There has been a focused effort to locate the flight data recorders and cockpit voice records, âblack boxesâ, from the aircraft that crashed into the World Trade Centre towers on 11 September.
Recorders used by commercial aircraft must be equipped with underwater locating devices.
According to Benthos, shortly after the crash, Rock Babicz, product manager for Benthosâ locator products, received several calls from the agencies involved in the recovery efforts. They believe there is a slight chance that the pingers may be active in the pile due to a combination of the water used to fight the fires at the scene and recent rainfall. Designed to go active upon immersion in water, the aviation pinger shorts out and triggers a switch that sends an acoustic signal every second for 30 days. The pingers are rated to 6,000 metres.
If the pingers survived the crash, fires and subsequent crush of the buildings, and they are active, it is hoped that their signal will lead investigators to the location of the black boxes.
Benthosâ engineers and technicians immediately went into action and within a day produced a device that would be capable of detecting the pingers at a distance of more than 60 feet through debris. Since Benthos manufactures a wide variety of pingers, pinger receivers, transponders and transponder interrogators designed for use underwater, they were able to quickly produce the portable device currently being employed to sweep the pile.
Visit http://www.pingers.com or http://www.benthos.com