Airframe life of S61? Plus how much is an S92?
 

hello,
Having spent some of my time hanging from wires and flying in big yellow helicopters and seeing how old the mk3s are getting. I was wondering what life was left in the civilian S61s? Being that some of them have been flying for a very long time too. Plus if the S92 was a good replacement and how much do they go for?

Thanks in advance.

The S61 can keep going safely so long as the airframe is free of corrosion and cracks and spare parts are still available at commercially acceptable prices. Helicopters tend to become difficult to support technically which makes them too expensive to run, thats what usually kills them. Remember, there are still Bell 47s flying daily.

S92, depends what you want in it. Offshore, $19m SAR $25m.

Thanks, the S92 would be used for passenger flying. Having seen the cracks in the frames im amazed how well they are doing so far!

Currently flying a S61 that has 40K hours on it, very sweet tight ride still, Carson Blades make it a pleasure to drive. I beleive the old girl is a early 70's frame.

Our 92's have a sticker price in the vicinity of 20M CDN in offshore config, you have to love the "new car smell" though.:D

MAKILA1A
----------

Tell us about the Carson blades? I've read all the blurb, how's the reality?

I do know an s61 flying SAR out of waterford in Ireland (ex Bristow) machine that had over 43000 airframe hours up over ayear ago, and add to that its usual 50 hour monthly flying rate and you have a high time current machine, as far as I am aware the only s61 in the UK that exceed this total is the s61 used on the Scilly Isles passenger service out of penzance in cornwall, it does somewhere in the region of 1300 hours annually.

Mr. Toad,
The Carson blades add a solid ton of lift for the same power, and some speed as well (less drag at the higher weight). The net efficiency of the new blade is roughly that of BERP, so the difference between them and the old 1959 NACA 0012 airfoil on the original 61 is stunning.
A plot of power vs hover thrust would show the Growth Black Hawk MRB and S92 to be about 2% better, the BERP/Carson blade in the middle and the old 0012 to be about 5 or 6% less than the BERP/Carson.

Carson designed built and certified that blade by themselves (they hired several key retired Sikorsky engineers and pilots). The US Navy adapted the blade, and asked Sikorsky to test and qualify it (be sure it was safe and that manufacturing was consistent.)

British International had two airframes IC and JL that broke the 40000 hours in the late 90's not sure if they're still gracing the skies if they are I think BIH from Penzance would own them possibly flying their Falklands contract now?

I know the S-61 was designed before safe life calculation was used . Am i right that the Blackhawk has a retirement life of 10K hrs , I am almost sure that the AH64 does . Does the S-92 have a retirement life ?

widgeo said, "I know the S-61 was designed before safe life calculation was used ."

Widg, I don't know what that means, since the S61 and the S76 and the S92 were all designed to have no life limit on the fuselage. This is perfomed by designing the fuselage so that the stresses are low enough to assure no fatigue failures, and then the monitoring and updating in areas where field experience proves this not to be true. I believe at least one S76 has also reached 40,000 hours.

Mr. Toad,

What Nick said;)

scatstar,

JL is currently WFU and the fuselage is stored at Longside.

http://i6.photobucket.com/albums/y20...head/gbejl.jpg

Wonder what the future holds for the airframe?

What a shame to see such a great sexy machine left like that. But maybe with the current North Sea and World shortages off Helis there still might be a chance for a her!!:ooh:

Long time since i've seen JL looks as good as it always did when it flew for BIH the way things are going they might revive it to help out its old friend G-ATFM which is up here on wet lease to Bristows:suspect:

IC went through 43,000 hours in 1998, it was and I believe still is the highest logged airframe hours S61 in the world. I think it went to Venezuala.

http://www1.airliners.net/open.file/0791782/M/

Jl in Better times

thats more like it, any idea what happend to some of the others like OO, BJ, EA etc?

BJ and EA are still with BIH at Penzance and "double bubble" went to the states in 98, JL has been de-registered and permantly withdrawn from use.

I'm currently flying a 1962 vintage 61 with 44800+ hours. SN 61222.

Is there a Vne increase or MGW internal increase with the Carson blades?

bb

You are flying G-BEIC, the afore mentioned aicraft !!

http://www.carsonhelicopters.com/composite_blades.htm

both i guess


they quote 10K hrs life on the tin blades , is that on the cuffs only . If you replace cuffs with zero TSN cuffs do you have 10k more hrs ?

Nick, this is something i am keen to understand in more detail. I am about to embark on another large project and want to make the absolute most out of FEA and strain guaging. I have read several articles on fatigue life estimation through flight testing. I imagine aluminum would prove harder to get right, since there is no fatigue limit stress like steel.

Could you point me in a direction to learn more about heli industry practices?

Mart

Graviman,
The concepts between the two metals (Al and steel) is quite similar. The value we use for the max stress to allow infinite life is called the "endurance" level, and is determined for each type of material by coupon tests, then adjusted for shapes and stress risers for any given design (K factors and knock downs). For critical parts, real data is taken by breaking parts, but airframes are not generally of that class, since they are designed with redundant load paths and a great deal of inspectability. Airframe stress gages compare flight loads to predicted loads to assure design adequacy, and beefups are applied if necessary during flight test.

There is a FAA AC on fatigue testing, and I believe some great AHS papers over the years. If you are building something commercial, I can recommend some expert friends!

Nick

MHS S-61's
 

I believe that a few Malaysian Helicopter Service machines have more than 50000 hours on them. Like the Eveready Bunny, they keep on going.:O

What ever happened to the original Chevron/ Bristow/ UNST S61's?

G-BAKC G-BFRI G-BFMY?????? the original team??????????

Russ S /Clive V / Pete C/ Michel Z/ Jaque Gassolene! and so many great guys' that linked the Ninian with Unst 79-93- they all deserve MBE's

Can anybody post some pictures please?

G-BAKC Transferred to France in 1987

G-BFRI Now with BIH Penzance

http://www.caa.co.uk/applicationmodu...01&imgtype=jpg

G-BFMY Transferred to Brazil in 2000

Bacon Slicer,

The Ninians are again (temporarily) being serviced by S61, flying out of Scatsta, while 332s are in short supply following last month's rollover.

Of the pilots ypu name, most are now in well earned retirement, though I believe that Pete C is still flying in some distant land.

OA

Bacon Slicer.
Those were the days, work hard play hard!!
Sad to tell you though, Russ passed away several years ago.

Nick, this is genuinely appreciated. The project is another off-highway mining truck, with frame design life 60'000 hours. The idea is to learn from another industry in a the transport sector, but not a competing arena.

Related technical papers:
AHS technical papers
Airframe Fatigue

If you wanted to PM me the expert friend contact details, i guarantee that i would treat the exercise with the level of commercial sensitivity befitting a professional engineer.

Warmest regards,

Mart

I am currently swinging spanners on a 44000 PLUS time 61 and she is in good shape. I see no reason why they can't go on indefinitely as long as Sikorsky keeps supplying parts or if they sell the type certification on when they deem it no longer viable a-la Skycrane/Ericson's.

Bacon

Pete C was flying with Bristow in Oz out of Essendon until a few months ago, I think he has just decided to retire for good now.

Michel was last known as a 332L2 simulator instructor at Helisim in Marignane.

Don't know anything of Jaques.

They were the days though, a Heavy Chevy out of Unst in BFRI, 3 trips, the first with the hayboxes to bring the food into the Unst terminal, drinks at the Baltasound hotel and 5 star accommodation in H block until it blew away!!

HH

NICK & MAKILA 1
----------------

Thanks.


EXCREWINGBOD
---------------

That pic of JL in Scatsta is seriously sad. Reminds me of my forebodings when our beancounters sold so many of our 61's in part-exchange (for early 332's I think) and they were stored in Bristow's Sumburgh hangar. They were acquired for pennies and put back into service by other, more savvy people elsewhere. I've got pics of some of them, must dig them out.

The picture of JL is Longside not Scatsta :ok: G-ATFM is currently working in Scatsta JL's mate.

Any idea who are flying FM out of Scatsta at the moment?? More ancients??

Unlimited life has it's limits. This is copied from the S-92A TCDS

NOTE 4 The term “Unlimited Life” is defined as 30,000 flight hours for the Model S-92A rotorcraft. Operation of individual aircraft beyond 30,000 flight hours is contingent upon a Life Extension Program approved by FAA Engineering

what are the major service intervals on the S92 ?.

Olde buses and like fossils...
 

Good morning all,
I had the whimisical pleasure recently of visiting with BIH at Penzance. BJ was indeed in the working mix, but I was told that it was headed for a quieter time and space in the near future. I believe they mentioned that it was well beyond the 40K mark for airframe time. The other ship working the Scillys at the time was EB, another long serving bus. EA is down with the Penguins and still going strong. As an aside, the BIH staff mentioned that they had picked up a pair (?) of ex-Bristow 61's to freshen the fleet mix. I recall that they were both manufactured in the late 70's, (among the last off the line?)
Ahhh the memories...

s-61's
 

The two machines that B.I.H bought from Bristows this year about July time. They where both in a poor state. The first one that B.I.H got was G-RI that last flew in the D.R.Congo on the U.N contract it has never flown since. the second was a machine that was getting prepared for another Rich American like G-LAWS that Bristow maintaned for an American Buisness men. From what I gather both machines Where in poor state similar to JL at Longside. They had been stripped down to keep the rest off the S-61 fleet witth spares. But heres hopping the B.I.H get them both airworth once again and maybe B.I.H might might get JL as well. Fantastic Helis the S-61.:)

Thanks for the info chaps, most useful.

S92mach,
That current S92 restriction is just until the FAA builds some experience in the model, based in successful inspections and field service. The S76 went through similar steps. I recall that there were main and tail rotor blade samples bolted to the roof of the Royal Flight Squadron in Amman Jordan, sunning themselves for years. Every several years, a Sikorsky engineer would take one back home and break it on the testing machines to show that the strength was retained, even after strong sunlight exposure for years.

The S92 has a 50 hour 1st service interval (pilot preflight daily of course) and a 500 hour rolling zone inspection, which can replace the annual if one signs up for that program.