Educated guess at an empty weight of 1860kg, calculated from SPIFR with other (but similar weight) kit in place of left seat PFD/ND screens & second sticks.

What's a winch & floats? Say 140kg?, plus 200kg for pilots & kit - so 2200 for cash ZFW. 1:30 to 1:45 endurance from arrival at first winch job, if Droopy's calculations are OK'd by CAA! :ok:

Description of Autotrim in EC-135
 

Can someone please pm me to discuss how the autotrim in the EC-135 works?
Either that or point me to somewhere that describes how it works?

Sent to PM

Shawn it's all witch craft.:}

Rotordompteur is the man with the knowledge in regards to operating 135 on windturbines.

My read.................A/TRIM

It trims the cyclic. Unlike older autopilots which just referenced themselves via the actuators against the force trim brakes until the actuators saturated (ran out of movement) the APM 2000 will reposition the cyclic via the Trim Actuators (which have an RVDT inside to tell the AP where they are.:p)

The Trim Actuators (parallel actuator) when in SAS/AP-SAS will re-trim the cyclic via the 4 way beep switch or release while centreing the EHA's and SEMA's when you push the FTR. When in UPPER modes of the AP the 4 way trim will change the coupled modes, L/R for HEADING, Fore/Aft (Up/Down?) for ALT, IAS, V/S as appropriate and the AP will re-trim as/if required. The A/TRIM warning serves also to tell you that there is something amiss with the upper modes and the AP is not AP - ing and you should fly it hands on.

It is not very noticeable. Most prevalent trim movement is if you couple ALT and change a big chunk of power. You will see the cyclic move. GA will make it move a fair bit as well depending on software and speed at the time.

The AP in the 135 is a bit of a mess in some ways. The SEMA's (series actuator) were installed because the EHA's (yet another series actuator) are prone to drifting over time. So you have the "basic" SAS with analog computer and EHA's then Autopilot over the top also doing SAS at a better job with EHA's with analog SAS as redundancy and then Autopilot UPPER modes with SEMA's.

SEMA - Smart Electro Mechanical Actuator
EHA - Electro Hydraulic Actuator

When you "decouple" the cyclic is always in a "trimmed" position. Saves you having to keep an eye on the "galvanometers" to see if they are reaching the stops and having to centre them by pushing the FT release.

The YAW "trim" is indicated on the PFD. Push the corresponding pedal! Takes a while to get used to as the aircraft flies left hand down and about half a ball out of trim in the cruise. Thats why your STBY AH is in the panel on a funny angle!

P.S. WTF is a BACON Relay?

Isn't that a part of the most complex equipment of every aircraft ? Relay between the airframe and 'labyrinthus membranaceus' . Latin name: 'nates' ?

You know... the thing you sit on.

RVDT,

So there is a reason for it after all! I had been wondering why they all seemed to be squinty.. :O

Thanks for the info on autotrim. From what I can gather it only works if the attitude mode and autopilot is engaged? Is that correct?
What happens in the cruise if the pilot pushes and holds the stick away from the initial 'trim' posiition?

Shawn, yes to the first question. To the second:- at speed it acts just like any other system in that the attitude and cyclic will return to datum as long as the trim release or beep trim have not been used. Below 40kt however the datum effectively follows cyclic displacement without you having to re-trim. It is however 18 months since I was current so would stand corrected.

Shawn,

1st - As long as the autopilot is ON you are in ATT mode. OFF you are in analog SAS. The A/TRIM switch and the light within and WARNING indication are to advise of a problem within the A/P.

2nd - If you push the stick it will NOT automatically trim. Let go of the stick and it will go back to the previous attitude. If you push the stick and press FTR or TRIM via the 4 way switch it will trim accordingly. In UPPER mode if you OVERRIDE ALT,IAS,GA,V/S,ALT.A,G/S or LOC you will get a warning indication on the PFD caption for the respective mode.

Now there are a few pitfalls, Google G-SPAU and G-IWRC accidents.

One thing I am not so sure of is the removal of the GONG and warning indication with A/P DECOUPLE in the latest software version. It served 2 purposes, it let you know if the A/P decoupled intentionally or NOT!

The issue with G-SPAU has been addressed in later software as the bug does not default to "N" any longer on startup.

A small point but the "HEADING" control should be on the ICP with a knob to turn it and push the knob to centre it. Same as the COURSE button. The AP controller should just have an engage pushbutton for heading - a la A109.

As I said before the AP on the 135 is a bit of a kludge.

Too many little things to be effected by heat, vibration etc etc..................
Although it is getting better slowly.

Bladecrack - the squint in the FCDS is in the AHRU!

Shawn,
I'm sure RVDT will correct me if I'm wrong, but making the assumption the EC-155 and EC-135 systems are essentially similar when in basic ATT mode (ignoring Upper Mode engagement) I think you are possibly misinterpreting the meaning of Auto Trim. The Auto Trim basically means the AP is operating in Attitude mode, and that Auto-trimming will take place to ensure continuous series actuator (SEMA) centralisation, and control movement to maintain Attitude datums - particularly noticeable with the heading holding (not HDG Hold.)

There are two basic modes of operation - Follow up trim, which ECF call 'Tactical Mode' and a conventional mode, which ECF call 'cruise mode.'

The follow up trim operates below 40 KIAS, and allows the pilot to push against the cyclic and the AP will re-datum to the new attitude. There is obviously hysteresis built into the transition, such that on departure the AP will have reverted to cruise mode BY 40 KIAS, and on deceleration the AP starts to transition back to 'Tac' mode at 40 KIAS and has fully reverted BY 30 KIAS, to give a seamless feel to the pilot. In 'Tac' mode it's a bit like the SFENA system found on some Bell 212s.

In 'tac' mode the AP respects heading hold at all times (if the pedal micro-switches are released) whereas in cruise mode it is roll dependant, and varies between heading hold and turn co-ordination. In cruise mode the cyclic behaves as with any other ATT system, when displaced.

The Cyclic and Yaw Auto Trim functions can be de-selected independantly using the APMS (Auto Pilot Mode Select) panel, which could be quite useful in the event of a trim runwaway - the pilot can retain the remaining AP functions whilst deselecting the relevant channel. (By comparison, if I have a yaw trim problem in the S-92 and deselect it, the whol AFCS goes into SAS mode and I have no coupled functions at all. In the 155, I could take out Yaw A.Trim and keep ALT, IAS and NAV coupling and just use my feet to keep trimmed in yaw. Anyway, don't get me started.....)

With the 155, the transition during the departure is programed to not only adopt cruise mode, but to alter the nose down attitude to that required for a Vy climb - so the pilot sets 10 degrees nose down in the hover, the AP trims to that datum, the aircraft accelerates and as it passes 40 KIAS the nose starts to rise and adopts an 80 KIAS climb attitude. I understand it's part of an intention ECF had for a fully automated Cat A take off. Still requires a bit of cyclic beep in roll, though, otherwise you end up in a climbing turn!

I sincerely hope that this is not 'duff gen' in relation to the 135, and should it prove so I will delete the relevant portions- the limited 135 info I have, though, (conversion notes from a large UK onshore operator) suggests the systems are near identical.

Thanks guys - it's as I expected. I just wanted to make sure. I'll read the two accident reports with interest!

Well flog me with a warm lettuce...................... (P.Keating one time Prime Minister of Australia.)

As 212 man sez.......................

The 135 does Auto Trim (follow up) below 40 knots. Just tried it. It is not very fast but works fine.

The RFM Supplement doesn't mention it and it is not in the AMM Systems Description. Although I am sure it is in the MM for the AP.

There is evidently an APM 2000 Pilot's Manual for the EC135. Never seen one and it does mention in the RFM Supplement that "Section 4.2 Operation - The sequence of AFCS mode shown within is not mandatory." :confused:

You might want to go back to your TRTO and suggest they expand the detail in their briefings and ground school notes! It's a pretty fundamental aspect of the aircraft's handling :ok:

In the USA? What's a type rating?

Was pretty much skimmed over on the frame course in Donauworth as well.

I will enquire with SAGEM on getting an APM 2000 Operators manual and find out whether it is "approved" documentation.

RVDT:
If you are able to get a copy of this manual, and the terms permit it, could you post it where others can get it?

RVDT, I don't think you will find an operator's manual, as the functionality is installation specific. There is, however, a CMM ( Componant Maintenance Manual) which should be part of the maintenance manual CD that comes with the aircraft. Also, the SDS should add some meat.

Shawn, 212 man,

I have put in a request to SAGEM and going on past experience should have a reply within 6 months. :rolleyes:

212,

I have dredged the SDS and it is very vague about the A/TRIM function. It is referred to variously between Attitude Trim and Automatic Trim depending on which document you are reading. No mention of the change in mode with speed as quoted by 212 man although it is there. I think it is a case of "who knew?"

As there is nothing in the published documentation that is required to operate and maintain the thing, how would you?

There is no Chapter 22 in the EC135 ECMM. There is an SDS description in the AMM but is very vague and I can't find anything about it.

The RFM Supplement 9.2-48 OPERATION 4.2.2 Takeoff and Climbout

NOTE: If unsymmetrical stick forces occur during hover, press FTR switch briefly.

This is the way I have been operating it for ~250 hours.

Might drop a line to my maulwürfe in ECD. :p

Quick Question: If i want to fly the aircraft without anycyclic augmentation system of follow trim...basically the same as with the FTR permanently depressed, what cb do i pull and is there any rule against it?...for instructional reasons before you ask!!

i.e You mean if the FTR switch was stuck "closed".

You cannot simulate this as the clutches require electrical power to open. If the switch was stuck closed which is highly unlikely as there are two sets of contacts both of which would have to be stuck.

Hardly a difficult situation. Like flying a B206 - yawn.

"If" it did happen - Pull CB "ATT TRIM REL" Overhead panel 12VE Breaker 7CC 1 Amp driven off PP10E Bus.

Is it illegal - most probably.

Didnt say it was a difficult situation... for demo purposes. Any idea why it would be illegal?

Is there no cyclic trim switch on the overhead panel?

Been a while since I was current on the EC135 but from memory I thought you could switch off A TRIM using the switch in the top left corner of the photo.

http://i189.photobucket.com/albums/z.../ATrimcopy.jpg

212 Man is correct about the CB, only way to fly without trim is to keep your thumb on the FTR.

FNW

FNW, I think you mistook my question - in the 155 there is a switch on the overhead panel that turns off the cyclic trim 'mag-brake' to give you a 'floppy stick' (ooh er missus, to pre-empt any comment!). This is equivelant to holding in the FTR button, but without the force required. Turning off the auto Tri
will just mean you can't engage any upper modes that use the cyclic, and the SEMAs may saturate and require cyclic position to be re-datumned to centralise them. But that's the 155 a the 135 may not have such a switch. I'd be surprised if the autotrim cb would yield this outcome.

212man,

There is no switch in the 135 to turn off the "force trim".
This may be helpful.


http://img90.imageshack.us/img90/5377/ftrjb4.png

No switch for force trim
 

Very convenient when you fly with the P/R sas inop for 7 days. Sure wish I could just turn it off and hand fly it. UUGH!

We've had an awful lot of inverter captions lately(t2+), engineers think it's due to the cold which made me wonder how you chaps in Norway or Austria get on. It's very intermittant and as far as my experience goes, completely unpredictable. Anyone else?
Rick

FYI,

The latest FMS 9.2-48 AFCS. Third Issue 18.02.2008.

http://img100.imageshack.us/img100/4158/fms9248my1.png

CyclicRick - don't know how cold it's been with you but, I imagine, colder than our infrequent -5 deg, which we think is "cold"; but I've not seen an inverter caption, in same type, in over 5 years. :ok:

Hi,
has anybody of you any experiance to operate an EC135 for pax charter operations?

More questions arising...

Radioaltimeter on EC135. I can't seem to find it in the supplement section of FLM to find answers to my questions. We fly NVG and from time to time rely on radioaltimeter for operational usage. I've noticed that the system does not detect trees or rough terrain. For example as we fly over trees the relative height indicated is not to the tree tops but mostly to the ground. That could be a 100ft difference when we would already be scraping the tree tops. I'm not use to having this problem on our older models (212, 412). I was told from our engineers that bell uses first radar echo as a indicator of height no matter how small the surface under the radar is. As EC135 has a logic of average surface area from echo. For example if a tree is right under the radio altimeter and the ground is a 100 below, the system will due to trees smaller surface average out the tree to a few feet only thus showing slightly less height than the height to the ground is.

Any clue or literature on that EC135 radio altimeter logic?



Second question is also the kind that I could not find in any manual. I know that I could access inflight EPC resoults from maintenance menu but I can't seem to do that now. I follow the procedure published in training manual but the inflight EPc resoult menu is empty when the system asks me for the flight number. I'm not sure if the EPC inflight tests are done regulary as we have 8 pilots flying one helicopter. I know that the flight report only shows the data for last 30 flights from maintenance menu. Is that the case with EPC menu also?

Thank you!

Radalt--Don't know

EPC results, if they're not in there, they are probably not being done, simple solution, do one yourself, then check once you've landed to see whether it's there!!

Our results seem to store correctly

Rad Alt - Bendix King KRA 405

Normally pretty accurate (<1m ≤ 200m Rad Alt).

The issue of course is the density or variation of the trees below you. Would you like it to indicate the height of each tree you have just passed over? The antennas are on the tailboom after all, it doesn't look forward. If the trees were ~ 100' each I guess as the indication would be wildly fluctuating you would assume that you were over trees! Having used them for geophysical work and from memory at a cover of >50% they would read the distance to the tree tops. That information was "smoothed" in the indicator to the pilot. The raw data which was recorded was all over the place and was smoothed in the data post processing. As opposed to your requirement we actually wanted to know where the ground was so estimated the tree height and flew at a lower Rad Alt accordingly until passing the trees. There is obviously a damping algorithm but who knows what it is. I would guess that it is probably the same as your old Bell was. Sounds like you are pretty low on NVG's in uncharted territory and relying on data that can be "incorrect". Rather you than me.

If you have some time on your hands you may be abe to work it out from here - TSO C87

As for the EPC - see the previous. Only so many kept "on file". An EPC trend is required if you operate "Cat A" - see RFM Supplement. Be aware EPC data, ECD Ground Power Check, and engine manufacturers data/method may vary. You cannot mix the 3. ECD EPC data is acquired at 2 x 60% Q at S & L. ECD Ground Power Check done using airframe data and "eyeball" with one engine in idle. Engine Manufacturer check normally on the ground with one engine in idle and acquired by ground based software using EEC parameters. See RFM Section 5.

It's not so much of uncharted territory as to unusual of being relatively lower than the RA would show. Colegues had the problem I described, but I've also noticed this before; during confined area T/O-LDG as the RA didn't catch any of the trees that we have flown over during departure.
Our pilots are aware of this "misleading" reading and we take some safety altitude with it.


I'll perform an EPC test today. We perform checks as per manual at every 100HRS for CAT A and we are some 50 HRS from that check, no wonder it isn't in the memory any more.

Thank you! :ok:

From a couple of pages back....

Boolean Autopilot CONnected, logical signal

Hi all,

back to the same over and over again!

Gentlemen, the EC135 is on order and we are getting real close to freeze the ordersheet.

We are aiming for the lightest possible configuration (still needs to be dual/single IFR), but in our environment we are a little limited with IFR infrastructure, so we are aiming to delete what we cannot use.

One fundamental question is still engine choice.
All the fleet is Turbomeca (...ok we have one lonely Bell206), but the question still is if Pratt's would be the better selection or not!

I saw the post about EC135s in Asia (pref. PW).
Our application is hot & humid, sea level to max 12.500 ft (highest elevation in the country .....)
The P&W wins with some 20+ hp better power in some situations, but the question is what is preferable overall in our specific environment.

So, if you guys/gals (mechanics/engineers) have any experience with the EC135 in similar conditions, please advice or let me know where this was already posted!


THanx!

3top:cool:

3top,

I hope you haven't deleted the air con in the weight saving exercise? Life in a hot and humid environment would be unbearable without it! The 135 is a hot, stuffy aircraft even in a British summer.

FNW

Thanx Guys!!

On the A/C I will try to push the Aircomm unit - least weight and best performance, no trouble!

Good point on the "guaranteed" weight - will definitely recommend this to the boss!!

Eddie1, is there anything specific pro/con P&W?
I mean start-up issues is a good one anyhow and maintenance/spares too.
However we probably will go with the power per hour program, so spares may be out of the equation.

I know the Arrius only from the EC120 and it does have a few issues there, but the donks in the 135 are different models....


Thanx again, ....and keep it coming!


3top:cool:

When I was in Donauworth for EC135 type rating I was told that PW compared to TM had a 1:10 FADEC failure ratio (partial or complete failure). I don't know if Turbomeca did anything on their systems to correct the problem since then.

EC135 does not have a particle separator. It has a sand filter system. We have a sand filter in our storage, but we really didn't use it for the last 550hrs. Depends on your enviroment. I saw saudi arabia using it, german army had it on, but removed it.

If you are intending to use your 135 in a cold enviroment, consider PW as it has fuel/oil heat exchanger.

Spot on on the dirty tail boom. PW's are really smoking. We have a metalic blue on the tailboom and you can hardly see any difference up until 50-70hrs unless you really look up close.