B747FE From Hong Kong, joined Jun 2004, 230 posts, RR: 3 Reply 1, posted (8 years 1 month 3 weeks 6 days 23 hours ago) and read 1480 times:
Each recorder, FDR and CVR is equipped with an ULB Underwater Locator Beacon, to assist in locating in the event of an overwater accident. The ULB, normally attached to the front of the recorders, is activated when the recorder is immersed in water, salt or fresh water and is powered by a lithium battery. In some models, the battery can be replaced in the field.
. Transmits an acoustical signal on 37.5 kHz ± 1 kHz . Operating depth is surface to 20,000 feet . Shelf life limit is six years . Operating life 30 days
"Flying is more than a sport and more than a job; flying is pure passion and desire, which fill a lifetime"