Reduced Vertical Separation Minimums

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Project Number: 

The term Reduced Vertical Separation Minimum describes a reduction from 2,000 feet to 1,000 feet of the standard vertical separation required between aircraft flying at levels from FL290 (29,000 ft.) and FL410 (41,000 ft.). RVSM reportedly enhances aircraft operating efficiency by making more fuel/time efficient flight levels available, enhancing air traffic control flexibility, and providing the potential for enhanced enroute airspace capacity.

The FAA has developed the System for assessing Aviation’s Global Emissions (SAGE) to estimate aircraft fuel burn and emissions for variable-year emissions inventories and for operational, policy, and technology-related scenarios.  One element of this effort is the ability to model air traffic movement in 4-D flight trajectories (latitude, longitude, altitude and time) using as much measured data as possible.

To examine more fully the environmental benefits of RVSM, PARTNER Project 18:

  • Assessed the accuracy of the fuel burn and emissions modeling within SAGE as a function of weather source, resolution of weather data, and modeling methodologies, through comparison to CFDR data
  • Utilized ETMS data from one month of representative days, just prior to and shortly after, the implementation of RVSM to quantify the effects of this transition
  • Reported on the results of the RVSM study, including reference to the previous EUROCONTROL and FAA studies

Participating university

Massachusetts Institute of Technology

Lead investigator

Ian Waitz, Massachusetts Institute of Technology,

Project manager

Maryalice Locke,


  • Assessment of the impact of reduced vertical separation on aircraft-related fuel burn and emissions for the domestic United States. Andrew Malwitz, Timothy Yoder, Sathya Balasubramanian, Gregg Fleming, Ian Waitz. November 2007. (Report No. PARTNER-COE-2007-002) Download (.pdf 1.3M)