'Pingers on missing Malaysian jet to stop emitting by Apr 6'

If the missing Malaysian plane is not found soon, the jet's two pingers may die with a whimper, possibly around April 6, a senior executive of a leading beacon manufacturer has warned.
The ping itself is unremarkable, Anish Patel, president of beacon manufacturer Dukane Seacom Inc. Said.
Sunday marked the 16th day of the massive multi-nation hunt for Malaysia Airlines Flight MH370, and near the halfway mark in the pinger's minimum battery life.
When the battery dies, possibly around April 6, the job of finding the flight data and cockpit voice recorders will get significantly harder. And so will the job of solving the mystery of the missing Boeing 777-200 aircraft, which vanished mysteriously on a flight from Kuala Lumpur to Beijing on March 8.

Every commercial airplane is required to have pingers -- technically called underwater locater beacons -- to help locate lost aircraft. One is attached to the flight data recorder; another to the cockpit voice recorder.
Patel believes his company manufactured the pingers on MH370.

"We are confident it could be one of ours," he told CNN. Malaysia Airlines is a customer of Dukane Seacom, and the company's pingers have been installed on Boeing 777s.
"We're preparing to address questions should it be ours," the Indian-origin executive says.
After 30 days, the battery will continue providing power and the beacon will ping, but the output will quickly drop, Patel says.

"As the battery 'wears down' the pinger output decreases until the battery reaches a point that no ping is emitted," Patel says.
"The pings get lower and lower in 'volume' as the battery weakens."
"Our predictive models and lab tests show 33-35 days of output before we drop below the minimal value," he says.
"Depending on the age of the battery, it could continue pinging for a few days longer with progressively lower output levels, until the unit shuts down."
Cockpit voice recorders, often referred to as a "black box", records the audio environment in the flight deck of an aircraft.

Flight data recorders capture a wide array of data, including altitudes, air speeds, engine temperatures, flap and rudder positions. Data recorders are built to withstand the rigors of flight and the trauma of crashes.
The pingers are activated upon immersion in fresh or salt water, and emit a signal at 37.5 kilohertz.
To detect the signals, searchers drag hydrophones behind boats, drop them from ships or planes, or use specially equipped submersibles.
Under favourable sea conditions, the pingers can be heard 2 nautical miles away. But high seas, background noise, wreckage or silt can all make pingers harder to detect.