On Wednesday September 18, 2002 an overhead satellite discovered an Emergency Locator Transmitter (ELT) emitting a signal in the Goodwater, Alabama area. MAJ David Boswell from the Alabama Civil Air Patrol was notified and an aircrew was dispatched. The only problem was that the weather was IFR. Two aircrews were sent out at different times to locate the ELT, but they could only give positions above the weather without being able to give any visual locations. Friday morning the weather had improved enough to send out another aircrew that consisted of CPT Perry Jaynes and myself. The only thing different about this crew compared to the other crews sent out was that they decided to incorporate their search with the aid of a hand held Magellan 315 GPS. The 315 has the capability of recording and displaying its track history. This would allow the aircrew to have a pictorial display of their ground track and fly a search pattern as depicted in figure 1. shown below.
The ELT search was performed under the most ideal conditions. The transmitter was finally discovered to be located in an open flat bed trailer with a large air conditioner on top of it (See photo 4.). The flat bed trailer was about two to three hundred feet from a red barn, next to a small house in a wooded area. The area was mostly flat land surrounded by small rolling hills. Also, there were no power lines overhead to reflect the signal. The ELT was on its side and in the auto activation mode. The unit was completely wet, and the activation switch was believed to have been shorted by the water, turning the unit on. Its signal mainly radiated upward, but was only readable from about four miles away. The signal was very strong within this range.
Perry and I flew over the city of Sylacauga at an altitude of 2500 ft. on a heading of approximately 120º toward Goodwater, AL. Within about ten miles passed Sylacauga, we heard a faint ELT signal. Perry then lowered the planes altitude to 1700 ft. and reduced its airspeed to 80 mph and added one notch of flaps. The DF sensitivity was turned up full and the CDI was centered. The Magellan 315 was set to the moving map display and its track history was turned on (See point A in figure 1) for our starting point. We then proceeded toward the ELT keeping the needle centered. When the CDI needle swung from its center position to a full deflection, we knew that we had passed over the ELT. I then told Perry to continue straight on the heading of 120º for at least one or two miles beyond the ELT. An estimated distance using the 315's nav. display. I told Perry that I would tell him when to turn left to a north heading. The 315's map was set to a scale of 1 mile to better judge the distances. When we reached the two-mile mark, position B (See figure 1), the plane was turned to a north heading. We continued on this heading toward point C until our position on the 315's moving map looked like a good spot for this location. The plane was then turned left until the CDI of the DF was centered and the plane was heading toward point D. Points (A-H of Figure 1) were all estimated using the moving map display of the Magellan 315. All points were spaced approximately one to two miles from the ELT's estimated location. Each time we passed over the ELT's approximate location, a mental picture was made of the area beneath the plane. When point D was reached, the plane was turned to the right to a north heading. Since we had a mental picture of the ELT's location, we used the airplanes right wing tip as a pointer. We turned to the east (Point E) just before the wing tip pointed to the ELT's location. Perry adjusted the east track so that we were on a 90º heading and the CDI was centered. This gave us a good chance to record the north latitude reading from the airplane's GX 55 GPS. When point F was reached, the plane was once again turned toward the north and I proceeded to estimate where point G would be located. The plane was then turned west from point C and we proceeded toward point G. Point G was to represent a location where the plane could fly on a north to south heading over the ELT's location. This time we used the left wing tip as a pointer. Again Perry turned the plane to a south heading just before the wing tip pointed to the ELT's location. Perry adjusted the south heading so that the CDI was centered and we continued on to point H. This gave us a chance to write down the approximate longitudinal heading. The real latitude and longitude of the ELT's location would come from the intersection of the track history (airplane's ground track radials) on the Magellan 315 and backed up by the GX 55 GPS in the airplane.
Once all of the plane's track radials were recorded on the 315, the location of the ELT was then identified. This was done by moving the pan-n-scan marker over the point were all of the radials crossed. Pressing the mark button on the 315 gave the Lat./Long location of the ELT as read by the 315. This mark could also be saved for future reference in the 315's user database.
