Kenya Airways 737 Search Satellite Fix was "Red Herring"

Cameroon aviation officials are claiming that data offered up by the French Satellite Tracking Centre in Toulouse was misleading as it centered their initial search area 150kms away, roughly along the Kenya Airways 737's planned track. The Communication Minister Ebenezer Njoh Moulle said: "The information they furnished pointed to two areas, one in South Africa and the other in Nyong and Soo (southern Cameroon). That is why the initial search for the plane was directed to Lolodorf and its surroundings, which is about 150 km from the actual crash site," he told reporters in Yaounde. "The question is why the plane's distress signal frequency failed to operate automatically, as ought to be the case," Moulle said. The explanation would seem to be in two parts. Firstly the Emergency Locator transmitter (ELT) located in the tail of the aircraft would only have emitted a few short bursts before being immersed by the rapidly filling crater. That 406MHZ transmission may have only been picked up by two satellites within Line of Sight of the ELT in its location below the partly shielding crater sides. The brief transmission would produce two line-of-position (LOP) arcs that intersect twice at very shallow angles (visualize two intersecting circles overlapping by half radius)). If a third satellite cannot produce another confirmatory LOP, the two points of intersection will represent two rough fixes, only one of which will be approximately correct (and therefore chosen). A four satellite fix by contrast will be quite accurate and without any fixing ambiguity....particularly after a brief resolution process based upon continuing transmissions. ELT's below the lips of craters have done this before....however a crash crater that fills rapidly with water provides a new challenge for ELT designers. Perhaps a floating antenna buoy that detaches upon impact?  Related Story