Radio Signals Raise Hopes for Lost Pair : Search: Based on new development, Nevada mountains combed for plane carrying Placentia couple. Then the hunt is called off.

Hopes were raised Sunday that a Placentia couple whose plane is believed to have crashed in the Nevada mountains more than two weeks ago could still be alive after authorities heard what they thought were radio signals coming from the downed craft.

Sunday night, however, Nevada Civil Air Patrol officials said that the signals may have been a fluke and that they had decided to put off any further search for pilot Larry Richards and passenger Barbara Keating, both 56. The search for the couple has involved 482 people and 812 hours of flight time.

“We feel we have attained a maximum effort on our part,” Civil Air Patrol Maj. Phillip Brown said. “We’ve searched an area that comprises two-thirds of the state of Nevada.”

Richards and Keating are believed to have crashed in the Ruby mountains, often referred to as “Nevada’s Alps” because of their steep terrain and frigid temperatures. The steepest mountain rises more than 11,000 feet, and temperatures there are rarely higher than 10 degrees this time of year, officials said.

Late Sunday, a hunter told authorities that he thought he may have seen a crash site in the mountains. Brown said that tip was being turned over to the local sheriff’s office.

On Oct. 29, Richards and Keating took off from a Jean, Nev., airfield in a twin-engine Beechcraft plane and were bound for their 107-acre ranch in Idaho. The couple had begun their trip Oct. 28, leaving from Corona.

On board was a heavy-duty survival kit along with sleeping bags, blankets, a gun and an ice chest full of food, according to relatives and Civil Air Patrol officials.

The couple were planning on roughing it while repairs were being made at their ranch.

“The ranch is not livable,” said Heather Wilson, Keating’s daughter. “They were trying to fix up two of the cabins on the property to be habitable.”

Richards is a certified flight instructor with 30 years’ flying time. He once served as a commercial pilot for Grand Canyon Scenic Tours, relatives said Sunday.

On Saturday, a Civil Air Patrol plane heard a series of clicks--approximating the international SOS distress call--on 121.5 VHF, an emergency aircraft radio channel. Officials thought the signals--originating from an area 25 to 30 miles east of Elko in the Ruby Mountains--could be coming from Richards’ plane.

Searchers then broadcast several questions on the emergency frequency. Around 1 p.m., they asked for 10 clicks if someone was in distress. Ten clicks were then made on the frequency. But many other questions went unanswered, including a request for the plane’s ID number that appears on its tail section.

Brown said the couple’s emergency locator transmitter, or ELT, was probably running low on power by now, making voice communications impossible. The couple would have to tap out any responses, he said.

Saturday evening, authorities used a helicopter with night-vision equipment in trying to find the downed plane, but were unsuccessful.

Early Sunday, 21 single-engine planes and four-wheel-drive vehicles searched the site in the Ruby Mountains that officials believe was the source of the radio signals. Ground teams tried to converge on a crash site too, but only one of six divisions picked up any kind of signal.

Officials began re-evaluating Saturday’s communications.

“We thought we had some contact on Saturday, but we’re beginning to wonder now if we actually did,” Brown said.

Brown said the couple’s ELT could have lost so much battery power by now that it simply can’t transmit anymore. Saturday’s signal, he further speculated, could have bounced off a mountain, thereby sending rescuers looking for the plane in a completely wrong direction. There was a third possibility: The signal may have come from a different plane or simply been caused by a blending of radio frequencies.

“We’re beginning to wonder why we have a large amount of activity (Saturday) and the next day we don’t,” Brown said.

Sunday’s search was called off at 3:30 p.m.

“This is very dangerous terrain and you don’t want your ground teams out in the boondocks with lowering temperatures at night,” Brown said.

Since Nov. 3 when Richards and Keating were reported missing, search teams have scoured more than 56,000 square miles.

Brown said officials think Richards and Keating may have crashed somewhere near the 9,180-foot Secret Peak. Temperatures at night there, he said, would be no higher than 10 degrees.

Richards owns Richards Automotive in Asuza, a mechanic’s shop. Keating owned a Santa Ana pet-grooming company--Grooming by Barbara--until she sold it a few years ago.

Both are described by relatives as being in good physical condition. Keating, who was born and raised in Scotland, golfs regularly and once studied physical education.

“The only thing that would keep them from surviving would be if they are too hurt to help themselves,” said Wilson, 33, of Placentia.

Four of Richards’ six daughters are in Elko helping search teams.

“We are all sitting on the edge of our seats,” said Larilynn Murphy, one of Richards’ daughters. “We were so hopeful last night. We thought it was over but it’s not over yet.”

Murphy, 36, of Meridian, Ida., said her father is “a pilot who doesn’t take chances. If he didn’t think something was right, he would land the plane.”

On one occasion Richards landed in a rather unlikely location.

“Something spooked my dad so he landed that plane in the Disneyland parking lot,” Murphy said.

Richards, Murphy said, used to reassure tourists flying over Grand Canyon--the site of several recent plane crashes--that safety was his foremost concern.

Times staff writer David A. Avila contributed to this article.