WASHINGTON, 6 March 2012. The FAA William J. Hughes Technical Center’s (WJHTC’s) Separation Standards Analysis Branch (ANG-E61) has recorded its 15,000th global positioning system (GPS) monitoring unit (GMU) flight for the Reduced Vertical Separation Minimum (RVSM) program. Engineers at CSSI, a technical and engineering services company, contributed to the RVSM monitoring program and to the design of the Enhanced GPS Monitoring Unit (EGMU) in support of the program.
RVSM, defined as the reduction of minimum vertical spacing from 2,000 to 1,000 feet between aircraft at flight levels from 29,000 feet up to 41,000 feet, was implemented to increase airspace capacity in optimum fuel-saving flight levels.
The International Civil Aviation Organization (ICAO) and its members mandated the use of RVSM in the North Atlantic in March 1997. The U.S. implemented RVSM domestically in January 2005. RVSM has been implemented globally and requires that aircraft operating between flight levels 290 and 410 (inclusive) be RVSM-approved.
Monitoring an aircraft’s height-keeping performance is part of the RVSM approval process. Monitoring supports the safety assessment and safety oversight function that is required with RVSM implementation. An operator must meet the minimum monitoring requirements established by its state authority to maintain RVSM approval status. The WJHTC’s EGMU is a key component of this process.
The first GMU flight occurred on August 26, 1996 as a test onboard a U.S. Airways flight from Paris to Philadelphia. Since that first flight, operators around the globe have been monitored using the original GMU, as well as the enhanced version (EGMU) that CSSI helped to develop in 2003. CSSI has worked on the RVSM monitoring program since July 1999, and has supported more than 7,000 monitoring flights worldwide.
In May 2011, ICAO member states implemented a long-term RVSM monitoring policy requiring that aircraft operating within RVSM airspace complete a recurring monitoring flight in order to maintain RVSM approval status. Operators must complete an RVSM monitoring flight every two years (or 1,000 hours of flight, whichever is greater) in addition to the initial monitoring requirement.
