Hi guys
Check the last post
- Linha da Frente Forums-viewtopic-Helicóptero com 18 pessoas cai no Mar do Norte
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VSOP
This summary is releasable.
1. Bond have delayed publishing information until now because they wanted to inform their own workforce (including those offshore) first.
2. Although the CVFDR, HUMS DFDAU and FDM card have been recovered and are at AAIB, they have not yet been downloaded. There is a technical problem with the FDR, and the FDM card is being "dried out". However, AAIB anticipate having some data within a couple of days.
3. The event history as briefed is based on the interviews with the aircraft Commander (who was PF). The copilot has not yet been interviewed as he is still in shock and under medical supervision by his AME.
4. The flight was scheduled for a mid-morning departure to the ETAP (about 125 nm east south east of Aberdeen) but was delayed until 1740 due to offshore weather (low cloud and poor visibility). Offshore weather reporting is a factor in that the conditions were rather worse than passed by the rig. A morning flight to the same destination only just got on despite reported weather close to VFR.
5. The transit out was at FL 55, VMC on top, and was uneventful. ATC cleared the aircraft direct to the ETAP. A weather update was received with 80 nm to run which suggested slight deterioration, and the crew discussed the option of an ARA, but the Commander elected to delay a decision until closer to the rig.
6. The aircraft started the descent at 100 nm from ADN and descended through some thin stratiform layers to 1500 feet. At this point, just under 20 nm from destination, the crew could see two fixed platforms (ETAP, the destination, and probably the Arbroath which was about 12 nm closer but slightly north of track).
7. As they approached the rig, they descended towards 500 feet, but went into some patchy cloud, so climbed up again. A short while afterwards, they were visual with the sea and descended to and maintained 300 feet. They were still visual with the destination.
8. There was a layer of cloud just above the flare. At this point the rig gave a further update on the weather with an estimated visibility of half a mile due to patchy fog/stratus. However, the crew could still see the rig and were happy to continue visually. Wind was light northwesterly (less than 5 kt) and the sea was "like a millpond".
9. The crew flew through their target gate at 0.75 nm downwind of the rig at 300 feet and 80 kt, heading just south of east (ie maintaining the outbound heading). Up to this point the aircraft had been fully coupled in 4 axes (airspeed and baralt holds). PF then decoupled and turned towards the rig for an into-wind visual approach.
10. As he rolled out of the turn, he "was surprised to see the rig a lot closer than he anticipated". He asked PNF (who was monitoring the instruments) twice to confirm he could still see the helideck, to which PNF replied that yes he could.
11. Supposition (because not confirmed by FDR or FDM data) is that PF pulled back on the cyclic to decelerate and lowered the collective to maintain height.
12. The next thing either pilot (or the passengers) knew was that the aircraft hit the water, at slight nose up attitude (tail first) but with low rate of descent and low forward speed. One passenger was quoted as saying he felt the landing and fully expected the HLO to open the door, until water started to enter the cabin.
13. The impact point was about 500 metres south of the destination on a projected track that would have passed south west of the rig. It was seen by the helideck crew who raised the alarm.
14. The impact stopped the tail rotor. the drive sheared round about the transport joint (Frame 9900). The forward section of the sheared driveshaft flailed inside the housing, cutting through the fuselage (and getting the tiedown strops wrapped round it) and causing the tail boom attachment to fail and the tail boom to come off and sink.
15. The cabin doors were jettisoned and both liferafts were operated. Most passengers entered the left raft (probably because they always use the left door for entry and exit to all Puma variants). About the only person who got slightly wet was the copilot, who jumped from the forward LH float into the LH raft. Both rafts were tied together and the subsequent rescue went well.
16 The aircraft was (eventually) recovered (that is a separate story) and is at AAIB.
17. Bond have reviewed their operating procedures and were happy to receive input from both Bristow and CHC. Many of the changes they are making are already in, or in the process of going in, to CHC manuals, as a result of the Blackpool accident.
Initial weather reports given to the crew prior to departure from Aberdeen indicated 8Km Vis and a cloud base of 800-1000ft with a light (10kt) easterly wind.
On departure the crew elected to climb to FL55 and were VMC (Visual) on top.
Enroute an updated weather report indicated deterioration to Vis 2-3Nm and a cloud base of 600ft.
The crew decided to wait as to whether they would carry out an ARA (Radar) Approach. They commenced an early descent and at approx 13Nm from the Etap again called for a further update in the weather. The report they received showed further deterioration now down to 0.5Nm vis and a cloud base of 500ft approx (top of Flare). During the descent at 2000ft they were visual with two platforms (assume the Etap and Arbroath) and so at 1500 ft elected to carry on with a visual approach. As such they continued descent to 500ft and at 6Nm continued down to 300ft, however at this point they went into cloud and so climbed back up to 500ft to remain visual which they did. Once clear of the cloud again dropped down to 300ft. This was to set them up for their Visual Gate Point of 300ft 0.75Nm and 80Kts as published in their company Operations manual.
As they approached the Etap they were on a left base approach, the Captain (handling Pilot) asked if the Co-Pilot was visual with the Helideck and he replied yes. The Captain then disengaged the coupled modes of the autopilot and flew the aircraft manually and initiated the left turn onto finals. Again during the turn the Captain asked for confirmation that the Co still had sight of the helideck and received a positive answer.
On roll out from the turn the Captain saw what he thought was the helideck/platform much closer than anticipated and thus thought that he had positioned too close and too high which resulted with him pulling back on the cyclic to raise the nose and reduce speed and drop the collective to reduce power and height.
The next thing they knew was that they were in the water 500m from the Etap. We do not know what he saw or why and is open to supposition.