407 Fadec
 

407 single channel, 130 twin channel

Hmmmm .... The 407 RFM states that with FADEC software 5.356 installed, "the engine uses a digital electronic control system based on two electronic governors called a primary channel and reversionary governor. The primary channel is a full-authority digital electronic control (FADEC) that controls, monitors and limits engine power while maintaining rotor speed. The reversionary governor can automatically take control of the engine in the event of a primary channel failure."

It is my understanding (possibly incorrect) that 5.356 software is installed on more recently produced aircraft.

That version software is certainly installed on aircraft from November 2008 on, not sure when it started on new production aircraft. There is a new software version, soon to be released per the Bell Training Academy, that will further reduce the type sensor failures that will cause a switch to manual mode.

The reversionary governor campaign on the 407 swaps out the A250-C47 FADEC's EMC-35A with the EMC-35R, a software change which incorporates the switch from single channel to dual channel.

The Arriel 2B1 on the EC130 (and later AS350B3s) features both a dual-channel FADEC and an independent automatic back-up channel.

I/C

Just received revisions to my RFM/MD today, and this is apparently 5.358. A quick read indicates that this has substantially the same dual channel capability as 5.356, but with some tweaking of certain parameters. Example: NG at which FADEC does auto relight test is 55% for 5.358 and 50% for 5.356. There are several similar tweaks. Will be at BTA next week and hope to learn more.

B407 FADEC Software
 

Have been at Bell Academy this week for B407 recurrent and received a good dose of FADEC related information which I have summarized below to the best of my ability. The experts may wish to add or correct as appropriate.

Software version 5.358 is now installed in newly manufactured helicopters and a RFM/MD revison was issued recently to cover the changes. The changes in 5.358 are primarily aimed at reducing the instances in which the FADEC reverts to manual control (direct reversion to manual). Software 5.358 (and 5.356) incorporate a software reversionary channel which can take control of the engine in the event of a primary channel FADEC failure. This reversionary channel is limited in its capability (but the FADEC remains in AUTO mode), and does not support:
1. Automatic start with starter and ignition operation
2. Ng power modulation based on Power Lever Angle (PLA)
3. Temperature limiting
4. Automatic relight
5. Surge detection, recovery, and avoidance
6. Quiet Mode

Some RR data was presented which indicates that reversions to manual have been reduced by up to 70% (depending on which software version one is comparing to). :ok:

The Arriel 2B1 carries 2 fully digital and independant lines within one DECU. If one fails, there will be no degredation of any engine performance as the other channel will take over with full authority. Upon shutdown the pilot will get an amber GOV light to inform him one of the lines were/is unhappy with something. It will give him a full flight report and for the technicians a maintenance screen is available listing fault codes with a list of posssible components causing the problem in sequence of probability. The code refers to the Maintenance manual were the fault finding steps are laid out step by step. Also, the 2B1 does it's own power checks and compute your margins. The DECU and VEMD is biased towards atmospheric conditions so the displayed fLI(first limit indicator) already takes atmospheric conditions into account. The vEMD also allow you to enter weight, alt, temp and will give you your IGE and oGE weight limits before and during flight.

If both of the lines fail you have a 3rd system called eBCAU which will regulate N2. The pilot will get a red GOV and the procedure is a caution to not do radical collective changes as the EBCAU does not read the collective as the 2 DECU channels does but it will govern the engine.

The nice thing about the 2B1 are the alternators driven by the engine(N1 signals). These power the engine and DECU so even if you have a full aircraft electrical system failure, the engine will retain full authority.

A generally similar arrangement on the 407: an engine (Np) driven permanent magnet alternator (PMA) powers the FADEC (with NP > 85%) in the event of an aircraft electrical system failure. "Full authority" is retained unless there should also be a FADEC failure.

victor papa,

I can only prosume that the DECU that you reffer to is the same as the DECAU ??
Not being sarcastic- just checking if I was given the right info?


Cheers
DC:ouch:

Dynamic component-I just double checked and it is according to Eurocopter called a DECU for Digital Engine Control Unit. The EBCAU is Engine Back-up Control Ancillary Unit.

I will double check tomorrow the Turbomeca books-one never knows with the French:rolleyes: but generally the A would be for ancillary which the DECU definately is not.

That would be NP, not NR.

It's actually N1 that drives the backup generator unless my memory is wrong.

For some of us (myself included) the memory is a bit weak; according to the BTA 407 Pilot Ground and Flight Procedures training notebook, "The Np (N2) gear train drives the PMA, the torquemeter, and the freewheeling unit." Its not N1 (Ng) or MRGB. Vaqueroaero wins a new 407! :ok:

victor papa,

My bad:O
Just double checked my manual.
Had the DECU and EBCAU confused:D

Cheers
DC

Thanks EN48 - just shows what relying on - what were we talking about again?

407 track and balance
 

RADS versus Microvib or some other system?
We use the RADS for 407 M/R track and balance and I want to throw it in the river. Tail rotors are not a problem. Rotor smoothing after major hub work makes me want to kick the dog. Anyone have any sucess with using a different system other than RADS on Bell 407's? We are looking for any input. If its not tracker problems, or garbage solutions that do not make the vibration levels better, its interference from the Air Conditioner, the Garmin GPS, the Transponder, etc etc. Looking for your input.

Besides the 407's we also have L3,L4, B3, and do work on R22,R44, Enstrom 480B. Looking for a system that could handle all these helicopters.

Vibrex 2000
 

Have been using vibrex 2000 on the 407 with no problems.
Fit reflectors to the blade tips and track as normal
Uses fore and aft accelerometer and one vertical accelerometer
Contact me for more info

Good news from Heli Expo:
"Honeywell Announces HTS900 Engine Upgrade For Bell 407 Operators" :ok:

I understand that a few days before HAI, Bell finished performance charts that will give increased numbers for greater than a min spec engine. While an L4 is generally torque limited, the 407 is often temp limited making this welcome.

Buzzing 407 rotor tips
 

I had a strange thing happen yesterday and was curious to see if anyone knew what had caused it.

Tied a Bell 407 down to the helideck yesterday, normal construction, 60x60 ft, in the face of an oncoming thunderstorm. After it passed about an hour later, I went to untie the machine with a couple of guys based on the platform. Getting to the aircraft I noticed a buzzing sound but assumed it was the lighting round the deck. One of the guys untied a blade and asked me why it was making that noise. Sure enough, it was the tips of the rotor blades themselves making a buzzing sound like standing under high tension electric cables. We got a step ladder and there was no damage to be found, and no water coming out of the vent holes. The noise was coming from each individual tip, and was audible approx 6ft away from the machine. The battery was off, and the blades were all handled (carefully!)so presumably grounded, and the noise continued for a good 20 mins or so. Engineering guessed maybe a harmonic vibration from the platform, but never heard anything similar before.

Any ideas?

Left your vibrator under the seat ??:eek:

I have no idea what the 407 is mad out off but the only idea I could come up with is: Any chance the salt air is reacting with the blades and that is making some sort of fizzing sound?

BS your name is SO appropriate :ok:

Perhaps the flanged adapted modulator is over modulating?

NTSB prelim on Virginia State Police 407

ERA10TA261

This is described in some detail in the latest Bell Rotor Breeze publication. The STC will be available to 407 owners at no charge.

Also, in a recent (Rev 9) update to the 407 RFM Normal Procedures section, the FADEC manual mode throttle check has been deleted (Section 2-6-B). At BTA last week the instructor stated that pilots were causing too much engine damage performing this check incorrectly, and that advancing the throttle to FLY sufficiently checks throttle control.

:ugh:

If the FADEC manual mode check is too much for them I guess than they shouldn't be flying at all. :=

I've had the vibration you described before, it really bugged me at first, but I realized its just the sound of the wind passing over the blades. I couldn't find any signs of anything wrong, nor could the mechanics. I have to assume that its really nothing, just an oddity that happens at certain times with certain wind directions/speeds.

If the FADEC manual mode check is too much for them I guess than they shouldn't be flying at all.

Where it was catching pilots, is they would forget the manual FADEC check at idle, roll up to 100 per cent, remember they needed to do the check, forget to go back to idle, push the switch to go to FADEC manual at 100 per cent -- and instant overspeed with an expensive repair.

This morning, I read on AvWeb where a CRJ crew went to take off in CA, advanced the power levers and had only one engine. They taxied back and reported this to maintenance. Maintenance explained they needed to start the second engine before take off. If a two pilot crew can forget to start one of their two engines, it is easy to see how a distracted pilot could make this mistake with the FADEC and it seems sensible Bell is making this change.

Agreed. However, this is poor human factors design IMHO. Now, it would seem appropriate to (re)place a guard over the AUTO/MANUAL switch to avoid inadvertent operation which may result in an overspeed. It would seem that the only need to operate this switch now is to silence the FADEC warning horn in the unlikely event of a reversion all the way to manual. Raising the guard would seem to be a reasonable tradeoff to prevent hitting the button in error.

As is often said of aviation "calamities." there are those who have and those who will.

Bell 407 experience
 

Hi,

I consider leasing a Bell 407 to do some charter. Does anyone have any first hand experience with this machine when it comes to performance, maintenance, cost per hour etc.? Any relevant info is highly appreciated.

Thanks,

Peja57

G1000 Bell 407
 

I just finished up 407 recurrent at Bell yesterday, and got to make an hour flight in the G1000 407 this morning. All I can say is wow!

I have lots of EFIS experience, including Chelton, Collins Pro Line 21, G1000, Aspen, Honeywell and G600. The 407 G1000 installation is much more than a fixed wing G1000 system stuffed into a helicopter, with a number of helicopter specific features like the single limit display of Torque, MGT and Gas Producer, the rear facing camera, the automatic display of full size engine parameters on the MFD in the event of an engine failure, and the power assurance check feature.

I hand flew an ILS into KAFW, in quite gusty conditions, using Garmin's version of HITS boxes, and the pathways keep the localizer and glide slope perfectly nailed. Later we shot an approach using the Cobham auto pilot, and it tracked the approach perfectly.

I had only seen pictures of the installation, and was worried about the extended panel blocking view during off airport operations, but that concern was unfounded, as the part of the panel that extends in front of the pilot is cut so as you can see under, around and over it.

This installation is the most exciting avionics advance I have seen in helicopters, and will likely change how helicopters are purchased and completed, as the average completion will probably go from a few months to a few weeks.

I will be at BTA end of April for 407 recurrent. Any tips on how to get soem 407GX time?

Tell them you are interested in one. :)

Aren't you in the east, and isn't Jeanette your Bell person -- she can arrange it.

They have one Garmin ship at X Works in Arlington, which is an older 407 that has been a test bed for many mods over the year (and the one I flew) and another one that was at HAI and is either the first one off the line or equivalent.

G1000 on the Bell 407
 

I received an email that you are interested in a demo in the 407GX (G1000 407). If you can provide your email, I can work on approvals and setting up that demo. My direct email is: [email protected]

thanks - hope to see you at the academy

BH407
 

Well, I know this may be a duplicate post but I'm new to the 407 and would like a current electronic RFM. If anyone could help that would be great. Thanks in advance.

Good Morning,

Just go to the Bell web site and register; all you need is the serial number you fly and you're in business :ok:

BHT - BHT - Error Page

Free subscription for up to date manual, from the OEM, can't beat that :cool:

Bell 407 xmsn oil pressure fluctuation
 

Am experiencing an xmsn oil pressure fluctuation which I have not previously observed. Begins about 5 minutes into the flight and varies between about 40 psi and 60 psi (always in the green) , and cycles this way about once per second. Until recently oil pressure has been steady at about 55 psi at all times in flight. This fluctuation continues on the ground after a flight while at 100% RPM, but is not visible at ground idle. Wondering of anyone has guidance on the cause and significance of this?

I have been told by more than one experienced individual that the transmission on this helicopter will run for an entire tank of fuel after a loss of all oil before seizing. Cant seem to get any "official" confirmation of this. May be true, may be urban myth. Any thoughts?

Probably the gauge or the wiring.
Get an external instrument hooked up to check.
I wouldn't want to fly with a dry tranny.

Could be a dodgy transducer. Your maintenance guys can look at BHT 407 MM 6, Chapter 63, Page 17 for troubleshooting. Or call Bell Product Support, or your local tech rep.

As for running it without any oil for a full fuel load even you should know that is a load of b*&^cks. You have attended the school.

There is nothing worse than a so called 'experienced individual' who has no idea of what he/she is talking about.