Bird Strike Committee Proceedings


Date of this Version

August 2001


Perching birds cause interference with data flow from the sensors used in a new version of Low Level Windshear Alert System (LLWAS). LLWAS is a US Federal Aviation Administration (FAA) airport, weather safety program consisting of a network of anemometers on top of tall poles used for detecting wind shear. Deadly wind shear has caused aircraft accidents with fatalities by creating a sudden loss of airspeed at low altitude upon take-off or landing. During installation of the LLWAS’s initial site at Fort Myers, FL, Turkey Vultures and Black Vultures were observed to perch on the arms of the sonic wind sensor at the top of a pole, blocking the data signal. This could lead to erroneous readings and can eventually cause hard failure of the equipment. Bird spikes have proven unsuccessful in preventing perching. As a temporary deterrent the FAA used a vulture effigy. With the assistance of the U.S, Department of Agriculture (USDA), the vulture effigy has been successful as a short-term solution. However, in consultation with the USDA and commercial interests, the FAA concluded that nonlethal electrical shock is the best long-term solution and is in the process of designing this for use on the LLWAS. This solution would permanently deter multiple species in an environmentally responsible manner for nationwide installation at all LLWAS sites.