Offshore performance planning (merged threads)

[sandy helmet]

Could anyone tell me what performance graphs should be used when planning a flight to an offshore platform in a twin, and how do you work out your MAAUW?

Thanks.......

[cpt]

Basically when operating under OPS3 and class of performances 2 (applicable to most of light and medium twins) the MTOW is determined by the 150 ft/mins at 1000 ft above heliport (or helideck)
When operating to/from helidecks it is advised to use the OGE limitation since the ground effect is very limited here. (on a relatively small surface)

If we operate under PC1 (class of performance 1) V1 , VTOSS, and RTOD will determine the MTOW.

If we forget OP3 and operate under other regulations, I think it makes sense to check the out of ground effect performances when operating on elevated helidecks.

[GLSNightPilot]

In which offshore area are you planning? It makes a huge difference, and "a galaxy far, far away" isn't specific enough to enable a correct reply.

[Another KOS]

GLS:

I, like you, would like to join the fray on this but am unwilling to until we have some ground rules.

We could wait for Sandy Helmet to come back down to earth and state that which he desires or, alternatively, we could do the thread a service and set out the comparative offshore performance standards for all to see and compare.

What do you think?

[GLSNightPilot]

Well, I only know of one area. Down here in the GOM, we just load up to max gross. For most types, the weight isn't limited at all until the temp approaches ~30deg C, then it is only slightly lower. We just plug the temp and altitude into the computer & get a number, which is the maximum allowable takeoff weight. Pulling out the POH and going through charts while the SLF in the back has a heat stroke isn't the best solution. We don't do Cat A, or OPS3, or any of the other JAR stuff over here. I realize things are different in Europe, but I'm not there. Try reducing the loads to that extent over here & you won't be employed long.

That's why I asked for the area in my first post - it's not the same in the UK as in Canada as in Oz as in Mexico as in..........

[Another KOS]

What about Canada, Australia and Mexico - what do you guys do?

[JimL]

Another KOS,

I can hear the sound of silence - anything we should infer from this?

[Old Man Rotor]

Its a little slow as we have just been down that road......but I am sure there are some lessons to learn if you spark it up again.

http://www.pprune.org/forums/showthread.php?s=&threadid=90224

[Bladestrike]

We Canucks use the same charts/limits as our North Shore brethern. Its quite complex to get into in detail, but in short, we can maintain OEI stayup at our MOCA, and we assure we can get there as well (Cat A). We may be exposed to a water reject for a short spell after takeoff, but its not really an issue with our high decks. Depending on sea state/vis/day-night we more often than not have fly-away weights at rotation.

[Another KOS]

Old Man Rotor:

Thanks - I watched that debate from the sidelines but it was more concerned with the carriage of return fuel than the calculation of performance.

Bladestrike:

Is it CARs that require operations in Performance Class 2, or some other regulation (OpSpecs or something)?

I guess you are also at risk from a deck-edge strike as well as a water reject (or ditching in plain language) - both on the landing and the take-off.

and we assure we can get there as well (Cat A)Where does Cat A come into this debate on calculation of weights?

Now you Aussies - what calculation do you do?

[Bladestrike]

Cat A weights are determined from charts in the AFM, and assure that you can meet a predetermined rate of climb OEI, and directly affect your take-off weight. Temps/DA go up, weights go down, if you want to be able to meet that rate of climb should you lose a can.

While the CARs have not yet adapted the Class 1/2 criteria, and the AFM for older aircraft do not have the charts, we have SOP's determining our takeoff weights that are much more stringent than required by the CARs. If the pilot determines that achieving flyaway at rotation is a must (night, rough seas, heavy fog....), he'll apply the more stringent weights from our SOP's, but its not a regulatory requirement.

At the very least, the CARs do require us to be able to maintain a MOCA OEI. By limiting ourselves to Cat A weights, we assure we can get to our MOCA (generally 1000 feet IFR offshore, CAT A weights assure 150 fpm at Max Contingency OEI to 1000 feet).

[Another KOS]

Bladestrike:

Thanks for the explanation. My interest was sparked because of your use of the term Cat A.

Although agreeing with what you have said, what you have not said is more important. Cat A isn't just a calculation of weight for en-route performance, it is the application of a take-off to landing trajectory to ensure adequate space is available for rejects, and distances are available to ensure that obstacles are cleared by the appropriate margins - in all phases of flight.

What you have described might more accurately be termed operations in Performance Class 2.

I am more interested in what you have said about company SOPs, do I understand that you have a method of calculating take-off masses to assure deck-edge miss and minimise drop down? How was the data derived? Does it give an assurance of engine failure accountability on and off the rig?

If you do not wish to broadcast, please do it by PM.

[Bladestrike]

Getting myself in trouble trying to be vague.

Yes, what I described is a Performance Class 2 helicopter should we chose to be exposed to a reject for a period after rotation. As such, I guess the CARs 704 requirement is for a Performance Class 2 Helicopter. We attempt to have Class 1 weights if the marine enviroment is considered "hostile".

Yet we sort of need to fly Cat A to assure meeting Performance Class 2 critieria with any certainty. It depends on how you interpret the regs, you could probally get away with simply being at a weight where you could maintian a zero rate of climb at your MOCA, and this would give you better than Cat A take-off weights. It would just take you longer to get up there. On a nice VFR day with calm seas I don't see it as a problem.

Cat A is indeed a specific take-off and landing profile, and if flown correctly, and WITHIN THE CHARTED WEIGHTS, will assure a reject within a certain amount of distance OR a rate of climb of 100 fpm at Vtoss, accellerating to Vbroc, yielding 150 fpm climb to 1000 feet, at max contingency OEI power, depending on where you are within the profile when the engine quits. You cannot just apply the profile and stopping distances if you are not within the charted Cat A weights for your OAT/DA.

If you do not meet Cat A, are you still Performance Class 2? The CARs are vague, and I don't know if its spelled out in the JARs. We apply them regarding on prevailing conditions, beit day VFR, night, IFR....

[Red Wine]

Oh come on Guys [Gals]......Why try to confuse the two different Certification Standards.........

You are either flying CAT A.......or you are flying to CAT B......but you can't fly both at the same time.

CAT A and Offshore is ridiculous.......no company, even the conservative UK Oil Companies do not insist on CAT A Offshore...its a nonsense.

[Another KOS]

Red Wine, thanks for that post it will do nicely…Oh come on Guys [Gals]......Why try to confuse the two different Certification StandardsNo confusion Red Wine:

The two terms Category A and Category B are used for the certification of helicopters: 'Category A' means multi-engine helicopters designed with engine and system isolation features specified in JAR-27/29 or equivalent and Helicopter Flight Manual performance information based on a critical engine failure concept which assures adequate designated surface area and adequate performance capability for continued safe flight in the event of an engine failure. 'Category B' means single-engine or multi-engine helicopters which do not fully meet all Category A standards. Category B helicopters have no guaranteed stay-up ability in the event of engine failure and unscheduled landing is assumed.However for operations, the use of these two terms alone is too constricting for a machine that is as flexible as a helicopter.

You are either flying CAT A.......or you are flying to CAT B......but you can't fly both at the same time.Absolutely Red Wine, now do you see the limitation of those two terms – we can’t exactly describe how we operate!

So what are Performance Classes Performance Class 1 operations are those with performance such that, in the event of failure of the critical power unit, the helicopter is able to land within the rejected take-off distance available or safely continue the flight to an appropriate landing area, depending on when the failure occur. Performance Class 2 operations are those operations such that, in the event of critical power unit failure, performance is available to enable the helicopter to safely continue the flight, except when the failure occurs early during the take-off manoeuvre or late in the landing manoeuvre, in which cases a forced landing may be required. Performance Class 3 operations are those operations such that, in the event of a power unit failure at any time during the flight, a forced landing may be required in a multi-engined helicopter but will be required in a single engine helicopter. CAT A and Offshore is ridiculous.......no company, even the conservative UK Oil Companies do not insist on CAT A Offshore...its a nonsense.Yes Red Wine, and that is why we use performance Class 2.

Flights to helidecks in the North Sea (and noting the comments of Bladestrike – Offshore Canada), operate in Performance Class 2.

A helicopter certificated in Category A may be operated in Performance Class 1, 2 or 3 – but a helicopter certificated in Category B may only be operated in Performance Class 3. Now can you see the flexibility of language and the potential for risk assessing an operation and prescribing the Performance Class such that it meets the perceived risk profile.

Finally, we have seen over other threads that modern twins have the potential to give engine failure accountability at MUAM (even the S76C+ has a Category A rig take-off profile at 11,700lbs).

Consider this; at the time when the installed power gives HOGE OEI at MUAM, we will be performing operations to helidecks in Performance Class 1 – no chance? Check the flight manuals of the latest clever twins - and hopefully the AB139.

Forgive me for hogging the thread and posting two replies - it was easier this way

Bladestrike:

In the absence of regulations prescribing the operating standard, that is an extremely well considered approach. You have also correctly identified that rig operations in Performance Class 2 may have an exposure to deck-edge strike and ditching (depends on the strength and direction of the wind).If you do not meet Cat A, are you still Performance Class 2? The CARs are vague, and I don't know if its spelled out in the JARs. We apply them regarding on prevailing conditions, beit day VFR, night, IFR....Operations in Performance Class 2, by definition, meet the requirements of Performance Class 1 just after the take-off phase. This is achieved by specifying that the second segment climb performance must be met (as you have said - climb performance of 150'/min at 1000' above the take-off site).

The way that you operate appears to be analogous to operations in Europe - the difference is that it is spelled out in JARs but not in CARs.

Try and avoid the term Class 2 helicopter - as you will have seen, it is not appropriate language for certification or operations.

Good luck.

[JimL]

Bladestrike:

Now your dilemma can be seen, CAR 704.48 prescribes flight at the MOCA for offshore operations when IMC and at night; and at 500ft for day VFR; but does not populate the Standards in CAR 724 Division IV (I hope the terminology is correct).

It is a credit to the operator that a Standard is incorporated in the Operations Manual. Is there some protocol between the operators in Canada that facilitates these safe practices - or do oil companies require them as part of their contractual agreements?

How often are offshore conditions hostile ?

[Bladestrike]

Hostile conditions are deemed whenever a ditching would be "high risk", beit night or high seas. High seas being common 200 miles out.

Our SOP's are stricter than any CAR's requirement, and the oil companies seem to vary from district to district on their requirements and standards, so I'd hazard to say its more of a protocol among operators. While Canadian's may have a reputation of "bush ops- getting the job done" mentality, I have seen a significant swing towards safety over the past two decades, specifically in the offshore industry. No doubt driven by fear of litigation, but I don't think we are up to JAR's standards yet.

Is there a big difference under the JAR's? Do Brits do things differently than Norwegians differently than the Danish?????

[SASless]

Uh Oh! The can of worms just got opened! Do the Brits do things differently? I cannot wait to see where this thread goes now!

With all of the discussion above.....and very articulate and informative it was.....what is the difference in the accident rates in the various areas for the situations under discussion? I dare say.....besides the odd BO-105 fluttering into the GOM after a single engine failure in cruise....the real accident rates are the same all over the world for post engine failure accidents.

Any takers?

[Another KOS]

Bladestrike:

My understanding is that the the Brits, the Norwegians, the Dutch, the Danes and the Irish (all of those with offshore operations in the North Sea plus the Irish) apply the Standards of JAR-OPS 3. Therefore in the context of this thread, they all apply Peformance Class 2 (as expressed in JAR-OPS 3 - i.e. with exposure).

SASLess:

I'm really surprised at you dumping on a safety discussion when your campaign for improvement in safety standards is well known.

The OPG statistics show that there is a similar accident rate for the (offshore) oil industry (with a few blips here and there) worldwide. The important thing about these statistics is that they only measure that which is undertaken. There are no engine failures for singles in the North Sea as none are operated there. Why, because the environment is hostile. Engine failures in the North Sea are a reasonably foreseeable event - mitigated by the operational rules.

It would appear to me that the message that comes loud and clear from the OGP statistics is that, where equipment and standards - appropriate to the environment - are: contracted by the oil companies; or are prescribed by regulations; or are as the result of SOPs facilitated by protocols, the accident rate is ALARP.the real accident rates are the same all over the world for post engine failure accidents.Yes for the reasons stated above.

When quoting from my PM you omitted the second part of the sentence:the Bo105 that fluttered into the sea having had an engine failure; and the Bell 407 that was flying in conditions where an engine failure would almost inevitably lead to a catastrophyIt is clear that the accident record for the GOM this year so far does not make for pleasant reading.

I for one applaud the Canadian operators and pilots for understanding that hostile environments should be treated with respect.

I shall now dismount from my high horse.

[JimL]

Thanks to Bladestrike, GLSNightPilot and Another KOS we are starting to form a picture of what the Performance Standard is for offshore operations - as requested by Sandy Helmet:USA (GOM): Performance Class 3 (with exposure) - singles and twins.

Canada: Performance Class 2 (with exposure).

Europe: Performance Class 2 (with exposure).all of whom use the AFM data to provide the RTOM.

With the exception of the comment from Red Wine, we have no information from areas other than those stated.

As the Australians have everything from extremely tropical to downright hostile, is it possible that they could join us in this thread - it would be interesting to see how they manage their offshore performance with such a varied range of climates.

Another question that might be interesting to answer is - do the oil majors have a Standard which they themselves apply by use of contractual agreements. I have heard a rumour that deepwater GOM might be the subject of such a standard in the near future.

When we have done this subject to death, we might attempt to have a similar discussion on equipment for overwater operations (ditching approval, floats, liferafts, lifejackets, survival suits etc) - for both hostile and non-hostile environments (always supposing that we have a common understanding of those terms).

[Red Wine]

Oz is in the progress of aligning itself with JAR Ops, but in the written format of the FAR's. [Just like a politician with a hand in each pie].

IFR Performance:

Once at Vy on Take Off, OEI and in IMC, must have a 1% climb gradient at Vy, upto and maintain 1% ROC at LSALT to destination or alternate. [assume you can't land at departure point]

VFR Performance:

Once at Vy on Take Off, OEI and in VMC, must have the climb performance at Vy to climb to 500 agl, upto and maintain 0 % Climb Gradient at 500 agl to destination or alternate.

Platform Arrivals:

No limit [By legislation, Operator or Client]

Platform Departures:

Use OGE weights at the local OAT [And if operating from low decks, MSV's, Dive Tenders etc, reduce your OGE Take Off Weight by another 500 lbs]...[Normally an Operator limit]

Always having Offshore return fuel.....And yes, Oz has tropical monsoons, through blue sky to low level icing....but I love my job!!!!

[Shawn Coyle]

What about if your flight manual doesn't have OGE performance in the 'approved' section - not required information for a lot of older helicopters???

[JimL]

Thanks Red Wine.

Summary so far looks like this (please correct me if I screwed):USA (GOM): Performance Class 3 (with exposure) - singles and twins.

Canada: Performance Class 2 (with exposure) – a reduction of exposure when the conditions are hostile (data from Operations Manual)

Europe: Performance Class 2 (with exposure) – AEO HOGE recommended

Australia: Performance Class 2 (with exposure) – AEO HOGE and reduction off RTOM of 500 lbs for low decks (operator’s limit)AFM data to provide the RTOM

For en-route (remember this is offshore so it is a little simplistic):USA (GOM): IFR 50 ft/min at MEA or 1 500 ft (whichever is the higher - FAR 135.181); VFR no requirement if helicopter is equipped with floats - FAR 135.183.

Canada: IFR 50 ft/min rate of climb at MOCA (company SOP); VFR zero rate of climb at 500 ft.

Europe: IFR 50 ft/min at en-route altitude (drift down and fuel dump permitted to MEA); VRF drift down to 1000 ft above the landing site (obstacle clearance has to be shown).

Australia: IFR (approximately) 50 ft/min at LSALT; VFR zero ROC at 500 ft.Additionally for fuel requirements:USA: no special requirements

Canada: return fuel programmed

Europe: return fuel programmed (under specific requirements, offshore alternates permitted)

Australia: return fuel programmed
However, we still have some gaps in our coverage of areas; anyone else wish to donate some information.

By the way Sandy Helmet - where do you come from?

[Another KOS]

Bladestrike

I have just re-read your post on the change of performance standard when the sea is hostile:Hostile conditions are deemed whenever a ditching would be "high risk", beit night or high seas. High seas being common 200 miles out.is there a Canadian definition of hostile in that context?

Is it perhaps tied to the ditching approval of the aircraft, or some other metric?

[Bladestrike]

The only regulatory required performance criteria are the aforementioned CARs. As far as determining a hostile enviroment, its left up to the PIC's discrection and endorsed by our SOP's. I'm being quoted far more than I intended here, simply trying to answer the question posed as vaguely as possible, but to correct an earlier statement; our SOP's also determine a OEI climb of 50 fpm at our
MOCA.

[JimL]

Thanks Bladestrike - I have amended the post and taken out the quotations (and attribution).

[Variable Load]

The issue of offshore performance was touched upon in the S92 design thread. As the topic was starting to drift to other ytpes I thought a new thread was in order?

JimL said:
PC2e will be required for operations offshore in a hostile environment from 2010. PC2 with exposure will be permitted after that in a non-hostile environment.

Profiles for PC2e are provided by Sikorsky S92 and S76C+ and C++; by Agusta for the AW139 (just about to hit the street); and by Bell for the B412EP. Any other manufacturer's helideck Cat A procedure could be used when the environment does not permit, or deck size is too small, for compliance.

Generally speaking, reliability is required to be established (in fact risk assessment) whenever exposure is to be approved (singles and multis; onshore and offshore). In fact VL you had it completely about face; Pure PC2 is the only one which does not require approval for exposure (it does require a profile which guarantees 'deck-edge clearance' but does not require drop down to be calculated). PC2 with exposure and PC2e both do (as does PC3 with exposure).

I say generally because it is not yet clear whether the reliability assessment (and UMS) will be required for HEMS operations in PC2 to the HEMS Operating Site; or for operations in PC3 over a hostile environment, post EASA.

Jim

Jim, my earlier use of the word "pure" was something of a mistake, I should have used that easy to say phrase "PC2 with exposure".

Back to my original point, I am surprised to hear that PC2e is dependent upon suitable engine reliability data being produced, but 'pure PC2' does not.

PC2 guarantees OEI deck edge miss, but accepts the possibility of the aircraft ditching before achieving Vtoss.

PC2e profiles and weights are predicated on OEI deck edge miss and fly away capability.

Take the scenario that a given aircraft type/engine combination is producing an inflight shutdown rate that does not meet the requirements. Are you saying that the regulators would stop an operator using PC2e and get them to increase operating weights by flying to PC2, a performance criteria that has more inherent risk?

I am aware of the helideck Cat A profiles for the S76C series. Have Sikorsky also produced some additional data regarding PC2e for the S76C?

Has there been any sign of movement from ECF with regard to PC2e and the looming deadline?

[Geoffersincornwall]

Did you read my post on the 92 thread?

PC2 is only permitted in non-hostile environments. If you are operating in a hostile environment you have, post 2010, two options.

1. Your helicopter has PC2e approval - operate to PC2e weights according to the appropriate RFM data. (not sure if all types will have a specific PC2e WAT)

2. Your helicopter does NOT have PC2e approval - You would have to delve into the RFM and find some way of extracting data that will indicate that you can safely fly away from the helideck if you go OEI at or after TDP. It may mean that you are unable to make use of any 'drop-down' and are left with only the 'OEI HOVER' graph to indicate a suitable weight. For most machines this may not even give you enough fuel to get home let alone take any payload. It is likely to be a show-stopper for some.

G

[Droopy]

Lots of rumours that the 2010 date will slip yet again.

[Variable Load]

Hi Geoffers,

I did read your post. I am also aware of the regulation and it's implementation date. My "exposure" :) to PC2e goes back quite a way as Jim can testify.

I am now lucky enough to be flying in a non-hostile environment according to the regulation, however my customer takes a different view and classifies all offshore work as 'hostile. Hence we fly to PC2e, or should that be PC2 with no exposure?

I am surprised that PC2e still requires adequate engine reliability data though. The logic seems to be lacking. If I am flying a procedure that has "no OEI exposure", something akin to Class 1 operations, why am I worried about engine reliability when it comes to PC2e (other than the obvious i.e. engine failures are not a good thing!).

If the regulators think this logic is sound, should the same principal not apply to Class 1 operations for all aircraft? Maybe it does already?

Back to my question about what happens if "Machine X" does not have adequate engine reliability. It now looks like it cannot do any offshore duties in a hostile environment post 2010. That's interesting :eek:

[Geoffersincornwall]

More than interesting. Its the elephant in the room waiting to embarass us all. If we look at what has happened in the past I fear a spate of failed engines in a particular region that are put down to 'local maintenance difficiencies' and the index fudged accordingly only to find that actually it's a basic design flaw that those with top notch engineering staff (properly apprenticed and aviation oriented) have managed to keep at bay for years (oh! we all knew about that - didn't you?). Does that ring a (92) bell?

With regard to PC2. You say you are flying a procedure with no OEI exposure. I would appreciate a description of that procedure and the origin of the data on which its based if that's possible. Thanks

G

[212man]

Actually VL, you might like to revisit the JAR AMC 3.517 and the flight regimes that require approval to operate with exposure - you will see penetrating the H/V curve is included. What's the TDP for the S-92 helideck take off without exposure? 30ft. Where does the base of the H/V curve start? 15ft!

I have queried it with the proverbial horse, and from his mouth came confirmation my logic is correct.

[Variable Load]

Geoffers,

Sure, I'm flying a PC2e profile at PC2e weights straight out of the RFM.

Something I am sure you will be encouraging AW139 customers to be doing real soon?

Still not sure why we need to consider engine reliability data as a fundamental behind PC2e operations. Aren't we giving up about a 1000 lbs of payload so that if a donk quits after my NHP calls "30 feet" we can still fly away and bring back the passengers safe and dry?

I am not saying that engine reliability data is not important. Of course it is. As is reliability of most components on these machines we strap ourselves to.
If there is a fundamental reliability issue, the manufacturer is duty bound to find a fix.

But should an engine reliability problem result in a ban on hostile offshore operations, operations that are being conducted with "no OEI exposure", when that same aircraft can fly from airfield to airfield with fare paying passengers on board?

[Variable Load]

212man,

This issue was covered some time ago when Sikorsky and ECF were first coming up with solutions and data to the PC2e performance requirements.

It was interesting that Sikorsky and ECF ended up with totally different interpretations. My recollection was that "we", JimL included, tried to persuade ECF that their position was perhaps incorrect.

If I were to say more it would be based on supposition, a failing memory and a very poor knowledge of the technical basis for the requirements! If more is required I could go and look at my old notes?

Maybe JimL can offer more guidance, technical input and history?

BTW, who is the "proverbial horse" :confused:

[Geoffersincornwall]

My comments on the 92 post about the JAA's ambitions for PC1 are perhaps relevant. PC2e is the 'get-out-of-jail' card for not being able to deliver it. It uses, or at least attempts to use, 'equivalence' via 'risk management'.

G

[JimL]

It's a little more complicated than 'not being able to deliver PC1'.

A Category A procedure is deterministic such that:

the site has to be surveyed and meet the requirement for size (remember that the adequate visual reference has to be provided which usually results in a requirement for a larger than 1D deck);
the environment must permit flight in accordance with the procedure and the limitations of the aircraft (including cross wind limits);
the performance calculations must be accurate - which means that
all aspects of wind accountability must be within some limits;
the actual level of the obstacles must be know (and that means the sea under conditions of tide and sea state).
the reject must be assured.Take a simple example; the wind is strong, from the direction of the derrick and exceeds the cross wind limits (which for the AW139 is still 17kts); the aircraft will probably be facing into wind (it would if I were flying it); the actual conditions of wind will be variable and none of the vertical components will be known (usually called turbulence); the sea surface will be chaotic and the level (of this obstacle) will be unknown. The take-off might be into wind and a sideways departure with a yawing manoeuvre effected.

None of these conditions are deterministic because the environment does not permit accurate planning and the manoeuvre, although comfortable, does not conform to the manufacturer's Cat A procedure. If an engine failure was to occur after the Rotation Point and whilst within the banking/yawing manoeuvre what would be the outcome - the truth is that none of us know.

We also have a number of aircraft for which there is no Cat A procedure (and/or flight test data) on which to base the PC2e procedure; in these cases, it has been accepted that a procedure can be provided (even in the Operations Manual) which is based upon modelling with a validated model. Most manufacturers (at least with modern aircraft) have numeric models on which profiles can be based. Profiles provided under these conditions will not be as robust as those which are provided for and tested under the conditions required for acceptance by the Certificating Authority (that is not the case for the S92 because the amount of testing for their PC2e procedure was at least as robust as that for the S76C+ Cat A Helideck procedure). (In fact before PC2e was written into the regulations, the efficacy of the profile was tested on three modern aircraft on the latest 'generic' numeric model - the one funded by the EU for the EUROPA Project).

For all of these reasons, it was decided to contain the text of PC2e within the exposure requirement.

Just a short word on Pure PC2; if an aircraft has a deterministic procedure for deck-edge clearance and operates under benign conditions, the regulations permits (Pure) PC2 (without exposure). These conditions usually exist where the Sea State is less than 4 (4-8ft and 17-21 kts); you can see that with these conditions, the take-off can always be taken into the 180 degree obstacle clear segment (and within the 5:1 falling gradient). Without assuring drop-down the aircraft will clear the deck but will be forced to ditch (under the worst conditions of failure - i.e. 1 second before RP). The text that permits a safe-forced-landing for PC2 (Pure PC2) has never been subject to any additional conditions and is therefore outside the exposure concept.

It could be argued that this provides a very good implementation scheme for those oil companies which are working in a non-hostile environment and for whom the ditching is an acceptable outcome. Up to 20 kts Pure PC2 could be flown and, from 20 kts (from which point most aircraft can operate to their maximum mass) PC2e. However, it is stressed that there must be a procedure for deck-edge clearance - which is usually provided within the Cat A or PC2e procedure.

Jim

[Variable Load]

Jim/212man

Having spent some time thinking about the PC2e profile and the obstacle environment issues, I can see why some element of engine reliability would be prudent, even with all of the benefits that PC2e brings.

Can anyone elaborate on Droopy's comment re the 2010 deadline. If it is true it would be interesting to learn who is pushing for the delay and why!


VL

[JimL]

Perhaps Droopy might wish to elaborate!

Jim

[HeliComparator]

When PC2 was going to expire with the only alternative being PC1, I was a big fan of PC2E. Now that its possible that EU Ops might provide the means to think again, I am not so sure.

We have to look at the big safety picture, and bear in mind that no-one has died from an engine failure during the critical exposure period in an offshore takeoff or landing. However, there have been a number of issues associated with hopelessly inaccurate TAFs, airfields closing unexpectedly, PPR diversion airfields declining to accept mass diversions, massive queues for procedural IFR approaches etc.

So my question is, is the hazard associated with engine failure when taking off or landing offshore greater or less than the hazard associated with flying around with legal minimum fuel most of the time (in order to maximise payload to the client)?

One of the great strides of the EC225 is the ability to carry max passengers and full fuel. It makes for very relaxing and safe operations. With PC2E it would be likely that fuel carried would have to be significantly reduced towards or to the legal minimum. I am not convinced this will improve overall safety.

HC

[Variable Load]

HC

I have to agree that the debate should take place. I do not believe that the risk analysis has been completed as accurately as perhaps we would expect. The point you make was also made by me with regard to the operation that 212man is now flying. There were recorded incidents because of fuel state, regulation and unreliable TAFs, yet we were faced with PC2e operating weights that would limit the options for carrying "additional" fuel.

My current operation also has similar limitations. We may be looking at flying about 265nm from a land alternate, but the fuel we can carry is being limited due to PC2e requirements. The balance between risks seems somewhat skewed, especially considering the "relatively benign" environment we are flying in?

I can also recall returning from Beatrice with an S61 on minimum VFR fuel thanks to the TAF. The METAR on return meant that an ILS to 34 was inevitable. On coasting in I asked if there would be "any delay". No was the answer, until I reached Inverurie when I was informed I would be No.10 for the ILS. That was immediately followed by "Pan, Pan...". Not a comfortable position at all!

Unfortunately the fuel issue is not statistically quantifiable?

Should Pure PC2 be the proper way forward? A performance criteria that balances the performance capability of current aircraft with the overall risks associated with the task we are carrying out?

[Variable Load]

So does anyone know where the JAR offshore performance requirements are heading. It's almost 2010 and something must have been formulated by now with regard to the way forward.

Out here in paradise we are still flying the S92 to PC2e weights, but we are operating alongside an S76C++ and and EC225 who are not - all for the same customer. It's a real farce - go figure.

Perhaps Mr "Shell Management" would care to comment why the only aircraft operating to PC2e are S92s flying in the non-hostile environment of SE Asia, whilst every over contracted aircraft, including those S92s flying in hostile environments do not???

[malabo]

Variable Load, I know what you mean - flying around in an empty helicopter just for that 10x-9 prob of an engine failure at a bad time. And on your time off from offshore you probably moonlight flying Class 3 in a single.;)

Offshore is catching up technically in all kinds of ways. Regulations will be last.