Sikorsky S-92: From Design to Operations
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Lift
Hey Nick, have not heard from you in a while.......I'm sure you are well ensconced in a hospitality suite at HAI at this moment, but when you get back online I have a question. How much lift (if any) is produced by the sponsons on the 92? Is it just enough to offset the drag produced or is there a benefit?
Cheers
And just so HC doesn't think we are ignoring his brand, the new EC175 looks great
Cheers
And just so HC doesn't think we are ignoring his brand, the new EC175 looks great
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Got back from HAI Sunday night. Great show!
The sponsons produce no lift at all, just drag. In fact, the hover performance is probably about 1% the poorer for the vertical drag on them - 200 to 250 pounds.
If you recall the Sikorsky Shadow (S76 with the long nose and extra cockpit) it lost 150 pounds of hover performance due to the extra length caught in the rotor downwash.
For the 92, putting the gas in there was a conscious decision, no gas in the belly, which is the first thing to hit the ground. the sponsons are lined with a crashworthy bladder and no fuel spills when the whole shebang is dropped from over 50 feet with full tanks onto concrete.
The sponsons produce no lift at all, just drag. In fact, the hover performance is probably about 1% the poorer for the vertical drag on them - 200 to 250 pounds.
If you recall the Sikorsky Shadow (S76 with the long nose and extra cockpit) it lost 150 pounds of hover performance due to the extra length caught in the rotor downwash.
For the 92, putting the gas in there was a conscious decision, no gas in the belly, which is the first thing to hit the ground. the sponsons are lined with a crashworthy bladder and no fuel spills when the whole shebang is dropped from over 50 feet with full tanks onto concrete.
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Ok, thanks for that Nick.
I was looking at the photo posted of the Air Harrods machine and for some reason that was the first time I noticed what looked like an airfoil shape to the sponson. I understand the reduction in hover performance as it is the same situation with the 61N vs the L model.
I was looking at the photo posted of the Air Harrods machine and for some reason that was the first time I noticed what looked like an airfoil shape to the sponson. I understand the reduction in hover performance as it is the same situation with the 61N vs the L model.
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Norwegian operator Norsk Helikopter yesterday celebrated the 5,000th fleet hour of its Sikorsky S-92(R) (Serial No. 11) helicopter.
The aircraft reached the milestone on February 5, a little more than two months after the Norsk S-92 fleet reached its 20,000th flight hour.
Norsk managing director Ivar Eie said,
The S-92 helicopter has demonstrated that it is well suited for its missions. It has performed above expectations.
The offshore oil segment in the North Sea is a challenging environment, so to realize these distinct milestones in such an aggressive time frame is truly remarkable.
Norsk began transport services to fixed and mobile installations in the North Sea in 1993.
It owns and operates six S-92 helicopters and in 2006 became the first offshore oil operator in the North Sea to reach 10,000 fleet flight hours.
The aircraft reached the milestone on February 5, a little more than two months after the Norsk S-92 fleet reached its 20,000th flight hour.
Norsk managing director Ivar Eie said,
The S-92 helicopter has demonstrated that it is well suited for its missions. It has performed above expectations.
The offshore oil segment in the North Sea is a challenging environment, so to realize these distinct milestones in such an aggressive time frame is truly remarkable.
Norsk began transport services to fixed and mobile installations in the North Sea in 1993.
It owns and operates six S-92 helicopters and in 2006 became the first offshore oil operator in the North Sea to reach 10,000 fleet flight hours.
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rotofix,
Sounds like a problem with the venting, which is sized to allow massive overfill, but if blocked and the system overfilled.....
My guess is that the machine can be flown back without pax using crossfeed from the other side for both engines, unless some damage to the other cell is also noted. I am sure some wise heads are working it out.
Sounds like a problem with the venting, which is sized to allow massive overfill, but if blocked and the system overfilled.....
My guess is that the machine can be flown back without pax using crossfeed from the other side for both engines, unless some damage to the other cell is also noted. I am sure some wise heads are working it out.
Originally Posted by NickLappos
My guess is that the machine can be flown back without pax using crossfeed from the other side for both engines, unless some damage to the other cell is also noted. I am sure some wise heads are working it out.
Maybe everywhere else in the world. In JAA-land, repairs can only be done at an JAA approved maintenance facility, which a helideck is not. I wonder if the same applied to the one in the jungle clearing?
My guess is that the machine can be flown back without pax using crossfeed from the other side for both engines, unless some damage to the other cell is also noted. I am sure some wise heads are working it out.
Maybe everywhere else in the world. In JAA-land, repairs can only be done at an JAA approved maintenance facility, which a helideck is not. I wonder if the same applied to the one in the jungle clearing?
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malabo,
I know that in FAA-land, maintenance ferry flights with less than perfect machines is allowed, as long as the operator has approved procedures for the operation, flies a route that does not endanger the public, and has FAA FSDO approval. I signed several such ferry letters (the procedure part of the equation) for S-76 operators in the past.
The "repairs" you speak of could be performed afterward, as long as a good inspection showed airworthiness, albeit with one fuel cell. It is also possible to carry a new sponson to the rig and replace it there. The sponson can be removed and replaced in a few hours. The people who are listed on the repair station license can perform the repairs elsewhere as long as the regulators agree. The idea that only the repair station roof covers the approved repair station is a bit quaint.
I know that in FAA-land, maintenance ferry flights with less than perfect machines is allowed, as long as the operator has approved procedures for the operation, flies a route that does not endanger the public, and has FAA FSDO approval. I signed several such ferry letters (the procedure part of the equation) for S-76 operators in the past.
The "repairs" you speak of could be performed afterward, as long as a good inspection showed airworthiness, albeit with one fuel cell. It is also possible to carry a new sponson to the rig and replace it there. The sponson can be removed and replaced in a few hours. The people who are listed on the repair station license can perform the repairs elsewhere as long as the regulators agree. The idea that only the repair station roof covers the approved repair station is a bit quaint.
Good point there Reflex:
I have often wondered why the APU is fed from the #1 side only.
Not with this scenario in mind of course.
However if you loose #1 eng due to fuel contamination or a leak you are kinda screwed if you want to use the APU.
Also if you end up using the APU a lot on multiple short legs you get a fuel imbalance which, while not critical, is annoying because, Xfeed not being an option in our normal ops procedures your realistic fuel calcs become "what's in the lowest level tank X 2". The beast hangs left low in the hover anyhoo so why not feed from the #2 side?
The APU auto switches between #1 and #2 prime pumps for each APU start so why not switch tanks?
Mind you this is all a very minor point so hardly worth a design change with all the plumbing problems that would engender.
Anyone know how many tanks they have had "Pop"? Is it "usually" the #1 or #2 that goes or does it vary?
I remember having a problem on a 212 because of a stuck rollover valve not allowing a tank to vent and therefore you couldn't get full fuel - it took a long time and a lot of headscratching to find that one!
Fuel right up to the cap but only 2000 lbs indicated ( Aux tanks installed ) After we confirmed that the fuel totalizer was OK there was much poking and prodding, much cursing.
Brand new apprentice:"Jeeze guys - I just helped with the rebuild on XXX and helped with the fuel system. Did you check the rollover valves?" Startled looks from all. Much more cursing and swearing
- 20 minutes later it was sorted. "From the Mouths of Babes..."
I have often wondered why the APU is fed from the #1 side only.
Not with this scenario in mind of course.
However if you loose #1 eng due to fuel contamination or a leak you are kinda screwed if you want to use the APU.
Also if you end up using the APU a lot on multiple short legs you get a fuel imbalance which, while not critical, is annoying because, Xfeed not being an option in our normal ops procedures your realistic fuel calcs become "what's in the lowest level tank X 2". The beast hangs left low in the hover anyhoo so why not feed from the #2 side?
The APU auto switches between #1 and #2 prime pumps for each APU start so why not switch tanks?
Mind you this is all a very minor point so hardly worth a design change with all the plumbing problems that would engender.
Anyone know how many tanks they have had "Pop"? Is it "usually" the #1 or #2 that goes or does it vary?
I remember having a problem on a 212 because of a stuck rollover valve not allowing a tank to vent and therefore you couldn't get full fuel - it took a long time and a lot of headscratching to find that one!
Fuel right up to the cap but only 2000 lbs indicated ( Aux tanks installed ) After we confirmed that the fuel totalizer was OK there was much poking and prodding, much cursing. Brand new apprentice:"Jeeze guys - I just helped with the rebuild on XXX and helped with the fuel system. Did you check the rollover valves?" Startled looks from all. Much more cursing and swearing
- 20 minutes later it was sorted. "From the Mouths of Babes..."
Hi Busdriver 02
S-92 RFM Limitations PT 1 Sect 1 page 1-18
Fuel Crossfeed Limits:
Fuel Crossfeed operations limited to
Catagory A - Emergency operations only.
Catagory B - Cruise flight only.
S-92 RFM Limitations PT 1 Sect 1 page 1-18
Fuel Crossfeed Limits:
Fuel Crossfeed operations limited to
Catagory A - Emergency operations only.
Catagory B - Cruise flight only.
Albatross: good point but in the latest case (Norway) it was the number 2 tank that went 'pop' (quite spectacularly too - I've seen the photos!)
Busdriver; Albatross has pointed you to the limitation, however the reason for this limitation is that using crossfeed introduces a single point failure mode that could result in a double engine flame out, which is an unacceptable concept in Cat A certification. Bear in mind that crossfeed is referring to the engine fuel supply, not crossfeeding between tanks (as in some types.)
Busdriver; Albatross has pointed you to the limitation, however the reason for this limitation is that using crossfeed introduces a single point failure mode that could result in a double engine flame out, which is an unacceptable concept in Cat A certification. Bear in mind that crossfeed is referring to the engine fuel supply, not crossfeeding between tanks (as in some types.)
Well said 212man - thanks.
I'll bet it was indeed an interesting event. "What the F---- was that!!!!??"
Haven't seen the photos - was it the tank top that let go? Was there a large spill?
I'll bet it was indeed an interesting event. "What the F---- was that!!!!??"
Haven't seen the photos - was it the tank top that let go? Was there a large spill?