Cruisers & Sailing Forums - View Single Post - 121.5 EPIRB activation after Feb 1, 2009?

sandy daugherty · 22-06-2008, 15:48

Radio Direction Finding on a 121.5 signal is a bear. It took a trained adult crew from the civil airpatrol two and a half hours to locate a tripped elt on a boat at Herrington Harbour North Marina last summer. Thats after an air search narrowed down to an area of several square miles. A civil aircraft radio will pick up the signal if within about 20 miles of a transmitter WITH A FRESH BATTERY, but it will not be able to tell Center any more than "Hey, I hear One." It would have no VHF direction finding equipment An airliner over the ocean would have to fly almost directly overhead to hear you, would not be able to see you unless you could actually hit the cockpit with sunlight reflected from a mirror (as in daytime, clear skies,) and certainly could not loiter while help came. So.....

Don't count on an old 121.5 epirb to be anything more than false hope and bad trouble.

I flew Search and Rescue in the Navy in the early 70's and several times we were still searching when an ELT battery died. Heart-breaker.

22-06-2008, 15:48	#10
sandy daugherty Registered User Join Date: May 2008 Location: near Annapolis Boat: PDQ 36 "Page 83" Posts: 772	Radio Direction Finding on a 121.5 signal is a bear. It took a trained adult crew from the civil airpatrol two and a half hours to locate a tripped elt on a boat at Herrington Harbour North Marina last summer. Thats after an air search narrowed down to an area of several square miles. A civil aircraft radio will pick up the signal if within about 20 miles of a transmitter WITH A FRESH BATTERY, but it will not be able to tell Center any more than "Hey, I hear One." It would have no VHF direction finding equipment An airliner over the ocean would have to fly almost directly overhead to hear you, would not be able to see you unless you could actually hit the cockpit with sunlight reflected from a mirror (as in daytime, clear skies,) and certainly could not loiter while help came. So..... Don't count on an old 121.5 epirb to be anything more than false hope and bad trouble. I flew Search and Rescue in the Navy in the early 70's and several times we were still searching when an ELT battery died. Heart-breaker.