Initial operational experience with CAT I Ground Based Augmentation System (GBAS)

The paper addresses initial experience and lessons learned with the implementation of the Category I (CAT I) GBAS in the US National Airspace (NAS) and internationally. The paper will review the GBAS system architecture including Boeing and Airbus integration and airline equipage. Next the paper will address institutional, operational and technical experiences encountered in the installation and operation of GBAS. GBAS is included in the FAA's NextGen Implementation Plan and part of International Civil Aviation Organization's (ICAO) Aviation System Block Upgrade Program. Aircraft Original Equipment Manufacturers (OEM) s such as Boeing and Airbus are currently delivering aircraft with GBAS Landing System (GLS) capability. CATI I GBAS facilities are operational or underway globally (Germany, Australia, Spain, Switzerland, Brazil, India, Russia) and as non-Federal systems in the US. A GBAS CAT I design, the Honeywell SLS-4000 was approved by the FAA in September 2009 as a non Fed system for use within the NAS. Category I (CAT I) GBAS has been operational for public use at Newark Liberty International Airport (EWR) since September 2012, and at George Bush Intercontinental Airport (IAH) in Houston, Texas since April 2013. They are owned and operated by the respective airport authorities. United Airlines and Delta Airlines achieved FAA approval to fly GLS approaches. In 2014 United Airlines reached the milestone of 1000 GLS approaches since their operational approval. An increasing number of international carriers are also taking advantage of the GLS capability at Newark and Houston (e.g. British Airways, Emirates, and Lufthansa). The main body of the paper includes three sections each dedicated to addressing specific challenges, lessons learned for GBAS implementation - namely the institutional, operational, and technical challenges. The FAA chose not to install CAT-I GBAS as a federal system but did approve the system for use in the NAS. Public and private non-Fed systems installed in the NAS require FAA inspection and monitoring. The challenge with GBAS is that no federal GBAS systems exist in the NAS, but FAA must have appropriately trained personnel, procedures, and equipment to perform the required functions. GPS/GBAS performance monitoring and service prediction capability had to be addressed when implementing GBAS. Operational aspects will address airline approval process, pilot training, airline/pilot perception of GBAS and GLS and experiences and perception during daily operations. The operational section will also address GBAS benefits and based on lessons learned expectations of the airline and pilot community for the need to rapidly to exploit GBAS potential in noise reduction and shorter approach paths and extended service volume of GBAS and additional operational capabilities like GBAS CAT II approaches against a CAT I system. A recurring topic is also the RNP-GLS transition, which is key to address operational improvements in terms of flight efficiency and environment while maintaining the precision approach capability. The Newark GBAS station encountered GPS radio frequency interference caused by illegal personal devices. Honeywell and the FAA worked together to develop technical and procedural mitigations for the encountered jamming. The mitigations are designed to allow the GBAS to safely operate during frequent RFI events. Modifications to the SLS-4000 were completed by Honeywell and this modified version of the system was approved in September 2012 and is now being used operationally at Newark as well as all other U.S. SLS-4000 sites.