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Bell 412

Old 31st Oct 2004, 14:15
  #21 (permalink)  
 
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Had the single engine fuel consumption question come up in preparing for a new contract. After doing a lot of work with FlightSafety and Bell Helicopters it was determined that the fuel consumption single engine at max cont. was the same in the PT6T-3b as twin engine consumption. The airspeed will depend at on what you can maintain but we had come up with 90 knots in the simulator.

Hope this helps.
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Old 31st Oct 2004, 20:20
  #22 (permalink)  
 
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Devil

Thanks mate, it's a bit scary considering the distances you have to go sometimes to the rigs, with limited fuel and maximum payload. That onshore alternate can seem like a mighty long way to go!

Changing the post a bit, any comments; pros and cons in taking off from the centre of the deck compared to moving as close as possible to the edge of the deck before commencing the rotation into forward flight.

Your imputs will be highly appreciated!
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Old 31st Oct 2004, 21:52
  #23 (permalink)  
 
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Try this.....

This was an interesting airing of views from a while back:

http://www.pprune.org/forums/showthr...threadid=54120
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Old 1st Nov 2004, 01:32
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The usual technique over here is to get as close to the edge as possible, with the rotor over the water, and the toes of the skids just barely inside the edge of the deck. The rationale for this is that the wind hits the wall below and is deflected up and into the rotor, providing some additional lift. The wind usually goes up, and then on the downwind side of the heliport is actually blowing down, much reducing lift, so the best place to be is as close to the edge as possible. All this is assuming a standard production platform heliport, but the same effect is usually felt coming off a drilling rig. The technique used when at 11,899 lb, little or no wind, and very hot, is to get to the edge, and move nothing. It's important to be very smooth, and to move neither the cyclic, the collective, nor the pedals unless absolutely necessary, and then as little as possible. Stirring things around destroys lift. We hover there at 100% torque, and eventually some lift comes along, which can be felt as the helicopter starts to rise. As this happens, smoothly lower the nose to move off the deck, and do nothing quickly, or else the deck may rise up and strike the tail. If 100% torque provides enough power, then the takeoff is made in one continuous movement. You usually know before the skids break contact whether there is enough power to go immediately, but it's still a good idea to do things slowly.

Some may be horrified at the technique, but it works, as evidenced by tens of thousands of takeoffs annually, without a single accident that I'm aware of during the past 20 years. The exposure time is minimal, a couple of seconds at most, and everyone involved has accepted the risk.
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Old 1st Nov 2004, 08:56
  #25 (permalink)  
 
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Devil Thanks!

Thanks RW, not trying to reinvent the wheel sometimes makes life easier!

GP, it's the same techique I use when heavy, by moving forward till the blades are over the sea and skids just inside the deck. The wind does make a huge difference!

Company policy dictates 85% IGE max to ensure enough power in hand to be able to get to 15-20 feet vertical, before rotating. But some of the SP's just can't do it from 85%, without a lot of praying, nursing and swearing in the same breath.
Thanks for the input!

Anything said on approach angles somewhere?

Especially taking into consideration wind / no wind, heavy / light load, turbulence and cross wind landings (especially wind from the right side) with the Bell 412's?

Last edited by Recuperator; 1st Nov 2004 at 09:36.
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Old 1st Nov 2004, 14:20
  #26 (permalink)  
 
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Your not writing a book by any chance are you???

Please don't think that the standard upheld in the GOM is the accepted International Standard, it is not.

If you have to wait for a gust of wind to become airborne, then your far to heavy, and negligent. But maybe don’t know it!!!
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Old 1st Nov 2004, 14:38
  #27 (permalink)  
 
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OMR....It is amazing how one large company....OLOG...with its two major companies...Bristow and Air Log ...can operate so differently. Not only between companies...but within the company itself at its various bases. The local management has as much effect on operating practice as does the Home Office crowd (if not more so).

Throw in the different governmental agencies overseeing the operations and you get a whole different twist yet again.

The FAA sees things much differently than does the CAA...thus Gomers approach the same tasks from a different viewpoint than do their UK licensed brothers (and sisters).

What is right one place...is poison at another...what came out of the Elevated Deck thread seemed to indicate that different techiques seem to yield very similar results but with lots of arguing about which side had the best way.

The GOM method of diving off the decks...and making flat approaches took some getting used to...after doing the Bristow steep...steep...steep approaches. In Nigeria...the takeoffs were not much different beyond the fact we reduced weight for temps in general and greatly reduced weight for Mud Barges surrounded by tall trees....not sure the Gomers would be allowed to do that by company and customer mandate.
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Old 1st Nov 2004, 20:54
  #28 (permalink)  
 
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Oh Sassy.

Your not saying that our GOM colleagues would be forced to trade off their meager safety margins in favor of increased profits?

Surely not.

Its been ten years since I was down in the Gulf, and now fully recognize there are Companies, Authorities and Flightcrew that demand and achieve a higher safety standard.

Cheap safety will cost significantly more in the longer term.
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Old 1st Nov 2004, 22:44
  #29 (permalink)  
 
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OMR, since the incentive bonuses of most upper level managers, both helicopter and oil companies, are based on quarterly performance, there is little reason for them to care about long-term costs. With the profit levels being posted, lawsuits are only minor annoyances, and there is little evidence that the managers care about the safety of employees other than from an economic standpoint.

Perhaps I'm too cynical, but I've been observing the actions of these companies at close range for well over 20 years, and that has been my consistent impression.
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Old 1st Nov 2004, 22:47
  #30 (permalink)  

Nigerian In Law
 
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Problem is, the "companies" call the shots !! Like it or not, operators are coerced by them and then go to the authorities to get a "dispensation". Fact of life. Nobody is wrong
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Old 1st Nov 2004, 22:48
  #31 (permalink)  
 
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I was not able to attend the PHPA Safety Conference...but heard some good reports about it. One of the statistics advertised there was the helicopter industry kills about 59 pilots per year....and that trend seems to be relatively constant.

Maybe someone that attended can enlighten us on that presentation of statistics?
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Old 1st Nov 2004, 23:19
  #32 (permalink)  

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Regardless of profiles/numbers/manuals etc, there are some things you can't budget for.
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Old 2nd Nov 2004, 10:45
  #33 (permalink)  
 
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Devil Hmmm

OMR No, definately not writing a book, and not taking anybodies advice as accepted International standard. This forum lends itself to learning more, as there is a vast amount of experience out there.

I am merely fishing for information to take, evaluate and to assimilate, then to use the best from everyone for my own use to improve on my own knowledge and skill, within or as close to company regulations as possible.

As for flying over MAUW, I don't go there! We work on Class 2 and OGE figures for take off, depending on location and with the temperature of the moment, we then calculate what we can lift. The OEW, fuel and manifest weights are added to together to determine TOW and then compared with take off data. Weight then gets adjusted or reduced to stay within allowable TOW parameters. This gets done before every leg on every flight. So there is never a doubt or any guess work involved what our actual TOW is or what figure will give us Class 2 take off performance or OGE performance. I am sure most pilots work on that basis in the offshore industry.

I have been very fortunate to have flown with pilots of various nationalities that have flown in the North Sea, GOM, Nigeria and Middle East, Australia and South Africa and have learnt from each and every one of them! Wasn't all good, some of it was kept as experience on how not to do it.

As SASless said there are differences in the same company. I have seen the flat approaches, the dive off the decks, the steep, steep approaches and have prayed many times! As said in the post Red Wine was refering to:"Flying and helicopter flying per say on and off decks/rigs/ships/mud barges/airfields are not black and white and every situation merits it's own tecnique.

I thoroughly believe that the day you think, as a pilot, that you know everything about helicopter aviation, it's best to step down before your attitude kills yourself, or worse some innocent passenger, who is relying on your skill and knowledge as a professional to get him to his destination safely. He is usually just a worker, a pawn in the system, like you and me and not usually directly involved in management with hidden agendas, short term planning and incentive bonusses.

Unfortunately safety margins do get "adjusted" to make up for profit. Maybe the Sikorsky S92's will be the answer to all this, with it's Cat A performance, with full fuel and full pax, and go capabilities.

But will the companies pay that kind of money, cut into their profits for their workers safety sake?


I would still like to hear the pro's and cons on approach profiles though, anybody willing to stick their necks out?
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Old 2nd Nov 2004, 14:00
  #34 (permalink)  
 
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At risk of poking again at the hornet's nest, who said that operating with full Cat A from a rig would measurably improve safety?

The data I have seen says that OEI enroute, with minimal exposure time at takeoff and landing is quite sufficient, since we are far more clever at making crashes than to simply wait for an engine to quit.

Yet again, I do wish we were willing to actually fix what causes crashes, rather than what we train for, which is burned into our collective brain, and therefore has our deepest concern, however unreasoned.
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Old 2nd Nov 2004, 14:09
  #35 (permalink)  
 
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Nick,

Why then the full Cat A performance of the 92.....? What drove that decision.....or design criteria?
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Old 2nd Nov 2004, 14:45
  #36 (permalink)  
 
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Notwithstanding that this will raise the hornets from slumber; Nick has managed to avoid comment on Gomer Pylot's post and remark only on the aspirations of Recuperator.

Compared to Recuperator's considered approach (which is based on the practical procedures contained in JAR-OPS 3), the description of the take-off procedure in the GOM results (for me) in a sharp intake of breath.

It might first be appropriate to highlight one particular element of Gomer's post; it has been observed from flight tests that a wind of up to10kts does not give the additional lift that one would expect (hence no wind accountability in the S76C+ Category A helideck procedure for winds below 10kts). Putting the disc over the deck edge might improve on this situation but would it compensate for the loss of lift that would result from the dissipation of ground cushion? Nick probably has the answer to this.

The fact that the authors of JAR-OPS 3 settled for second segment performance (climb performance of 150ft/min at Vy at 1000ft above the take-off altitude) or AEO HOGE was no accident, it ensured that vertical acceleration would be possible and the decision to pull above a limit would not be required.

If one is already applying the take-off Tq of 100% (and going no-where vertically) what if the sudden improvement in lift, due to a transient wind, disappears at the time that the helicopter is in transition over the deck edge? Isn’t this the Las Vegas approach to performance?

How many pilots, faced with this situation, would allow the helicopter to descend rather than pull a ‘transient Tq’! This might not be reportable but is it good practice?
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Old 2nd Nov 2004, 15:39
  #37 (permalink)  
 
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Devil Not so safe on all fronts

Maybe all areas of the offshore market needs some attention to detail when it comes to flight operations, human factor, maintenance and training to improve safety and standards in our industry.

Some interesting reading.

The 2004 report for 2002 from the OGP at http://www.ogp.org.uk/pubs/354.pdf
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Old 2nd Nov 2004, 16:03
  #38 (permalink)  
 
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JimL is right, but I use the same logic on this thread that I did when my young son asked me where the knives were kept. I asked him, "Why do you want to know?"


SASless, please understand that my questioning here has NOTHING to do with the performance of ANY aircraft. I am not the S-92, I am a person. I have opinions and ideas that I share here that do not infer ANYTHING about ANY helicopter. I believe the S-92 has the best OEI performance of any aircraft in its class.

I contend that we are channeled by our training from the first flight to think of engines as safety, and this creates an automatic response that hurts us.

More engines, More OEI performance, More safety. This builds in our minds the belief that no other investment in our machines will pay bigger benifits. Our regulators grow from our pilot pool, they are part of our self-hypnosis, so the safety rules grow from this same delusion.

I ask anyone to show the data to prove this wrong-

For twins that have basic OEI capability:

The safety of those aircraft will NOT be increased in any measurable way by adding full OEI performance. If we invest in full OEI performance, we will FAIL to make our aircraft safer, we will just make sure an aircraft with bigger engines crashes in the same way it now does, with all engines running happily while the real cause has been ignored.
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Old 2nd Nov 2004, 20:19
  #39 (permalink)  
 
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Nick,

We have discussed this before...and actually agree about having a focus upon "real" accident causes....vice grinding away with the same old wheel. My point was merely to point out that in previous posts to other threads you have talked of the 92's load it up and go capability. Believe me when I say as an oldtime pilot...I understand the beauty of that capability....but....following your logic that we are only exposed to an engine failure during the critical phase in takeoffs for .0000008 percent of the time...or some such number....then why all the wonderful performance for the 92....maybe some of that weight and power could have been expended upon range and cargo volume and thus step back to the current status of most twin engined helicopters wherein we all risk a saltwater dip should one of the Donks give up the ghost during a takeoff at "max" weight?
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Old 2nd Nov 2004, 22:23
  #40 (permalink)  

Nigerian In Law
 
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Nick, I agree with you on may of the points you've raised, but in that case why haven't the big operators taken on the EH-101 ? 3 engines, total redundancy (so they say) ? Sounds too good to be true.....................
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