OSU Moves Part 150 Forward Without Adequate Verification

April 14, 2008
What is an INM?

In a Part 150 airport study, one of the most important components the Integrated Noise Model (INM), a computer program which outputs noise maps displaying what noise levels are to be expected at what locations.

Different characteristics of the airport are estimated to create the maps. These include flight paths, flight frequency and times, and the "fleet mix", i.e. the percentage of different types of aircraft that arrive and depart the airport.

Getting these estimates as accurate as possible is crucial in order to get the best noise maps. As the saying goes: garbage in, garbage out. It is double important that the night-time fleet mix be accurate. Because of the increased impact night time noises have, night time operations are weighted much more heavily when computing the noise maps.

Local residents Scott Whitlock and Kim Nixon-Bell performed an analysis of the inputs proposed by OSU's consultant for the Integrated Noise Model (INM). They found that the proposed inputs need additional verification before they could be accepted.

Among their findings was an apparent under-reporting of night flights and jet aircraft, both of which would result in a study that would under-report the impact of noise in the community.

While OSU's consultants were provided this information and made some corrections, OSU has decided to move forward without adequate verification of the data they are using.

  • 2008-04-07 Night Operations Test Week Analysis.pdf
  • 2008-04-07 Response to RS&H.pdf
    From: Kim Nixon-Bell
    Sent: Monday, April 07, 2008 7:19 PM
    To: 'Marie Keister'; 'Alan Harding'; 'Amanda Cooper'; 
        'Bill Carleton'; 'Chris Lenfest'; 'David Zoll'; 'Deral Carson'; 
        'Don Peters'; 'EJ Thomas'; 'Jane Weislogel; 'Matthew Brown'; 'Dennis Shea'
    Cc: 'Amanda Cooper'; 'Tedricks; 'Scott Whitlock'; 'Mary Jo Cusack'; 
        'Bud Baeslack'; 'Kim Nixon-Bell'
    Subject: Response to RS&H Memorandum
    Ms Keister and the Part 150 Technical Subcommittee:
    Please see the attached two documents. The first is a response the to
    RS&H Memorandum we received from Ms. Keister on April 4, 2008. You
    will see that we have accepted their information regarding Greenwich
    Mean Time (GMT) and have found a calculation error in one footnote.
    However, the rest of their criticisms do not appear to be valid.  We
    have also found that RS&H is incorrect in their statement that
    information is not included in the FlightAware data base.  We found
    the information needed for the preparation of flight mix including the
    information regarding the four aircraft types which RS&H stated were
    omitted.  Based upon our investigation, there is no need for RS&H to
    have used a restricted data base as the sole data base for the
    preparation of the flight mix.
    The second document is an update of our test study revised to reflect
    Greenwich Mean Time (GMT).  You will see that we have combined the
    data from WebScene, which the RS&H team used to develop flight tracks
    but not fleet mix, with the data from FlightAware including data on
    the supposedly omitted operations of certain aircraft.  We believe
    that our resulting data base is significantly more complete than the
    data base RS&H used.  Further, in reaching our conclusions we relied
    only on the empirical information contained in the two data bases and
    did not use any unverified assumptions or anecdotal information.
    As we originally stated on March 26, 2008, and now following the
    revision of our test report, we continue to recommend that the Part
    150 Technical Subcommittee should not accept the proposed night-time
    inputs without further verification.
    In order to permit us to do a more detailed verification of the
    proposed fleet mix we have contacted FAA Representative Ms. Annette
    Davis to request access to the Columbus Regional Airport Authority
    Noise Office data which was used by RS&H to prepare the fleet mix.  We
    await her reply.
    Kimberly Nixon-Bell
    Scott Whitlock

    This page last modified on Mon Apr 14 2008 at 5:53 pm
    Information about copyrights and our privacy policy.
    Have questions? Please contact us.