Sikorsky S-76 [Archive Copy]
Re: Sikorsky C Plus Plus !!
GLS,
What's in a name?
Does a coat of paint cover up the Bubba Suggs brand on the butt?
What's in a name?
Does a coat of paint cover up the Bubba Suggs brand on the butt?
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S76 & Sloping Ground
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?
I believe the EC 155 has sloping ground angles mentioned in the FM but that does have a nose wheel lock. Any comments?
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Re: S76 & Sloping Ground
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.
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.
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Re: S76 & Sloping Ground
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.
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Re: S76 & Sloping Ground
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+
Hope your time at Gulfstream is going well - we operate one of those too. Critics are everywhere!
Regards UG
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+
Hope your time at Gulfstream is going well - we operate one of those too. Critics are everywhere!
Regards UG
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Re: S76 & Sloping Ground
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.
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Re: S76 & Sloping Ground
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.
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.
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Re: Sikorsky C Plus Plus !!
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)
fadec...glass cockpit. luxury
Come on oil companies. Give us a break
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) fadec...glass cockpit. luxury
Come on oil companies. Give us a break
Avoid imitations
Re: S76 & Sloping Ground
"I always thought the GAMA designed flight manual wasn't as good as the military ones"
Those manuals were designed? That's almost unbelievable.
Anyone know the sloping ground limits for a G-5?
Those manuals were designed? That's almost unbelievable.
Anyone know the sloping ground limits for a G-5?
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Re: Sikorsky C Plus Plus !!
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.
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Re: S76 & Sloping Ground
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
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
Re: Sikorsky C Plus Plus !!
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.
Re: strange marks on S76 blades
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 !
You were right Nick !
Not enough $$$ ...
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Re: strange marks on S76 blades
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. 
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!
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!
