Absence of mobile signal,locater hampers search

“Tawang as a district has only three base trans-receiver stations (BTS),with each of them covering an area of 5-6 km in radius. And,given the topography of the district,mountain ranges often create barriers for signals to move,” a senior BSNL official based in Itanagar said on Tuesday.

While a mobile BTS normally covers 5-6 km radius in the plains,the signals might work even up to 10-15 km in hilly terrain. But people located in valleys between two steep mountain ranges are normally not in the network,he said.

The Nagar GG (grazing ground) area that has been pinpointed for focused search is one of the vast tracts in Tawang district that shares about 100 kms of international boundary with China.

Nagar GG adjoins Sela Pass,located at a height of about 14,000 feet,and is not covered by any mobile BTS.

“We don’t have any BTS in the Sela range. While the Army has its own radio network,mobile signals sometimes work like magic in Sela as well as Jaswantgarh from the Tawang or Dirang BTS provided the weather is clear. Those signals,however,do not last long,” the BSNL official said.

But,while mobile connectivity is one thing in this strategically located district,the helicopter should have been located by the signal of its emergency location transmitter.

But despite the use of fighter aircraft and satellites,the absence of a crash-proof emergency locater on board the missing helicopter has made it impossible to trace it even four days after it went missing.

The emergency locater — the only equipment on board the helicopter that would have given its precise location — is feared to have been destroyed in the crash.

According to current flight safety standards,the crucial piece of equipment does not have to be crash proof.

Even in the case of former Andhra Pradesh chief minister YSR Reddy,the wreckage of the chopper was located almost 24 hours later as the emergency locater was smashed.

The government is now contemplating making it mandatory for helicopters to have the new Automatic Dependant Surveillance-Broadcast (ADS-B) system that would enable air traffic controllers to keep a real time check on its location and path. with ens,delhi