A brand new Pawan Hans' Sikorsky chopper with 9 people on board crashed into the Arabian Sea, about 50 nautical miles from the Mumbai coast on Tuesday, killing four people -- including three Oil and Natural Gas Corporation employees.
The helicopter, which was part of the six Sikorsky S-76D helicopters that Pawan Hans had recently leased from Milestone Aviation Group, was about 4-5 minutes away from its destination -- ONGC's Sagar Kiran rig -- when the incident took place, company officials with direct knowledge of the matter said.
The chopper went down around 1145 hrs, just 1 nautical mile away from Sagar Kiran, but managed to stay afloat with the help of the attached floaters, helping rescuers pull out all the nine, including two pilots, after ONGC and Navy/Coast Guard scrambled in one of the fastest rescue missions in the western offshore.
Four of the nine pulled out were unconscious and airlifted in a Navy chopper to a hospital in Mumbai, where they were declared dead, an official said.
Three of the dead are employees of Oil and Natural Gas Corporation, the state-owned firm which had hired helicopter service from Pawan Hans to support its oil and gas exploration and production operations in the western offshore.
The fourth person belongs to a contractor working for ONGC.
The circumstances that led to the incident were not immediately known but western offshore had inclement weather and there was a swell in the sea.
Officials said ONGC has already instituted an inquiry into the incident. The Directorate General of Civil Aviation is also likely to order a separate inquiry.
Detailing sequence, officials said the chopper took off from Juhu helibase this morning just like any other day but 1 or 1.5 km from the landing zone on the rig, it went down into the sea.
It, however, managed to stay afloat with floaters fitted on such helicopters going offshore.
"What we don't know is if the helicopter toppled during the float," an official said.
On first information, ONGC and Navy scrambled vessels for the rescue.
A high-speed boat from Sagar Kiran rig was first to reach the spot. In a matter of 90-100 minutes, all personnel were pulled out.
While vessel Malviya-16 rescued four persons, one person was pulled out by rescue boat from Sagar Kiran rig. Navy choppers airlifted four unconscious persons to hospitals in Mumbai, the official said.
The helicopter sank soon after.
A multi-support vessel (MSV) is already at the spot, trying to salvage the helicopter wreckage, he said, adding divers too are at the spot.
ONGC has key oil and gas fields off the Mumbai coast and Pawan Hans helicopters routinely ferry company employees and officers to the oil installations that are situated as far as 160 kilometres from the coastline.
The fields in the offshore include Mumbai High, the nation's largest oil field, and Bassein fields, the largest gas field.
The helicopter crash is not the first accident in ONGC's history. In August 2003, a Mi-172 helicopter crashed off the Mumbai coast, killing 27 people and the pilot on board.
On January 13, 2018, a Pawan Hans helicopter with seven people on board, including five ONGC officers and two pilots, crashed off the Mumbai coast minutes after it took off for the state-owned company's oil installation in the Arabian Sea. All seven died.
In 2002, a Dauphin helicopter hired by ONGC crashed into the sea but the 10 passengers were rescued.
In April 2003, a Bell 412 helicopter ferrying ONGC personnel crashed while landing at the Juhu aerodrome.
Later ONGC in a statement said the helicopter carrying nine persons on board "made an emergency landing around 11.45 am today on the Arabian Sea".
The regional contingency plan was immediately activated. "With prompt action, one person was rescued by lifeboat launched from ONGC rig Sagar Kiran and four persons were rescued by ONGC stand-by vessel Malviya-16," it said.
"Despite inclement weather conditions, the rescue operations were carried out very swiftly," it added.
Four persons rescued by a Navy chopper were brought to the base unconscious. "Unfortunately, they could not survive," the statement said. "ONGC deeply mourns this tragic loss of lives. ONGC is reaching out to the affected families and extending all possible support."
"#SAR #RescueAtSea All nine survivors rescued. Four survivors picked by OSV Malviya 16, one by boat of Sagar Kiran oil rig & two each by #IndianNavy ALH & Seaking helicopters. Four critical survivors being evacuated to Juhu by Navy helicopters for management at @ONGC_ hospital," PRO Defence, Mumbai, tweeted.
The Navy had deployed the Seaking and ALH helicopters and Indian Naval Ship Teg for the rescue of passengers and crew of the ONGC helicopter 60 nautical miles from Mumbai.
The Coast Guard also diverted a ship to reach the spot, while another ship sailed out from Mumbai with dispatch to join the rescue operations.
The Coast Guard aircraft also dropped life rafts for survivors and the international safety net was activated by the Marine Rescue Coordination Centre (Mumbai), the defence official said.