The search for the missing helicopter is focussed around roughly 300 sq. km. of Nallamala forest in Kurnool and Prakasam districts, a daunting task indeed for the police teams that have fanned out into the thick forest area, once a Maoist stronghold.

Large contingents of Grey Hounds, the elite anti-naxalite commando force, have been rushed to Kurnool and Prakasam districts for the search and rescue operations. The commandos are the most competent for the job as they are well-versed with the forest terrain, but inclement weather is hampering the progress of the units.

The forest is spread over nearly 6,000 sq.km. and traverses through Mahabubnagar, Kurnool, and Prakasam districts, which incidentally were on the flight path of the Bell-430 helicopter that carried Mr. Rajasekhara Reddy.

The search teams have narrowed down the area on the expectation that after being airborne for one hour, the chopper would have crossed or have been in the vicinity of Atmakur town in Kurnool district.

What has surprised officials is the complete radio silence from the Bell-430. Every helicopter, sources in the aviation industry say, is equipped with High Frequency (HF) and Very High Frequency (VHF) sets.

Puzzling fact

While HF is used for long range communication, the VHF is used for communication within 150 km. In the event of a crash, however, these sets might not function if the external antennae are destroyed under the impact of a crash.

The other puzzling fact in the episode is that every helicopter is expected to have an Emergency Locating Transmitter (ELT) fitted to the aircraft body, while the pilot is expected to carry a Personal Recovery Beacon (PRB).

The ELT would start giving distress signals in the event of a crash and the PRB, once activated, would start beaming the Global Positioning System (GPS) ‘latlong’ (latitude and longitude) details.

This would have helped authorities pinpoint the location of the chopper, if it had crashed or force-landed in an interior place.

However, none of these details are available, making it more difficult for the search and rescue teams, officials say.