Sorry, maybe didn't convey this concept too well.
What I had in mind was an aircraft receiver/transmitter that was essentially a mini-cell system installed in the aircraft (interfaced into the existing intercomm).
This would enable communications directly between searcher and survivor, totally independent of any external cell site.
Essentially any equipped aircraft would become an airmobile cellphone site, it would provide all communication capability, limited only by the range of the cell phone. With the altitude of the aircraft, this could cover a quite significant area, and would be continually expanded as the search area progressed.