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It says connected but not switched on. Also repeated in the Thales service information letter.

Nick

Presumably airframe manufacturers get data on engine life expectancy from the engine manufacturers, based on empirical research including actual destructive testing, from which the acft manufacturer, along with authorities, establish lifespans based on the relevant spectrum.

Out of academic interest, about how long would an engine statistically last before it would fail at say the 2min 30sec OEI limits? Just interested to know what sort of approx % reserve you guys work to.

What about tranmissions? If there is a 5 minute take off limit of say 100% Tq, what sort of Tq would you expect the MGBX to typically actually catastrophically fail at?

Head Turner, 407 and rotorspeed,
You have all shown that you really understand the concept, and all your questions are valid. The problem is that the current regulations that we work to were made before it was realistic to be able to determine the actual usage so they froze the state of the art back in the 1950's. Changing the regs is a massive effort that requires a series of civil servants to stick their necks out and advocate change is a more liberal direction - after all, today's system works, so why risk my career messing with it? Remember, the CAA/FAA/JAA don't spend 5 cents operating anything, right, so there is no advantage to changing anything.

Look for a new presentation on my web site discussing this, maybe today!

Nick, do you have the link to your website? The only one I have is the old s92heliport.com one. Thanks.

Those having problems with the electrics (EMB)must be mechanically lacking because my question is;- Why would anyone need to start an engine without a battery fitted and connected?
I come to this conclusion from the information given above. Connecting a GPU for power to operate the electrical equipment to lessen the drain on the battery during ground training is understandable, but using a GPU for a start without a fitted battery doesn't seem logical to me.

Head turner:
there is a little lost in the translation between ECD and us ignorant anglofiles!
The battery being physically connected to the electrics system is taken for granted. It is installed and electrically in series with the looming!
Where the confusion came in was whether the alert letter (when it stated battery must be connected) meant the battery must be swithced ON.

I have talked to ECD personally and they say:

Physically plug the external power supply into the a/c first,
THEN switch the BMS on,
THEN switch the ext pwr on.

The battery is there to act as a buffer.

Many Thanks TC for the clarity of your information. I have done it as you explained, which is the system in most aircraft.

One further point on the 24v issue.

I have seen the voltage drop from 25.4v to 24v during the time it takes to complete the cockpit pre start checks, once the voltage dropped to 20 volts and the GPU was connected, then switched on for the start.

Surely the minumum voltage for starting ought to be stated both in the Limitations section and in the pre start check list prior to putting engine switch to ground idle.

And instructions for disconnecting the GPU.

Failing any instructions we run both engines up to ground idle , with the BMS on. When both engines are stabilised at GI we disconnect the GPU, by switching off the GPU then removing the plug from the a/c.

Is anybody else confused by the logic of the EC information?

My understanding of the system, suggests that when you plug in the GPU and switch the Battery Master switch on, the battery and generators are isolated from the Primary Bus Bars to prevent any flow of current between Battery and GPU. If this is the case, how does the Battery act as a 'Buffer'.

Eurocopter also recommend that the battery is disconnected when operating with an EPU for an extended period of time.

TeeS:confused:

TeeS, that's also had me confused. As regards the extended operation, I understand that's for battery carts as opposed to mains supplied units.

Hi Droopy

The wording in the manuals suggests that it is to prevent the battery running flat since it is still supplying the Battery Master Box and the Essential Bus Bar.

TeeS

Increase in AUM EC135
 

Has anyone heard when the increase in the AUM for the EEC135 will come into effect and what will be the new weight?

I understand that it will go to 2,900 kg. No doubt TC will be able to give chapter and verse

2910 Kgs as I understand it. Due to start appearing around the middle of 2006. It will also come with a change to the "Cat A" system which will make it semi automatic......... and, apparently, it's free of charge to existing T2 owners. :D

As an aside. Change to "Cat A" was going to be automatic (allegedly!). Until some bright spark pointed out that if you are flaring a bit heavy and as your airspeed drops below the threshold the Cat A kicks in - you can watch your Nr disappear off the clock! Not a good scenario! So semi-automatic it is.

:ok: Does anybody know how to fly this thing?

Despite being a committed 135 fan, I could never come to terms with the designer insisting that at two fairly intense stages of flight (just after CDP and just prior to LDP) you take one hand off the controls, look and lean across the cockpit and firmly (if you jab it, you screw the system!) press a button on the far side of the cockpit! All in the name of safety!!

Without doubt, semi-automatic is the way to go - you know you are about to carry out a Cat A/confined procedure, then arm the system! If you are reducing speed for surveillance ops etc. at altitude then don’t bother.

Bobby, I know what you are saying about the Nr/Cat A switch, when I first converted to T2 I was very worried that an overenthusiastic flare would produce an overspeed, however, with many mishandled approaches under my belt I am now ‘reasonable confident’ that the fadec is competent enough to not throw in extra fuel when I am out of control! No doubt I will be proved wrong at some point.

Cheers

TeeS

The T2 Cat A switch seems like the familiar Eurocopter cockpit/box-office design policy - let the engineers, not the pilots, decide what goes where.

If they have the wit to put a wiper-sweep switch and an ILS go-around button where they are needed, why not do the same with the Cat A? I don't mind what they choose so long as the pilot's hands don't have to move away from their normal positions on the collective and cyclic.

Then perhaps they can start on all the other controls that need sorting... getting rid of switches in the roof would be an excellent beginning.

The gripe about the 'CAT A' is a very important and flight safety gripe which I also find hard to understand the logic of putting the switch in such an awkward position. An arming button on the left side of the collective switch box would have been a better choice.

For those who remember the tragic accident in Northern Ireland a couple of years ago which more than likely happened because of a badly sited wiper on/off switch.

There are many gripes about the MD902 but in my opinion the cockpit switch logic and layout is the best I've come across.

However, the weight increase must be eagerly awaited by all users, so EADS get your finger out!

Now, as I understand it, and I could be wrong - the cat A system is fitted only because of a noise certification issue, nothing to do with safety, its a lot of work just for 3% Nr. The 145 has an automatic Cat A and I believe works just fine.

Interesting that the upgrade will be free to T2 owners, I didn't think ECD did anything for free!

I have to agree with some of the comments about switchology on the 135, some strange ideas about where to put things.:hmm:

The increase in RRPM I understand reduces the torque (at the same rpm) and therefore gives more available power for the critical take-off and landing stages of flight. It does not make it quieter or to be complient for noise certification.

When engaged, the Cat A switch (i.e. the 3% nr increase) actually makes the aircraft noisier. The threshold at which it is deselected is due to noise abatement considerations. The combination of the higher nr combined with airspeeds in excess of 55 kts cause the EC135 noise signature to exceed the level at which the aircraft was certificated....

...at least that's what the bloke down the pub told me.

2910kg when ECD get sorted. TM all ready to make the transition. Estimated mid 2006.
T2 only, FOC. Fadec tweak and thermal limits on 2B2's extended.
Over 400 switches and c/b's in an EC135T2:(Mid life upgrade (2012) will see these reduced by half apparently. The PEUG have forwarded 47 amendments to the EC135 cockpit layout, including the sighting of the cat a switch.
Cat a switch fitted exactly as bomber ARIS stated. Unfortunately this has now knocked the T2 EC135 of the top slot for quietest light twin in europe. That honour goes to the 902 variant.
[T1 still retains top slot and now shares it with the 902].

Thanks for that ARIS but the vital info that you ought to have included was the name of the pub!

Wouldn't it be nice if ECD included a short chapter in the supplements for the FLM; which apart from giving the limits of the system, gave a brief description of what it is for :hmm:

An increase in NR for a lower torque does make more sense. I must try hovering and switching the Cat A on and seeing how much the TQ reduces (given that the AUW and wind will not change), and thereby see just how much extra power is available.

3% of hover torque power I would suggest?

TC. waiting for the phone to ring so that I can go out and try, but Hovering at 100% Nr with say 65% torque, Cat A pushed to get 103% NR, Tq decreases, but I can't see a direct correlation % for % :hmm:

I thought I remembered from the gallop through conversion that the CAT A switch boosted Nr in order to give a bit of flex for the good engine when recovering from a donk stop and subsequent Nr droop... or was I asleep and dreamt that?

I think that what we require here is a response from Eurocopter to detail exactly what the Cat A system that is installed on the T2/P2 entails therefore cutting out the guesswork/assumptions. For sure all that has been said is generally near the truth.

Just come back from harrassing innocent members of the public and the findings are as follows:

OAT +2, 135ft AMSL, wind 040/09, 2795Kg gross weight

4ft hover, without Cat A 58% Tq, with Cat A - 58% Tq

No discernable difference, Tq initially climbs when Cat A selected, but when everything has settled down, same figures on the VEMD. I didn't take the figures for N1 & TOT as they are not a limiting parameter.

Open to suggestions :confused:

T2 cat a switch
 

The cat a switch was introduced to the uk with the introduction of the 135 t2 variant and was also part of the upgrade for existing t1 models to t2 standard. The raising of the Nr during cat a operations reduces droop following engine failures which means cat a t/o weights are increased. The airspeed at which the cat a mode is deselected was driven by noise constraints ie turn off as soon as possible due to increased noise in cat a mode.

EC135 equipment wishlist
 

So hypothetically speaking a boss asks his pilot to create a wishlist of equipment for a new EC135. The aircraft would be mainly used for VIP transfers and would also be doing quite a few long distance trips. Any suggestions on what I.................I mean what the pilot, should ask for? :E

CH :cool:

Air Con......

Before you go into all the nice things to have fitted look into the possibility of getting an airframe that can accept an auxillary tank. We discovered that as our airframe was not modded for an auxillary tank, having one fitted would have meant major airframe work. 2hours 20 minutes endurance is a real hindrance for long trips. You can spend as much time on the ground refuelling as flying and it costs you landing/handling fees every time you stop. We also went for low skids as more convenient for embarking/disembarking. Small boarding lights that illuminate the skids and steps are really good. Weather radar we did not consider an advantage nor did we go for air con. Tinted sun shields and windscreen wipers are a must. As performance is a problem we fly usually with only two rear facing seats fitted and a convenient cover is fitted over the third seat fittings. No bar or other weighty fittings.
I have not included here the piloty things as the list is very long.
Try and keep your ship as light as possible. Ours weighs in at 1832.

Be wary of the extra fuel tank. The C of G is far enough back as it is. Air con is vital it can get VERY warm in the back, let alone the effects of all that perspex in the front. We normally fly with the middle seat removed. But, I realy wish we had the radar. Also buy it some pyjamas. Its' a joy to fly and the temptation is to take it home at night and cuddle it:ok:

JC Aviations aux fuel tank kit, Bruces custom covers nose bag, Engle fridge and you do already have a stereo don't you?

Hi CaptainHollywood,

don't tell me you hit the lottery again. Isn't flying a brand new EC130 more than you can ask for??? What's next? EC 225????

Why does the devil always have to take a dump on the biggest turd?:ouch::{
(Does this phrase exist in english?)

Just kidding, good luck to you CH and if you need a holiday replacement just send me a pm.:ok:

Under normal climatic conditions in the UK and Euroland air con is not normally necessary and the penalty in cost,weight and CG is something you have to consider. With air con and an aux tank there will be a aft CG problem. You will have to decide which has the greatest benefit. We would have had the aux tank had the airframe been modded at birth. We have our own solution to long ferry flights.

Captain Holywood:

How about asking for an Agusta Grand instead, then you might be able to go somewhere far away, very quickly and in comfort too!!:)

Those of you who advocate a weather radar I have to ask you why do you need this item. I cannot see an advantage in having one flying in UK and Europe as there is ground radar available which if you are receiving Radar Informantion or Radar Advisory you should be able to request rerouting assistance due to adverse weather. Or am I wrong. It might be that I don't fly in nasty thundery weather because a little EC135 is no match for the brute forces of nature in CU and CB and remember you said it was VIP and for sure your VIP will not like flying in nasty weather.