Sikorsky S-76: Ask Nick Lappos
Avoid imitations
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Recent experience in the sim would make me think that 110 kts OEI is optimistic for an average weight, say 10,500lbs or above. I recall 95-100 kts as a more likely cruise figure at MCP. I don't remember the fuel flow as there was too much else going on and that was the least of my worries 
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As a general rule, OEI always has better range that twin engine, and the C+ is no exception. For those in doubt, slip an engine back (don't overtorque!!) and just take the readings! Plot speed vs torque and fuel flow, and see the magic. Usually about 15 to 20% more range than twin engine. (Good fodder for my typical rant on not asking for too much power, because it robs you of lots of other goodnesses).
The factory TI sheets are a good source, and are conservative, in my experience. Generally, the range is figured at a worst case engine at min power (highest fuel flow and lowest speed means worst range)
The factory TI sheets are a good source, and are conservative, in my experience. Generally, the range is figured at a worst case engine at min power (highest fuel flow and lowest speed means worst range)
If I ask a "return of experience" it's only because I have been using RFM datas for a while now, and I know, as everyone in this business, that they may differ sometimes a great deal from the real thing.
It is useless to publish figures in an OPS manual, if everybody knows they are not realistic.
Crews may be tempted to disregard company's documentation as unrealiable, and it's also a troubled picture of company to show to well documented customers.
It's always interesting to know what others think about various matters and experience sharing can be very valuable.
Basically my question is to know if by experience, somebody can tell if figures of RFM on OEI on cruise reflect reality or not....knowing that reality is normally less bright than graphs on paper.
It is useless to publish figures in an OPS manual, if everybody knows they are not realistic.
Crews may be tempted to disregard company's documentation as unrealiable, and it's also a troubled picture of company to show to well documented customers.
It's always interesting to know what others think about various matters and experience sharing can be very valuable.
Basically my question is to know if by experience, somebody can tell if figures of RFM on OEI on cruise reflect reality or not....knowing that reality is normally less bright than graphs on paper.
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Nick,
I'd like to rebutt rant your rant about not asking for too much power. I just recently got out of Iran where I was flying an A++ and it was definitely power challenged taking off from a rig in the Persian Gulf at 38C and no wind. We were down to five pax so that we could achieve OEI MCP stay up at 1000 ASL. More engine power (N1 and T5) would have been nice. Yes, the cruise fuel consumption would have been higher. Our rigs were only 100nm away so range wasn't our problem.
I'm flying a C+ in Thailand now and it seems that Sikorsky has finally put enough power in the 76. We can usually take off with 12 pax and a full load of fuel for a 130nm trip offshore and offshore it seems to be hard to get the machine heavy enough that you have to grunt to get it off the deck even with the OAT around 30C.
Note for CPT;
Nick is right. If you can make it on two engines you've got more than enough to make it OEI unless your trying to fly into a hurricane. Don't get your shorts in a knot about the exact numbers. Use the RFM numbers and include a blurb in your SOP about the OEI fuel flow beinging lower than the TEI fuel flow for the same speed/power combination.
I'd like to rebutt rant your rant about not asking for too much power. I just recently got out of Iran where I was flying an A++ and it was definitely power challenged taking off from a rig in the Persian Gulf at 38C and no wind. We were down to five pax so that we could achieve OEI MCP stay up at 1000 ASL. More engine power (N1 and T5) would have been nice. Yes, the cruise fuel consumption would have been higher. Our rigs were only 100nm away so range wasn't our problem.
I'm flying a C+ in Thailand now and it seems that Sikorsky has finally put enough power in the 76. We can usually take off with 12 pax and a full load of fuel for a 130nm trip offshore and offshore it seems to be hard to get the machine heavy enough that you have to grunt to get it off the deck even with the OAT around 30C.
Note for CPT;
Nick is right. If you can make it on two engines you've got more than enough to make it OEI unless your trying to fly into a hurricane. Don't get your shorts in a knot about the exact numbers. Use the RFM numbers and include a blurb in your SOP about the OEI fuel flow beinging lower than the TEI fuel flow for the same speed/power combination.
Thank you for your answers. Yes,usually we have a better ratio FF/TAS in a OEI configuration, although it's not true for all of light twin engines helicopters (i.e SA365 C ) and by experience, with a heavy S76A++,in "hot" condition,TAS falls quickly around Vy to maintain 0 Vz and the ratio falls quickly on favour of AEO....but so many other factors are involved.
It's true that the S76C+ does a very good job in regard with payloads and speed at above ISA conditions ! besides this, it also provides a very good every day serviceability.
It's true that the S76C+ does a very good job in regard with payloads and speed at above ISA conditions ! besides this, it also provides a very good every day serviceability.
S-76 Baggage Door mounted life rafts...a good idea?
Dart has received FAA certification for baggage door mounted liferaft systems. Is this a 'better' concept than standard in cabin rafts?
http://www.verticalmag.com/control/n...es/?a=1877&z=6
http://www.verticalmag.com/control/n...es/?a=1877&z=6
Putting one of these inside the baggage bay on both sides can't leave much room for any bags!! They may have some use in the corporate world where baggage is limited, but I would say they would not be practical for working offshore.
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When did Pitchlink last fly a corporate mission? I would suggest that VIP`s tend to travel with a number of huge cases which fill the existing space remarkably quickly. A quick glance at the Dart proposal suggests it might be a good idea but the cost would be prohibitive for most operators.
Anything that means the passengers and/or crew can egress without having to worry about unstrapping and deploying a valise type liferaft installation must be a good thing, however does it not impede installation of a baggage bay overload fuel tank ?
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Not excited about the raft well behind the pax compartment, the external jettison handle being even further back on the tail boom (impossible to access in a rollover), the loss of baggage space, etc.
Maybe 212man can describe the EC-155 "Reach Around" raft/float handle?
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External liferafts (as fitted to most of our 76's) seem the best option. Space saving, fairly aerodynamic, easy to deploy (one handle in cockpit), good manual backup with external handles. I haven't had the pleadure of deploying them yet though!
Avoid imitations
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Originally Posted by pitchlink
Putting one of these inside the baggage bay on both sides can't leave much room for any bags!! They may have some use in the corporate world where baggage is limited, but I would say they would not be practical for working offshore.
They should have mounted them on the OUTSIDE of the doors
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helped to install the prototype kit for apical, just to clarify a few details
- raft kit adds approx 4" of depth to either side of door, very little loss considering the gain
- you gain approx 6.00 cubic feet of storage under the seats where current rafts are located
- the rafts deploy such that when they inflate, they position in front of the main cabin doors
- in a roll over (late firing etc) rafts can be inflated either external or internal. very possible the difference of survival if crew is incapcitated upon impact
dr
- raft kit adds approx 4" of depth to either side of door, very little loss considering the gain
- you gain approx 6.00 cubic feet of storage under the seats where current rafts are located
- the rafts deploy such that when they inflate, they position in front of the main cabin doors
- in a roll over (late firing etc) rafts can be inflated either external or internal. very possible the difference of survival if crew is incapcitated upon impact
dr
SASless, you have a good memory! Yes, that was one of the less inspired ideas that ECF came up with for the 155. Particularly impractical with an inverted machine (D handle would be about two feet under water)
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Anybody have an pictures of the S76 raft mounted? In the EMS operation in Canada the raft is mounted in the cockpit, pilot's side, between the seat and the door. It makes closing the door on most aircraft difficult to say the least...
Walter
Walter
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"Shy" is right the Corporate world sometimes carries the "kitchen sink" - certainly between Battersea and Gloucestershire
The baggage door idea is OK but I like the raft between the Captain's seat and my door. My current corporate chariot has an 8 person Heliraft positioned so, and the Offshore boys and girls have a 13 person in the same place.
The door trim is sculptured to accommodate the bulk of the boat - helps the CofG as well. No good on the co-pilot's side unless you like flying split controls down the approach!!
If the Captain plays a blinder, the feet will remain dry! Who says rank does not have privileges. One back-up in the baggage door might be nice if you didn't put any money in the tin on "Lifeboat Day".
All you need then is a Ocean Going Masters Ticket - Bon Voyage
UG
The baggage door idea is OK but I like the raft between the Captain's seat and my door. My current corporate chariot has an 8 person Heliraft positioned so, and the Offshore boys and girls have a 13 person in the same place.
The door trim is sculptured to accommodate the bulk of the boat - helps the CofG as well. No good on the co-pilot's side unless you like flying split controls down the approach!!
If the Captain plays a blinder, the feet will remain dry! Who says rank does not have privileges. One back-up in the baggage door might be nice if you didn't put any money in the tin on "Lifeboat Day".
All you need then is a Ocean Going Masters Ticket - Bon Voyage
UG
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Of course the down side to the side mounted raft pods; if you have a sliding RHS door (winching etc), you cannot fit the kit. Unfortunately the door rail and bottom of the door occupy the installation area. V. expensive door and body mod to convert to 'Car type',