Mr. Michael Harrison
Federal Aviation Administration
800 Independence Avenue, SW
Washington, DC 20591
Re: Satellite Navigation Transition
Dear Mr. Harrison,
On behalf of over 384,000 members, the Aircraft Owners and Pilots Association (AOPA) submit the following comments in response to the draft Navigation and Landing Transition Strategy dated June 5, 2002. As requested, we have reviewed the strategy and submit the following insights.
It is disconcerting to AOPA that major decisions on the nation's navigation architecture and infrastructure are about to be made in less than 45 days. We understand that the Department of Transportation (DOT) has met with the modes to discuss issues of Global Positioning System (GPS) interference since September 2001 when a report by the VOLPE research center was released identifying GPS interference as an issue. From our perspective, aviation industry involvement began for the first time five weeks ago, not nearly enough time for adequate information collection, validation, and development of feedback. Additionally the discussion about decommissioning today's navigation infrastructure generates many concerns at AOPA. Should the focus remain on GPS and the changes necessary to mitigate interference, our concerns diminish.
AOPA has three primary concerns in regards to this transition strategy. First, the transition strategy fails to provide adequate time for a transition of all aircraft to satellite navigation. Additionally, despite Federal Aviation Administration (FAA) assertion, the infrastructure for the transition to satellite navigation (SATNAV) is not currently in place, nor will it be soon. This issue is compounded by the aggressive decommissioning schedule proposed for ground-based navigational aids. Lastly, the government needs to establish a visible, multi-agency GPS interference elimination "go team" with proven experience at identifying, searching, and terminating GPS interference.
Before discussing details of the transition strategy, it is important to understand the perspective from which these comments are written. For many years AOPA has consistently worked with the FAA advocating for incentives years before any changes in today's navigation infrastructure begins. Those incentives include:
From the end-user perspective, WAAS is not available for IFR and will not be until December 2003, less than four years from fiscal year 2007 when the first VOR services are proposed for termination. A four-year transition to satellite navigation is unacceptable to general aviation. What is acceptable depends on the availability and quality of the satellite navigation incentives. AOPA disagrees with the assertion that major incentives will develop in the next 18 months. No GLS approaches (CAT I ILS minimums) will exist using WAAS without dual frequency receivers sometime after 2010. This change to the WAAS program may negatively impact transition incentives for general aviation. To what extent is unknown at this time, and it may not be known for several years of LPV approach availability. Re-equipage to dual-frequency GPS requires additional time, a factor not mentioned in the strategy for ILS decommissioning.
Once the incentives listed below exist or are nearing completion, AOPA believes that general aviation will begin the transition to satellite navigation. Until such a time, the use of today's ground-based navigation aids and unaugmented GPS to supplement VOR continues.
In addition to the concerns about WAAS and the lack of incentives available to general aviation, AOPA is concerned about the transition strategy's premise that the change in the ground infrastructure services can begin incomplete satellite navigation infrastructure, a poorly performing information dissemination process, and a fundamental lack of multi-departmental coordination of GPS interference events.
First of all, the FAA must understand that aircraft owners could consider investment in WAAS navigation equipment a high risk without a third geostationary WAAS satellite in space and operating. Loss of the WAAS system will severely impact general aviation operations, and the users must be given time to develop confidence in the system's availability and reliability. The threat of losing WAAS coverage (and receiver investment expenses) over major portions of the United States with a single satellite loss may be an issue to many general aviation pilots.
GPS interference information is disseminated poorly. If a notam is issued for GPS interference, it is sometimes issued as a local notam, reducing the broadcast to a very small geographic area. Pilots are unable to obtain local notam information prior to departure on most cross-country flights. User groups such as AOPA seldom, if ever, are called upon to utilize resources available to quickly and accurately broadcast such information to users.
The satellite navigation information dissemination system needs to be fixed. This includes broad notam dissemination, immediate notification to news media, flight service, and user organizations who can then re-broadcast the information quickly to many users. This improved system must be utilized several times before users can increase confidence in GPS interference notification. In the past, there have been extremely poor response times to interference events. The federal government must develop a multi-agency GPS interference elimination "go team" capable of eliminating interference extremely quickly.
Given the current status of incentive availability and the additional issues identified above, we strongly object to any decision to decommission ground-based navaids as discussed in the transition strategy. AOPA supports the continuation of deadline-driven discussions/decisions on the initial operational capability of WAAS and the next steps to achieving GLS. Additional deadlines and milestones are also required for the development and publication of operational approvals to use WAAS, instrument approach procedures, and RNAV routes, and the development of incentives for manufacturers to use low-cost navigation databases.
AOPA recommends that the FAA immediately establish timelines/milestones for the improved response to GPS interference impacting civil aviation operations. The FAA must have in place all necessary memorandums and agreements, and interagency issues resolved and in place, before proclaiming that the ability to mitigate GPS interference exists. If general aviation is expected to transition to satellite navigation, the FAA should focus on maintaining confidence in the government's ability to identify, locate, and eliminate GPS interference in under six hours. This "anti GPS" team should be highly visible and publicly known. The presence of this team should be used as a deterrent itself.
While some parts of the document are well thought out, some parts are still clearly notional. For example, the strategy includes some operational contingencies, which generates many questions. In what airspace, and under what condition, is a backup capability required on board an aircraft? If required, does it need to be installed, or can it be portable? How will the use of temporary flight restrictions be effectively used in the manner prescribed? Will VFR operations navigating without GPS be impacted? If so, how? It is AOPA's position that continued discussion needs to occur before AOPA supports the further development or use of this strategy.
AOPA agrees with the FAA observation that loran is the best theoretical backup to satellite navigation. AOPA members continue to use loran in its present state (loran-C). It is AOPA's understanding that to utilize loran for a backup under IFR including approaches, that today's loran-C receivers will be rendered useless. AOPA encourages the FAA to continue researching loran and other systems that enable area navigation during GPS interference. This capability increases navigation capabilities and itself acts as a deterrent against intentionally jamming of GPS navigation equipment.
AOPA provides the above comments as they relate to the draft Navigation and Landing Transition Strategy of June 5, 2002. It is our desire to continue to work with the FAA and DOT as key infrastructure decisions are made. However, AOPA remains committed to general aviation, objecting to timelines and strategies that negatively impact operations in the United States. We look forward to continued dialogue during this difficult but important process.
Director, Advanced Technology
June 11, 2002