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Nil wind rig operations

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Old 14th Feb 2010, 16:25
  #21 (permalink)  
 
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check:
Lose an engine now most will recover and fly away with about 10 ft to spare based on a 100ft helideck
Aren't you supposed to clear all obstacles by 35ft (JAR-OPS 3 and all that)? I imagine the 35ft is there to allow for variations in pilot technique etc eroding the margin. If the margin's only 10ft it's surely not a margin. If you're at 10ft and still not at Vtoss you still only have one option - keep it going down to give you enough speed to climb.

And what about at night?

NS
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Old 15th Feb 2010, 13:51
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Northsouth,
You are correct in what you say, however after many years of sim work, I found some made the water, but most kept it in the air but many were down to 10ft or lower. Some are smooth on the controls, some not so. Reaction time between individuals is different and so a target is set and if you are on the ball then perhaps you will meet 35ft. if not, but still dry - you are a still a winner.
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Old 15th Feb 2010, 17:03
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1985 and I found myself re-employed as junior co-pilot on the S61N after 2 redundancies in 3 years on the North Sea, following 10 years as a military heli pilot. New employer sent me to the Shetland Islands to fly from their Sumburgh base to Shell installations in the East Shetland Basin.

One starry and completely windless night I found myself paired with their worst pilot. He would shout "Shut the f**k up!" to any co-p who tried to read from the checklist and he swatted my hand out of the way when I tried to turn the radar to standby after landing on a helideck. He was a bullying swine and an ignoramus of such matters as performance.

The met info showed nil wind anywhere within 200 miles of the ESB, which was confirmed by the vertical platform flares and limp windsocks. As luck would have it, the last stop of our offshore shuttle was a semi-sub with low helideck and the client wanted a full 19 taken back to the beach.

You can imagine the abuse I got when I dared to suggest shuttling the pax in 2 loads to a nearby platform with a much higher helideck. Now you just have to believe me. We lifted into a low hover with not much more than the prescribed fuel minima to return to Sumburgh. Matched torque was wavering around the max 103% as he tried to gain a couple of feet.

We continued hovering like this for 16 minutes while he muttered rubbish like "waiting for a wind gust". Then an engine fire light glimmered for obvious reasons. To my brief relief he landed and the fire light disappeared quickly. I was starting to undo my harness with a view to getting the pax off for dividing into groups, when the collective shot up.

We leapt (slowly) into the air as the torque went above 110%. On forward rotation, we sank close past the helideck edge and I saw out of the corner of my eye our rotor wash ruffling the mirror-flat sea. The anguished gearbox transmitted the remaining horsepower from screaming engines to struggling blades, while the airspeed increased at snail's pace.

After descending to 10' on radalt we returned to Sumburgh in silence, apart from him telling me about take-off techniques like "bouncing off the cushion". We landed with less than 150 lbs fuel per engine, perhaps 5 minutes before a flame-out.

Next morning I told everything to the spineless chief pilot who told me not to worry myself too much about their very senior captain, who really wasn't nearly as bad as people made out. Why didn't I report it to the CAA? Well, it was one man's word against another and in those days we didn't have IHUMS data recorders. But I moved swiftly to another employer as soon as they accepted my application.

The bullying swine has long since retired and you can imagine what kind of retirement I wish him. I believe it's not for nothing that his colleagues experienced gearbox problems resulting in ditchings.
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Old 16th Feb 2010, 09:07
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I'm not a helicopter pilot but have been offshore as a pax a few times, including launching off a semi-sub in the ESB at night in a gale and horizontal rain, sitting in the back in awe at what the guys up front were doing in that split-second transition from dazzling floodlights to pitch black 50ft above a raging sea. I'm very pleased I hadn't heard your story then Colibri49. But I would just like to say that I think the job you guys do/did offshore is amazing.
NS
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Old 16th Feb 2010, 09:47
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Colibri49 that story is horrifying..I just want reassure non aviators and non North Sea pilots that sort of thing is/was so rare... I've been flying in the North Sea for 30 years and I have never seen anyone else or personally been in, anywhere near, that position....10ft rad alt...Its bad enough at any time to descend below the helideck, never mind just skim the sea. In 1985..in the days before CRM...there were old and scary old captains flying..maybe there still are But I can not imagine anyone getting away with the
He would shout "Shut the f**k up!" to any co-p who tried to read from the checklist and he swatted my hand out of the way when I tried to turn the radar to standby after landing on a helideck.
...never mind the sort of actions that should have got him grounded immediately.
...thanks for sharing that.
As for nil wind operations, I flew 76s for years and it could be hard work in nil wind at higher weights..especially in the 76A. Now with the superb 139 its a dream...so much power... vertical take off with a fullish load...nice
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Old 16th Feb 2010, 11:15
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I came across this video clip sometime ago. Perhaps it is relevant to the discussion.

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Old 16th Feb 2010, 12:55
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You guys can relax a bit. I never met or flew with anyone else remotely like that bullying swine. One thing he was reputed to have done was to “moon” his arse/ass out of the helicopter window while it was being taxied, but I doubt that he could have contorted himself that much in the pilot’s seat. Surely he must have gone to a cabin window, perhaps leaving the co-p to do the taxiing. Some older guys who will remember this story could furnish us with the specifics. Surely he qualifies as the ultimate arsehole.
The greatest leap forward during my ¼ century + on the North Sea was the introduction of regular CRM (Crew Resource Management) courses, which teach pilots how to interact properly with each other and undoubtedly have prevented helicopter and airline accidents due to arguments/sulks/disagreements. Our few remaining potential bullies now have to keep themselves in check, or else!
Another huge advance was IHUMS (Integrated Helicopter Usage Monitoring System) which provides data to engineers on the health/condition of every critical heli component, even down to which gearwheel tooth has a chip or crack. It also acts as a “spy in the cab” to monitor pilots’ control actions which exceed defined parameters. It is said that the Chinook disaster off Sumburgh wouldn’t have happened if IHUMS had been available then.
As regards nil wind operations (which require the most horsepower to transition from hover to forward flight) no helicopter today has such reserves of power that if one engine should fail while transitioning forward and heavily laden, it would be certain not to descend a bit. But a comforting thought is that the statistical chances of this happening at the crucial moment are vanishingly small (never on the North Sea) and when the wind is nil the sea is calm, so ditching is very survivable.
Now I fly the mighty EC225 which has got to be the best for years to come. I’m sorry it’s a bit cramped for the guys in the cabin, but has the best power to weight ratio of the 19 seaters, quickest cruise of 145 + knots, can always carry full fuel with 19 pax on the North Sea, 440 nautical mile range, superb glass displays and automatics which enhance flight safety. Need I go on? Yes it’s more expensive than the S92, but you gets what you pays for. And no bullies allowed!
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Old 16th Feb 2010, 18:50
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looks like a downwind take off to me
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Old 17th Feb 2010, 00:11
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Deck Clear u could be right as the rescue/tug boat seems to be into the vaves; but it's minimal wind as far as I can see; also the HP sided right of the deck before he went forward and lost his lift...
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Old 18th Feb 2010, 19:51
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Gents, I think the "diving off the rig" scenario is a common misconception of the pax.

Most of us offshore pilots utilise the standard rig take-off technique which can give the pax the impression that we are "diving" the helicopter when we rotate at the theoretical "TDP". Especially if the rotation is overly aggressive which tends to be our instinctive reaction when winds are slack and TOM is high. (Its a good experience just to sit at the back during a rig take-off) not suggesting you vacate a crew seat to do this of course!!!

In Europe we are still operating Class 2 with exposure but the mass of the helicopter should equal that required at least for an AEO OGE Hover, to provide an adequate thrust margin for take-off. See JAR-OPS 3.517.

DB
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Old 18th Feb 2010, 20:11
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"North South" and "Check",

both of you have your wires well crossed. A clearance of obstacles by minimum 35 feet, is a requirement of full blown performance models such as BCAR Group A or CAT A where the helicopter is required (in the event of OEI - an engine failure) to either continue the take-off or land safely, clearing where necessary all obstacles by the prescribed 35 feet.

It is simply not possible to provide an unequivocal performance solution in the offshore environment. This is because of obstacles, turbulence and the inability of the crew to adequatley plan approach paths into predictive wind flow patterns.

To get around this thorny issue the regulators have long since accepted that under certain conditions the loss of an engine could result in a catastrophic crash. Horrific right!! well it would be if that was the end of the story.

To mitigate this risk the regulators require that the engines are maintained to a certain standard, trend checked and subject to a reliability program and monitored in flight with a full HUMS system. These requirements carried out to reduce in so far as possible, the chance of the engine failing.

Also the flight crew are trained and checked in their flying profiles and procedures to minimise the risks of deck edge impact in the event of OEI. Hence the funny vertical climb followed by swift rotation to clear the deck edge.

There are measures afoot to try and increase the performance criteria for offshore helicopters but so far non has come close to being workable.

I, like all my collegues have come to accept this risk much as we do the chances of the tail rotor failing, which under almost all conditions would result in catastrophy during the early phase of flight.

I think until someone comes up with a better design than Igor Sikorsky's basic original we must live with what we have and continue to improve the monitoring and reliability systems that we have to nail down those pesky in service failures before they actually happen.

The system does seem to work very well.

As for the S76 take-off above...he is either showboating or is not at the prescribed AEO HOGE mass. I have no idea where in the world he is so maybe he is not required (like we are under JAR) to operate to this mass.

Taking off downwind when heavy in the offshore environment is just plain stupid......but we have all done it when the wind appears really slack apart from the residual 5 knots that developed up the arse whilst we were refuelling....right!!!

DB
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Old 19th Feb 2010, 03:43
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Following an engine failure on a rig take off, information was obtained that depicted the profile of an S-76C having an engine failure at CDP. I've built the following illustration based on that information.

Test Conditions

CDP 25 Feet
Sea Level
OAT 30°C
Gross Weight 10,800 Pounds (NB. Book allowed 11,350 under these conditions)



The RED line is aircraft flight path. Please note the angle of descent. I've included a notional deck edge (BLUE) - I used to keep the upwind edge of the deck just in sight through the chin bubble, so the aircraft would be positioned further back from the deck edge than depicted. The aircraft attitude depicted is 25° nose down, as that is what the copilot says is what we reached.

Last edited by Brian Abraham; 19th Feb 2010 at 03:57.
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Old 19th Feb 2010, 18:36
  #33 (permalink)  
 
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Nil Wind Rig Ops

Brian,
Surely the helicopter path will be displaced to the right from CDP. There should be upward momentum( thank heavens for Sir Issac) which you convert to forward speed at CDP/Rotation point. This must be part of the technique to get deck edge clearance. If you had no vertical speed at CDP would you not need to use a modified TO technique?
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Old 20th Feb 2010, 02:21
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Pofman, does not show too well on my graph, but the raw data shows the peak at 26 feet. With a called for minimum of 200 feet/min ROC, inertial effects are not going to carry you very high.

Below you can see the effect of reducing the gross weight down to 10,400 pounds (with our aircraft this would typically represent a combined fuel and pax load of 2,431 pounds) with the conditions remaining as before ie CDP 25 feet, OAT 30°C.


Last edited by Brian Abraham; 20th Feb 2010 at 13:05. Reason: Add graph
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Old 4th Mar 2010, 02:19
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Ouch!

G'day Brian,

Reference your post of 12 Feb....Ouch!

What you describe is circa < 2004 and not present day.

One point to ponder. The term 'alternate' that you refer to and is also used in the Flying Ops manual is inaccurate. AIP dictates the requirements of an alternate and they are required for weather, lighting, and navaids...period.

What you refer to is a land based OEI landing area for the offshore installations that used to be included at the front of the RFM but has now been removed from the RFMs and included in CASA Regulatory Policy CEO-PN029-2005 "Multi - Engine Helicopters Operational Performance Standards" dated July 2005.

The verbage is the same vis:

Full OEI accountability requires the ready availability of an OEI landing area following engine failure or adequate performance following engine failure, which assures continued safe flight.

An area may be selected as an OEI landing area if it has:
  • A smooth level surface
  • An obstacle free approach gradient of 5 degrees from 500ft AGL to touchdown
  • Two directions of approach not less that 150 degrees apart
  • A strip width of at least 30 meteres
  • Landing distance available in accordance with requirements of the RFM for OEI landings.
The Longford runway meets these requirements. AIP alternate criteria do not apply, CASA confirms this (they most certainly do to IFR and VFR flights with respect to weather, lighting, and navaids). When the Longford runway is nominated as the OEI landing area, a constant weather watch is maintained. If the heliport clags in, the fleet does not fly until it becomes available again. If an advantage can be gained by applying AIP weather minima to the TAF for another unsighted aerodrome such as Bairnsdale, then it can be nominated as the OEI landing area and flights can go ahead.

Also,

New charts have been developed for CAT runway ops taking into account continued takeoff distance and headwind.

New charts have been developed from the RFM HOGE chart for offshore lifting that are dead accurate.

regards,
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Old 5th Mar 2010, 01:27
  #36 (permalink)  
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S76C, Offshore helideck 120', OAT 30C, Nil Wind, QNH 1013: the MAUW is Lbs 10,450

That is what we are supposed to use as reference; but some pilots go to MAUW of lbs11,000 and simply overtorque, overtemp to get out.... seen it many times and when you say something to the contrary, you are looked upon as a sissy

Thanks God for VEMD and HUMs our days on more modern machines, as the "she'll be right" attitude is getting non existant...

Last edited by WLM; 5th Mar 2010 at 13:02.
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Old 5th Mar 2010, 08:02
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That is what we are supposed to use as reference; but some pilots go to MAUW of lbs11,000 and simply overtorque, overtemp to get out.... seen it many times and when you say something to the contrary, you are looked upon as a sissy
One word! Begins with A, ends with S, has rsehole in the middle!
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Old 14th Mar 2010, 13:55
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Well may you say Ouch!, given the price I paid I think the term should be reserved for myself.

One point to ponder. The term 'alternate' that you refer to and is also used in the Flying Ops manual is inaccurate.
Really!!! I’m not sure to what you refer as “inaccurate”. The manual was quite specific in stating “The PIC shall comply with the requirements of AIP alternate requirements” and also “All offshore operations require a land based alternate”. Certainly most interesting to see you state “AIP alternate criteria do not apply“. I hope you don’t really mean that.

CASA Regulatory Policy CEO-PN029-2005 "Multi - Engine Helicopters Operational Performance Standards" dated July 2005.

I don’t know why they bothered. The requirements were covered in full in the prevailing documents (AIP, Ops Manual, Flight Manual). The Policy document (CEO-PN029-2005) merely regurgitates what was already required/stipulated.

Ops Manual
Whenever a forced landing is made due to weather, an ATSB Incident Report and Level A Early Alert Report are to be submitted.
Having made literally hundreds of shutdowns on platforms due inclement weather at Longford I’m not aware of any reports called for by the above having ever been made. Or does a landing on a platform due to inclement weather at Longford not constitute a “forced landing”.

For the readers, a couple of examples as to how we operated.

Call out in the middle of the night. Management in the Captains seat, moi in the other and having made his displeasure known. A platform is dead in the water with no electrics and personnel need to be moved from one platform to the other to get the down platform back on stream, for production is paramount above all other considerations. Alternate minima for the only available bolt hole is 1,097 feet, with the TAF calling for 8/8ths at 1,100. Launch with 30 minutes reserve fuel and punch into the overcast at 600 feet. No flight plan as required by all regs/ops manual, to do so would be self incriminating (IMC flight). Half way out to platform become VFR on top and not having fuel to do a legit ARA (would add 20 track miles which we don’t have fuel for) conduct an enroute descent and break out at 300 feet. Pick up pax and make a successful landing on the next (destination) platform sans lighting – its got no electrics remember. Having landed, Longford require us to spend the night on the platform as Longford is now closed due weather – surprise, surprise? – well it wasn’t to some.

TAF forecasting fog till 1100, take off made at 0730 and returned at 0915 to find fog rolling over the heliport. At the time of shutdown viz 100 or so feet, fuel remaining 318 pounds (statutory 30 minute reserve 280 pounds). The question was asked of management what would you expect the crew to do had they had an engine failure on the way home with an ETA >0915. You have unwarranted concerns was the reply – and shut the f$&^ up and do what you’re told. Somebody want to reiterate the responsibilities of a PIC?

HC or 212man, there's a job awaiting.

Last edited by Brian Abraham; 14th Mar 2010 at 23:01. Reason: Fuel
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Old 15th Mar 2010, 00:24
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Come on Brian

"All offshore platforms require a land based alternate" is NOT (emphasizing not shouting) an AIP requirement, it was written in the Ops Manual, extracted from that defunct para in the RFM and "alternate" is not the correct word as I have painstakingly pointed out. You are wrong about this. We are endorsed by the regulator. What else can be done.

If you can direct me to the whereabouts in the AIP that requires a land based alternate for all offshore platforms (regardless of the weather) then I will gladly comply and apply AIP alternate criteria to it. It does not. As I said, it is a requirement of the Ops Manual taken from the CASA Policy that used to be in the RFM. Therefore AIP criteria do not apply, how we provide that land based OEI landing area is up to us. We do it by real time weather watch at Longford by qualified observers or, if an operational advantage can be gained by using the TAF at an unseen airfield, we DO apply AIP alternate criteria and use it.

You obviously have a beef with management about the way things were done circa 2004 and for the many years before, things are different now. You could have always put your hand up for one of these positions and effected change.

Most criticism in my experience that is directed towards any management comes from the Monday morning quarterbacks in the crew room.

You are well respected for your many years of tireless service and Vietnam experience that I admire and can not conceive of, but there are a lot of things that the current crop have done in helicopters that you haven't.

There has been a complete overhaul of culture and personnel attributes in the last six years.

As for your treatment by the global multinational, can't comment but they are doing all right by the rest of us.

best regards,

Last edited by fender48; 15th Mar 2010 at 02:57. Reason: better explanation
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Old 15th Mar 2010, 03:06
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Aaaaaaah, I think I see what you might be getting at.

Regulatory Policy – CEO-PN029-2005
Multi-Engine Helicopters Operational Performance Standards
Performance Standards – Non Passenger Charter, Aerial Work and Private Operations – All Weights
VFR/VFR Night/IFR
For all non-passenger charter, aerial work and private operations, a multi-engine helicopter may be operated without OEI accountability.
Whereas
Performance Standards – Passenger Carrying Charter Operations – All Weights
VFR
En-route. The helicopter, in the OEI configuration, shall be capable of maintaining 500 feet terrain clearance to a location suitable for an OEI landing. Drift down techniques are acceptable to meet this requirement.
Approach and Landing. At the destination or the single-engine alternate, the helicopter in the OEI configuration, shall be capable of maintaining a zero gradient of climb at 500 feet above the landing level.
As for
You could have always put your hand up for one of these positions and effected change.
Why is it deemed necessary to take on a management position to effect change? As she would have said, "Please explain". Management at all levels at the time had absolutely no interest in affecting the slightest change, witness the take off charts - how many years did that take?
there are a lot of things that the current crop have done in helicopters that you haven't
Only too true, and was a major failing within the organisation at that time as no fertalisation from outside sources was to be had. Always inward looking, as when the C models were obtained and the TRE given the responsibility of introducing them to service was not permitted to contact current operators. May have undercut someones empire presumably, he never found who was so anal. Great to see that people of the calibre, and with real world experience, such as CH, HS and the like are on board.
they are doing all right by the rest of us
At the moment. Best keep naivety and rose tinted glasses in the top drawer.
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