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Sikorsky S-92: Operations

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Sikorsky S-92: Operations

Old 13th Apr 2011, 18:26
  #61 (permalink)  
 
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incorrect application of collective, pulled up inadvertently when applying parking brake
Most definitely not the first time on the S92 (or many other types). I know of at least a couple of other similar incidents on the S92, although they were considerably more benign than this incident, but largely due to luck and good fortune. Procedures in place have in a large part prevented it happening again, whereby the co-pilot is required to cover the collective at the same time as the captain pulls the parking brake lever. This was certainly my immediate assumption of the cause when i first heard of it, so I am not surprised if this is confirmed. Perhaps new procedures or a modification or two is required. Even with good procedures in place it can still happen. Distraction, stress, tiredness, unusual or unexpected situations arise and the procedure is easily omitted, and mistakes are made. Just confirms the old theory that if "shit can happen, at some point, it will". It could probably happen to any one of us given the right set of circumstances. Perhaps a simple guarded brake lever would help, or moving the brake lever altogether.
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Old 13th Apr 2011, 19:06
  #62 (permalink)  
 
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From the FM:



The PARKING BRAKE handle is located to the right of the center console. This hand-operated handle allows brakes to be locked by either the pilot or copilot after brake pressure is applied. The parking brakes are applied by pressing the toe brake pedals, pulling the parking brake handle to the fully extended position, and then releasing the toe brakes while holding the handle up. An advisory illuminates indicating
on. Pressing either the pilotís or copilotís left brake pedal releases the parking brakes; the handle returns to the retracted position and the advisory extinguishes.


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Old 13th Apr 2011, 19:28
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Sorry to ask Sqib, but what is your point?
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Old 13th Apr 2011, 19:47
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Smile

Do I need a point beyond providing a factual extract connected to one aspect of the discussion?
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Old 13th Apr 2011, 19:54
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Nope of course not. I was just wondering if I was having a slow moment and missed something and it triggered some more thought in my shell. It is worth pointing out at this point, that whilst the RFM does state that the parking brake can be operated by either pilot, reality states that it is simply not very practical nor easy to do so from the left hand seat due to the ergonomics of the cockpit in that unless you are blessed with the arms of an ape, it is quite a stretch. I believe many operators have recommended that it is only done from the right hand seat to prevent possible back injury due to the left hand seat pilot having to stretch over and pull the lever up.
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Old 24th Apr 2011, 03:45
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Is the automated bypass system now in use?

Scheduled Flight Turnaround Incident April 14, 2011

Suncor has notified the C-NLOPB of a scheduled flight that turned around this morning. It was a shared flight between the Terra Nova FPSO and the MODU Henry Goodrich. The flight was approximately 86 miles offshore when they received a Main Gearbox oil by-pass indicator light. It was intermittent, however the decision was made to turnaround. They did not declare an emergency. The flight arrived at 10:15 a.m. and the passengers were briefed. The Board is following up on the incident with the Operator.

Last edited by zalt; 24th Apr 2011 at 03:55. Reason: Typo
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Old 25th Apr 2011, 01:49
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No it is not fitted yet. There are two likely explanations: one, it is a misquote and was - perhaps - the ENG OIL BYPASS caution which refers to the engine oil filter bypass functioning (due to clogging etc.) Two, perhaps there was a fault in the MGB Oil Bypass system sensor or the test function.

The first choice would be my bet.....
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Old 27th Apr 2011, 17:01
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Maybe, but the last I was told is that the automated bypass would be certified Q2, so it might just be one of the first.
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Old 29th Apr 2011, 21:01
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Since then more problems for Cougar, this time with faulty engine anti-icing causing abandonded flights.
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Old 30th Apr 2011, 09:19
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Since then more problems for Cougar, this time with faulty engine anti-icing causing abandonded flights.
Hardly interesting news there. Just more random reporting of very uneventful irrelevant events by those who are hellbent on making drama. Go and find out about every minor caution on a Puma, 365, 139, 155 to find some sort of perspective. Our reporting system shows vastly more reportable events and incidents involving system malfunctions with those types than with the S92, and I mean a huge difference. Every helicopter has technical faults, and this is hardly a big problem. The system operates with in built redundancy and fail safe logic anyway, so if it fails you still have protection. If we are referring to engine anti-icing protection, then it consists of two systems - bleed air and electrical inlet heater mats. Operated using the same switch, but separate systems. If the heater mat fails, you still have bleed air feeding the inlet guide vanes. Heater mats can obviously fail, and is not fail safe, but the bleed air system, if it fails, the valve will be in the open position, so still providing protection. Not a particularly common failure in the 92 in my experience, but does happen and generally very quickly fixed. If either system fails, a warning is generated and the aircraft will be required to vacate icing conditions, and not fly again in icing until fixed, as redundancy and double protection is now lost. Not something I would lose any sleep over.
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Old 30th Apr 2011, 13:43
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I agree the S-92 is a leap forward in technology.

But it pays to study ever technical malfunction in order to reduce risks to ALARP.

It also pays to study human errors too.

I see no one wants to discuss the S-92 parking break anymore.
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Old 30th Apr 2011, 17:27
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S-92 Vibration

It has been widely reported on this thread that the S-92 vibration levels are not anything to brag about. How does the 92 handle icing conditions? Barely noticable, tolerable, or wish I was somewhere else?

The Sultan
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Old 30th Apr 2011, 19:16
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It has been widely reported on this thread that the S-92 vibration levels are not anything to brag about. How does the 92 handle icing conditions? Barely noticable, tolerable, or wish I was somewhere else?
In my experience, based on comparison with several other types - very well indeed. The most direct comparison I can relate to is the Puma L/L1, which had a limited icing clearance. The S92 is considerably more comfortable. With the RIPS on and functioning (which is now pretty reliable), I feel a lot more comfortable in icing conditions than I have whilst flying other types. I fly regularly in a varying degrees of icing conditions, and even in heavy icing the aircraft copes well. In heavy icing, it is noticeable but not desperately uncomfortable and I don't notice the pax waking up. There is a noticeable increase in vibration as the ice is allowed to build and a torque increase, then as the ice is shed in accordance to the calculated schedule the vibration reduces. This pattern basically continues to varying degrees depending on the level of icing. The most recent versions are reliable and work well. The ice detection is in general a good indication, but can be over-ridden if necessary. I have often landed and seen how much ice is stuck on the airframe and been pleasantly surprised at how well the machine faired and how relatively comfortable it was in flight.
Some recent studies have also been done to see how well things work without the RIPS, in order to provide some limited clearance in the event of failure. Although nothing has been officially produced in terms of results, early indications from those who flew the tests were positive indicating that it still performed pretty well.
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Old 30th Apr 2011, 21:30
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Collective Parking Brake Lever

It is interesting that the S92 now has Pilots pulling up the collective lever in lieu of the parking brake lever.

I say it is interesting in that this happened on the S76 in the Company for which I worked but much later in its operating life.

They were called "action slips" and what happened was that the Co-pilot reached over to select the parking brake on but actually grabbed a handful of collective. To my knowledge this happened twice in our Company and both times the helicopter got airborne and some damage was caused with the subsequent heavy landing but the bizarre aspect was that we had been operating the aircraft for some10 years before it happened at all.

I'm an engineer so fail to see why this should happen?

Our pilots of course wanted modifications of some kind to ensure that it couldn't happen again - what about root cause and our new Safety Management Systems? That was the route we took at the time but Pilots weren't happy - worrying that someone would do it again !!
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Old 1st May 2011, 01:20
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We have the LHS pilot guard the collective while the RHS pilot applies the brake, and have done so since we started operating this type, based on knowledge of similar S76 incidents. Perhaps this operator had the same policy but the guarding in this case was a token effort that couldn't overcome the rate and force of the application? They certainly have this policy on their S76 fleet. I agree, though, that it's not the best place for it and suggest that the centre rear of the lower console might have been a better choice.
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Old 1st May 2011, 15:27
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S92A Collective

This is not the first helicopter type to get airborne inadvertently (happened on the EC225, which has a collective lock, the S76 as already mentioned, and even the Bell 212 which does not have a parking brake!).

The S92A Rotor Head is fitted with elastomeric bearings. Without hydraulic pressure the collective will rest in a mid-range position. Despite a Note in the RFM this has not prevented the helicopter 'jumping the chocks' during single pilot engaged rotor ground runs by several S92A operators, until the appropriate SMS training corrected the error of not lowering the collective as hydraulic pressure builds.

Thus a collective lock cannot be fitted to the S92A.

The operator did not have a policy of covering the collective lever whilst applying the Parking Brake on the S92A, and following this incident a Global Standard has now been adopted on all helicopter types.
Originally Posted by coning angel
From the story I heard last night, they were lucky!
You were obviously told the story 'send three and four pence we're going to a dance'. The actual story was 'Send re-enforcements we're going to advance'
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Old 2nd May 2011, 11:42
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It is great that the BSP Aviation Safety Case identified the need to take the remedial action of extra procedures.

I would have hoped that SAI would have ordered a change in the design and contractually required the same approach with all their contractors.
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Old 17th May 2011, 16:00
  #78 (permalink)  
 
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S-92 + (engine) Oil
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Old 17th May 2011, 23:17
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Well is it any surprise they had issues with oil if they were flying to the sun. I am sure Sikorsky will claim that the helicopter was not designed for such extreme temperatures
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Old 18th May 2011, 02:29
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oil

Another oil issue listed as a proposed AD:

Airworthiness Directives; General Electric Company CT7-8, CT7-8A, CT7-8A1, CT7-8E, and CT7-8F5 Turboshaft Engines

SUMMARY: We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD would require the installation of an accessory gearbox (AGB) axis-A oil slinger nut to the axis-A shaft assembly. This proposed AD was prompted by four reports of unrecoverable engine stalls, during hover in a left-roll attitude. We are proposing this AD to prevent an unrecoverable engine stall, leading to a helicopter forced landing or accident.

General Electric Company CT7-8, CT7-8A, CT7-8A1,
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