Integrated Noise Model (INM)

The Integrated Noise Model (INM) is a computer model that evaluates potential aircraft noise impacts in the vicinity of airports. It is developed based on the algorithms and framework outlined in the Society of Automotive Engineers (SAE) Aerospace Information Report "Procedure for the Calculation of Airplane Noise in the Vicinity of Airports" (AIR-1845). SAE-AIR-1845 highlights the use of Noise-Power-Distance (NPD) data to estimate noise, accounting for specific operation mode, thrust setting, source-to-receiver geometry, acoustic directivity and other environmental factors. The INM can output exposure-, maximum-level- and time-based noise contours, as well as levels at pre-selected locations.

What is INM Designed to Do?

The INM has many analytical uses, including:

Assessing current aircraft noise impacts around a given airport or heliport
Assessing changes in noise impact resulting from new or extended runways or runway configurations
Assessing changes in noise impact resulting from new traffic demand and fleet mix
Evaluating noise impacts from new operational procedures
Evaluating noise impacts from aircraft operations in and around National Parks

In the United States, INM is the preferred model typically used for FAR Part 150 noise compatibility planning and for FAA Order 1050 environmental assessments (EA) and environmental impact statements (EIS).

INM7.0a

INM7.0a is the most recent release of INM. It is a minor update of INM7.0, which is a significant improvement over the 6x series. INM7.0a includes updates to noise/performance data for commercial aircraft, updates to substitution aircraft data, and corrections to minor software issues.

Database Updates and Changes

INM Version 7.0a includes new noise and flight performance data for the first Very Light Jet (VLJ) to be added to the INM database: the Cessna Mustang Model 510 with PW615F engines (CNA510).

Minor corrections were also made to the data for several existing aircraft for INM Version 7.0a, including:

Profile weight for the A319-131 STANDARD approach profile;
Data for Spectral Class 110; and
Level noise adjustment coefficients (B0, B1, and B2 for each of the Left, Center and Right NPDs) for the MD600N.

INM 7.0a also includes several updates to substitution aircraft data:

A new entry for the T-6 Texan (T6) which is substituted with the GASEPV;
The existing Piper PA-31 Chieftain (PA31CH) is now substituted with the PA31; and
The existing Piper PA-39 Twin Comanche C/R (PA39) is now substituted with the PA30.

Corrections

INM Version 7.0a corrects minor issues related to differences between runway end and airport elevations, behind start of takeoff roll directivity, version conversion for metric INM studies, and the handling of reference speeds for helicopter Noise Power Distance (NPD) curves. These and other corrections are further clarified in the INM 7.0a Release Notes.

Previous Versions of INM

INM 7.0a, released on September 17, 2008, is a free update to INM 7.0. You must already have INM 7.0 installed to use this update. If you do not already have the previous version, you can order a complete software package using the INM 7.0a Order Form available below. The INM 7.0 User's Guide and Technical Manual are the current manuals for INM 7.0a.

The files below comprise the INM Version 7.0a update, installation instructions, and order form.

Release Notes of Previous Versions of INM

7.0 (April 30, 2007)
6.2a (November 30, 2006)
6.2 (May 22, 2006)
6.1 (March 4, 2003)
6.0c (September 21, 2001)
6.0b (January 16, 2001)
6.0a (May 19, 2000)
6.0 (September 30, 1999)

Helicopter Modeling

Prior to the release of INM Version 7.0, helicopter noise impacts in the vicinity of terminal operations were modeled with the HNM. Current helicopter noise assessments should be conducted with INM Version 7.0a.