Agusta AW139

[pitchlink]

This is exactly the sort of discussion that is required to try and iron out the problems with operating this aircraft. As someone said to me the other day, he would, "give Agusta eleven out of ten for concept, but only three out of ten for execution!"

The idea of putting together a wish list made up from all operators through out the world can only help to bring these problems to the attention of Agusta. We never know, there may be a few common themes running through out!

Geoff, having an Owner / Operator conference is a GREAT idea but we must ensure the right people attend! As you know the biggest operator of the aircraft in the world do not own the aircraft directly, but lease them off an inhouse third party who have no expertise whatever in operating the aircraft at the coal face. No doubt it will be them who get the invite, and if past experience is to be believed will not think about canvasing opinion of the pilots and engineers prior to turning up in Vallencia!!!!!!

Red, for what it is worth here is my top ten. I have tried to put them in some sort of order of importance but I am sure others would order them differently.

1. AVAD - it seems to me the hardware for the system is already there! As well as producing a MIN warning when going through the decision height bug, surely the software should be capable of it triggering a "check height" warning aswell?!!

2. Aural warning regrade caption on CAS - Agusta have produced enough warnings on the CAS but seemed to have ignored this one! At least make it a guarded switch like the others on the MISC panel.

3. "Gear Up" warning triggered by an airspeed switch. I would have thought that this could once again be done through software modification.

4. Searchlight location.

5. Radar software compatible with the aircraft TCAS.

6. Independent DME display on PFD.

7. Seats that move independently forward / aft, and up / down.

8. Totally seperate power supply for the standby ADI.

9. Glide slope info on HSI.

10. FMS suited to the roles the aircraft is being sold into;
i) Search patterns for SAR
ii) Auto flyovers for offshore shuttles
iii) Fuel to nearset Kg on progress page rather than right at the back of the FMS in the engineering Data.

Looking at this it seems six out of ten of the above faults could be software related - Significant??

As an asside I wonder if anyone can explain to me why the CAT B WAT graphs indicate an increase in weight with decrease in windspeed at altitude. My limited knowledge thought that it should be the other way around, but I am waiting to be corrected. After all the graphs have been certified and therefore must be correct. It could be another one like Reds anomoly with airspeed at height placard.

[speds]

Pitchlink

7. Seats that move independently forward / aft, and up / down.

The fully adjustable pilot seats on your wish list are available as an option. I think it is around an additional Euros 9000 each seat.

As an asside I wonder if anyone can explain to me why the CAT B WAT graphs indicate an increase in weight with decrease in windspeed at altitude.

What you describe as "an increase in weight with a decrease in windspeed at altitude" is a misinterpretation of the way in which a weight penalty is imposed for operating cross-wind or downwind at altitude.

The chart title actually states that this is the WAT for TAKE-OFF, LANDING and IGE MANOEUVRES with a RELATIVE WIND AZIMUTH 10 to 350 deg ie wind from 10° right of the nose clockwise through to 10° left of the nose. ie The chart accounts for out of wind manoeuvres.


There is an important NOTE on the CAT B WAT Chart which says: "no windspeed limitation exists for headwind conditions (wind azimuth +10 deg) Check your QRH and RFM revision state if you cannot find this statement.

Therefore as long as you are into wind you do not have to apply the weight penalty ie you can use the "20 KTAS and BELOW" line even in a 45 KIAS headwind and do not suffer a weight penalty.

Hope this makes the graph clearer.

speds

[Geoffersincornwall]

Red

Red

Ref the Vent Limitation - Must have missed that one and not one of my trainers or colleagues has ever mentioned it so it needs some homework to find out the whys and wherefores before I comment further.

VNe - I have an electronic copy of the placard but cannot paste it here. What's the query?


Pitchlink

Conference Reps - start agitating now for adequate representation but make sure you are well informed. Example - you don't like the 'cheap' pilot seats but better (more expensive) ones are available well that's down to adequate comms between he who draws up the spec, he who pays the bill and he who has to sit in it. Not an OEM problem. There are other grumbles that are in similar vein. If you buy the wrong kit that's down to you.

Software changes are something that sound very simple but they cost a lot of money so are you prepared to pay? Many good ideas from the two of you but I fear you will have to wait for the 'B' model - unless you have deep pockets and can force the issue with a bit of cash. The lessons learnt MUST make it to the 'B' model (if and when it's made, bearing in mind there is a long queue for this current one) so keep the list and bang them on the table at the Operators Conference.

Meanwhile I'll tell anyone I bump in to that the Operator's Conference should include end users (pilots and engineers) not just bean-counters and their suits.

DME - Yes, a real dogs dinner and I cannot believe that this system has been approved. All that MFD space and software telling how the Wx Radar is set up and no space for a constant read out of at least one DME.

G

[RedWhite&Blue]

VNE Placard

Geoff

I don't have a photographic memory, but I think the relationship between the limitated KIAS and density altitude breaks down between 6000ft and 10000ft if I remember correctly. Look at the 8000ft column.

I just wondered if this was a Fractional Undulating Compressability Konstant - Under Pressure effect or not?

ATB

Red

[Geoffersincornwall]

Red

It looks like the 8000 and 10000 ft columns have been transposed. I'll try to find out WIHIH. Think it was a Certifiable Operational Compressibility Knot-UP.

Ref the Vent Issue - In my view the start-up regime is equivalent to MPOG but the Vent selection is missing from the normal start checklist in the RFM but included in the 'Quick-Start Checklist' where you are invited to select the vent 'as required'. Inconsistent and unhelpful would be my observation. I'll follow it up.

G

[rjsquirrel]

Pitchlink asked, "As an asside I wonder if anyone can explain to me why the CAT B WAT graphs indicate an increase in weight with decrease in windspeed at altitude."

This is the way you are allowed to load the helo beyond the tail rotor's control range - expressed by the way you lose crosswind capability when you load up higher. At the higher weight you use more main torque - more torque than the tail rotor can handle. That is why the allowable crosswind is reduced to nil at the higher WAT curve weight - above the lower weight limit, you will lose yaw control if you try to land hover or take off.

Nice, huh? Sort of a great way to make an LTE event, and get to blame the pilot while publishing capability that is bought by challenging the pilot beyond reason, IMHO.

[RedWhite&Blue]

Oh Sock

And I thought those clever designers had discovered a new atmospheric phenomenon. What's more I thought they had dicovered the link I needed, the final piece in the jigsaw to prove that Global Warming was caused by wind turbines and not aircraft (cause and effect - more turbines = more ice shelf melting). Oh well back to the drawing board on that one.

Seriously now, I guess we can safely say that all that is certified is not necessarily perfect. So, I ask again, why - in simple terms - is it safe to arm the floats at 155 kts?

If we were told that the system was inhibited by the ADCs at above say Vy, corroborated by the air data from the FMS and/or maybe limited by the rad alt to say below 500ft then I might be more relaxed. But, no one is saying anything. Just that it is brilliant and everyone should do it this way. Convince me, resolve my 'misconception' someone please.

One other thing, Geoffers. It seems that there are very few well ‘informed’ people who could go to this conference. This thing is so new and so complex that I think people, from all walks, will have to learn as they go. If they don’t know they have the cheap seats (and Pitchlink does, his bottom has told him a thousand times) then so what? I guess, in time, as all the misconceptions and misunderstandings are ironed out a few people will become Yodas. The process just needs to get moving.

Yodas, more it is that we need - the wisdom amoungst the Agusta Jedi to spread. Overcome the Sikorskiis and Eurokopts we will.

ATB

Red

[Geoffersincornwall]

Red

Seriously now, I guess we can safely say that all that is certified is not necessarily perfect. So, I ask again, why - in simple terms - is it safe to arm the floats at 155 kts?

Could possibly be for the same reason the blades don't fall off, the wheels don't fall off and the windows don't fall out...oh no I'd better not use that one. But seriously, the float system logic circuits must be pretty good and, at least in theory, 100% reliable. None has failed thus far so why the apprehension? You are reading across other electrical failures and computer glitches that are unrelated and irrelevant. The inadvertant inflation was almost certainly down to the test circuit on one ship malfunctioning. Nothing to do with the activation circuit.

You know that a blade failed on a 76 a while back but we were told by those that are supposed to know that no fleetwide grounding was necessary and we just got on with it. I could list the same type of story about Dauphin fenestrons, 332 gearboxes, 332 controls, S92 Tail Rotors. None of these incidents stopped the pilots getting into their machines the next day and getting on with the job....... and these were real-live incidents.

So now - with no evidence you want to compromise the very basic principles of having an automatic system.

If an uncommanded inflation occurs in the cruise ever happens then you would be entitled totake action but not I suggest on mere inuendo and ill-informed heresay.

In the old days we used to say that chopper drivers were born pessimists and that if something had not yet failed then it was about to. Without being complacent I think we have moved on a bit since then.

G

[TomBola]

It's interesting that in Africa's most populous nation, and one which has enormous onshore and offshore gas reserves there are only 2 serviceable civil AW139s and one unserviceable one and most of the flying they do is over a relatively short distance carrying around the same payload as an S76 or Bell 412 which cost considerably less. An idea why there aren't more?

[spinwing]

Geoffers .......

....."In the old days we used to say that chopper drivers were born pessimists and that if something had not yet failed then it was about to. Without being complacent I think we have moved on a bit since then."

Are you really sure about this?????

[RedWhite&Blue]

the float system logic circuits must be pretty good and, at least in theory, 100% reliable

Why?

Geoffers, the VNE placard is in theory 100% reliable; in fact it looks like we can report that it has failed in flight on every machine, on every flight. The consequences of its failure have so far been benign. If we decide to apply prudence/logic then all good and well.

So mistakes happen, both from a OEMs and Aircrew point of view.

I accept that there are occasions that crews go to disarm floats on deck, to find that they were never armed in the first place.

This is a problem that must be addressed. But the solution must 'fail to safe'. A solution that in it's design might deploy in a flight regime that will probably kill is no solution at all.

Now, in the overall context of the AB/AW139 I’m but a small rotary knob which compresses the pilot seat cushion, but that's how I think about this system when I strap a 139 to my back. And, I can tell you I’m not alone on this one. We still have no solid explanation as to why the system is fail safe.

It is the basic concept that people don’t like, not solely that there were uncommanded deployments (pre start) one airframe, for one reason (maybe) or another.

In the same light crews have found themselves about to land with the gear up. Should we fly with the gear down at all times, just in case we forget it? Maybe we should have and automatic gear extension system or maybe have it down when feet dry and raise it when we are feet wet.

Maybe we should have auto RPM select too. Actually why not? ‘AutoRPM’. Just press the CAT A button on the collective, to let the computers know what you intend, and the machine does the rest as you accel and decel through Vy. Has the limitation for CAT A ops to be flown by the RHP only been reviewed. Here’s a solution.

Geoffer, as you can see I’m not yet convinced. Will someone please show me the light?

ATB

Red

PS. The emergency check list requires me to confirm that the floats have deployed, once on the water, before lowering the collective completely, and if not blow them with the guarded switch on the collective. Why? This is a system that is 100% reliable. That’s a given so we're told. There is no chance of it failing is there? Well yes 100%, in theory, well we think – no we’re sure, I guess… uhh… aren’t we?

[212man]

In the same light crews have found themselves about to land with the gear up. Should we fly with the gear down at all times, just in case we forget it? Maybe we should have and automatic gear extension system or maybe have it down when feet dry and raise it when we are feet wet.

Would it be too radical a suggestion that they use their checklist?

[RedWhite&Blue]

212man

Would it be too radical a suggestion that they use their checklist?

No of course not. But...

As Geoff quite rightly points out sometimes things do get forgotten normally, when attention is focused elsewhere for what ever reason.

We are mostly human beings and humans make mistakes. Hand on heart have you never had a Phewwww moment? So please forgive my sarcasm over the landing gear argument.

In the UK the floats are both finals and after take off check list items. The company has chosen to supersede the OEM's normal procedure with its own. And, of course the crews use the checklist.

This defeats the OEMs objective of eliminating the 'human' factor should the floats be needed. But of course there is the perceived downside to their procedure.

I have just had a quick look through the material I was given when I did the type rating. Not a word about the floats. Other options like the WX Radars and heater yes, but not floats. So here, maybe lies the problem. I guess I have not been fully educated as to the finer points of the system, so don’t really trust it not to deploy at 155kts (this is in the context of being forbidden to arm the floats above Vy ish speeds on both AS332 and S76).

I guess if I had been on the factory course this would not be the case.

At the moment, as is clear, I'm with those that chose to supercede the SOP and I will use the checklist, as always.

But, I'm open to persuasion.

ATB
Red

[212man]

Clearly we are all prone to errors, as humans. That's why the use of a well designed checklist is so important - precisely to catch items missed. NASA refer to them as 'killer' items : a little melodramatic perhaps but meant to emphasise that what's in a checklist should be important and other stuff should be left to SOP.

Regarding the floats, what speed have they been certified to for deployment? There have been floatation systems around for a while now, that are armed in th e cruise. Bristow introduced them for the 332 about 10 years ago. The EC-225 floats are armed in the cruise, as will the EC-175 ones. I would have thought it would be essential that the manufacturer demonstrates deployment at whatever arming speed they choose to nominate, and ceratinly AC29-2C implies this.

[RedWhite&Blue]

212man

the 139 floats are deployed on contact with the water ie not in flight. Agusta's SOP says they should be armed as you coast out, and disarmed coasting in again. I guess any speed under VNe/VNo.

If they have been deployed at cruise speed for demonstration purposes, with no 'ill effects' then... happiness! And, Geoffers wins this little debate.

This is the crux of the matter for the uninformed, who fear that things would become a little exciting under such circumstances, because they are unaware of the results of such a test. If Agusta have a real probllem with this operator's revised SOP then they need to knowlege share pdq.

As the floats are certified then surely we can assume the AC29-2C, that you mention, has been complied with. Or is assumption the mother of all "Certifiable Operational Compressibility Knot-UP[s]"?

Geoffers, I take your point.

Could possibly be for the same reason the blades don't fall off, the wheels don't fall off and the windows don't fall out.

The inertia may simply because on the machines we have been flying, prior to the introduction of the 139, don't tend to shed blades or have the wheels fall off. Although there has been at least one inadvertant/uncommanded deployment of the floats while airbourne. It has been drummed home that you don't fly around willy nilly with the floats armed.

In most other areas the 139 is no different to that which we are more familiar with. So we don't question the more 'normal' aspects. Well not so much.


ATB

Red

[Geoffersincornwall]

Red et al

The good news is that we are making headway in at least one area - ventilation! The background was made clear in a quote receive today.

This is a JAA limitation. JAR 29.831 (ventilations) wants at least 0.3m3/min of air for crew member. The only way to respond to the JAR while on ground or in hover is to do what we wrote in the RFM.

Still some work to do to fully understand the reasons behind the need for ventilation and the 'acceptable means of compliance' chosen by AW. I will try to get some more info.

The ongoing debate about floats is a testament to the price paid by our community for inadequate disemmenation of information. I have been reluctant to be too bold about my support for the AW approach to the problem because I have to admit that until recently I was one of the old school and armed my floats when I got into the OEI 'zone'. When I sat down and thought it through I began to realise that my attempts to manage the situation according to my rules were self-defeating.

Of course anything can go wrong at any time and in the first 30 years of my career I lost 30 close colleagues to a variety of incidents including one who died, along with his son, for want of a quarter-inch nut. In our world we trust the designers and makers of our trusty steeds because if we didn't we wouldn't get off the ground. We base our own qualitative assessment of each machine on experience, rumour and sometimes heresay on Pprune. We then have a choice about following the manufacturer's advice or not, the Ops Manual advice or not. We all know what we should do but in the end we may choose to follow the lead of someone or some organisation that has not taken the trouble to find out why things are the way they are before blithely accepting that because it looks like a duck, quacks like a duck and swims like a duck it must be a bloody duck!! But it isn't - its a blooming swan.

If I had been the Ops Director signing of a potential 'killer' change to my Ops Manual I would have jumped on a 50 quid return flight to Milan Malpensa, paid the 50 euro taxi ride to Vergiate and spoken to the horses mouth. Of course, sitting on my right hand all the way would be my Tech Director (damn the expense) because I'm just a dumb jockey and couldn't tell a wiring diagram from a London Underground Map. Then and only then would I have casually said 'eh-up lads, it's just another chopper - lets do it like we did on the old one'. WHY THE HELL DO YOU THINK WE WENT TO ALL THE BOTHER OF DESIGNING THIS B****Y swept up system ??????????????

G





STOP PRESS - this just in

Vne PLACARD
Believe it or not there is no mistake!

For JAR certification, the windscreens had to be proven able to withstand a birdstrike at up to 8000ft PA at up to ISA+35°C (Note Bene UP TO 8000ft Hp)
With the glass windscreens (17mm thick and 45kgs each) there was no problem but the acrylic windscreens are not so robust and failed the tests at lower airspeeds hence the dip in Vne on the placard at 8000ft.
Above 8000ft there is no certification requirement to provide protection against birdstrike and the limiting airspeed is again determined by all other aerodynamic factors.

You have to go to Figure 1-5 on Page 1-11 of the RFM and look for the area of the chart maked with a dash and two dots thus _.._.._.._ This area goes up to 12000ft Hd which is equivalent to 8000ft Hp and +34°C (or ISA +35°C)

[speds]

RW&B

When you said

Although there has been at least one inadvertant/uncommanded deployment of the floats while airbourne.

Are you implying this happened in an AW139? If so what is your evidence?

I believe that both the inadvertant float deployments occurred on the ground. They were both in the same aircraft (while at different bases). They both happened when the pilot pressed the TEST BUTTON with the FLOATS ARMED. The aircraft was one of the first delivered and is now approaching 2500hrs. It regularly flys to the rigs and since the last incident when the cause of the deployment was determined and rectified by the gingerbeers, it has never misbehaved again.

If any one knows of any other incident of an inadvertant float deployment on an AW139 I think we should know the facts. But please don't embellish a rumour to fit your mindset.

speds

[RedWhite&Blue]

Well done Geoff!

Vne Placard - Well there's a suprise, it wasn't either the Fractional Undulating Compressability Konstant - Under Pressure effect or Certifiable Operational Compressibility Knot-UP.

Thank god we have you to ask the right people. I guess without this debate we would have all been none the wiser for ever and a day. Much appreciated.

The ventilation thing is interesting too. At least we know.

Floats... I submit!!! What the hell I do on my next line check? I think the answer to that is to tell the check pilot that you said I should not "choose to follow the lead of someone or some organisation that has not taken the trouble to find out why things are the way they are before blithely accepting that because it looks like a duck, quacks like a duck and swims like a duck it must be a bloody duck!!"

That should do it. Can't fail.

I'll duck out now, or swan off and leave you in peace.

So, untill the next time...

Oh just one other thing cold you ask your guys when will we have CAT A 'AutoRPM'?

ATB

Red

PS Speds, no don't worry not a 139. I know the machine you refer to well, and yes, you are right it's floats system has not misbehaved since.

[pitchlink]

One last input on the float debate; Why is it that it has an amber caution on the CAS and not a green advisory as I would expect for a system which is OK to be armed for the majority of the time? The search light is green, heater, landing light, brakes etc..........., it seems the logic is flawed somewhere?

[speds]

Pitchlink - Cautions and Advisories

All armed systems are Cautions.
Tried arming the Hook?

The Caution is there to tell you that if you press the appropriate button with the Caution on, a significant event will happen.

Is that flawed logic?

speds