My understanding is that the VEMD in the EC135 functions slightly differently than the VEMD in the AS350. Probably has to do with German airframe and French electronics, some things got lost in translation. :}

Well in our CPDS machine from 2002 we do not get any fuel management apart from the gauge for the three tanks. Which is within 4%-6% accurate as it says in the manual. But maybe the current machines are more accurate or have more standard options.

3top,

I assumed that you may have flown a helicopter before but maybe your watch no longer works. Do you keep a log of your fuel flow/consumption based on past history?

Trusting the gizmos implicitly is probably not so wise in any respect.

Study the available tech data you have and work out what is "wrong" with the fuel system. (Read between the lines).

Get back to me when you have worked it out.

BTW MEGHAS and CPDS are not related. A B3 or a 120 are pretty simple compared to a 135.

It is simple. The b3 and/or 120 has 1 tank which serves as the storage and feeder tank. This means the VEMD display only has one transmitter telling it the fuel available for the whole system and then as you said before the DECU tells the VEMD how much it is using vs the airflow available and power setting. Simple sum for the VEMD and accordingly you get on the B3/Ec130/120 time remaining on current fuel. The 135 has more than 1 tank per engine and the "storage tanks do not feed their info to the vEMD. The result is that the vEMD still gets from the DECU how much fuel is used, but it does not know how much fuel in the system so 1 halve of the sum is gone.

Okay guys,

that's all good.
What I don't get, is that EC wants to charge extra, what I would call an essential item, considering the rest of the equipment.
I would certainly assume that it should be a standard/basic feature on a full-blown IFR-MEGHAS ship. Maybe on an old VFR ship you sell this as a "useful" add-on, but on a glass-cockpit-IFR ship - it should be included....

Anyway, based on the answers given, I understand there is no way to look at the panel and get a direct info on "flow + time remaining", without having to calculate - so the fuel management option will be added! (And again, it is a "no-weight option" - just software, extra charge....)

RVDT!

YOU assumed right! I have a few hours rotor time (11.5K and counting)
I know what you get at, and you certainly right!

Just as a basis for discussion, here is what I did in the past/present:

ALL VFR in mostly hostile terrain.
My first two jobs, I did not have a fuel gauge! Everything done by watch!
Of course it is possible to do it by fuel level and watch alone, but:

At my present job (long lining in a mining project) you would have an extremly hard time to do the watch thing, due to the ever changing weights you fly. Flying time with the same fuel load can vary as much as 30 min (50% fuel load).

Fuel gauges are regularly checked/calibrated (tanks drained and refilled by the gallon to check low fuel light and quantity indication).
So they are actually VERY acurate!

I got very appreciative of the "time remaining" feature on the 350 VEMD (by the way in the EC120 you have to pay extra for this too).
It is extremly helpful to know that under pick-up load time remaining may show 27 min to "zero fuel", however once under way power required drops and I will get some 7-9 min back (35 min) - indicated on the VEMD (no need to guess fuel flow and calculate).

One of the missions for this ship(EC135) will be SAR, medevac - over generally hostile terrain. Although we certainly will not plunge into this from zero, we expect to work up to night and IFR missions fairly quickly.

As it is, the EC135 seems to be a rather heavy ship already and fuel will be a limiting factor. Being able to get a few more minutes, based on exact data available may be crucial someday.

But don't worry RVDT, if I ever get close to my empirical flight times on the same fuel load and the gauges/indicators didn't change - I'll be on the ground before the big silence screams at me!

Thanks for all your inputs!

Is there anything else I should consider? experiences? suggestions?

Tomorrow (Monday) is the last round with EC to freeze the order spec sheet ....


Cheers,

3top :cool:

sir, for your SAR mssions, will you be using searchlight or flir camera? if so, do you need mounts?

If SAR becomes a need, this will be only a daylight affair for a long time to come...

why? you got mounts to spare?


3top

yes we do, easa and faa stc'd
send a pm, will reply with all the data
cd

EC135 Certification Limits
 

Can somebody settle an argument for me and confirm that the EC 135 is certified to +45 degrees C.

RFM Section 2 Page 5 -

With the proviso if you have MEGHAS (Glass cockpit) ground or hover is limited to 30 minutes with OAT ≥40C.

EASA Approved Rev. 14 P2 CPDS

FLM:

2.10.1 Ambient air temperature limitations

Minimum air temperature is -35°C
Maximum air temperature is ISA+39°C
(max. +50°C)

RVDT
 

Thanks, I assume that was a typo and you meant ISA +35

G. :ok:

Geoff,

No typo it is at it says - meaning I assume you can operate up to ISA +39 not to exceed +50.

ISA +39 at sea level would be ~54 but at ~2000' it wouldn't.

Temp lmits
 

Not being a 135 man I'm not sure of the implications of the 'glass-cockpit' side of things. Are these aircraft in the majority or minority and what sort of intrumentation do you have if no glass cockpit. Is it back to analogue dials and basic DH/HSI ? What if you need an IFR capability with 2 pilots?

G.

Although the T2/P2 option is now the weapon of choice, I believe that it is still possible to choose between the traditional 'analogue' style intruments (CDS version) or the 'digital' style (CPDS). IFR and two-pilot intrumentation is also an option for both.

I would imagine that most are of the CPDS style although a few T1 CDS linger.

The CPDS is not the same as "glasscockpit", just the engine instruments are "digital style, while in the CDS they are traditional. The actual machines are sold only with CPDS as standard, but you can choose between analog or digital ( "TV screens" ) flight instruments.
The reason for the temp limits with glasscockpit is, that these screens produce a lot of heat and with high OAT may come offline.

skadi

And so I am told, (without looking it up) the "steam" instruments are heavier.

Appreciate there are about 15 flavours of EC135.

I was also told "never again!"

The MEGHAS (which is now probably the norm) does generate a lot of heat. Add Garmin GPS, FM's etc etc...................................

Death on a hot day!

Appreciate also that the operation/installation or not of the A/C is not within the certification criteria.

We have 9 displays.

The boys and girls using the EC135 in the Middle East will have much better information than me, but all that glass cockpitry is a bit sensitive to high temperature. Flying for the police in the UK we occasionally get a warmish day and if the aircraft is left out on the pad it can cause problems. Various units use portable radiation shields in the cab to reduce the heat soaked into the instrument panel, which seems to help.

Generally, the glass cockpit is pretty reliable but it does play up when it gets hot. EC have setup the vent system so that it diverts the air to the instrument panel rather than the crew, so they obviously are aware of the issue. I don't have an FM to check but I recall the whole issue starts at 30 C.

Sadly nothing will pass muster with the bean counters. However in this never ending saga of 135 vs 902 for police/HEMS go and ask ALL off them what their (the user or customers) view is. Am sure all of them will say their machine is best................ then ask the ones who have used both.... or more. I prefer 902 as it is a stable. non shaky platform blah blah blah . But yes I am biased.

Any information on Switzerland 635's that were grounded lately?