Sikorsky S-76: Ask Nick Lappos
Join Date: Jul 2002
Location: mostly in the jungle...
Age: 59
Posts: 502
Received 0 Likes
on
0 Posts
Hi Gomer,
that's what I was I afraid it would be.
On paper it looks the weightlifter, but after all is said it is a Huey in disguise, doing the bodybuilder routine....
Anyone else with experience in the 412/212 and on the 365/76?
How does the 412 compare in the field?
Sturdiness?
3top
that's what I was I afraid it would be.
On paper it looks the weightlifter, but after all is said it is a Huey in disguise, doing the bodybuilder routine....
Anyone else with experience in the 412/212 and on the 365/76?
How does the 412 compare in the field?
Sturdiness?
3top
If you are talking EMS, forget the 212, as it will shake the fillings out of your teeth as you bop along at 105 kt, and the noise will deafen anybody not wearing defenders. Seats are uncomfortable, with vertical backs. A slow, bumpy, noisy ride. And if you are using it for lifting (lots of hovering) you will burn the tailboom rather badly.
Go for the 76. Or look at the AW 139?
Go for the 76. Or look at the AW 139?
Join Date: Jan 2003
Location: Norway
Age: 56
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
froggy pilot:
Nigerian pilots: Calculating CG in flight? Never heard of. Why is that? Must be a really thight operation.. Having flown the C+ for years in the offshore configuration, (and loving it..
) this is new to me. Since the S-76 is already at a tail low/ nose high config. I assume that it will be the critical point of int. when fuel is burned off. What else will change during a flight? Could it be about any restrictions regarding landing weight at defined sectors of the rig due to wind changes? But surely, they should be able to have that scenario on paper before t/o? At that time landing/take off performance class 1 or 2 should be calculated as well. Or could it just be the most common thing to do: calculating the wheight/CG values at t/o when their return-payload is known?
Nick Lappos: Any comments?
Steve76:
Just one comment: About your comments regarding onshore versus offshore obstacles/problems, turbolence is absolutely a factor when landing on any offshore installation. Rigs (movable or not), production ships, drillig/diving rigged boats and so on. Night or day. Landing in the sector of the "flare tower"/cranes/major installations or any other obstacle when the windspeed exceeds 50 KIA ( or the limitations of the landing zone) is not always a "walk in the park".
We might be blessed with the fact that most wires and mountains are not present offshore, but still there are factors involving the most critical period of the flight: the landing.
Happy flying!
Nigerian pilots: Calculating CG in flight? Never heard of. Why is that? Must be a really thight operation.. Having flown the C+ for years in the offshore configuration, (and loving it..
) this is new to me. Since the S-76 is already at a tail low/ nose high config. I assume that it will be the critical point of int. when fuel is burned off. What else will change during a flight? Could it be about any restrictions regarding landing weight at defined sectors of the rig due to wind changes? But surely, they should be able to have that scenario on paper before t/o? At that time landing/take off performance class 1 or 2 should be calculated as well. Or could it just be the most common thing to do: calculating the wheight/CG values at t/o when their return-payload is known?Nick Lappos: Any comments?
Steve76:
Just one comment: About your comments regarding onshore versus offshore obstacles/problems, turbolence is absolutely a factor when landing on any offshore installation. Rigs (movable or not), production ships, drillig/diving rigged boats and so on. Night or day. Landing in the sector of the "flare tower"/cranes/major installations or any other obstacle when the windspeed exceeds 50 KIA ( or the limitations of the landing zone) is not always a "walk in the park".
We might be blessed with the fact that most wires and mountains are not present offshore, but still there are factors involving the most critical period of the flight: the landing.
Happy flying!
Last edited by ChopperIMC; 9th Oct 2006 at 20:07.
Join Date: Jul 2002
Location: mostly in the jungle...
Age: 59
Posts: 502
Received 0 Likes
on
0 Posts
So, ....for SAR?
Okay,
WHAT would be considered the best choice for a SAR outfit then? (for the size/class discussed in this thread....)
Considering new and used machines....
Anyone, but especially folks with experience in that field!
(...'cause I have none, .....yet)
3top
WHAT would be considered the best choice for a SAR outfit then? (for the size/class discussed in this thread....)
Considering new and used machines....
Anyone, but especially folks with experience in that field!
(...'cause I have none, .....yet)
3top
Join Date: Jan 2003
Location: AFRICA
Posts: 153
Likes: 0
Received 0 Likes
on
0 Posts
ChopperIMC
I never said
that they have to do CG calculation during flight(on 76), but they have to do it before T/O, and this never happen in a 365 
ANY SERIOUS S76 PILOT CAN CONFIRM THIS? SO WE STOP THIS **** !!!
I can tell you they do it in CHC Nigeria (or supposed to do it)
Why is the 155 autopilot so good ?
Just because in all Eurocopter and Aerospatiale history, they always used fixedwing autopilot, this is the first model which has an autopilot specifically designed for helicopter...
I don't know about Bell and Sikorsky, any comment is wellcome
Sorry it looks like they are some serious S76 pilot around. ChopperIMC please go back to your studies
Sikorsky made only 3 mistakes with the 76: The A, B, and C models, and they are ready to do the 4th mistake the D model
I never said
that they have to do CG calculation during flight(on 76), but they have to do it before T/O, and this never happen in a 365 ANY SERIOUS S76 PILOT CAN CONFIRM THIS? SO WE STOP THIS **** !!!
I can tell you they do it in CHC Nigeria (or supposed to do it)
Why is the 155 autopilot so good ?
Just because in all Eurocopter and Aerospatiale history, they always used fixedwing autopilot, this is the first model which has an autopilot specifically designed for helicopter...
I don't know about Bell and Sikorsky, any comment is wellcome
Sorry it looks like they are some serious S76 pilot around. ChopperIMC please go back to your studies
Sikorsky made only 3 mistakes with the 76: The A, B, and C models, and they are ready to do the 4th mistake the D model
Last edited by froggy_pilot; 10th Oct 2006 at 01:05. Reason: forget the joke
Join Date: Apr 2003
Location: USA
Age: 75
Posts: 3,012
Likes: 0
Received 0 Likes
on
0 Posts
Mr Frog has a strange way of making his point, a bit jumpy, perhaps.
Calculating CG is required of every pilot of every aircraft prior to flight, and indescriminate loading is not possible in many helicopters. A simple plot on your kneeboard can serve as a way to do CG, it is not hard, unless you think it is, in which case, stay away from transport helicopters, and pull legs off frogs for a living.
What crap we can stop is believing that there is a stunning deficiency in the most popular, fastest, longest range and best equipped helicopter in its class. The Sikorsky soixante-seize is a mighty fine helicopter, the best in its class, as judged by all those who bought it, fly it and buy more when they get the money. Many more than those who bought the 365, many many more. Plus more. Tres more. Beaucoup more.
Calculating CG is required of every pilot of every aircraft prior to flight, and indescriminate loading is not possible in many helicopters. A simple plot on your kneeboard can serve as a way to do CG, it is not hard, unless you think it is, in which case, stay away from transport helicopters, and pull legs off frogs for a living.
What crap we can stop is believing that there is a stunning deficiency in the most popular, fastest, longest range and best equipped helicopter in its class. The Sikorsky soixante-seize is a mighty fine helicopter, the best in its class, as judged by all those who bought it, fly it and buy more when they get the money. Many more than those who bought the 365, many many more. Plus more. Tres more. Beaucoup more.
Join Date: Jan 2003
Location: AFRICA
Posts: 153
Likes: 0
Received 0 Likes
on
0 Posts
Mr Lappos
With all my respect, I agree that any pilot is supposed to do CG calculation prior to fly. But please don't try to convince me that you always T/O with your CG calculation done...
What I am trying to say that on 365 as long as you dont put a full container of hammers in the cargo compartiment, you won't go out of CG, this obviously not the case in a 76
Or maybe my collegues in Nigeria are just masochist and enjoy useless calculations (can't believe it...)
Let's forget this trans-atlantic war and be honnest for a change!!!
With all my respect, I agree that any pilot is supposed to do CG calculation prior to fly. But please don't try to convince me that you always T/O with your CG calculation done...
What I am trying to say that on 365 as long as you dont put a full container of hammers in the cargo compartiment, you won't go out of CG, this obviously not the case in a 76
Or maybe my collegues in Nigeria are just masochist and enjoy useless calculations (can't believe it...)
Let's forget this trans-atlantic war and be honnest for a change!!!
Join Date: Jul 2002
Location: mostly in the jungle...
Age: 59
Posts: 502
Received 0 Likes
on
0 Posts
Yeah right!
Get back over here on the sunny side of the Atlantic and give me some advice on my question about SAR equipment!
My friend spotted a whole bunch of 412's and I am not in the mood to get my back cracked with the old thumpers!
SO, please, some serious data and arguments, if possible with some reference, 'cause that will be the only way to convince him to at least look at something else!
I don't know why some folks defend a certain airframe to the point of fanatism, just because they used it a lot in the past, but have no objective view for lack of comparative experience.
Personally I don't care which machine will make the cut, but I really would like to have a couple in the race to at least look at different alternatives.
Hell, I hear the Kamov Ka-32 is a monster in that class)
3top
Get back over here on the sunny side of the Atlantic and give me some advice on my question about SAR equipment!
My friend spotted a whole bunch of 412's and I am not in the mood to get my back cracked with the old thumpers!
SO, please, some serious data and arguments, if possible with some reference, 'cause that will be the only way to convince him to at least look at something else!
I don't know why some folks defend a certain airframe to the point of fanatism, just because they used it a lot in the past, but have no objective view for lack of comparative experience.
Personally I don't care which machine will make the cut, but I really would like to have a couple in the race to at least look at different alternatives.
Hell, I hear the Kamov Ka-32 is a monster in that class
)3top
3top, you might want to start another thread if you are looking for guidance as to which helicopter people think will be best for you. Otherwise it could get lost in this thread, which is, after all, supposed to be about discussing the flying qualities of the S76.
But just to be on the safe side I like the BK117 for lightweight SAR/EMS work. Can't beat those clamshell doors, and the small rotor helps with tight spots. Getting a bit small nowadays, but still a good workhorse. EC145 if money no object, although I see REGA are now going for the Agusta Grand.
My 2 cents.
But just to be on the safe side
I like the BK117 for lightweight SAR/EMS work. Can't beat those clamshell doors, and the small rotor helps with tight spots. Getting a bit small nowadays, but still a good workhorse. EC145 if money no object, although I see REGA are now going for the Agusta Grand. My 2 cents.
Join Date: Jun 2003
Location: United Kingdom
Age: 61
Posts: 24
Likes: 0
Received 0 Likes
on
0 Posts
Froggy Pilot Quote: "With all my respect, I agree that any pilot is supposed to do CG calculation prior to fly. But please don't try to convince me that you always T/O with your CG calculation done..."
I can assure you Froggy Pilot that for Every T/O we do a C of G calculation prior to departure in order to confirm the exact C of G location with the S76A+ fleet we operate. That can sometimes be 10 to 15 sectors on one trip. It is easily achieved by use of a handheld computer carried onboard.
Generally the C of G is not an issue as most of the fleet have an aft C of G so if you load from the front pax row back it is usually no problem. However we do operate one or two which have a very forward C of G. The result being you can have full fuel and fly single pilot and still be in C of G. Not possible with our other machines.
Happy calculations!
I can assure you Froggy Pilot that for Every T/O we do a C of G calculation prior to departure in order to confirm the exact C of G location with the S76A+ fleet we operate. That can sometimes be 10 to 15 sectors on one trip. It is easily achieved by use of a handheld computer carried onboard.
Generally the C of G is not an issue as most of the fleet have an aft C of G so if you load from the front pax row back it is usually no problem. However we do operate one or two which have a very forward C of G. The result being you can have full fuel and fly single pilot and still be in C of G. Not possible with our other machines.
Happy calculations!
Join Date: Jul 2002
Location: mostly in the jungle...
Age: 59
Posts: 502
Received 0 Likes
on
0 Posts
noooby,
will do!
Please everyone, pass by on the new thread and help me confince my friend, that there are alternatives to the 412, may the best win!!
3top
will do!
Please everyone, pass by on the new thread and help me confince my friend, that there are alternatives to the 412, may the best win!!
3top
Join Date: Oct 2005
Location: Canada
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
76 - Czech built, powered by Polish engines
You may not know....
The 76 airframe is manufactured in the Republic of Czechoslovakia, shrink wrapped and air freighted to Stratford for powerplant, drivetrain installation and completed in Pennsylvania.
The Arriel is actually a Polish design… well ok, it was designed by the company (Turbomeca) that was established by a Polish emigrant, Joseph Szydlowski. Look for his name on various dataplates on the Arriel.
http://en.wikipedia.org/wiki/Joseph_Szydlowski
The 76 airframe is manufactured in the Republic of Czechoslovakia, shrink wrapped and air freighted to Stratford for powerplant, drivetrain installation and completed in Pennsylvania.
The Arriel is actually a Polish design… well ok, it was designed by the company (Turbomeca) that was established by a Polish emigrant, Joseph Szydlowski. Look for his name on various dataplates on the Arriel.
http://en.wikipedia.org/wiki/Joseph_Szydlowski
Join Date: Feb 2001
Location: Canada
Posts: 579
Likes: 0
Received 0 Likes
on
0 Posts
I flew the S-76A, A+, and A++ for about 10 years. I really enjoyed flying the aircraft, it is a great IFR platform weather(pun) you're flying raw data, flight director, or coupled.
I am really interested in seeing how the D model will turn out with the MR anti-ice stuff. It (MR anti-ice) is really needed in Northern climates to be a true IFR aircraft.
PS.
I really like the S-76.
I am really interested in seeing how the D model will turn out with the MR anti-ice stuff. It (MR anti-ice) is really needed in Northern climates to be a true IFR aircraft.
PS.
I really like the S-76.
Join Date: Nov 2006
Location: Death Star
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
S76A++ Unusual Snag. Help Required.
Hi Chaps
For those of you who are seasoned S76A++ drivers I hope you can possibly help with regards a snag that has had my engineers confused for a couple of weeks now.
Symptoms:
Whilst in flight there is an unusual amount of feedback through the cyclic. Almost as the helicopter is doing it's own thing. The feedback is as if someone has grabbed hold of the cyclic and moving it around eratically. It appears to be more common to the pitch than to the roll. However, I do experience unusual feedback in the roll as well.
Trouble Shooting so Far:
1. No 1 AFCS Channel is disengaged, symptom persists
2. No. 2 AFCS Channel is disengaged, symptom persists
3. All common denominators to the AFCS have been isolated. Heading Control removed, PBA removed etc etc. Problems still remains.
The problem dissapears when both AFCS Channels have been disengaged. Now we have swapped every component we can think of with other aircraft. the problem remians with the aircraft. I am beginning to think there may be a short in one of the looms to the AFCS.
Anyone got any idea's or have experienced similar problems. Please give me a clue as to how I can resolve this issue.
Regards
HJ
PS We are not operating the Helipilot AFCS system.
For those of you who are seasoned S76A++ drivers I hope you can possibly help with regards a snag that has had my engineers confused for a couple of weeks now.
Symptoms:
Whilst in flight there is an unusual amount of feedback through the cyclic. Almost as the helicopter is doing it's own thing. The feedback is as if someone has grabbed hold of the cyclic and moving it around eratically. It appears to be more common to the pitch than to the roll. However, I do experience unusual feedback in the roll as well.
Trouble Shooting so Far:
1. No 1 AFCS Channel is disengaged, symptom persists
2. No. 2 AFCS Channel is disengaged, symptom persists
3. All common denominators to the AFCS have been isolated. Heading Control removed, PBA removed etc etc. Problems still remains.
The problem dissapears when both AFCS Channels have been disengaged. Now we have swapped every component we can think of with other aircraft. the problem remians with the aircraft. I am beginning to think there may be a short in one of the looms to the AFCS.
Anyone got any idea's or have experienced similar problems. Please give me a clue as to how I can resolve this issue.
Regards
HJ
PS We are not operating the Helipilot AFCS system.
Join Date: May 2006
Location: Philippines
Posts: 30
Likes: 0
Received 0 Likes
on
0 Posts
S76A++ Unusual Snag. Help Required
Hi HJ,
While I haven't had the same problem, it brings back to mind a quite related experience on the 109C. 1st symptom encountered was a vertical vibration (med freq) whether coupled/decoupled-- more of periodic and not persistent, but happens unpredictably. No stick feedback. Sure it had the tech dept scratching heads and couldn't find the cause. Even replaced all M/R rod ends, changed dampers, checked Hyd Sys, to no avail. We were maintained by Agusta branch.
One day we decided to reproduce and just stayed on hover and watched all instruments. Voila, the #2 Art. Horizon (not ADI) vibrates in pitch just as the a/c vib comes on. Finally, we've localized the problem with the art. horizon. I was told that part of the SAS (one of 2) is wired to the #2 display and the SAS is correcting the error. Replaced & problem resolved. Installation is a Sperry System.
In another a/c (AS350B), experienced cyclic feedback while flying offshore-- no pressure loss on Hyd Sys, no caption light. Suspected valve problem inside Servo and continued flight "isolated". Whew! drained all my energy! Replaced lateral servo and problem resolved.
Hope this helps.
b@6
While I haven't had the same problem, it brings back to mind a quite related experience on the 109C. 1st symptom encountered was a vertical vibration (med freq) whether coupled/decoupled-- more of periodic and not persistent, but happens unpredictably. No stick feedback. Sure it had the tech dept scratching heads and couldn't find the cause. Even replaced all M/R rod ends, changed dampers, checked Hyd Sys, to no avail. We were maintained by Agusta branch.
One day we decided to reproduce and just stayed on hover and watched all instruments. Voila, the #2 Art. Horizon (not ADI) vibrates in pitch just as the a/c vib comes on. Finally, we've localized the problem with the art. horizon. I was told that part of the SAS (one of 2) is wired to the #2 display and the SAS is correcting the error. Replaced & problem resolved. Installation is a Sperry System.
In another a/c (AS350B), experienced cyclic feedback while flying offshore-- no pressure loss on Hyd Sys, no caption light. Suspected valve problem inside Servo and continued flight "isolated". Whew! drained all my energy! Replaced lateral servo and problem resolved.
Hope this helps.
b@6
Join Date: Apr 2003
Location: USA
Age: 75
Posts: 3,012
Likes: 0
Received 0 Likes
on
0 Posts
The problem is called "SAS Nibble" and is due to the lack of enough friction between the sas actuators and the cockpit. There is a friction set on a bell crank just forward of the sas actuators that is cranked up to make the friction forward of the sas actuators higher than the friction back to the main servos. (The friction set looks like a coil spring and washer stack-up at the bell crank end.) The friction device assures that any sas actuator motions will work downstream, and make the main servos move instead of the cyclic. Because there is so little friction going toward the cockpit, the sas actuators are happy to just juggle the stick and leave the main servos sitting still.
The only concern I would have is to be sure there is no problem with the controls downstream of the sas actuators that makes very high friction, indicating a bad bearing or some kind of interference (wire bundle?) so inspect the system downstream to be sure it is healthy. If you open the system up at the sas actuators, the friction to the main servos should be smooth as butter, and almost zero friction.
PM me and I will send you my phone for more discussions if you wish.
The only concern I would have is to be sure there is no problem with the controls downstream of the sas actuators that makes very high friction, indicating a bad bearing or some kind of interference (wire bundle?) so inspect the system downstream to be sure it is healthy. If you open the system up at the sas actuators, the friction to the main servos should be smooth as butter, and almost zero friction.
PM me and I will send you my phone for more discussions if you wish.
Join Date: Nov 2004
Location: Cambridgeshire, UK
Posts: 1,334
Likes: 0
Received 0 Likes
on
0 Posts
Nick, is there any technical detail about SAS (76A or otherwise) on the Sikorsky website? Search revealed nothing. I am interested from the point of view of an engineer trying to gain familiarity with helicopter systems.
Mart
Mart
I'm sure you can find everything that a marketeer could teach you about SAS on the Sikorsky website!
-- IFMU