Search crews at Grand Canyon National Park have turned to high-resolution photography in their search for a single-engine plane that went missing over the park.

Crews from the National Park Service and Coconino County Sheriff’s Office have been searching for Joseph Radford for almost three weeks since determining that he and his plane were last seen on Friday, March 11, at the Grand Canyon Airport located just south of the national park.

During the search, an NPS helicopter and fixed wing aircraft flew approximately 2,000 air miles over a search area originally estimated at 600 square miles.  To date, the Park Service says no signs of Mr. Radford’s plane or of a crash site have been detected.

With the search area thoroughly covered by the available technology and weather  worsening, search and rescue personnel last week turned their efforts toward sorting and analyzing the clues investigators had been gathering while the search progressed, a Park Service release said.

This past Tuesday NPS and CCSO staffs, along with Civil Air Patrol and Air Force Rescue Coordination Center experts, gathered to analyze those clues alongside the latest interpretations of the technical data.  Through their analysis, SAR personnel were able to define smaller areas within the larger search zone that could be searched again with more advanced technology.

On Thursday, members of CAP’s Nevada Wing used a Surrogate Predator aircraft to search six areas in the Fossil Corridor identified as probable areas where Mr. Radford’s plane might have gone down. On Friday the CAP crew was to complete its flights over the six search areas and provide the Surrogate Predator footage to park staff for review.

The Surrogate Predator’s sensor ball, mounted underneath the wing of a CAP Cessna 182, provides high resolution imagery.  The areas where CAP pilots are focusing their efforts were identified based on FAA radar track and cell phone signal analysis, as well as visual sightings.

This is the first time a Surrogate Predator has been used for a search mission, according to park officials.  To date, CAP has relied upon this new technology to help train soldiers and airmen for combat operations overseas.

After Friday's flight, the NPS will analyze the new imagery provided by the Surrogate Predator in a continued effort to locate the missing plane.  Search activities were to continue on a limited basis as new evidence and information becomes available.