But We're Not Transmitting!
First: The signal was reported as dual-frequency (121.5 MHz and 243.0 MHz) by AFRCC. Furthermore, they reported one of the SARSAT hits about 80 miles East of Rapid City. The lesson: verify everything that AFRCC tells you. The signal was only readable by our equipment on 121.5, and was obviously not 80 miles East of here.
Second: Good equipment is always a good idea. I had initially hoped that I would be able to find the ELT quickly using only my handheld aviation radio. Because there was no audio being transmitted, the source could only be found using proper DF gear. Thankfully the Rushmore Squadron had a Little L-Per that was in good repair, also stocked with a fresh set of batteries. Good job, Rushmore!
Third: Carrier-only signals aren’t as hard to find as it sounds. You can find a carrier-only signal with no tones using DF equipment (either ground or air) if you have RELIABLE DEFLECTION on the frequency of interest. Further, compare the frequency of interest to a nearby frequency. In our case, we compared 121.5 to 121.6, because the Little L-Per we were using still had that frequency installed. There was a marked difference in the “noise” between the two frequencies. Because this was the case, we knew that 121.5 was NOT noise at all, but a silent signal. We used our standard 6 steps in DFing procedures and they pointed North off of the Rapid City Airport. This concerned me because I thought that perhaps an aircraft had crashed unobserved the evening prior, and its ELT was operating in a damaged mode. Damaged ELTs sometimes operate carrier-only. By the way, you can practice DFing a carrier only or “ghost” signal if someone qualified modifies your squadron’s practice beacon. You can find detailed instructions (including pictures) of this at http://www.cap-es.net/ES%20Electric%20Technology/Practice%20Beacon%20Modifications.htm
Fourth: There’s nothing like good intel and good information. We were hard-pressed to find a good map to plot out the lat-longs of the SARSAT hits. If you have a connection to the internet, there is a tool designed for just this purpose. You can even use it from a cell phone web browser! Check it out at http://www.cap-es.net/Gridfinder/gridfind.html.
Fifth: If your initial attack (IA, hasty search, whatever you’d like to call it) doesn’t locate the beacon, launch an airplane. It should be able to locate a signal more quickly than a ground team. After initially driving around the airport and learning the signal was off-airport, it would have been a good idea to launch an aircraft then. The UDF/ground team in this case, however, also would have been the aircrew. We simply did not have enough manpower to do both. Squadrons and ICs should take the soonest opportunity to review their contact information and recall rosters – and squadrons ought to provide this information to the Wing’s ICs. Getting the word out quickly cannot go quickly enough!
Sixth: Once you locate the source of the signal, don’t take no for an answer. The UDF was able to narrow down the source to the exact antenna it was coming from on Ellsworth AFB. We called the Tower, the Supervisor of Flying, Command Post, and the Radar Approach Control facility. All of them said, “It’s not us transmitting!” While they may not have actively been transmitting, it WAS their facility that was offending. In this case, it was the air traffic control Ground to Air Transmitter Relay, or GATR (“gator”). I was finally able to convince a supervisor to get radio maintenance out to the site, who confirmed that their 121.5 MHz transmitter was keyed up and transmitting. They shut it down at 2136z. You may have to explain yourself several times and speak in simple terms—you probably know more about this stuff than the person you’re talking to. Additionally, you need to impress upon people you come into contact with the importance of silencing a transmitter—most people simply cannot understand the urgency unless you explain it to them. Had no one come out to silence the bad transmitter, our next step would have been to contact AFRCC and law enforcement—AND in this case, Ellsworth AFB leadership. The IC should have a heavy hand in making these decisions and it behooves a team (air or ground) to have close communication with the IC for these types of situations.
This page of the CAP Emergency Services Resources™ website was last updated 07/01/2008
©2007 Scott E. Lanis. All Rights Reserved.