As mentioned last week, the recent loss of the Bond Helicopters Eurocopter EC225 Super Puma in the North Sea involved the proverbial perfectly serviceable aeroplane. A version of events apparently sourced from an official or quasi-official document on the early investigation findings is now public and it's no surprise to see that pilot disorientation features high on the agenda. A perennial, and seemingly insoluble, hazard in the tough environment of UK offshore operations. Here's the document below - I'd stress that I don't know precisely what it is, (and can't easily find out as I'm on the road), but nobody's so far questioning that it is an authoritative account of what is believed to have happened.
The accident came two years after the horrific loss of
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.
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.
on March 25, 2009 8:06 AM | Reply
Nice article... Thank you
on April 1, 2009 9:34 PM | Reply
The crash two years ago (as mentioned above) did not involve a "earlier Super Puma"(AS332), it was a "SA365N" known as "Dauphin" in Europe and sold with different maingearbox and engines as "Dolphin" in the US (major customer: US Coast Guard).
If you have ever flown Agusta-Westland,MD or Bell,
you never want to change back to the actual crap produced by EC.
The only performance is nice pictures in their brochures.
on April 1, 2009 9:50 PM | Reply
Medevac,
you're absolutely right - careless error by me.
on April 10, 2009 10:57 AM | Reply
Medevac,
what do you mean by the statement "actual crap produced by EC"
On what facts is this statement made
Fergus
on March 13, 2010 2:32 PM | Reply
Kieran, interesting article. Do you know what actually changed in the procedures to counteract pilot disorientation ? Frank