‘How 11 persons survived Bristow helicopter crash’
More facts have emerged on how 11 occupants of Sikorsky S-76C++ Helicopter, belonging to Bristow Helicopters Nigeria Limited, survived the February 3 crash in Lagos.
The crash, of which cause is still unknown, might have gone fatal but for the efforts of the two pilots onboard and combined search and rescue work of local and multinational agencies around the Lagos shores.
It would be recalled that the domestic chartered flight, with registration number 5N-BQJ was reported missing in the early hours of Wednesday, February 3, 2016. Barely an hour later, the helicopter was said to have crashed into the Atlantic Ocean.
The Accident Investigation Bureau (AIB) released a preliminary findings into the incident, availing details on events leading to the crash and rescue efforts.
The helicopter departed Lagos on the fateful day for ERHA FPSO (Floating Production Storage Off-loading). Instrument meteorological conditions prevailed at the time and Instrument Flight Rule (IFR) flight plan was filed.
Two flight crewmembers and nine passengers were on the outbound trip that was almost uneventful. The captain was in command as the pilot flying (PF), upon landing in ERHA (Off Shore Platform location) a passenger onboard seated in the middle row complained about perceiving a burning smell; although, the flight crew did not perceive any smell.
The PF had a word with the passenger and went back to check the internal and external of the aircraft for smell, the check result was negative. However, the crew reported that Digital Auto Flight Control System (DAFCS) and TRIM FAIL lights illuminated twice and were reset on the outboard leg to ERHA FPSO.
The flight departed ERHA for the inbound trip to Lagos at 09:50:00hrs with nine passengers and was flying at 3000ft with the co-pilot as the pilot flying (PF) and the captain as the pilot monitoring (PM).
The captain, with name undisclosed, said that within 15 minutes after departure, “we got repeated illumination of the TRIM FAIL and DAFCS.
The Emergency Operational Procedure (EOP) was consulted and the pilot flying was advised to fly hands and feet on the controls, which he did”.
Continuing, he said: “Initial contact was established at 75NM with Lagos Approach. The PF called my attention to the collective being heavy and the power dropping anytime he pulled to maintain power.
“I noticed a slight turn to the right and I called the PF to check his heading and almost immediately he came back with a problem with the compass. I noticed a fast spinning of the Electronic Horizontal Situation Indicator (EHSI) and compass, the instrument readings inaccurate/inconsistent, the aircraft started a turn to the right with a high rate of descent.”
The captain further said “I remembered taking the controls from the PF. I noticed the controls not responding properly, I made a distressed call on the Approach frequency. We stabilized at 1500ft”.
According to Air Traffic Controller’s transcript, also gathered by the AIB, the flight first contact and the first clearance with Lagos Approach were at 10:04:37hrs which stated “5N-BQJ is cleared to the field not above three thousand expect visual approach for runway 18L report for descent”.
While the Lagos Approach efforts in trying to raise 5N-BQJ were abortive, an aircraft 5N-MPN agreed to help relay between the Approach and 5N-BQJ. At 10:09:13hrs 5N-MPN relayed “Lagos standby they are calling that they stabilized on a thousand five hundred. Just standby”.
At 10:09:44hrs 5N-MPN relayed: “Okay they lost all their instruments. Aircraft stabilized at a thousand five hundred on the radial 143 65NM proceeding back to Lagos I believe”.
At 10:16:22hrs, Lagos Approach asked another aircraft AZM 2322 to help raise 5N-BQJ stating: “Please can you help me raise 5N-BQJ a helicopter from ERHA declared Mayday (emergency distress signal) shortly to know his intention, estimates to LAG or he’s going back to ERHA?”
The Captain stated that “I noticed the cyclic not responding to lateral movement. I updated the Mayday call on Lagos Approach frequency and declared a Mayday on ERHA frequency”. Two aircraft relayed the complaint from the crew that the aircraft was not responding to control inputs. AZM 2322 followed the communication until the aircraft ditched.
At 10:17:58hrs AZM 2322 relayed to Lagos: “They are ditching the aircraft Lagos. They are declaring an emergency they are ditching the aircraft. They have 13 souls on board. They are ditching. Position is 136 75 miles. It’s an emergency”. The souls onboard were later confirmed as 11.
Other aircraft joined in the search and rescue, no visual contact was reported by Caverton Company aircraft at 10:36:44hrs. At 10:38:49hrs, Approach reported “Copied still negative contact with the other aircraft on 78NM radial 138 confirm?”
However, the aircraft ditched safely at about 10:25:00hrs into the Atlantic Ocean at about 75NM to Lagos, the two life rafts were deployed, although the left raft was slightly damaged during jettisoning of the left side door. The passengers and crew safely evacuated into the life raft and were rescued one and half hours later.
More passengers transferred to the right life raft, thus creating a tilt of the aircraft to the right. The aircraft later capsized with the Emergency floating devices holding the aircraft afloat upside down, fully submerged in the salty waters of the Atlantic Ocean at about 75NM to Lagos.
A speedboat was dispatched from the Sea Truck Group (STG) Jacson 25 ship to rescue crew and passengers. Several other boats from CHEVRON, AGIP and SHELL were involved in the rescue effort.
Passengers and crew were all taken to the ship, which subsequently berthed at the Eko Support Quay. They were later taken to the Lagoon Hospital where toxicology tests were performed only on the crew. The tests were negative to any substance of abuse. The first interviews were also conducted at the Lagoon Hospital.
The cause of the accident has not been determined, as the investigation is still ongoing. Meanwhile, the initial FDR download confirmed some of the crew assertions like an un-command rapid rate of descent and speed reduction. The aircraft descended within 60 seconds from 3000ft to 1000ft approximately at the rate of 2,100 Feet Per Minute (FPM) also loosing speed from 148 KIAS to 64 KIAS over the same period (60 seconds) before stabilizing at 1,500ft.