Cheers SASless, this should not be about EC/SK, as the thread title implies.
So what criteria do we go with, if helo is predominately used over water and > 30 minutes between landing options, 30-minute run-dry time is mandatory?
If sea state warrants SS6 flotation design, then this is also a mandatory requirement for these operations?
No usage of extremely remote and statistical data to justify a dispensation from the above?
So for the Grand Banks operations the S-92a fails on the dry-run requirement, and the SS5 flotation implementation means tighter weather/sea state restrictions.
Assuming that the revised RFM takes into account no dry-run capability with tightened land immediately requirements, we still have the issue of no SS6, and inadequate flight suits IMO. We've still go some way to go before PAX will be more comfortable with this helo's application.
FYI at least one of the oil operators over here has gave PAX the option to return by vessel until further flight suit evaluation is complete, as we've all noted how poor the sealing properties are with the current versions during our HUEBA training.
On a side-note, it is true that SK didn't retain the removed titanium studs for further analysis as stated in the US lawsuit? The TSB are still investigating the root cause of the failed studs on Cougar 491, having the removed studs from the rest from the fleet would surely have allowed a more detailed analysis to have been performed...
You can test the fitness of the 92 however you wish.....but if you do....apply the same criteria to the other aircraft that are out there today...but do it in a logical, reasonable, even handed manner.
I personally think the review should be focused upon the FAA, their application of Part 29 and the results of that.
As the 92 and the 139 are the only two aircraft certified under part 29 that excludes the EC line of aircraft as they have been approved under a less strict set of rules than the 92/139.
That being said....either we have to accept the EC line are inferior aircraft due to that lack of certification under Part 29 and the 92/139 are therefore superior unless we can prove the FAA implementation of the Part 29 standards compromised the intent and purpose of the certification standards they set out to require.
This logical argument is not to be viewed as suggesting the EC line compared to the 92/139 is better or worse in reality but rather do the certification standards on each side of the Great Saltwater Divide meet the need of the industry and live up to their published goals. Somewhere in the discussion it should be determined neither standard as they exist now and are implemented are the final answer. The followup argument will be to define just what the standard should be.
I have stated my views.....but it they are those of a long time helicopter pilot and not a lawyer, aeronautical engineer, statitican, or an actuary.
I want to see an aircraft design that is safe to fly, dependable, and properly designed, tested, and certified to a fixed set of easy to understand set of standards. I do not believe in waivers....either you meet the required standard or you do not get the certification.
Looks like we've had an APU failure and a MGB chip detect in the same week over here in NL, as expected the newspapers are spinning faster than a UK politician, certainly not good for PAX confidence in the S-92a albeit sounds like Cougar did everything by the book as expected.
I know that these things happen from time to time in helo operations, but here's my questions, how often are they expected to happen with the S-92a from a design perspective, what's the track record been on these alarm modes i.e do the S-92 MGBs make metal as much as the Super Pumas. From CADORS the last NL chip light appears to be from April 2008, so that's pretty good IMO. I don't recall hearing about an APU failure before.
I recall one of the reasons stated for going for the S-92a for NL was to reduce the MGB maintenance costs that were notably high with the Super Pumas that they had. Only a rumour, but I did hear it from a good source a few years ago...
Ask the Bristow folks about MGB problems with the Super Puma's.....and how they had to reduce the power settings they were using that seemed to cause the gearboxes to require changing way too frequently. Perhaps it was the same situation with Cougar.
What's the big deal about an APU failure?
Gear boxes make chips.....all of them do....nothing new about that.
Sounds like some folks are looking for things to be worried about.
Looks like we've had an APU failure and a MGB chip detect in the same week over here in NL, as expected the newspapers are spinning faster than a UK politician, certainly not good for PAX confidence in the S-92a albeit sounds like Cougar did everything by the book as expected.
That really should not be newsworthy IMO. Neither are a big deal at all, and it sounds to me like a whole lot of scaremongering by NL journos who clearly do not know very much about helicopters, let alone the S92. To try and make any sort of news out of an APU failure is frankly absurd. Next NL journos will be getting worked up about a blown light bulb (which actually is propably more of a problem if it is a landing light on a dark night) As has been stated before - this is taken out of all context, and if you want to look at figures and stats such as these, then compare them with other aircraft types, and I suspect the S92 will come out favourably in a comparison. I think we are all for a sensible investigation and debate, but it is not looking very sensible when rubbish like this is going into the news, to further bias people opinions on the basis of inaccurate and unqualified reporting. These journos are doing no favours for anybody with this type of reporting. Those of us flying this machine and going to work in it still have an important job to do. The pilots often get to see the news for what it is, but the PAX don't always have this fortune, so may not always be able to filter the crap. I would hate to be responsible for worrying the pax and their families any more than they are already, especially as it is generally completely unnecessary. The most dangerous part of their journey to work remains to be the drive to the airport despite what irresponsible journos want to print.
1. If you think a 30 min run dry will save you from going in the drink in offshore aviation, think again.
2. Flight suits, I assume you are talking about immersion suits?
What do they have to do with the S92? Maybe start a new thread.
3. One day you might be a passenger on an A330 so you might want to get on the AF447 thread and try to get to the bottom of what happened there!
4. If the press starts reporting on all the chip lights, APU failures etc on the A330 fleet (over 600 I believe) you will probably never want to fly again!
Nice to see there's still some debate and fire running in the participants of this thread. IMO all debate is good, even at the price of sarcasm.
The immersion suit is irrevocably linked to the S-92 thread as the helo design and its over-water use is what requires us to wear such PPE. That's why we need good immersion suits, because a dry-run capability does not mean we're not going to ditch, albeit hopefully if the situation arises it can be executed in a safe and controlled manner and we can do so knowing our cold-water survivability is reasonable.
A separate thread sounds like a good idea though as it will hopefully instill constructive discussion on other people's experiences.
Going on a A330 or any other fixed wing aircraft has its own risks, as does anything in life, but it hasn't stopped me doing either. I just flew recently in France in a A320, big deal. There are certainly more qualified people than myself to find the root cause of that disaster, thank you very much, but I'm just not that good!
Where I wholeheardedly agree with you fellow posters is that the media is doing this industry no favours and only scare-mongering us mere mortals. Why not ask them to give the standard family-type SUV the same treatment, I'm sure lots of soccer mums will really appreciate that...
As I said a while ago, let's just get on with it, improve what we can and move on with life, it's too short to worry about every single thing that can go wrong.
BTW, I still want to see SS6, better immersion suits, less vibration, more transparency and discussion between pilots and PAX. Then I will have a more chilled-out flight, but only because my nose-hairs won't be constantly waking me up, the suit won't be trying to cook me, and I can catch some shut-eye while you drivers do your thing.
Hot off the press, Remington is teaming up with SK to provide in-flight nasal hair clippers to improve PAX comfort on the S-92a!
Last edited by maxwelg2 : 21st June 2009 at 01:17.
I'd be curious as to input concerning the level of acceptance it has at present amongst pilots, operators and customers, and what may have to be done to the aircraft to sort problems noted.
WIII
Last edited by WhirlwindIII : 23rd June 2009 at 17:08.
Gee I do not know. Maybe the excessive flair angle, the fact you had two trained test pilots doing it on a hard strip after working up to it for awhile and that is the best they can do.
If all agree that auto is safe to do into rough seas then you are left with the "fact" that the S-92 can not survive a loss of tail rotor drive. Something else for the FAA to look at.
1. Does the S92 have a Cat A Helipad profile approved for take off and landing from ground level AND elevated helipads?
2. If so what is the minimum size helipad required?]
Well, firstly, the new copy and paste function in iPhone OS3.0 works !
Geoff, the procedure is being certified as we speak. I believe it it has been tested with a 1D (20.88m) pad. Obviously National regulators my require 1.5D for Public Transport operation.
I don't understand why it's not possible to create a MGB transmission that can "run dry" for 30 minutes. I thought of a way to do this, and rely on my fellow ppruners to critique this idea. Surely I'm not the first to think of this.
Why not use an automatic grease system to lube the bearings and gears for 30 minutes after loss of MGB oil? It would consist of several light weight tubes (inside the transmission) running to nozzles that apply an appropriate grease (heavier than the normal MGB oil) to critical gear and bearing areas. The application device could be some small electronic (aircraft battery powered?) device that runs a pump activated at predefined intervals once started (by a switch in the cockpit?), that could run at least 30 minutes or until the grease runs out. The grease could be contained in cartridges, that are easy to load and unload. I don't think the whole system needs to weigh more than about 30 lbs or so, and would be pretty simple.
The technology for this already exists. Grease is cartridges exist, small grease pumps (pressure and demand sensitive) already exist, and the control device (in some form) already exists. Each nozzle tip on the end of a tube, could be properly sized and shaped (point, fan, etc) to distribute the grease correctly, and proportionately between the various nozzles. Also, there would be torque increase with grease (compared to oil), but far less I would think than the latter stages of running dry. I also think this system would work better than a melting wax system.
MGB oil does of course provide lubrication, but for most of the gearbox at least, its to lubricate roller or ball bearings, rather than the plain bearings that you would find in a car crankshaft etc, and gear teeth meshing. Unlike car crankshaft bearings, such bearings and gear teeth continue to be lubricated by residual oil even after loss of all oil from the sump. I think the primary issue is cooling not lubrication. Consider how much heat is expelled via the oil cooler and how that heat, if left localised in the gear teeth and bearings, would affect the materials. The oil does a good job of being a heat transporter, something grease could not do.
And to answer your initial question, it is possible to create an MGB transmission that can "run dry" for 30 minutes, its just that so far Sikorsky decided not to do that for the S92.
Sultan - I seem to recall that there was mention of 20g at touchdown for the Cougar aircraft. The video looks like max 2 g or so, so although an engines off landing might cause damage, I don't think the video shows that it would be in the same ballpark for catastrophe as the Cougar event.
Sultan - you clearly don't know much about EOLs, especially in large aircraft - you need a big flare to stop a 10-ton helo and it will never look pretty at the bottom unless you are very light and into a strong wind.
On the water, all you care about is making it survivable and that means reducing water entry speed as much as possible, even if it means putting the tail in first (which if you did have a functioning TR would probably trash it anyway).
HC, did you see the photos of the ring and pinion gear of the TR drive from the Cougar S92? Hard to say whether the grinding of the gear teeth was caused by the lack of lube to the teeth, or the failure of the bearings that have to hold a ring and pinion in near perfect alignment (or both). I would point out however that ring and pinion arrangments place a great deal of pressure on the gear teeth surfaces, and thus require lubrication to survive.
No heat is transferred after the loss of MGB oil anyway. Grease by its nature isn't normally used in flowing or recirculating applications, and therefore isn't normally used for heat transfer. Grease always lubricates in place, and is quite heat resistant. I think some basic testing would show whether the idea has any merit or not.
Geoff, the procedure is being certified as we speak. I believe it it has been tested with a 1D (20.88m) pad. Obviously National regulators my require 1.5D for Public Transport operation.
Great news! Seems odd that a helo requires a runway to operate Cat-A...
Linear Mode
