Sikorsky S-76 [Archive Copy]

[ATPMBA]

CAE Simulflite has a course, and I think they charge less.

[HOSS 1]

Either of the above will provide training, but a Type rating is not required (in the U.S.).

You can get your license in a R22 and then hop in a C+ with 41 hrs total piloting time.

See FAR 61.31

Hoss

[flipcelia]

Does anyone have any cockpit noise data from the C model at hand.

In the process of a hearing protection review, which this data would be handy for.



Thanks - FC

[Mr Toad]

Say Again?

By the way, don't forget it's when the noise stops you have start worrying...
The most painful sound level is in the front row left hand seat of the cabin; the cockpit is not quite so close to the 'box. Some guys use Bose noise attenuating sets and swear by them, but they're not cheap.

None of the Utility models is quiet; I understand the VIP versions are quite different; and they don't even vibrate. Funnily enough manufacturers are shy of cockpit noise level figures, possibly constrained by their lawyers. I once asked for the cockpit noise levels in the AS 330L from the visting sales team; I'm surprised I ever worked again. But then I also flew the Chinook with early Clark headsets and we had a major fight to get our company to appreciate the problem - I recall that NASA did some research with us on the loss of human performance after 5-6 hours of sitting underneath so much angry machinery. The results were never made public as I believe it was paid for by a certain oil major and considered private. The ATCOs at ABZ were quite accustomed to our request to say again our inbound clearances.

Most of us had our hearing checked and found that we could still pass our medicals as the hearing test didn't pick up the problem; actually we were suffering a loss of noise discrimination. Two people talking together, no hearing problem; go to the pub and you can't understand anybody, especially when they call time. So we kept practising.

So keep up the campaign to force recognition of this Health and Safety issue; I wish you all better luck than the "old" generation.

[Steve76]

Esso Australia in Longford, Victoria did testing on the S76C in 2000.
Contact engineering there and perhaps they might offer to help.

[rjsquirrel]

Take you own data, guys! The Radio Shack meter I bought works fine. Just be sure you know what you are measuring. The number of different scales and systems is boggling, and they don't actually translate. Mostly, the dBA scale is used in regulations. Take several readings with the mike in several places, and then average the data. The meter I use is a digital one, but similar to this:

http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=33-4050

[Mr Toad]

rjsquirrel -

Yes, but what will you prove? Only that cockpits are noisy, and the bean counters prefer it that way.

I believe you have to prove a loss of human performance and a resultant degradation in flight safety to the Regulatory Authorities to make headway on this problem. At the moment ships and aircraft are exempt from most Health and Safety Regulations in most countries and the Authorities find the helicopter industry too small to bother with. It barely arises in planks anyway so why bother?

Human Performance can be scientifically measured before and after flight; but like all research it needs funding. There are NO fairy godmothers around.

flipcelia -

I recommend that while working along this line, you and your colleagues buy the best headsets you can afford as an investment in your own sanity; wear them anywhere an engine is running; and ask your engineering department as nicely as you know how if that set may be used in THEIR aircraft - PLEASE! Cos you'll have to wait awhile for the beancounters.

I admit that ; I wish you luck.after a lifetime of helicopters, this subject is close to my heart

[rjsquirrel]

Mr. Toad,
You ask, "What will it prove?"

It will prove that unlike you, I read the question that sparked the thread, which is (try reading it now, if you have a moment!) " Does anyone have any cockpit noise data from the C model at hand."

I do disagree with the point of the thread, as I feel that the noise in a cockpit can be fully reduced with the right headset and earplug combination.

Here is the capability of a David Clark (-24dB rating, -35 in the high freq damage range):
http://www.davidclark.com/HeadsetPgs/h10-20.htm
Typical earplugs add 15 to 25 dBA to that, so available protection is about -40 dBA.

Here are OSHA noise regs, where protection is required at about 90dBA:
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=9735&p_table=STANDARDS

Note that the requirement is that protection is required at 85dBA.

I have no info to say that aircraft operators are exempt from OSHA protection (in the States, of course!)

With -24dB reduction, the cockpit could be at 109 to 114 dBA and still be acceptable.

Here is a table of noise standards worldwide:
http://staff.washington.edu/rneitzel/Standards.htm

Here is the Canadian standard (85 dBA) Note that the phrase "Statutes or regulations covered by other jurisdictions apply to aircraft operations" is inserted in the Occupational Health regs for Aircraft Operatons (Part 29):
http://www.worksafebc.com/law_and_policy/public_hearings/assets/pdf/OHSR_public_hearing/part_7_clean.pdf

[Tynecastle]

Hearing lots of different views on the 76 C+, especially about engine problems, any feedback from the Rotorheads in Nigeria, Macau, or anywhere else where they have put some hours on the C+ would be appreciated.
Cheers,
Tynecastle.

[flipcelia]

Thanks guys for the comments,

have been doing some study on the matter, and the whole thing is quite interesting. The decibel ratings that are advertised on headset data are more than likely far in excess of what you will actually get.
For example, a well known headset (that a lot of you are probably using) quotes 25db of noise reduction and in independent test only reached between 5 - 11db noise reduction depending on the environment. Its for this reason that one of the best headsets on the market do not quote any level of attenuation because of the wide range of levels that will be achieved depending on the situation (head shape, noise freq's, sunglasses etc).

The other interesting fact to come out of this is that using foam plugs under you existing headset in a crewed environment, while giving you pretty good attenuation may be making your crew deaf if they aren't using plugs as well because the intercom is turned up so loud to compensate!

ANR seems to be the way to go, but once again has it's down falls. Not all ANR will attenuate the freq's required in your operation so care should be taken when selecting your next ANR headset.

FC

[NickLappos]

flip,
I agree fit is important, and if the ear pieces are too old and hard, it simply wll never seal. My experience is the soft silicon seals (almost sensually soft!) do a great job. Do you have a source for that miserable result?

[flipcelia]

Nick,

the figures quoted are from a US Military study for the acquisition of new crew headsets for use in a large transport A/C.


FC

[MD900 Explorer]

This is the reason why Bose Headsets (http://www.bose.com/controller;jsessionid=BW55XQvvZLhXyzjw9LhQqqq1nFRTsrQyHgCLCQ 1tvshQY4KH58m4!1855195594!103858704?event=VIEW_PRODUCT_PAGE_ EVENT&product=headsetx_headset_index&linksource=centernav_img_pilots&pageName=/index_2.jsp) are the nads.

I always use them and i hope it helps

MD :uhoh:

[Outwest]

How are you all starting the A++ in regards to the trigger? Some companys advocate pushing the starter button and going into the gate, then trying to reach up and pull the trigger and pull back and modulate the start. Others pull the trigger down, push the button and move forward and then modulate. Any/all comments appreciated.

[Gomer Pylot]

The RFM says to pull the trigger and then move the lever. That's how I do it.

[peter manktelow]

In China we "pull" the trigger altho to be pedantic the RFM does say to "hold" the trigger.

"hold" is to "pull" ????

The way I was trained many years ago (when a particular Canadian company took delivery of its first A+ ...yes it was an A+ not an ++ but same throttle) was that if the engine went hot and you had not "PULLED" the trigger ; in your panic to shutdown , you may well jam the throtttle up against the idle stop.....in any case the RFM says you may have to move the throttle back past the throttle idle stop in order to modulate the T5 during start , so why would you not pull the trigger.

The analogy to the above is the 212 where you can hit the idle release switch but if you have a death like grip on that throttle , you will not move it ie the force you are applying to close the twist grip is jamming the cam against the pin and not allowing it to retract thus not allowing closure of the throttle past idle.

The late Peter H. had somewhat similiar happen to him in Bombay on a 212 years ago (he also had a battery problem) and in his desire to stop that awful noise and ever increasing TOT , he pulled the Fire T Handle.....clean out of the instrument panel.

:8 Peter

[Camp Freddie]

Hey,

In my part of the UK on the A+ we hold the trigger and move the lever for the very reasons that Peter M states.

regards

CF

[Mr Toad]

rjsquirrel -

Thanks for the advice, it's always welcome, if somewhat confused this time. I recommend you stop believing the writing on the box (-40 dba?) and listen to what flipcelia says about actual reduction.

I maintain that the implied point of this very important thread from flipcelia is how to cope with human performance reduction, stress and long-term hearing loss due to extended exposure to excessive noise; otherwise why should we concerned with it?

Esso's figures would be useful if available as they relate to this particular aircraft. When you know the characteristics and frequencies of the multitude of noises then you can select an ANR headset that matches that signature.

MD900 Explorer is correct, Bose sets are good. Some of the guys in Macau are using them, perhaps they would give advice. whether Bose covers the requirement.

[rjsquirrel]

I guess I am confused. "Headsets don't work, so we must buy a Bose." Isn’t a Bose a headset first, then a noise canceller? The Bose manual says in several places that they only protect low frequency noise, and only when the cups seal properly, which is your gripe about headsets!

It seems this thread has already convicted the old headset technology, and now thinks only a Bose active headset is acceptable, when a Bose depends on its ear cups, too.

Here is a paper that describes how well helmets and earplugs work to suppress noise, and how ANR does not change the noise above about 500 HZ (see Table I which has tons of studies together. It shows that ear muffs (headsets) and helmets work on your head):

http://www.aearo.com/pdf/hearingcons/limits2.pdf

Also, the hearing loss most of us get is high frequency, which is where the Bose does not work. Above about 500 Hz the active nose canceling is not at all effective. Bose used to say that on their web site, probably until they realized that they were losing sales that could be gained if they blurred the distinction between comfort (which they do provide) and protection (which is a very marginal product of the Bose technology). Here is a scientific paper that describes the fact that ANR does NOT protect you better than a good headset (but that the better communications and comfort are good to have.):

http://www.aearo.com/pdf/hearingcons/anr.pdf

Without someone who knows what he is talking about, this thread is wandering into strange territory!

Here is the Bose site, check out their manual, page 19 for example:
http://www.bose.com/controller;jsessionid=BXLchCq9KhgLsw9tTP2vznLlXJ3bgRh0q7J2rJ Br5LCs06T7R58J!103858704!-174109993?event=VIEW_PRODUCT_PAGE_EVENT&product=headsetx_headset_index&linksource=centernav_img_pilots&pageName=/index_2.jsp

Here is a web site that discusses hearing loss, showing that it usually occurs far above the range where Bose helps:

"When damage first occurs, it usually affects the part of the ear corresponding to the mid-frequency range of 3 to 5 kHz. On an audiogram, this type of hearing loss configuration is commonly referred to as a "noise notch." These frequencies correspond to the region where our consonant sounds are heard. A person with this type of hearing loss may have trouble understanding speech because the speech sounds "muffled"........ because the louder, lower frequency vowels are audible but the softer high frequency consonants are made even more difficult to hear, due to reduced hearing sensitivity in that spectral region."
http://www.hei.org/news/factshts/nihlfact.htm

[Joker's Wild]

Hmmm, can't believe there aren't any takers yet!!!

The C+, ok machine I guess, still a 76 afterall. 2S1 engines, lots of jam, much more so than A or A+ (maybe A++ too?).

No. 1 weak link IMHO though is the DECU (Digital Engine Control Unit). Reason - Single Channel Digital Engine Control with good old fashioned cable backup for manual control, if required. This component is very capable of generating NO END of faults, most of which are minor in nature and pose more of an inconvenience than a genuine mechanical problem. Trouble is, even being an inconvenience means you need to call an engineer to clear the fault before you can go flying again. It can be a right royal pain in arse.

No. 2 weak spot is engine power assurance procedure and results of same. While things have gotten better from where they used to be, power margins can at times be right on the line. Assuming the on board calculation system fails to give a valid check, you are left with going to the chart and that can sometimes be entertaining. It's best if you make sure your pencil is not TOO sharp.

My two cents.

[Outwest]

Thanks for the comments. Not sure why our procedures differ from the RFM.

[cpt]

I have been flying for a company operating a fleet of 4 C+ since a little more than 1,5 years and despite 2 decu major faults during this period of time, they seem to be surpringly reliable.....remains to see with time !

[NickLappos]

Outwest said "Not sure why our procedures differ from the RFM."

peter manktelow had it right - they don't.

G.B Shaw said we are separated by a common language!

[Outwest]

Sorry Nick, now I'm really confused.
Peter says he "pulls or holds" the trigger, pushes the starter button and then advances the throttle to light-off and modulates the temp. Right?
Our company procedure is to NOT "pull or hold" the trigger, just push the starter button, advance the throttle thru the gate, then reach up with one of your fingers and "pull or hold" the trigger so as to be able to come back behind the gate and modulate. Maybe I was not clear in my first post, but as I see it this is contrary to what the RFM says.
Please advise

[NickLappos]

Outwest,
You are right, I didn't see the distinction before.

Why do you fail to follow the flight manual? What reason do you have?

[son_of_igor]

Yep,

I agress pull in the trigger start the engine and then set it to the 50+- for one minute as per the fm

[Outwest]

No worries Nick.
I am trying to find out why we have this procedure. I have asked training pilots and they don't seem to know either. Will update you if I get an answer.

[ATPMBA]

Can a S-76 be used for helicopter logging?

Can a hook be attached to it? There doesn't seem to be a lot of clearance between the bottom of the heli and the ground.

[Collective Bias]

No problem with a hook on a S76, it will be installed "inside" the fuselage so only the bottom part of the hook (5000 lbs unit) will stick out.

You can use the S76 for sling load work, but there is far better helos for it. The pilots vision outside for sling work is no good and the mirror installation is not the best.

Depending of the weight of the load, it has high Vne with load on though.

Very stable helo for precision work also.



CB

[Cyclic Hotline]

Why on earth would anyone want to use an S-76 to log? It would be the most pointless, money losing exercise in the history of the business.

You can't log with a mirror, you could modify the seat installation to move it to allow for vertical reference work, and install a bubble window - but why?

The S-76 might have a 5000 lb rated hook, but what would it's actual payload be with 1 hour fuel and 5000' DA?

Best consign this concept to the "stupid ideas better never admitted to" file.

:ok:

[Aesir]

I have done quite a bit of sling work on the Bell 222 which is not that unsimilar to theS76 in that it is also a executive type fast helicopter.

Actually I thought it was great fun to sling with the B222, the visibility outside is terrible but you learn to work around that.

I guess if there is no other helicopter available in the area, you use what you can get!

[ShyTorque]

We used it for fire-bucketing amongst other USL jobs. Workable but underpowered and poor vis.

[NickLappos]

If you have little equipment (inn other words, if the 76 has the same radio/nav gear as a typical Huey) it can carry a reasonable load. Light 76's can tow in at about 7000 lbs EW while the typical corporate and offshore ones are at 8300+.

The vis is certainly an issue, there is one bubble window version out there somehwere, though.

IMHO, logging with an S-76 is like logging with Nichole Kidman. While she might do the job, there are surely better things she can do.

[offshoreigor]

Who in their right mind would even cosider a 76 for heli-logging? It can sling but the vis is terrible!

Cheers,

OffhshoreIgor

[HughMartin]

So I am not the only one who has escaped to a quite corner on Christmas day to get away from the chaos for a few moments. I thought that we had done well to avoid having to buy my son a set of drums for 19 years but on his twenty'th Christmas, we couldn't think up another excuse. I dread what his flatmates will say when he arrives back at Uni with it.

As for this topic; Nick, you really are stretching the imagination to compare the S76 with NC. My imaginary activities with her have got NOTHING to do with flying.

By the way, with whom would you compare the 92?

Merry Christmas to everyone from a very snowy Scotland.

[NickLappos]

HughMartin,

I have that old poster of the reclining beauty superimposed on the 76. With helicopters on the brain, it lulls me to sleep some nights....

The S-92 reminds me of Xena, frankly!

;)

Here is Xena balancing the rotor:

http://users.frii.com/suzannem/chakram/thumb_old_chakram_finger.jpg

And a very Merry Christmas to you all from frigid New England, USA!

[Red Wine]

You leave our silicone enriched, talent depleted airhead alone.

[ShyTorque]

Nick,

Are you sure that's not Xena giving her personal opinion of the EH101...she's not exactly looking friendly and that's not the full set of fingers she's waving with....

Bags I volunteer to do the ground runs with her :E

[Ascend Charlie]

Well, I have had the best of both worlds, I had Nicole Kidman in my S76!

We weren't logging, and I didn't "have" her, in that sense, you know... Her minders and Russell Crowe (who was there too) would have killed me, but they would have needed a taxi to get home afterwards.

[Texdoc]

Red Wine,

How dare you! Silicone enriched indeed....

Natural, ALL NATURAL I SAY :8

[Encyclo]

I'll trade you one logging 76 for a 204B doing V.V.I.P. missions:ok:

[Giovanni Cento Nove]

Red Wine,

"ours??"

NC is as Australian as Mel Gibson or Russell Crowe. Not Australian at all in other words. Born in the US of A - Hawaii.

[Red Wine]

Hollie Torleado.....

Your correct.....so that explains the result......fancy being half Yank and half Aussie.

Torn between Gods country and that other mob.

PS......Who is Mel Gibson and Russell Crowe...????, what do they fly??

[John Eacott]

Hmmmm......born to Australian parents, Australian nationality from birth.

Bimbo? IQ of 132+.

Now, about Xena: which of your ex wives were you thinking of, Nick ;) :cool:

(Getting cold out here on the balcony at 22C, time to move indoors :p )

[Red Wine]

Thats the measurement around the Plastic Bumps......[In millimetres]......

[John Eacott]

One, or both?

;) :D :p

[Red Wine]

Either one...!!!!

Come on Sassy, join in.

[John Eacott]

Rob,

Your second or third bottle of red ? ;)

All sorts of trivia about our Nic, here. (http://www.imdb.com/name/nm0000173/bio)

In the meantime, about S76 sling loads: I did, once or twice :cool:

[Red Wine]

Actually I'm oncall tonight....so coffee it is!!!

Do you do it with the gear up or down??

[Disting]

Lovely aircraft. You also feel a bit more like a hot and sweaty lift pilot when you switch off the aircon button....but switch it back on in the cruise to get that smug feeling.:D

[Giovanni Cento Nove]

Hey JE

"our Nic"

S'pose that must make Kylie a Brit.

RW

Mel Gibson flies Porters, OH58's and Hueys and stuff, I seen it in a movie, so it must be true.

Russell, he just gets anyone (http://www.pprune.org/forums/showthread.php?s=&threadid=112115&highlight=russell+crowe) who sez they're a pilot to fly him around.

[John Eacott]

That query could lead to all sorts of replies....

But for the S76, only a few sling loads in the dim and distant past, but mostly the gear was left down: with the load on, there was no way the gear was an issue re speed. Fairly lousy lifting platform, with little or no pilot reference coming into the hover. IIRC, the only way to make an approach was to drift in sideways, looking through the pilot's door window, which was interesting taking tools out to the rig.

G109,

Huh?

[SASless]

Sorry guys...have been forging that special bond between man, machine, and the open highway. Driving from the Pacific NW to where the Wright Brothers first flew. Due to some inclement weather enroute....went south to Bakersfield and turned left. Lots of pretty sights along the way. For some perspective....in Barstow, CA....as you start east on I-40....a sign says "Wilmington, NC. 2554 miles".

Thinking of Xena.....one could become a Toggled- eyed Git -Watcher if not careful.

Poor ol' Nick sure has a thing about Nicole....however when seeing pics of Nick....I think Anna Nicole would be more his style....especially since she has blossomed.

[NickLappos]

SASless,

I agree, in principle that even Anna Nichole would be challenging.

Of course, your secret fantasy is with Nick Faldo, isn't it?

[FlyingHead]

Hi PPruner, I'm looking for some info about the 76 B for VIP flight. So I wonder what is the normal empty weight, the fuel burn, standard config., etc.. anything can help.

Cheers
FH :cool:

[Ascend Charlie]

No such thing as a standard 76, all are customised.

Ours is kitted with air con, full SPIFR, EFIS, every gadget known to mankind, and it weighs in at 8200 lb empty, 11700 full.

Burns 700lb/hr at 70% cruise and 140Kt or 800lb/hr at 80% and 145-155kt. Fuel capacity is 1800lb, endurance is only 2 hr 20 to dry tanks, so don't get into any IFR holding.

Took out one row of 4 and installed wider seat benches, so we carry 8 in comfort facing forward plus 1 in the front. We chose against the rear-facing club car config because we lose 2 seats and the pax don't like going backwards.

Marvellous machine, lots of guts, FADEC makes it almost idiot-proof, but it is sadly rear-heavy - watch your CG.

[the coyote]

AC, you could put me up the front to help that C of G thing.....:E

[SASless]

Put me up front and kick off two front seat pax for weight and... balance......I must start eating right.

Hand me the chips and salsa!

[Chopper Jog]

Hi Coyote,

Good to see you are well and alive!

Happy New Year!

Regards,

CJ

Note: Drop me a private message or email and tell me what you have been up to and your plans for 2005!

[international hog driver]

Sorry Coyote,

The jobs mine because with your weight you will lose too much payload,:E :E

But with my size i fit real nice next to AC:ok:

Merry Chistmas to you all, Hope its hot there 'cause is bloody cold here.

You still in the ****adella or are you chassin mossies further north now coyote. Nothing else handles better than an Eimasa car....:E :E

IHD

[John Eacott]

AC,

XUX had (has?) the same problem when it arrived as the first A+. Heavy engine cover, all the extra avionics in the tail, Urst didn't like the club seats, either. Both forward float bays were eventually filled with as much lead ballast as we could fit, to get the CoG within limits. About 140kg, IIRC, but I don't know if it's still there :rolleyes:

[Gomer Pylot]

Ascend, that's a huge fuel burn. I guess there's a reason B models are relatively rare. In the A++, we burn well under 600 lb/hr, if we can get above 3000 ft, flying at Vne. We rarely see more than 600, and that's at sea level pulling max continuous power. We plan for 3 hours fuel, and usually have more. That extra fuel makes a big difference.

[Ascend Charlie]

The fuel burn is the price we pay for having 1033 horses lined up on each side.

The boss wants the grunt, we can take a full load of 9 pax with baggage, polo sticks etc and a reduced fuel load and still launch with the greatest of ease. The cost of the fuel is the least part of the equation, and range rarely matters if the normal run is only 130-150 nm.

[Gomer Pylot]

Well, horses for courses. Over here, range always matters. Going 200NM offshore, the customer always wants to carry the max load, and 800 lb/hr with about 2.5 hrs fuel max is why the 412 won't cut the mustard (the slow speed is another, which contributes to lack of range). The S76C+ looks like the coming thing, with good range and payload. There are no B models in the GOM that I know of, but for VIP work they may be very good. I've never even seen one other than in pictures.

[Rotator]

Ascend Charlie's spot on. Buy the 'B' model for the Grunt or for Hot 'n High. Strictly from a pilot's point of view, the best model S76. Loads of power and an excellent fuel control system with a simple manual override if the duplex computers fail. FADECs on the 'C' have maybe gone too far.

We operate a corporate 'B' that weighs in at 8546 lbs on the ramp with aft-facing club seats and credenza. That's without the noise cocoon. As with everything in life, there's always a price to pay. In this case, always PLAN to use 800 lbs/hour.

C of G has been a problem in all 76's but the 'B' was helped by placing the battery(s) in the nose. The range can be improved by fitting the extra tank in the boot, but just try positioning single pilot with all tanks full !!

Hi to John Eacott (It's Urs without the T). XUX is still spending 11 months / year in the hangar. An excellent ship. Used to get fuel flows down to 520 lbs/hour at 8,000 ft.

I thought about asking to take it to Sumatra where it could be put to much better use. However, COALIN says the boys with the Stars and Stripes can hack it (see the Tsunami thread) so best leave it at Bankstown.

By the way, I used to be an S76 devotee until I flew the Agusta 139 last year.

[Collective Bias]

According to Sikorsky info there has been two S76 mishaps this week. On C+ in the Pacific Rim and one A in South america.

Anybody knows more details - crew, WX, mechanical, unknown???



CB

[Geoffersincornwall]

Nothing official yet but a Brazilian S76A suffered loss of control at the commencement of a maintenance flight. It ended up on its side. Two pilots and three engineers on board. No serious injuries but one engineer apparently had his seat belt undone and sustained minor injuries.

[ScotiaQ]

S76C+ in Japan. Carrying out Rescue training........one engine ran down and aircraft landed in the water. No floats deployed so the aircraft sank in 500+ meters of water. Attempts are being made to recover the FDR. No fatalities so far as I am aware.

[Collective Bias]

I have tried to find an answer on this but nobody seems to know, so I am trying PPRuNe for help.

Most of the parts in the rotorhead is similar in apperance on the A and B (C) models except the rotating scissor link. On the B (C) model this link is offset and the end result is angled pitchlinks.

Anybody know what the reason for this is???

I do not want to start anything with phase angles:ok: but I am guessing this could be the case.


CB

[NickLappos]

The offset swashplate is rotated so that the blade's pitch angle increases with aft laging motion. This is called "alpha 1 coupling", and it makes the blade a bit more stable, and it also makes a bit more collective pitch available. The way it works is that the swashplate horn is behind the blade pitch horn, so the pitch link must lean forward to meet the blade. If the blade lags aft, the pitch link stands more vertically, and is therefore a bit longer, and makes more angle on the blade. This helps damp any lag motions.

The change was made as the gross weight was increased from the A to the B.

[Collective Bias]

Thanks a lot Nick.

It seems like there are very few around that knows this reason. Intresting way to solve a "problem".


CB:ok:

[Joker's Wild]

Ok, so what happens when the blade experiences a leading motion? :confused:

[NickLappos]

The stability works both ways, as the blade leads, the angle is reduced; as it lags, the angle is increased. This makes the blade more stable in-plane. The idea of using alpha 1 is not new, it is part of the designer's bag of tricks. Look at the push rods of many helicopters to see how this angle is used. I recall seeing it on EH-101 as well.

[Lu Zuckerman]

I figured that if I did Nick would think I was giving him a dig. However, it is a valid question. If there is a positive effect when the blades lag is there a negative effect when the blades lead?

I may continue this when I get a bit more information.


:E :E

Overtaken by events. See above.

[HOSS 1]

A new model of S-76 is announced at HAI !

http://press.arrivenet.com/bus/article.php/579382.html

[ShyTorque]

Sounds great, the type could now use more performance to compete with the AB139.

However, one question comes immediately to mind.

Bearing in mind the weight of the new equipment, such as enhanced anti-icing, new soundproofing, HUMS etc, will there be any REAL increase in usable performance / payload / endurance?

What appears at first glance to be an increase in performance sometimes gets "swallowed up" when the whole package is considered. I hope not - perhaps that quirky "short field" takeoff profile will be no longer required. ;)

[whatsarunway]

anti icing?
i dont suppose these blades could fit a b model?:{

[Collective Bias]

Getting the latest engine technology into the S76 is great, but, why not have the choice between Turbomeca and P&W. The S76 with Turbomeca is a mature and proven aircraft, and think of fleet operators, I think they will be pissed by getting a new type of engines. Have a choice I say, othervise the idea seems good.

Must say though, have a hard time se that little tiny PW210S with single compressor, single gasturbine and single freeturbine produce more power than the PT6. At what, 60 000 rpm and 1000 deg C?

MTBF?


CB

[Bruised Armpit]

Simply---Does pulling up to 115% (230% total) torque for under 5 seconds exceed RFM limits?
Long version---In the limitations section of the RFM, reference is given to figure 1-5 which states “Transient – Time: 5 Second – Transmission Torque Limit: 115%”. This is not an OEI limit. One could interpret this as a 230% total torque limit. FlightSafety seems to agree with this interpretation.
Right after the RFM reference to figure 1-5 is “NOTE: …the sum of the individual torque values does not exceed 200%” there is no other reference to the 5 second limit.
Which is it?
Also, there is not an "Intentional use of transients prohibited" clause. What is Sikorskys position on this?

Bruised Armpit

[IHL]

“NOTE: …the sum of the individual torque values does not exceed 200%”

I think that 200% limit is for normal operations i.e. take-off
so you could have 1 engine at 104% and the other at 96% and that would be OK for take-off. Transient limits are notnormal ops they are transient.

[SASless]

Transient limits are not normal limits....did the man say?

Please expound upon that for the audience....if the transient limits are in the limitations section and allows one to do certain exceedances without notation in the maintenance records then what is not "normal" about them?

All limitations are for normal operations. Operations that exceed the limitations are not "normal".

As to my view...."Limitations are for normal operations, Bloggs!" holds here....if you are crashing....on fire....or approaching the ground at an injurious rate.....then all bets are off and limitations become a reference to which you describe the exceedances.

:E

[magbreak]

had a similar one myself several years ago where it was either a sharp pull or watch the gear arrive through the airframe (flat approach to rig due cloud base, lost all lift as I got over the deck). The limits in the engineering manual are different to the flight manual. I think up to 230% all that is required is a look around to make sure the gearbox is still connected etc.. It was a while ago as I said but the engineers didn't seem too worried by the whole thing.

I stand by to be corrected by Nick :O

[SASless]

The Bell 212 Maintenance manual and the Boeing-Vertol CH-47 maintenance manual for sure have engineering limitations that exceed those listed in the flight manual.....which makes sense to me. That way, we ham handed guys that wear boxing gloves when we fly, are tricked into being a bit easier on the hardware. Something our benevolent employers appreciate because it helps their bonus packages at the end of the year.

[NickLappos]

Bruised Armpit,

Sikorsky's position is stated in the flight manual and the maintenance manual. For transients, you can exceed the RFM limits, and still not have to do anything, as explained in the maintenance manual. When you pull an overtorque, write it up, and maintenance will disposition it.

The transients are to cover those times when you get an oops, and they prevent you from pulling a gearbox. Thus, they should not be counted on or purposefully used. As a rule, Sikorsky gearboxes cannot be harmed by the engine(s), because the box is stronger than the engine(s).

Let's face it, the limit is for daily use, the max transient is for a very small number of occurrences in the life of a box (once or twice).

I don't have the max transient limits at my fingertips for all the models of the 76, but the 76A's OEI max transient is about 155 torque for 15 sec, the DE transient is about 115 for 5 sec.

[Bruised Armpit]

Thanks for your replies. I completely agree about not intentionally using transients. Oops factor.

So, just so I can win an arguement....

Pulling between 100-115% torque Dual Engine (200-230% total transmission torque) for under 5 seconds is within the transient limits as per the RFM and no limit has been exceeded.

Correct?

Thanks

[Nigel Osborn]

How do you read 155% TQ????:O

[IHL]

SASless my humble apologies. What I meant to say is; Joe Average Aircraft Captain (JAAC) would not plan on using more than maximum torque.How ever on any given day should JAAC be a little off his game and approach down wind and carry a little extra speed then JAAC may need a little extra [transient]Torque to get stopped at the bottom.

But then again I may not know Jack.

[NickLappos]

Bruised,
Yes.

Nigel, good question! The actual torque cannot be 155, because the engine only delivers 152 at worst worst case, so the Xmsn is OK by default! This was a subject for the original certification way back when, and is now part of S-76A lore! We can read ultra high torque on the instrumentation, if not on the cockpit gauge.

All this is good stuff, I know a 365 captain who had to change a transmission because he went to 107% torque for a few seconds, and got no relief from the factory.

[HeliEagle]

I win from this post.

Nick,
you said,' The actual torque cannot be 155, because the engine only delivers 152 at worst worst case, so the Xmsn is OK by default! '

but,how's A++?

and IHL says, 'I think that 200% limit is for normal operations i.e. take-off
so you could have 1 engine at 104% and the other at 96% and that would be OK for take-off. Transient limits are notnormal ops they are transient.'

followed by IHL,I can use 115% for 1 engine and the other one at 85% for 2min for take-off. of course, normally it won't happend.

correct?

[NickLappos]

I am sure it meets the same certification logic, but I will check with the guys who did that, to be sure.

[Taff In Exile]

My company is looking to replace their ageing S-76++'s. What is the preferred choice of Ppruners as a replacement I wonder?

The operational environment is offshore, flying to rigs and accommodation vessels between 50 and 100 miles away from the main base. Seasonal temperature varies from -25C to +45C.

[Gomer Pylot]

I would have to say that the S76C+ would be hard to beat. For that matter, the A++ is hard to beat. Put those 1S1 engines in the A airframe, with no increase in allowable max gross weight, and you have loads of power. With C+s, you have a degree of commonality of parts, and both pilots and mechanics already familiar with the basic aircraft. It should be cheaper all around, rather than toss out all the spares and experience you alreadyi have.

The AB139 might be viable, but it hasn't been around long enough to tell.

[Mars]

As a matter of interest what is a S76++, what is 'my company' with respect to a 'PPL' and, more importantly, where on earth does one find a single offshore province with a temperature range from -25C to +45C?

[ShyTorque]

Mars,

My thoughts exactly......

[Taff In Exile]

The old suspicion showing through chaps ;)

"my company" as in my employer, my PPL is a plank one and for fun only, S-76++ cos that's what I've been told they are. I might have got a + wrong though.

The working limits for temperatures here are -40C to +40C but over the last few winters it's rarely gone below -25C but occasionally up to +45C. Think FSU rather than North Sea.

I'm asking about the options available as I am part of a team assessing the alternatives available to us. I thought that getting info from the people at the sharp end of the industry would be a sensible thing to do. Far better than reading manufacturer's brochures and listening only to the bean counters for example.

[Disguise Delimit]

Why is somebody who obviously hasn't got a schmick about helicopters on the procurement panel?

Why is this person acting on information from somebody else who hasn't got a schmick about which machines they already have?

Where on this planet is there a seaside variation in temperature like that?

Reel the suckers in, and wind it up.

:8

[Taff In Exile]

DD, strangely enough not everybody in a logistics department is an expert on helicopters. I have just started in the department and therefore am not, as yet, on intimate terms with the trucks, helicopters, hovercraft, tugs, barges, ice breakers, supply boats etc etc etc that we have / hire. I am however very familiar with the problems of operation and construction in the area and the restrictions that face the execution of transportation in this area which is why I'm on the team.

The hint as to the area remains FSU and, believe me, those temperature variations ARE real and not the worst around, Siberia gets at least 15C colder in the winter and nearly as hot in the summer.

[noooby]

FSU (Former Soviet Union), prolly Kazakstan (wild guess, forgive the spelling). Heard there is a 76 out there. Not sure how hot it gets there in summer, but it sure does get cold in winter!!
139 has potential, once they start spitting them out of the factory at a reasonable speed, and there is a possibility that one will be heading FSU way soon (ish).

noooby

[simfly]

Bristow should be replacing their S76s in Norwich with EC155 as part of the new shell contract.

[pitchlink]

Having looked at both the 155 and 139, if your company is looking to move forward in terms of performance (Safety), the only choice you have is the 139!! At present the 155 offers nothing that you do not already get from the 76 apart from the fact that you can say you have new technology.

[212man]

To fill in the gaps; a 76A++ is an A or an A+ that has been upgraded by having the Arriel 1S1 fitted. The A+ has the Arriel 1S. The 1S1 is the same engine that the C has fitted, but not the C+; that has the 2S1.

I would think those temperature ranges are perfectly possible if looking at Azerbajan, Kazakhstan or Turkmenistan; in fact +40/-40 is a comonly quoted variation.

The EC-155B1 offers a significant advantage over the B model in hot climates.

[Eurochopper]

Rumour has it that Sikorsky are brewing up an S76D - anyone know anything about it? Otherwise I'd go for the AB139, but it won't be available for a couple of years. Could the location be Sakhalin Island?

[Ian Corrigible]

The S-76D was launched at Heli-Expo after several previous false starts. New main rotor (fully de-iced and drawing on the Comanche design), new low-noise tail rotor (also de-iced, and allowing the D model to comply with SFAR 52), 1,000 shp Pratt Canada PW210S donks and a glass cockpit. 300-1,000 lb higher hot-day payload, 50 nm longer range. Available ‘mid-2008’ (so early 2009 would be a safe bet).

For now, the AB139 is still setting the standard, the result of Agusta actually listening to the operator base during the design phase. Strongly advise you get a test flight if you can – call BAAC in Ft. Worth.

I/C

[noooby]

Or if in UK as your profile says, call Agusta in Italy

[Taff In Exile]

Thanks for the replies so far, any further supporters of the AB 319 over the S-76?

[Plastic Batwings]

"At present the 155 offers nothing that you do not already get from the 76 apart from the fact that you can say you have new technology"......And....

....longer range, better payload, bigger cabin, bigger boot, faster, smoother, decent cockpit ergonomics, good vis, and a great 'pole'.

At least with the 'D' Sikorsky seem to be stirring from their slumber to smell the coffee in Marignane and Milano, even if it is still 3 years away.

[155driver]

The only thing I would add to that is the fact the 155 is far easier to maintain. We have very few problems with ours while we are surrounded by 76s in routine maintanence all the time.

[212man]

Hear, hear!

It will be interesting to see how the 76D has progressed. I recently had a chance to look at an S-92 FLM and was surprised to see reference to the fact that if the nosewheel isn't centred it may jam on retraction. The 76 has had that problem for nearly 30 years; don't you think they could have addressed that? Eurocopter use a micro switch to inhibit retraction if the nose wheel isn't centred! There was also reference to the pilot having to set the Nr after start and to avoid certain N2 ranges (again, like the 76); isn't that what FADEC should be doing?

[Red Cougar]

In favor of the 155, I would stress that she has a seamless and safe record of offshore operations and a good lineage with her ancestors ...

The AB139 is to be proven, has not even started operations, and may reserve some surprises.

S76, in its current versions is outdated !

[Hippolite]

If you really work for an oil company, you will probably have your own aviation department.

The EC155 has performance problems in B and B1 form. The B1 is an improvement but not that much of one. The aircraft still has engine problems, 212 man will surely attest to the number of engine changes that have been done since Shell bought them a few years ago. Can't tell you who, but a senoir Shell Aviation person was recently heard to say that the 155 was the worst decision they had made.

The S76C+ also has engine issues because its a Turbomeca broadly similar to that in the 155. Howevr, its a well know aircraft with a good safety record and offrers good payload if you don't overload it with too much equipment.

The 139 has often been touted as the panacea to the medium helicopter market. BUT, its unproven and, being an oil company, you will need HUMS which isn't available until 2007 or 2008. If you can wait that long, you may be able to have a 76D.

My vote overall would go to a S76C+ or C++ which has just been released.

Hippo:cool:

[noooby]

Hippolite,

Do you mean that HUMS for the 139 won't be available till 2007, or that the helo itself won't be available till 2007?
Wondering because the 139 has the accelerometers installed on the gearboxes already, with all the wiring. Track and Balance gear isn't installed yet, but thought that if they were installing accel's and wiring now, that HUMS would be closer than 2007. Any ideas?

noooby

[Double Echo]

As far as I know, only Mil 8's are operating on Sakhalin, or at least thats all that was there when I last visited last year.

Sikorsky are indeed churning out a new S-76.

Heard whispers that on Sakhalin the Mil 8's are being replaced by either S-92 or AB 139, last I heard the 139 was favoured.. if thats any use???

[155 Man]

Hippolite,
The 155 has its share of technical problems like any other helicopter, but we operate from the same location as a whole bunch of 76s (of all marques) and the 155's serviceability record beats the 76 hands down. Its also easier to work on, so downtime overall is far less.
Comparing the 155B1 to the 76C+, the performance is very similar. The new 76C++ may give a performance advantage, but for all the reasons already mentioned on this thread I'd go for the 155.
Incidentally, Bristow operate the 155 for Shell in Nigeria and so are aware of all the "problems", but they are still planning to buy 155s for the Southern North Sea, so it can't be that bad!

[FletchTheBone]

We looked at the grande S, 155, 76 and 139 aswell, and, for our money the 139 seems the best of the bunch but at the moment the 139 is only Single crew VFR during daytime and 2 Crew IFR - so what happens on an overnight stop and the met man gets it wrong......dear Boss sorry I need another pilot to fly back!!! Does anyone know if the 139 is looking to be certified single pilot IFR like the 76 and 155??

[Old Man Rotor]

I seem to recall that when you convert a straight "A" to a "A++" by replacing the C30's with 1S1 Arriels, you also increase the Maximum Take Off Weight from 10500 lbs [4762 kg] upto 10800 lbs [4898 kgs].

Its been a while, but I think this is correct??

[Ascend Charlie]

What sort of TCAS do you 76 people have? I am getting tired of having to take avoiding action for the bugsmashers which appear from behind the thick pillars of the machine, despite constant head movements during visual scans. A little more warning would save a lot of adrenaline.

We are looking at putting it into our 76B, and would like to know what is the most popular fitment out there. TCAS 1? 2? I suspect that TCAS 2 is not really needed (as well as the $300,000 price tag!) What brands have an STC for the 76?

All replies appreciated.:ok:

[slgrossman]

At PHI in the Gulf of Mexico we use mostly the (formerly) Goodrich Traffic Alert System (TAS). It actively interrogates the transponders of nearby aircraft and shows those within six or ten miles depending on the type of display. In the S-76 I've found it to be very reliable and accurate with respect to altitude, range, and bearing. It's my favorite piece of safety equipment. I understand the price tag is in the neighborhood of $15,000 US.

-Stan-

[GLSNightPilot]

We have the BFGoodrich Sky497 Skywatch system, which is a TAS (Traffic Advisory System), not a true TCAS. It only sees other aircraft with a working transponder, but it does a good job. We see lots of stuff that we would never see at all if we didn't have it installed. It doesn't do resolution advisories or anything fancy, it just has a display which fits into a standard hole in the panel, and a voice interface which announces "Traffic, traffic" when it thinks there may be a conflict. I have no idea of the cost, but I do think it's worth whatever it costs.

[Mars]

GLS:

What is your estimate of the number of helicopters equipped with 'Traffic Alerting' systems in the GOM?

[GLSNightPilot]

It's hard to say. I have no idea how many the competition has installed. All our mediums have them, and the light ships that don't already have them will be equipped in the foreseeable future. I hope they all do, but I simply can't speak for the other operators.

[Droopy]

We had a Skywatch on our previous aircraft and presently have a TCAS791; you get what you pay for. Skywatch is adequate for short range low level ~2-3000ft; TCAS is definitely more accurate and obviously greater range - but a lot more expensive and a bit heavier.

[Hilife]

I think I’m correct in saying that TCAS II is not an option on a helicopter – variations in predictive rate of climb with fixed-wing aircraft or something like that.

The SKYWATCH HP (TAS) is pretty popular amongst the rotary fraternity and would be worth a closer look.

Several years ago there was a limitation on the number of TCAS I operators within the UK and although restrictions were eased, it may be worth contacting the National IFF/SSR Policy Board before you plumb for a particular type.

http://www.caa.co.uk/docs/7/DAP_SSM_CAA_Doc_714.pdf

[Jez]

Rob

A couple of suggestions:

1. Get Mr and Mrs P to look outside for you ; or
2. Prohibited area around the family compound

Unfortunately a real hazard.

One question to all:

Doesn't TCAS require transponder derived data from other aircraft? (ie. sqwarking 1200 in Class G airspace).

Alot of bugsmashers around the Hunter Valley :{

[GLSNightPilot]

I don't know about all TCAS models, but the Skywatch TAS we have requires other aircraft to have an operating transponder in order to see them, although they can be on any code, not just 1200. I don't know of another way to do it. With no transponder, the only thing that could possibly detect another aircraft is radar, and although we do have weather radar in our mediums, it won't pick up another aircraft well enough to do any good. Some models do use the weather radar for the display, though.

[chopperguy]

Hi guys,

does anyone have more information as to why Sikorsky issued an ASB requiring main rotor hubs to be inspected every day?

[Hilico]

Errrmmm....don't you inspect it every day anyway?

[chopperguy]

Hilico,

the ASB requires an AME to sign the inspection every day.

[Hilico]

Sorry, half-expected it would be something like that. Does this mean the AME takes a wrench/spanner to it, rather than the ordinary pre-flight fiddle?

[sycamore]

Over here an AME is the Aviation Medical Examiner,so what do you expect him to do to it ??????/

[200psi]

Some of the more recent hubs were machined to the incorrect thickness and there is a concern of cracking on the underside. Interestingly these were the hubs that were supposed to have a 10000hr life up from the 3000hrs. The hubs need to have an ultrasonic check prior to the AD being lifted on the effected aircraft.

[chopperguy]

Sycamore,

great sense of humour, maybe you should see your AME more often.

[magbreak]

I was told some cracks had been found on an A model "in the pacific rim" recently. The aircraft in question at some point had been in an incident involving high wind (I know laid myself wide open there:O ) and Sikorsky were attributing the cracks to that incident. Apparently the A model head is thinner than the B and I assume the C's.

The head is to be inspected by an engineer before every flight, unless the head has had an NDT test done on it.

[whatsarunway]

On the auto pilot console on the 76 there is a hov button, bit like auto hover, but not all that accurate, when should you use this mode? is it mostly for the sar stuff or can it help in other aspects of corporate flying?:hmm:

[Ascend Charlie]

All the other buttons on that selector have well-defined uses, but I have not yet found a situation where I have wanted to use HOV. It makes a good demonstration on conversion to type, to show a hands-off hover and even smack the cyclic to show how it restores itself, but unless you have a big airfield to drift over, it is not particularly accurate.

Too much residual drift requiring constant trim inputs for any useful hovering. Do it manually.

SAR birds have more swept-up inputs which may include doppler positioning to hold a spot over the ground. Adds a lot to the cost.

[NickLappos]

The button is used to aid the pilot in holding a precise hover, it is not intended to allow hands off hover.
Basically, when HOV is selected, a set of acceleration sensors is linked into the sas, so that a drift produces a slight counter cyclic, automatically. It is called hover augmentation on some helos.

If you need to hold a precise hover in some bumpy conditions, it is a definate help.

The SAR mode hover uses this hover acceleration feedback, and also adds the doppler/inertial, a much more powerful sensor.

[ShyTorque]

"can it help in other aspects of corporate flying?"

It is a great help in corporate flying. While the aircraft is shut down on the ground and you are waiting for your pax, it helps to pass the time.

"On....Off.....On.....Off....."

Normally used after you have read all the newspapers. ;)

[400 Hertz]

If you are talking about the SPZ 7600 AFCS, I thought that this button was originally marked 'HOVER' and on later versions of the system became renamed as 'VELOCITY'. It's a nice way to allow engineers to fly the A/C smoothly at low speeds, beeping it into a hover with the trim button. I've not seen it used by real pilots too often though, I guess they can probably hover the aircraft using their own on-board accellerometers!

[hovering]

I will have opportunity to try this as an 'augmentation'. I do hover exit work occasionally. That button has always puzzled me too. The next time I am fighting the gusts trying to keep one wheel on a rocky outcropping, I will engage this mode, and report back on the difference it made.:ok:

[Wizzard]

hovering,


Might I suggest you try it before you get the wheel onto the craggy outcrop - it might not be a good place to find out you don't like it!
;)

[hovering]

wizzard, good idea...
So I went out to do a limiting check today, and tried HOV out for a few while over the threshold of the runway in 10Kt winds.
I noticed little difference. Engaging COLL driving made us go up and down a few feet while in a 5-10 foot hover....good for a laugh.
My final thoughts? It certainly didn't make thinks worse laterally, but I did not notice much improvement. I wouldn't use the collective driving/RAD alt. mode too low....
I was hoping it would smooth out some of the lateral dancing the A/C likes to do in the wind as air swirls over the tail rotor...no luck there.
:}

[Geoff Williams]

In the non IIDS C+, when you touch the 'Test' sensor on the N1 indicator, without the engines running, it displays;

rANO

Looked in all the manuals I can get my hands on, but cannot find what the code is meant to indicate. Obviously the DECU engine gen is not turning so no corrected N1 is available, but what do the letters stand for? Got our engineering staff perplexed as well.

Ta
Geoff

[NickLappos]

Geoff,
Not ignoring you, but this is one I've never seen, I've emailed the Chief Pilot to help with the answer.

[Nigel Osborn]

What do you expect from a plank wing bloke????:ok:

[NickLappos]

Yes, Nigel, I have forgotten everything. Sitting in a G-V, with a glass of wine, reading The Wall Street Journal, I seem to see some poor sod in a rotory winged craft flogging slowly out to sea, several miles below. I lean forward, turn down the volume on the DVD movie set, and think, "There, but for the grace of God, go I!"

[Geoff Williams]

Thanks Nick, I hope I haven't put you to too much trouble.

It will probably be one of those useless pieces of information that tend to clog our day.

[R. Cal]

Wow, round gage 76C+. That's a rare bird! You're part of a small group that knows what a DDR is...

Like most things on helicopters, the issue of displaying N1 in the 76C+ isn't a simple as it appears. In fact, the N1 you are looking at is a "corrected" N1, and not necessarily the exact N1 speed the engine is turning. It's due to the fact that Turbomeca rates their engines primarily on N1 speed and the precise rated (takeoff, 2min, 30sec) n1 speed is different for different ambient conditions (alt, temp).

So the kind Sikorsky engineeers, realizing you really didn't want to pull out a chart each time you set takeoff power, came up with a scheme for a "biased" or indicated N1. This allows you to memorize only one number for each rating. The mathematical correction is made in the DECU and sent (via ARINC) to the indicator. As a backup, the N1 indicator itself is also capable of calculating "Biased N1". It receives a raw N1 signal from the alternator, and oat from the ship's OAT. So what you're actually doing when conducting this test is confirming the gage calculated N1 is within tolerance to the DECU calculated value.

So with all that I STILL haven't answered your question! I don't have an exact answer for you right now, but will find the indicator spec and let you know. In the meantime, check all the inputs to the indicator for proper connections. Seems to me it's missing a necessary input to do its own calculation.

R. Cal

[Geoff Williams]

R. Cal

Thanks for your reply, but you might have missed in my description that the engines are off....so no N1 anyway. I am aware of the dual sensors on the phonic wheel and the frequency proportional signal from the DECU engine alternator all provide N1 signals. And when we are running, no problems, all indications are fine and the test shows the backup N1 signal is within 0.2. But curiosity was aroused when pressing the test with the engines off I got a code I can't find any info on.

rANO doesn't seem to fit any scenario I dream up??

Nothing in the 2S1 training manual either that I can find.

Geoff

[NickLappos]

Goeff, I will bug the Chief Pilot again. I suspect it is French for something the Taunting Knight said to Arthur, "You are brave little people who wipe other people's asses..." (Python fans out there, anyone?)

R. Cal, you are right, when we adapted the original Turbomeca to the A+, we test pilots were aghast that someone would actually allow the OEI limit to vary by each degree of OAT and foot of altitude, and expect that the pilot would use a look-up table while wrestling with a failed engine! The folks who make the gages were able to work with us to produce a small computation that always showed "corrected" N1 so that the limit number shown was always a constant, thus you had to memorize one number and it was valid for any ambient.

I am always struck that those who like the single limit calculator for the latest Super Puma don't mention this vast shortfall on another EC product!

[ShyTorque]

I think it means "read Air Navigation Order".

You might as well, 'cos you are obviously bored silly being a hangar pilot with the engines switched off so you aren't going flying today.

;)

[212man]

"I am always struck that those who like the single limit calculator for the latest Super Puma don't mention this vast shortfall on another EC product!"

Nothing as crude as having to look at an N1 gauge in the latest ECF products. In the 155, with the arrial 2 series, you just pull to the stop for the power rating selected. May not even be N1 limited, but who cares? The computation is done for you!

On the 225 it's even better; YOU don't pull at all, it does it for you. The AP will pull to 96% Nr with the 2 minute rating selected, then fly you at the automatically calculated Vtoss (it knows the weight and ambient conditions). Very civilised!

Say what you like about the French, but don't knock their innovative and clever MMI (Man Machine Interface) concepts. For us in the pointy end, they have got it right:ok:

[R. Cal]

Nick -

I reckon it aint French fo anytin. Them N1 gages are from the Lone Star State. Prolly some intelligent cryptic Texan message.

Nah, strike that. Texan and Intelligent don't belong in the same sentence...:)


R. Cal
(Z. Cal's tightwad brother)

[sprocket]

Willy: Does this N1 indicator type have a battery/cell inside it?

[R. Cal]

No batteries in the indicator.


It's a Sikorsky, not Mattel...

[SASless]

212man....These the same French that build the Airbus things that fly themselves despite what the pilot wants to do? Something about an airshow crash with passengers aboard as I recall.

Also...on the 155 one has to remember to put the lever down or hit a button at some point do you not....or burn up an engine?

Thinking of a situation where you are zinging along at warp speed at 7500 feet and one engine flames out......the aircraft senses the power demand for your flight condition...pours the dead dinosaurs into the combustion chamber.....and throws out all sorts of display pages at you. Then at some point the pilot is supposed to put down the cross word puzzle...and do something...since the one engine is pretty well humping to meet the demand?

[212man]

SASless,
as for the Airbus it's the same as with any computer; garbage in, garbarge out!

Regarding the 155 and burning engines out, that's not a fair understanding of the situation. ANY aircraft having an engine failure will use the remaining engine to try and meet the power demand at the time of failure. If the demand is too great then, for engines with a 30 second rating, the 30 second rating will be required. This will still result in Nr decay unless either the pilot intervenes (if no outer loop modes coupled) or the AP lowers the lever (if outer loop modes coupled).

With the arrial 2 series, when it was in its relative infancy, there was no cumulative time available for the 30 second rating (same on the 76 C+; same engine) and it required a module 3/4 change (equals engine change for practical purposes). It was not BURNED OUT! the engine is now in a more mature state and TM have allowed cumulative consumption of the 30 second rating.

Having seen various FDR traces, I can tell you that the AP does a much better job of handling an engine failure, than the pilots, in these sorts of incidents. But then it's easy to be an armchair critic and no criticism is intended.

Don't knock it till you've tried it!!;)

[NickLappos]

212man and SASless,

The response to engine failure is often governed by the engine fuel control, which limits all paramenters to assure that the rotor droop occurrs, but that the engine is not harmed during that event. Thus the pilot has to use the lever to hold Nr properly, and all is right with the aircraft. With this engine limit protection scheme, no autopilot or pilot intervention is needed to assure protecting the engine, and the pilot does not have to fly using a combination of two gages, (the first limit gage and the Nr gage.) The fly away task is simply "make sure the rotor droops, and hold it to about a 2% droop." In other words, the engine limiter makes less workload than the first limit gage.

To rely on an autopilot to protect the engine is to have said "the job is too colplex for the pilot, so he must keep his hands off". This might be necessary at some time in the future, but is not needed now.

[Geoff Williams]

Ok, Shy Torque might be right. I am bored, been here since 1100 on a Sunday for a 1200 departure, its now gone 1500 and some of the pax still stuck in LOS I've been told. Going to be 1700 I bet before the job is on.

So went down and turned on the BAT. After the initial start sequence on the N1's with both usage lights and all digits showing '8' s, I covered the test cell to see

drNO for about 2 seconds then rANO.

Subsequent tests with the power still on gave the previous rANO.

Now here's a guess.

drNO might mean dDrNotOperating. Yes? The DECU was still going through its 10 second 'wake up' and it was during that time that this code was displayed.

Using some of the same lose logic, might rANO mean referenceAlternatorNotOperating.

Checked the 2S1 Maintenance Manual, zip.

Sprocket......nope, the ginger beers say there is no battery.

And yes, I agree with all you that are shouting.....get a life!

[212man]

Nick,
I'm not sure what you are trying to say!

Firstly, when flying an a/c with an FLI, and an engine failure, the only thing you have to check is that you have the corect power rating selected (it defaults to 30 sec on failure of other engine, but you may need to select lower ratings), thereafter you just fly Nr. You do not refer to the FLI to check the power; it is simply telling you what the FADEC is doing. It is mischievous to imply you have to monitor two gauges!

Secondly, using the 30 second rating (on the 155 B) does not 'harm' the engine. It just requires a maintenance inspection, which in turn requires module 3/4 removal.

Thirdly, I fail to see how the 76 C+ can be any different in this regard; same engine! if the power demand at the point of failure is such that it is equal or greater than the 30 second power, the 30 second power will be used and this will result in the same inspection (unless the 2S1 now has cumulative usage, which the 2C1 does not). Obviously this will not apply to the 76 C++ and D, or the current 155 B1 (2S2, 2C2.)

I think the point about APs and engine failures is that in all probability they will do a more accurate job than the pilot, in the real world. Remember, that in most cases, a failure is a surprise to the crew and the subsequent handling will not be the same as a pre-briefed OPC/PPC or test flight, where the pilot will be poised with a hair trigger reaction, and a set of carefully recalled numbers in is head waiting to be applied.

It's a question of phillosophy; do we use automatics as some form of add on nicety, to be used from time to time, but fundamentally fly the a/c as we always have, or do we use them as the core operating function, with manual skills kept in practice to serve as the back up mode?

Sorry to divert the thread but I hate to see innacurate comment about some b***dy clever products!:(

PS. Geoff; get a life;)

[NickLappos]

212Man,
Sounds like the two are flown the same way, using the engine limiter to control engine limits, and flying the Nr to keep workload down. That was not stated previously, you hung your hat on the first limit indicator and the autopilot! Sounds like they are all flown the same way, except the 350, which requires the pilot to look up a bunch of data on his kneeboard!

Yes you did steal the thread, when you defended the French by bringing up two other, irrelevant pieces of kit when we were talking about the 350. The 350 is still a bear to fly OEI, but I do concede, the other EC models are well governed!

[212man]

Nick,
Re-reading your post I see you don't mention the 350 directly and I therefore thought you were bashing the 225 (latest Super Puma.)

'Steal' is a bit harsh, I thought 'divert' was about right!

[NickLappos]

Diversion is why we log in here!! I learned from your posts, thanks!

[HOSS 1]

Here's the answer. (We had a similar situation in the test 76C++ last year, so I had looked it up)

When Test switch (Initiated Test) is touched, if the DECU ARINC is not being received the digital display will read "ArNO", if the DDR data is not being received the digital display will read "drNO", and if the Raw N1 signal is not being received the display will read "rANO".

As you observed, it takes a bit for the DDR & DECU to start sending their outputs. Until then, you'll get the appropriate error message.

Good Luck.

Hoss

[Geoff Williams]

Hoss

Thanks for the info.

You said you looked it up, could you tell me where you found it, which publications describes the codes.

Thanks
Geoff

[HOSS 1]

It helps when you have an "inside connection" !

I got it from the N1 indicator specification document. You'd be hard pressed to find it anywhere other than the Sikorsky factory.

See ya,


HO5S

[Ascend Charlie]

Just an update:

We fitted the Ryan 9900 BX TCAS, with its stand-alone indicator and voice alert system with mute and refresh button on the collective. Provisions for future expansion for lightning alert and EGPWS.

Absolutely marvellous, and the altitude alert functions and approach modes work like a charm. They would want to, coming with a price tag over $55,000. But a lot cheaper than bumping into somebody.:ok:

Heck of a time finding somewhere to put it on the dash. Eventually had to toss the ancient Garmin 165 and shuffle a few dials around. Still got two other GPS to help me not get lost, so the 165 can be a spare for the Huey.

[212man]

Ascend, for information, TCAS 2 is not compatible with helicopters as they do not have the performance to follow its instructions.

Skywatch seems to be a popular choice.

[NickLappos]

Jez,
Yes TCAS depends on both aircraft squaking on transponders, it uses the answerback for range, and uses an antenna array to get bearing.
IMHO, it works fantastically, and is very valuable.

[rotornut]

S-76 Fleet Exceeds Four Million Flight Hours
Wednesday July 27, 9:12 am ET

STRATFORD, Conn., July 27 /PRNewswire-FirstCall/ -- Sikorsky Aircraft is pleased to announce that its S-76 fleet has accumulated more than four million total flight hours.
This achievement was made possible by the over 220 operators currently flying close to 600 aircraft in 59 countries around the world.

"The S-76 is a versatile product capable of flying anywhere, under difficult conditions, with unmatched range and speed. Its success has been built by meeting the needs of our customers throughout the S-76's long and distinguished tenure," said Jeff Pino, Sikorsky's Senior Vice President of Marketing and Commercial programs.

Pino said further that, "Hitting four million flight hours attests to the S-76's status as the preferred choice for hundreds of commercial operators around the world. It combines total reliability, comfort and safety."

Even legacies leave room for improvement however, which prompted Sikorsky to announce in February 2005 a series of engine, air vehicle, interior and avionics upgrades available for order immediately on the new S-76C++(TM) helicopter and a set of additional product improvements that will lead to the launch of the new S-76D(TM) model in 2008.

The extensive product upgrades ensure that the S-76C++ and the future S- 76D will remain best-in-class in the corporate VIP, offshore oil, airline, EMS/ search-and-rescue and law enforcement segments.

Product improvements available immediately on the S-76C++ include: a Turbomeca Arriel 2S2 engine upgrade, a new VIP interior, a new health and usage monitoring system (HUMS), and the implementation of new quiet zone technology(TM) which will enable significant interior noise level reductions without weight penalty.

The S-76D will build upon the upgrades slated immediately for the C++ by offering additional product improvements to include: a new composite main rotor blade, a new quiet tail rotor, a rotorcraft icing protection system (RIPS) that will provide the ability to launch into known icing conditions, a new cockpit with an integrated avionics system designed to the latest FAA/JAA requirements, and a new Pratt & Whitney Canada PW210 engine.

These product improvements will ensure a bright future for the S-76, one that builds on its strong legacy and holds true to its mission to fly anywhere and perform any mission at anytime.

Sikorsky Aircraft Corporation, based in Stratford, Conn., is a world leader in helicopter design, manufacturing and service. Sikorsky is a subsidiary of United Technologies Corporation (NYSE: UTX - News), of Hartford, Conn., which provides a broad range of high-technology products and support services to the aerospace and building systems industries.

[the coyote]

Hi all,

With reference to the S76, fitted with Arriel engines, no DECU/FADEC etc:

Two engine N2/Nr is set at 107%. If one engine's power is removed, and with the remaining engine within limits, it seems to droop and stabilise at around 104-105%.

Each engine doesn't know whether the other one is functioning or not, so I view the loss of one engines power simply as an increased demand of the other one providing power, similar to raising the collective in a single.

My understanding is that if you ask an engine to deliver 107% N2/Nr, the engine will do everything it can to give you that, including maximum fuel flow (N1 topping) if need be.

I can't quite seem to get my head around why this droop happens.

[maxtork]

I'm not sure if I can explain this for you and make things better or just muddy the water more but I"ll give it a shot.

First your assesment of the control system is correct in a perfect world however we haven't taken into consideration "static droop". The basic principal says that the engine will do what ever it can to acheive an N2 datum vs actual N2 match. The datum is whatever value we decide N2 should be, in this case 107%. In real life however what the FCU is going to try to do is match centrifugal force against a spring pressure. The centrifugal force is coming from a flyweight that is driven by N2 and the spring pressure is set by the anticipator cable (connected to your collective lever). As you raise the collective you increase the spring tension and upset the balance which causes the FCU to increase fuel flow instead of waiting for the N2 to droop. If we didn't have this system in place you would have a "static droop" where the N2 rpm could be 107% on the ground but as you add load you would see a droop in N2. You would basically be behind the power curve all the time. The governor will increase fuel flow but not enough to maintain the RPM.

So in twin engine operation the system is setup to maintain a nominal N2 rpm (107%) by increasing fuel flow by a given amount to each engine as you raise the collective. Now when you stow one stove your only adding half of that additional fuel flow for the same collective position and hence you see a bit of a static droop effect.

If the system worked like the FADEC controlled aircraft you should not see this effect as the governor system simply adjusts fuel flow to maintain the N2 RPM datum. We still have the anticipator system in FADEC engines to reduce the transient droop. In the mechanical system the FCU doesn't care what speed the rotor or the N2 are at...only the centrifugal force that those speeds create and how it balances the anticipator spring tension. So at an OEI hover we have the same collective pitch postion adding an additional fuel flow to only one engine which will help carry the load but not quite enough to keep the same RPM as if it was operating along side it's partner engine.

This is much easier to explain if you have a diagram in front of you to see how the whole mess works. At any rate, if this explaination helped then good "I"ll be here till Tuesday!" and if it didn't then disregard all the above and listen to someone who can explain it better!!

Max

[delta3]

Hi,

Here is a control systems answer, not a S76 experienced technicians answer.

Control systems can be made as complex as imaginable, but in practise they tend to be based on simplified rules.

The static droop referred to is associated with a static feedback system (proportional control). If the control is calibrated for two engine operation, then the loss of an engine will create an N2/NR offset that makes the proportional control react (proportional increase in fuel flow). There is however always a 'remaining offset' necessary to drive the control system when operating out of its design point. So a disturbed proportional control system will always display a static offset.

Now most systems are not just 'proportional systems', and classical control theory would among others include 'integral control'. The latter 'integrates' or 'sums over time' the control error to drive the correction, so over time it will reduce the control error to zero, since as long as it sees an error this error will drive corrective actions. This is equivalent to thinking that this system is capable of compensating the permanent offset. The problem here of course is that some care with this permanent driving should be exercised not to create dynamically unstable or out off limit situations.

So to me it seems that the system is close to a (basic) proportional control system.

d3

[NickLappos]

delta3 has it pretty close. The "permanent droop" is built into the governor to make it stable and thus prevent the rpm from hunting up and down around the set rpm. If there was no permanant droop, the governor would behave like a dropping a steel ball on a steel plate, it would bounce forever. The premanent droop is like a pillow on the plate, it allows the ball to sink slightly.

A FADEC digital control has the mathmetical sophistication to use integrators as delta3 describes, so it can be truly "isochronus" - constant rpm - and still be very stable.

[the coyote]

Many thanks O wise ones, I'll run it through the grey cell.....

[HOSS 1]

A FADEC digital control has the mathmetical sophistication to use integrators as delta3 describes, so it can be truly "isochronus" - constant rpm - and still be very stable.

Unless you have an engine ARINC crosstalk failure. Then, they both go to good old proportional mode and the Nr droops in a similar fashion. (And, 30sec power is armed due to each FADEC not knowing if the other engine has died)

Hoss

[hovering]

Rumor has it there have been several #3 Power Turbine Wheels failing catastrophically on S76As (and possibly other A/C types?). A new idling restriction has been placed on the engines (no steady state 72%-90.5%N2)

What is going on? What has changed with these engines?:uhoh:

[Hippolite]

Haven't heard of it yet in the S76 but in 2004, there were some in the GOM on 206L3s. Also been similar problems on the C47 on the Bell 407.

[hovering]

I am suprised that nobody knows any 'stories' about these engines. Something seems to be going on, considering the new restictions to N2 after all these years, and the failures.
Anybody?

[McGowan]

I don't know about the S76, but some time ago Rolls Royce came out with a requirement to have a sticker on the instrument panel in Bell 407s stating the need to avoid steady state operations between 68% and 86% NG. They have recently amended this to a more accurate set of numbers, something like 68.6% to 87.4%, like I'm going to pay that much attention.
I have asked people in the know and can't get much of an explaination as to why things have changed.

[bb in ca]

Hey hovering,

I work with CHL in the EMS division and we operate a dozen A model 76's.

We had at least one recent engine failure that may have been related to fatigue caused by idling in the 72%-90.5%N2 range.

We are now abiding by the N2 area of avoidance and also recording N2 overspeeds of 112% and greater (not sure if they ever happen though as I've never been remotely close).

Interesting topic and will be interesting to see what RR does in the future with operations and maintenance.

bb in ca

[Geoff Williams]

Rolls Royce CEB A-72-3272 refers:

The max. cont. Nr/N2 RPM is 107.2% with trainsients allowed up to 112.7 for a max. of 15 seconds. Maintenance action is required for transients of 112.7% and above for more than 15 seconds.

This is a high end restriction, added to the already steady state restriction, and is more likely to occur when in a low pitch descent manoeuvre such as an auto. Easy to do if you are doing an auto RPM check.....beware!!

The CEB is interesting reading if you can get a copy from your engineering folk

[Plank Cap]

Am doing a little, er, research and wondered if anyone remembers the early Sikorsky PR picture of the 76 with the reclining lady super-imposed across the fuselage. Might be considered a little un-PC today, as I seem to remember she wasn't wearing too many clothes. Don't know if it helped Sikorsky sell any more aircraft, but it surely had a certain impact. Maybe Capt. Lappos got to choose which model was used, and I don't mean A or B??!!

[ShyTorque]

I heard it was Capt. Lappos himself - mind you, he did shave his legs and his moustache first.... ;)

[cpt]

Hello and season greetings to you all !

A strange thing happened on some of our S76 blades....Very small, few, pin hole like marks,showing a burning aspect, making think of lightning strikes or sparks (they are also sometime present on horizontal stabiliser and T/R blades) They are deep enough to go trough the protective coating.
Of course, affected helicopters are grounded for deeper investigation.
It seems strange that ligthning strike (a rather rare phenomenom on helicopters here) affect more than one helicopter at once in such a short period of time.
What else could it be ? Did some of you ever seen something similar....could it be related to static electricity or maybe some flaming oil dropllets caught in oil rigs flares smoke ?

[maxtork]

It's hard to say without being able to see the marks but just a suggestion that it may be something from the engines coming out and impacting the blades. Has there been any engine issues lately? Maybe some carbon bits breaking loose or something of that nature. They may be hot enough to make a burn type mark. Just a thought.

Happy Xmas and Merry New Year!!

Max

[BigMike]

Sounds like some was grinding something made of steel near your aircraft. Got any pictures?

[ShyTorque]

My company's S-76 used to suffer pinhole marking on the rear edge of the stabiliser, which sounds like a similar problem to yours. It also used to suffer radio distortion in the cruise in certain wet weather conditions, which we put down to static build up.

It was allegedly lightning strike damage, although none of the pilots had reported this (I'm sure they would).

It has now been modded with static wicks on the rear of the stab. and the problem hasn't recurred since.

[NickLappos]

cpt,

You don't mention where on the blade the marks are, and if they have any appreciable depth to them. What size are they? Have you looked at them with a 5 or 10X maginfier? I don't know what protective coating you refer to, is it the black paint?

The black marks on the trailing edge of the stabilizer could be simple static discharge spark trails, which have fairly high voltage. They can be prevented by adding back the static wicks, I think. I seriously doubt that a crew could not recognize a lightning strike.

thanks,
Nick

[IHL]

Heli Jet Airways, Vancouver BC Canada. Had a lightning strike about 10 years ago. The aircraft was in the shop for almost a year. Reportedly all the gears in the transmission had arc damage ect.

Usually with lightning strikes there is an exit hole where the high energy electrons leave the aircraft.

[cpt]

These marks are located on upper surface of blades, and behind the leading edge protection....I didn't have the occasion to look at them with a magnifier myself.When I talk about protrective coating is actually the paint layers.
I don't think it's coming from a particular engine exhaust since it affects several helicopters. Although we have experienced stormy weather recently I don't have the feeling it comes from direct lightning hit, and beside this as Nick states a lightning strike wouldn't have stayed unoticed to crews....
Sorry, my position here doesn't allow me to send pictures and it could be misinterpreted by managment.

[Hairyplane]

A mate of mine was unfortunate enough to have his brand new aircraft parked alongside a hangar construction.

The paint was found to peppered as you describe. THe cause was an angle grinder being used. Despite being some distance away the particles were hot enough to burn deeply into the paint.

I'd look seriously at that possibility if I were you.

Hairy

[cpt]

Thank you for this information Hairyplane, there has indeed been some work performed on hangars and parkings recently, but I think that the marks are more recent, maybe have they stayed unoticed untill now ? it deserves to be investigated.

[rotorrookie]

Also damage caused by angle grinder spray are most likely to occur and be found on glass and windshields.
go and check them and if you got damage there you pobably found the cause of the blade damage

[SASless]

Somehow the thought of an Angle Grinder and helicopters seem to be a troubling image! I know Igor builds them tough....but really?

What might one need an Angle Grinder for around helicopters to the extent it would damage multiple aircraft?

Someone care to describe that situation for us?

[Hairyplane]

A simple scenario -

Ugly blokes in rigger boots, resplendent in tattoos and earrings but not many GCE's - and definately no hard hats, goggles, ear defenders - on price-work to erect a steel hangar frame.

They dont give a stuff where the red hot particles they have ground off go. 'Its bound to make a bit of dust guv'.

Take my advice. If any construction of this nature is planned at your airfield, ask the operator what measures are in place to protect aircraft from damage, specifically from welding/ angle grinding fallout. Most important - people need to be protected too. A Health and Safety Statement is mandatory these days. Ask to see it. You have a right to see it if there is even the remotest chance that you might be at risk of injury.

As previously stated, these particles will still cause significant damage a long way from source.

In the case I mentioned it was because of the distance that the cuprits struggled to accept the damage was down to them.

I have personal and painful knowledge of the damage angle grinders can cause too.

On my own site here, a mate of mine was grinding off some bolts ( he had all the kit on!) and I walked into the end of the building he was in just as he switched on.

I suffered eye discomfort for 6 months thereafter - tried everything to get rid of that 'bit of grit' in my eye - and in desperation went to the vet.

He found 2 deeply embedded steel particles - embedded because they had burnt their way into my eye. He told me that I was lucky to have avoided an infection - something that would have cost me my eye without a doubt.

I had not connected the 2.

Take it from me, having your head clamped in a vice like contraption, your eye clamped open, an anaesthetic needle stuck in it and then - horror of horrors, seeing a scalpel blade 'up close and personal' and feeling it digging into your eyeball.

The pain was excrutiating for 24 hours afterwards. Ugh!

Sorry if i've put you off your mince pies.....

Hairy.

[BigMike]

Regards to checking windows, hot metal sparks WILL stick to "glass" but not to plastic unless they fall vertically on to it.

[NickLappos]

cpt,
This is an entirely unofficial response, and not to be confused with any official response from any authority:
I have seen these kind of small pits on the blade surface, usually in the filler material that is a kind of putty/body filler, almost like a spackle. The areas where the airfoil contour are smoothed in seem to have this imperfect system of popped bubbles, most quite small, none into any actual structural material.
I believe they are quite normal, and probably cause by a mild ablation of the outer layer of the filler (rain? light dust/sand?) that exposes the pits caused when the slightly bubbled material is worn down a bit and the bubbles are opened at the surface. I have seen this especially near the tip caps, where this filler might be used more.

Certainly, this is not a sign of lightning or static electricity, which would show on the sharp ends of the blade airfoil where the charge leaps off the blade. It is also not a sign of exhaust heat, which would cause a fairly large bubble/void to form directly over the exhaust, with a diameter of perhaps 5 or 6 inches (I was the first on the planet to burn a blade, thank you very much!) And I seriously doubt that it is the product of someone's grinder, which should be nowhere near a fueled aircraft, else the specks will be your least worry, and a big fireball/barbecue pit where your helo used to be should be your biggest worry.

[cpt]

Thanks Nick,
We are now of course, waiting a Sikorsky official answer and plan of action before winding our rotors up again.
Having look closer one of the marks with a magnifier,it doesn't seem to be too deep and very tiny blisters around the hole can be seen (not on all of them), but there is also what looks like a superficial burning trail oriented in what could be near the relative wind direction (about 45° from chord towards the blade tip.)
Really curious to know the answer ...hope it will come quick...Fed up walking on parkings,still addicted probably.

[HOSS 1]

It was down to the wire, for sure, but behold, the latest S-76 iteration.


STRATFORD, Connecticut

Sikorsky S-76C++ Receives FAA Certification

Sikorsky Aircraft announced today that it has received Federal Aviation Administration (FAA) certification for its S-76C++ helicopter. Sikorsky Aircraft is a subsidiary of United Technologies Corp. (NYSE:UTX).

Since being certified, two C++ aircraft have already been delivered. The inaugural C++ aircraft went to Petroleum Helicopters Inc. (PHI) and will be used for offshore oil support and employee transfer missions. In total there are over 60 S-76C++ helicopters on order.

First announced at the Heli-Expo trade show in February 2005 as a series of engine, air vehicle, interior and avionics upgrades the new S-76C++ helicopter will make way for a set of additional product improvements that will lead to the launch of the new S-76D model in 2008.

“The S-76 helicopter's success has been built by meeting the needs of the customer. We continue that tradition today by securing certification for the new S-76C++. Able to provide more power, range, operating efficiencies, reliability and comfort, the S-76C++ truly is a continuation of the venerable S-76 line,” said Jeff Pino, Sikorsky's senior vice president for corporate strategy and commercial programs.

Product improvements available immediately on the S-76C++ include the new more powerful Turbomeca Arriel 2S2 Engine, an inlet barrier filter to protect the engine against erosion and environmental contaminants, a new VIP interior, new HUMS (Health and Usage Monitoring System), and a quiet main gearbox utilizing Quiet Zone Technology that will significantly reduce interior noise levels without any weight, maintenance or TBO penalties. The more powerful engine in the S-76C++ provides approximately 350 lbs of additional payload capacity as compared to an S-76C+ on hot days and high altitude conditions.

These extensive product upgrades ensure that the S-76C++ and the future S-76D will remain best-in-class in the corporate VIP, offshore oil, airline, EMS , search-and-rescue and law enforcement segments.

*******************************************************

Buy me a beer and I tell you about the looks of amazement as over half a bag of home depot potting soil was tossed into the engine inlet during testing. :eek:


HO5S

[SASless]

Where did that come from...Nick's old office?

[GLSNightPilot]

According to the local newspaper, Petroleum Helicopters Inc. is no more. As of 1/1/06, the name was officially changed to PHI Inc.

[SASless]

GLS,

What's in a name?

Does a coat of paint cover up the Bubba Suggs brand on the butt?

[GLSNightPilot]

Don't know, just trying to keep you fully informed. :8

[DeltaNg]

We're still operating the S76C at Humberside, UK, in the offshore role.

Is anybody else out there operating such a vintage?

[Ascend Charlie]

We run a 1986 S76B, with only 3000 hrs on it. Looks a treat.:p

[Lenticular]

I am wondering why there is no mention of sloping ground limitations in the FM. Is it because of the absence of a nose wheel lock it is not a maneuver that should be attempted in which case I would of thought it would be a prohibited maneuver in Part 1 of the FM or am I missing something.

I believe the EC 155 has sloping ground angles mentioned in the FM but that does have a nose wheel lock. Any comments?

[NickLappos]

The absence of a limit does not signify a limit! The S-76 has no published slope limits because they are not required, and were considered of little real use. I know this because I was the chief test pilot on the S-76 and wrote or edited much of the original flight manual.
The slope capability of a given helo is very dependant on many factors, only a few are the helicopter, so the numbers in the typical flight manual serve as guidelines only. Many helos have rolled over on slopes half that published in the manual, due to those other factors.
For the typical S-76, one can easily achieve 10 degrees laterally on dry paved ground without using full control. The behavior on slopes is very predictable, and the landing gear makes the landing pretty soft and smooth - makes the pilot look good. There is a bit of rotation down slope when the collective is reduced to the bottom, about 1.5 degrees, so the slope looks worse when at flat pitch, on the artificial horizon. At full control, the S-76 is capable of 16 degrees of right wheel upslope and 12 degrees of left wheel upslope, and 8 degrees nose up, and 12 degrees tail up slope. These slope values are extreme, to say the least, and probably not achievable by operational pilots, because at 16 degrees, things look like a mountain goat sees them.
A nose wheel lock is hardly necessary, as the aircraft does not tend to rotate or pivot on slopes, and the pedals are very effective in keeping things straight.

[ATN]

Is there any further restriction with rotor stopped ?
ATN

[NickLappos]

nope, since there is no restriction, there can be no "further" restriction. I have shut down on slopes up to about 8 to 10 degrees with no difficulty, except for some rocking because the blades lag themselves into odd angles until the rotor spins up.

[Upland Goose]

Nick

All that information after so many years - yet none of it available to S76 pilots until now!

As far as the Flight Manual is concerned - the S76 is one of the worst in the business, hope you didn't have a hand in the S76A+:rolleyes:

Hope your time at Gulfstream is going well - we operate one of those too. Critics are everywhere!

Regards UG :hmm:

[Upland Goose]

Ask Sikorsky how the Barrier Filter operates in snow!

Looks like a real snow catcher to me!

UG

[Lenticular]

Thanks Nick, that info is very helpful. The angles you mention are indeed extreme. I carried out a left wheel up the slope of about 7 degrees and it felt awful although stable on firm grass.

[NickLappos]

Upland Goose,
I used to start S-76A pilot discussions for operational pilots by telling them, "I am sure that you have looked at the aircraft and said to someone, 'I wonder who the A**hole was who thought of this?' Well, I am either that A**hole or I know him!"

I always thought the GAMA designed flight manual wasn't as good as the military ones I use, but I also know there are plenty of ways to improve the 76 flight manual otherwise. I was the guy for the S-76A, others did the A+, B and so on.

[Deck Clear]

S76C.....you're lucky....wish I had an autopilot,etc.
We fly very aged S76 A+'s. Spend most of the time in winter IMC over water with much of it at night.
We long for a 76c...or C+ ...or c++:= (or a 139):p
fadec...glass cockpit. luxury:D
Come on oil companies. Give us a break:{

[ShyTorque]

"I always thought the GAMA designed flight manual wasn't as good as the military ones"

Those manuals were designed? That's almost unbelievable. :E

Anyone know the sloping ground limits for a G-5?

[GLSNightPilot]

We're still flying 20 year-old A models re-engined to A++. We're slowly going to C+, and eventually C++ and D, but Sikorsky isn't turning them out very fast, and there is lots of competition for those that do come off the line, so it's going to be a long time before we get fully upgraded.

[Upland Goose]

Nick, your honesty shines through yet again. Thanks for all the info.
Did you know that an S76C 'minus' roams the sky? Now there's a Flight Manual that's as rare as the Dead Sea Scrolls. My fault I'm afraid!
Max normal twin take-off Tq 86.6% and indicators to match. They carry a spare indicator because HSI can't paint them fast enough.
Shytorque and I are still waiting for the G-5 sloping ground limits.
Why not start a rumour at Savannah that EASA require this for all new aircraft. They'll have to employ some folks off the Lockheed C-130 programme.
Now there's an aircraft, it's up there with the DC-6 for me
UG;)

[Jack Carson]

I believe that Malaysian Helicopter Service operates 6 S-76C's. When I left Malaysia in 1998 they had already accumulated more than 6000 hours per machine.

[cpt]

As a following up, these marks have been idendified by a Sikorsky blades expert, as an effect of erosion revealing little bubbles in the "filler material"
You were right Nick !

[happyhamster]

Any chance of a picture guys ? Thanks.

[wishtobflying]

I spent a week off work after forgetting just that once to put on the safety glasses when taking a little nick off a piece of steel with a bench grinder. Ditto on the "head in vice ... scalpel, etc" story. :eek:

More recently, I was working in a dodgy part of town in a rented shed, and because of the local ...errrm ... nightlife ... decided putting the car inside the shed would be better. I happily drop-sawed, welded, ground away for a few hours, with all my safety gear on and totally absorbed in my work, not even thinking about where the car was parked and where all those sparks were going ....
.
.
.
.
So now I have a Ford station wagon on offer, cheap, needs a new paint job and windscreen but drives well .... !

Lesson learned!

[Vfrpilotpb]

Just for the record(not a record) but debris from a 9" angle grinder will travel in still conditions 60Ft and will at that range stick to auto glass, the sparks you see start life at about 1200Degree's and transfer that heat (or variations of it) to whatever they land on and will burn through Plastic coated steel roofing sheets with ease, if using a cutting disc (not a grinding disc) these sparks will be the hottest when cutting through High Carbon steel.

Leave your Auto or Heli or Plank at least 100mtrs away from any halfwit with any sort of grinding or cutting equipment.

Vfr

[cpt]

Usefull to know specially when we land near construction or industrial sites !

[Deck Clear]

Just curious really....some of the S76A+s we are currently flying have hours just short of 24000:sad: What about others around the world and what was the original "planned" hour life when designed?:ooh:

[NickLappos]

The S-76 has an unlimited planned life, and should be able to go on indefinately, as long as the normal maintenance is done and time change components are replaced.

[unhappyhamster]

Just a quick Q - what are the prime differences in the S76 + varients ?

Thanks.

[ShyTorque]

From my own experience of the type, just about every single one of them is different! :ok:

[Deck Clear]

Is it true that some oil companies have a limit on the age of the aircraft that fly for them. I've heard 10 years for some operators in some locations?
Are most of you guys flying with newish machines in the offshore world?

[Jack Carson]

When I left Malaysia in 1998, Malaysian Helicopter Service (Supporting Exxon) had already accumulated more than 50,000 hours on each of their S-61's and had surpassed 10,000 hours on each of their S-76C's. With quality maintenance these Sikorsky's could go on for ever.:ok:

[76001]

The S-76 has an unlimited planned life, and should be able to go on indefinately, as long as the normal maintenance is done and time change components are replaced.

Nick, At some point it tends to loose its cost effectiveness due to the high price to rebuild the airframes. One thing to keep in mind is the price of replacement engine parts also.

76001 :)

[SICKorSKI]

The cost of rebuilding a A model is half of the cost of buying a new C+.
I am working on a A++ with 19000 hours on it.
And every 76 I have worked on is different.
Hamster, A Allison, A+ 1S , A++ 1S1, B PT6, C 1S1, c+ 2S1, c++ 2S2

[unhappyhamster]

Thanks for that - so which varient over the years has been the pilots favourite ?

[oldgit]

If you don't need the range it has to be the 'b'

[Heliport]

The 600th S-76 was delivered recently.

The S-76 fleet has accumulated more than 4 million flight hours since the first aircraft was delivered in 1979 with more than 220 operators in 59 countries currently flying the type.


I think Nick Lappos may have flown the maiden flight of the S-76. If not the first, then one of the very early flights.

Heliport

[NickLappos]

Heliport,
I did fly the first flight on the S-76 prototype, back in 1977, and did much of the original flight testing. It was an impressive aircraft from the start, and I am proud of all those who operate her around the world. The high time bird now has about 30,000 hours (Air Log)! Many of the records we set back in 1982 still stand, a testament to the advances the 76 made to helo flight.

[SASless]

Ah yes...and trying to teach the machine was great fun as well....feeding the alligators in the canal next to the picnic table.

What was more fun was keeping up with what modification state the aircraft was in when delivered to the customer.

Nick...did you ever hit the Great Wall at Pahokee in the Sim?

Ever taxi off the one foot drop in the apron at Miami in the Sim? Taxiing into the one foot jump the wrong way was really a thrill.

Those were good days!

Lived next door to Bert Reynolds....I had an acre and a half...he had 250 acres and Lonny Andersen. Tough life for old Bert!

[Sioux4D]

The S-76 really was leagues ahead in terms of technology, and I still think that it is by far the most beautiful helicopter out there!

[Barndweller]

Flown the 76 in various guises and though she had her limits, I still enjoyed her. Now fly something new and french which is superior in most ways and equal in others - Its' got no soul though! (you can, however, understand the electrical system)
Still love the 76 and always will - learned all my important lessons on it, but it has to change sooooooo much to compete with what is new and coming - not sure if it can. The S76 D will have to be superb in everything from cockpit, endurance, Class 1 perf' and single engine performance (plus an icing clearance please). Is it going to be all that - It would be nice. If it is'nt then i fear it's the end of the line for the old gal'.

[Fatigue]

Gentlemen,

When the S76 was first launched many,many years ago, it suffered a couple of fatal crashes...in a conversation with a fellow pilot the other day, he asked me what caused them but being a "Bell man" now (and not in the company of any Sikorsky pilots)! I couldn't remember!
Can anyone shed some light on this? I am more curious for myself now but when I meet him again I will let him know the answer !!!!!!!!!!!

Many thanks,

Fatigue.

[IHL]

There is one I know of where a maintenance error lead to the tial rotor cables wareing through which resulted in the Tail Rotol Control going into a hard over position which resulted in the aircraft spinning out of control , which resulted with an impact into the sea, resulting in the deaths of all on board.

The S76 now has a spring assembly as a result which places the tail rotor in a setting that would allow a safe run on landing in the event of a cable failure.

[Hilife]

If my memory serves me correctly I believe that a couple of turbines let fly in the early Allison 250-C30 powered S-76A’s and there was also an early problem with the MRB spindle bearing outer races migrating outward, both sadly with disastrous consequences and thankfully no longer an issue.

[SASless]

One 76 in South America crashed due to a head failure/blade spindle failure.

Fix was made.

Bristow lost one that killed Jerry Hardy and some other folks.

Second fix made that worked.

Early models were prone to kill opposite engine when the first one went to pieces.

[Nigel Osborn]

SAS is quite correct. Due to a spindle failure, a main rotor blade flew off both those 76s. One was on about a 1 mile final to an oil rig in South America & killed all 14. The Bristow 76 was on a training flight with 2 pilots & 2 farmer pax on board doing IF practise over Longside. The tail rotor problem killed 14 off Songkla much later. All those problems were fixed long ago.

[Brian Abraham]

Jerry Hardy
One of natures gentlemen and fortunate to have had him as an instructor when he was in Oz on exchange from the RN and as "helper" at wedding.

[SASless]

Jerry Hardy was all of that and more. I thought the absolute world of him.

[NickLappos]

March 13, 1977 John Dixson and me in the first S-76 flight. For the astute, name the differences between this aircraft and an S-76!

http://webpages.charter.net/nlappos/76firstflight.jpg

http://webpages.charter.net/nlappos/76firstflight2.jpg

[212man]

For a start; it looks like it has a moveable tail plane

[Ian Corrigible]

Looks like there's an additional cooling duct on the top of the fairing.
The nose lights were swapped for the retractable under-nose spotlight.
Am I right in thinking that the fin is longer than production ships ?
I/C

[212man]

Am I right in thinking that the fin is longer than production ships ?

Looks like it I agree, plus it has a ventral fin too. Plus S-76s don't hover that level any more!

[Deck Clear]

I didn't know Jerry, but Joe Harris was a mate, he was on my AAC course and was doing his IR training. Would have been a great asset to the industry. He was an ex REME having done one AAC tour.
I was just about to start my S76 conversion having been offshore for a couple of years and the various incidents with the 76 over the next few years caused a lack of confidence in the machine by some oil companies. Shell banned them from landing on their platforms for a while, I was turned away from a Brent platform in the early 80's during a medivac!!
I flew the 76 from that time till now:uhoh: ....through the times with the Alison engines problems .... remember containment shields?
After we re-engined them they became a real winner. (see thread..600th 76)
and I have enjoyed flying them over the past 25 years. (I'm in bed with old pilot's complaint, a bad back. S76 seats are/were rubbish:E )

[IFMU]

The pitot probes are missing from the nose. However, I'm willing to bet the pilots look more different from themselves than the prototype looks to today's models rolling out the door!

-- IFMU