As 350 B3

[UnDies]

Gents/Ladies - with the fadec system on the B3 is it still required that one should crank when needed? I’ve been told that the Fadec takes care of everything but that’s it’s always healthy to crank a hot turbine(and I`m talking about the B3 specifically) before starting but not a necessity and, if any, what would the downside be to not cranking?

[arismount]

Haven't flown a B3 but have experience with the 2B1 installation in the B4 and it's the same. The dual-channel FADEC does indeed seem to take care of everything quite well on the starts.

I've started within 5 minutes of shutting down in temps ranging from 37C to -10C and in tailwinds without cranking, and have never noticed a problem.

Of course one should always been focused on T4 during a start and prepared to abort if there's any indication of an incipient hot start. This applies to all turbine helicopters, all the time.

However, the single most important factor in getting a good start is to have a strong battery, and using battery power to crank and reduce residual engine internal temp is a waste IMO.

If a pre-start crank was "necessary," the RFM would prescribe it. It doesn't. So draw your own conclusions.

[JimEli]

>
The B3 does NOT have the same fadec as the B4. It is not a dual channel fadec therefor yes it is always a good idea to crank the engine if you feel it is to hot for start...
<

Grain of salt warning: there exist several versions of the B3.

[maxtork]

Jim is correct. The newer B3s come with the same FADEC as the B4 being dual channel.

[I-IIII]

the b3 plus is fullfadec dual ch,the old b3 was not full fadec but anyway don't need crank in both versions

[oscar bravo]

So the B2 came before the B3 and the B3 came before the B4?!!?:}

[I-IIII]

YESSS:ok::ok::eek::eek:

[UnDies]

I fly the newer B3 with the dual FullFadec system - it seems there are some mixed feelings about the cranking option. There must be a reason why it was included as an option......I guess there`s no harm in cranking when needed.

[I-IIII]

there is for wash the compressor:E
anyway if you have hight t4 during start the fadec is gettin start more slowly if t4 is greater than flight manual parameters will cut the start (you have to go overparameter more than 1 second) very easy

[widgeon]

Oscar Bravo , full chronological order is B ,D BA , B2 . B3 , eC130 ( b4) , there are also DA and D2 FX1 and Fx2 models ane one or 2 allstars ( C30 engine )

Was there ever an A model and what heppened to the C model

[I-IIII]

b3 plus also.......:O

[rotorpol]

Hi
I fly B3 single channel fadec, so the old model.
I fly it daily in sling load operations and perform many starts a day.

We Never, repeat never crank before start regardless of T4, the Fadec takes care of the fuel adjustment, therefore controlling the temp.There is no need to crank, thats what the fadec is there for.

:ok:

[Hiro Protagonist]

I fly the newer B3 with the dual FullFadec system - it seems there are some mixed feelings about the cranking option. There must be a reason why it was included as an option......I guess there`s no harm in cranking when needed.

Check out your Emergency Procedures... Fire during start...

[UnDies]

Thanks for all the posts - Have come to the conclusion that cranking, although not needed, is a healthy habit to have regardless of whether it is needed or not.

Safe flying yo`ll :ok:

[antonk]

I spoke to Eurocopter SA (Lanseria), and they informed me that it is NOT nessessary to crank, although the chief pilot says he does if the T4 is above 150 deg.

[I-IIII]

make no sense crank in b4 and b3 plus absoluty no sense.Is use battery for nothing

[I-IIII]

make no sense crank in b4 and b3 plus absoluty no sense.Is use battery for nothing.I will pay for your damage....try start up with hot engine and strong wind in the tail and tell what happen.........the start shoul take 10 second more........

[Dynamic Component]

widgeon,
You forgot the B1.

We also have the B3 with the 1B engine in it and do multiple starts a day. We have always been told to monitor the T4 and abbort if need be, but cranking out in the bush leaves you with a chance for no start at all if the battries don't like it.

Just my 2c:}

[I-IIII]

yes is very easy cannot start because the battery is 1 or 2 volt below normal voltage

[Squirrel]

For the EC120, the RFM says crank if T4 is >150 (EC120 is not fadec). There is nothing in the B3 RFM to crank prior to start - it is not needed. I've started the B3 within 30 seconds of shutting down (yes, even on a hot day & even numerous occasions of tailwinds during start), the FADEC takes care of everything. What you have to do if it starts to go hot (ie: caused by the FADEC having a glitch vs. T4 hot prior to start), is shut off the start switch. That is why you should hold onto that switch during start.

[maxtork]

I'm a bit getting in on this but I think I can help.

First, the B3 and B4 are both FADEC equiped although one is single channel and one dual (the newer B3s are in fact dual channel as well). The FADEC system uses a few things for the start sequence. It uses OAT to set a basic fuel flow law. Then it indexes T4 to N1 to modify that law and effect the start. Basically speaking it adjust the fuel flow to get a certain T4 for a certain N1 speed. Now most folks used to think that it would automatically handle a hot start situation. THIS IS NOT TRUE!! with the laws as stated above it had a limited authority over fuel flow and you could still have a hot start. I have seen engines removed for going to over 999 degrees T4 when the pilot did not react and abort the start.

Now with the new TU standard DECU software (TU143 for the single channel and TU144 for the dual channel) it will automatically abort the start if it reaches 865 degrees T4. So with the old system it would not do anything to hot start itself but if you dumped in a bucket of fuel it wouldn't stop it either. With the new software it will close the stop electrovalve if it hits 865 which SHOULD cool things off but it also shuts off the starter...so if there is still fuel in the chamber you will have to hit the crank button to clear it out.

Now as far as cranking to reduce residual temp in the engine prior to a start, I don't see why you would need to. The Arriel engine (as well the Arrius) both initiate a start with fuel being delivered right away. They don't spool up to a certain speed before introducing fuel like C-20 types. Below about 10% N1 the only fuel going into the engine should be through the start injectors. These injectors will only supply enough fuel to get about 200-300 degrees T4.
So if the T4 is indicating say 200 degrees and you want to start and you do a ventilation to reduce temp with cool airflow you are going to cool off the turbine wheel and blades and then as soon as you start you will hit them with 200-300 degrees right away from the start injectors. So if you are at only 200 then you should be able to go ahead and start and the FADEC laws will adjust the fuel flow as needed to get things moving correctly. No need to drain the battery bringing the temp down and then adding it right back in again.

Now this is for the FADEC equipped engines. If you are flying an EC120 or an older 350 without FADEC then you are the only one modulating fuel flow during the start. In the case of the EC120 which has gotten a reputation for hot starts it is probably best to get the temp down first, otherwise you will need to be Johnny on the spot with the twist grip to avoid overtemp.

Hope it helps!

Max

[oxi]

Never had any probs with either the B4 or the 350 (2B1) with start up straight after a shutdown but for memory there is no mention of cranking the engine prior to start as with say a B206 to reduce temp's, but if she gets hot Abort Start (switch off), Boost Pump off, GEN off and crank.

The EC120 is a little different but still reasonable just keep an eye on the procedings....modulate.

As with all of em stay focused.

does anyone know if they (the frenchies) intend uping the 120.....wider chord blades and squuzing a little more power out of the donk?

It would be well worth it a great little helicopter.

[Squirrel]

Further to the above (re: crank for engine fire during start & also for other maintenance duties), Eurocopter states that the "CRANKING" function as:

"This function is independent of the starting function; it is used to cool the air duct and drain out any fuel remaining inside after an aborted start."

For an engine relight in flight, cranking also is not used - NG has to be below 5% for the 2B engine prior to selecting ON on the starter switch (otherwise it will not start), however on the 2B1, the switch is turned ON and will automatically start once the NG goes below 17%.

[Squirrel]

Re: EC120 - heard someone is looking at STC'ing a Honeywell which will boost hp enough to make a difference - not sure what will go along with the new engine.

[UnDies]

This is the reply I was looking for!!

Thanks a mil Max

[maxtork]

Anytime! glad to help

[Flyting]

Our one B3 (Arriel 2B) keeps getting an amber GOV that comes on after 15min flying and stays on until shut down and then it goes on when going from gnd to flt idle.

It's got everyone stumped and we need help...
Anyone have any ideas :confused::confused::confused:

[oge]

We've had this happen when the rotor brake micro switch was a bit dodgy, dunno if it's a reason, maybe a highly clued up engineer can say if it could be the cause.

[PapaechoIT]

Got the same problem a couple of times, check rotor brake, normally is the micro switch malfunction that prevent the GOV to work correctly.
Troubleshoot it, first to touch everything else. I know for sure that RMM says something about that problem. Try to look in it...

:ok:

[grumpytroll]

Turned out to be the collective position potentiometer, or something like that. Took our mechanic about 4 hours to replace the faulty one. It is located under the floor inside the right stowage compartment near the bulkhead, front end. It is a small part but a bugger to replace. He had to remove the O2 system tank and hardware first and then remove the faulty unit and solder all the wiring into the new one.

Hope that helps.

Cheers

[Sir Korsky]

This is a known issue with some multi engine aircraft. The fadec gets fooled into either delivering max power or minimum torque on the affected engine until the coll is repositioned Not fun either way.

[Flyting]

Thanks for the help so far...I've passed all that on and I'm now getting the whole story out from the engineers:
"not only does it give you a gov light but the engine does not go from flight idle to ground idle and some time's does not shut the engine down if you select engine off."

:(

[victor papa]

We often turn to the engine immediately if we see a GOV to look for the fault. We forget the VEMD is "Vehicle" and "engine" and if 1 of your screens fail you will get a flashing or solid GOV dependant on mod status and so the sensors on the airframe(interface) and leading to the VEMD will also activate a GOV. One I had was for pitot static gen to the VEMD vs what the DECU send and it set the GOV on due a discrepency.