First Such System Installed, Tested And Approved For Use In National Airspace

The FAA recently published a memo announcing the approved use of Audio Visual Warning Systems (AVWS) in the National Airspace System (NAS) and the administration’s intentions to update Advisory Circular 70/7460-1K, Obstruction Marking and Lighting, the recommended marking standards for obstacles that penetrate the NAS.

An AVWS is described by the FAA as "a system that activates obstruction lighting and audio signals to alert the pilot of potential collisions with obstacles." The FAA memo goes on to state "OCAS is the first AVWS to be installed, tested, and approved in the National Airspace System (NAS)."

An AVWS is designed to significantly reduce the potential for a wire strike or obstacle collision for low flying aircraft. There are over 5000 such incidents/accidents in the National Transportation Safety Board database.

The Obstacle Collision Avoidance System (OCAS) uses a small radar to detect and track an aircraft’s proximity to an obstacle. Two warning zones are defined. The first warning is the activation of medium intensity strobe lights to allow the pilots to visually identify the obstacle. If the pilot does not take avoidance action and the aircraft enters the second warning zone, a VHF broadcast is transmitted to the pilot’s radio. The message includes warning tones and a description such as “POWER LINES…POWER LINES.” The OCAS system has the ability to simultaneously broadcast on several frequencies within the VHF range of 118-136 MHz. The FAA/FCC will determine acceptable broadcast plans based on the geographical location of the system.

No additional onboard equipment is required, which makes it available to almost all aircraft. OCAS says the audio warning is the most powerful aspect of the system as it provides a warning in any type of visibility or weather conditions.

OCAS is currently operational in the US, Canada, and Europe.

FMI: www.ocasinc.com