Friday will mark one week since search efforts began for a missing couple and their aircraft, lost somewhere in the Sierra region.

Using a joint command, the Civil Air Patrol and Mono County Sheriffs Department are working together to search the rugged, snow covered terrain for the downed aircraft.

First Lt. Matthew Scherzi with the Civil Air Patrol reports that the plane, a motorized glider, was scheduled to arrive in Modesto Friday evening after leaving from Tonopah, NV. The pilot had filed a flight plan and was last picked up on RADAR east of Mammoth. So far no sign of the plane or the two occupants has been seen despite close to 150 search flights so far.

Searching for a white plane in the Sierra snowpack is difficult enough, but the search area is large. Lt. Scherzi reports that the search area is basically a fifty mile radius around Mammoth, about 2500 square miles in size.

Scherzi says, flying in the mountains at these altitudes generally requires the crews to be on oxygen as either a requirement or as an added safety feature. Communication between aircraft, as well as the Base has its own challenges due to terrain obstruction of radio signals, and distance. At least one airborne communications aircraft is airborne at all times, flying as high as 16,000 feet.

Flight crews look for any evidence of an aircraft or people on the ground, but they also monitor an emergency transmitter frequency in case they can pick up a signal from an emergency location transmitter.

Six days into the search effort and Scherzi reports that the search is scheduled to continue at least through the weekend if needed.