and 8:00 a.m.

Are aircraft flying Noise Abatement Departure Profiles at MSP?

Yes. The standard protocol for airlines and cargo jet aircraft operators is to use the Distant Noise Abatement Departure Profile (NADP-2).

According to a Delta Air Lines Chief Pilot, all Delta Air Lines aircraft fly the NADP-2 (Noise Abatement Departure Procedure –Two) procedure out of MSP.  That procedure is their standard departure procedure as approved and requested by most airport authorities, including the MAC.  Occasionally other procedures are used at other airports, but only when specifically requested by those airport authorities.

What is the MAC’s role at MSP?

The MAC provides and maintains MSP airport facilities for airlines and air cargo companies to conduct air commerce activities. Services provided by the MAC include developing and maintaining airport roadways, runways, taxiways, ramps, terminals and other buildings, and parking facilities.

The MAC can be viewed as a landlord of the airport, and airlines, air cargo companies, airport restaurants and stores, and car rental companies as tenants of the MAC. Counter to what some may think, the MAC does not:

  • Screen passengers at security checkpoints (this is the role of the federal Transportation Security Administration, or TSA);
  • Decide where aircraft fly or which runways they use (this is the role of the FAA);
  • Regulate air traffic operations at the airport (this is the role of the FAA);
  • Schedule air traffic in and out of the airport (this is the role of the aircraft operators, such as airlines and air cargo companies);
  • Control entry into the United States by international passengers (this is the role of the federal Customs and Border Protection agency).

What new technology is available to reduce aircraft noise?

Since the invention of the jet engine, aircraft manufacturers, aerospace engineers and airlines have taken strides to reduce noise emitted from aircraft by leveraging new technology. Engine technologies such as high-bypass ratio and very-high-bypass ratio turbofans have significantly improved noise emissions across the United States. For example, Boeing’s new B737MAX aircraft is reported to have a 40 percent smaller noise footprint than the B737-800, and the Airbus A320NEO is reported to be 15 decibels below the Stage 4 noise standard – currently the quietest noise standard in the United States.   

MD80 aircraft are among the loudest aircraft operating at MSP on a regular basis. Delta Air Lines recently announced it will be replacing these aircraft with newer, quieter and more fuel efficient models. Eighty-two Airbus A321 aircraft will be used on routes flown today by MD80s and B757s, phasing these older planes out of service.

By next year, American Airlines plans to retire its fleet of MD80s as it begins taking delivery of 100 new Boeing B737MAX aircraft. Additionally, Southwest Airlines will begin taking delivery of 170 B737MAX aircraft next year.

Is the MAC able to charge higher landing fees for flights operating at night?

No, federal regulations do not allow the MAC to charge differential fees to the airlines on a basis of aircraft type or time of day. Since MSP is a public-use airport, the MAC cannot restrict access to aircraft operations. The Federal Aviation Administration (FAA) prohibits public-use airports from charging differential fees for the purpose of controlling noise exposure without going through a Part 161 Study and approval process with the FAA. Under a Part 161 Study, the FAA requires a cost versus benefit analysis and an analysis that supports, by substantial evidence, that six statutory conditions for approval have been met. The six statutory conditions are:

  1. the restriction is reasonable, nonarbitrary, and nondiscriminatory;
  2. the restriction does not create an undue burden on interstate or foreign commerce;
  3. the restriction is not inconsistent with maintaining the safe and efficient use of the navigable airspace;
  4. the restriction does not conflict with a law or regulation of the United States;
  5. an adequate opportunity has been provided for public comment on the restriction; and
  6. the restriction does not create an undue burden on the national aviation system.

The use of a differential fee structure for noise control efforts would fail the first criteria because it would discriminate against an aircraft that is certificated, and thus can legally operate in the United States.  

The 1990 Airport Noise and Capacity Act was created, in part, to standardize aircraft noise planning efforts. Many local communities and states had begun imposing restrictions on aircraft and managing noise planning without federal guidance, leading to a patchwork of restrictions at airports across the United States. This act established a federal framework for airports to manage noise exposure but also eliminated an airport operator’s ability to impose new restrictions without receiving approval as a part of a Part 161 submission. Airports that had restrictions in place prior to the 1990 legislation were allowed to maintain them. To date 39 Part 161 applications have been submitted to the FAA -- and only one approved.