Connecticut Department of Transportation’s Five General Aviation Airports Obstruction Analysis


This large project involved evaluating both on and off airport obstructions for six 6() airports owned and operated by the State of Connecticut, including Bradley International (which serves the metropolitan area of Hartford Connecticut), Groton – New London, Hartford Brainard, Windham Airport, Waterbury-Oxford Airport, and Danielson Airport. The airports included in the study ranged in complexity from an air carrier airport with a Category (CAT) II/III approach to a single-runway airport with visual approaches.

In addition to the FAR Part 77 “Imaginary Surfaces,” this study evaluated all relevant FAA criteria and standards including; Terminal Instrument Procedures (TERPS) and Airport Design Standards such as Obstacle Free Zones (OFZ), Runway Safety Areas (RSA), Runway Object Free Area (ROFA), Glidepath Qualification Surface (GQS), Departures Surface, One-Engine Inoperable (OEI) Obstruction Clearance Surface (OCS) and Threshold Siting Criteria. Clear areas associated with NAVAIDS, visual aids, and Approach Lighting Systems (ALS).

The format of the analysis took advantage of the benefits of Graphical Information System (GIS) which provided the client with greater flexibility, analytical and sustainable tools. With the data as well as the surfaces in GIS, Connecticut Department of Transportation (ConnDOT) will be able to do “What if Studies,” enabling them to see the effects of removing an obstruction or to determine how far a threshold needs to be displaced because of an obstruction. The GIS format will provide greater efficiency and cost savings to ConnDOT in the future by allowing them to rerun the analysis with updated survey data quickly and in-house. It will also allow them to track obstruction removal projects by associating the grant number, date of removal, and cost with each obstruction identified.