AS355N versus EC135

[WLM]

Hi

We're looking at upgrading and considering the above aircrafts. Our work requirement is for private ops, mainly corporate transport, with some range/endurance required.
Delivery delays for new are quite long for the EC135, 12 months +. We can have the AS355 in 4 months
Apart from this delay problem, what other comparisons could you highlight please for my presentation
Much appreciated
WLM :)

[helmet fire]

I did an operating cost comparison for these two types. The typical mission was an ENG one which required approximately 15% hover ops, 5% loiter and 80% transit. Over a typical 500 hour year, the EC135 was US$40K cheaper to operate. That had to be countered against depreciation, and capital tie up issues of the types which will be particular to your situation.

If you increase the transit percentage of your mission profile, then the advantage should increase. Note that in out mission analysis, we did not allow for changes in the costs given the EC135 greater range capacity, ie we compared the two over the same legs flown in the previous year by an AS355 F1. The EC135 might also present reduced costs as it could track direct rather than via fuel points, and might be able to go out and back rather than go to a fuel point, etc.

For ENG, the noise issue was also a consideration, the EC135 the obvious winner. Cat A was roughly comparable in terms of all up weights, but the EC135 was able to carry more weight and be cat a.

For pax, the 355 had better positions: all face forward, bigger windows, but the EC had much better and easier to use cargo area in the pax cabin, and was "sexier" to the eye.

Servicing intervals is the biggest difference. The EC135 a clear winner.

Why dont you use the 355 as an interim?

[JimL]

Nick's response was obviously written in haste and is not quite correct. Both of these helicopters are certificated in accordance with Part 27 (not Part 29); Light twins certificated in accordance with FAR/JAR 27 may be certificated to Category A in compliance with Appendix C of FAR/JAR 27. Appendix C calls up a number of requirements from FAR/JAR 29, which provide a similar (but not equivalent) level of airworthiness and the provision of performance data. It should not be assumed that all light twins certificated in accordance with FAR/JAR 27 have been certificated to Category A.

Category A is a certification standard which provides assurance of continued flight in the event of a failure or design assessment to reduce the probability of failure. Engine isolation ensures that one engine failure is unlikely to lead to a second, and fire in an engine compartment can be detected, contained and/or extinguished. These provisions give a level of confidence that the helicopter can be operated for continuous periods over a hostile environment.

Category A also requires the provision of performance data so that One Engine Inoperative (OEI) obstacle clearance from take-off, through climb, cruise and landing can be calculated; this data includes: mass related take-off and landing procedures; heliport/helideck size limitations; distances and climb gradients (or rates of climb); and one-engine inoperative climb performance graphs. From these procedures and graphs an operator/pilot can establish a complete OEI flight trajectory.

Jim

[Brilliant Stuff]

@Nick Lappos

Does this mean in your opinion the 135 is the better maschine?

I could not make head or tail from your post.Appologies.

[NickLappos]

Oops, JimL is right, I hastily read 355 as 155 and blew it. I deleted the previous post to avoid confusing readers.

The 365/155 is a part 29 aircraft, the 355 is not. My error in answering the wrong question!!


This is where we can miss Lu for not making me into sauce for the error!!

Now that I am on the same page as this thread (at last!):

The 135 is a much better aircraft. The design and cert of the 135 is quite a bit more strict, since the 135 has a Catagory A twin engine installation (it is actually designed and tested to a mix of part 27 and 29). This means that the 135 engines, fuel systems and engine fire zones are designed to much higher safety standards than the 355.

[Eurobolkow]

For corporate transport you dont really want either of those aircraft. Do you and your pax a favour and look at a used A109 Power or an Agusta Grand. These are the aircraft of choice for this role.

[SASless]

Nick,

Seems the fixed winged influence is getting to you? Must be all that golfing or something?

[rotorspeed]

My views as follows.

Firstly 355N is quite different from 355F; significantly more power, faster (130kts low skids no floats), much better Cat A performance, much more reliable (engines), very quick to start and go, 1 min shutdown v 2 mins on the Fs.

Advantages 355N are mainly much better range than 135 (3 hours endurance v 2.30) , better ride comfort (135 is more fidgety esp in turbulence), better pax seat comfort and view, pilot/pax communication, ability to pick up/drop rear pax through big pilot door rotors running safely, lower price and hence insurance costs.

Advantages 135 are lower operational costs and downtime from maintenance, speed (probably 7 kts faster spec for spec), Cat A performance, baggage space, cabin volume, quieter outside, better quality avionics, generally more solid, more modern systems, better crash-worthiness.

Both excellent, popular aircraft with different role strengths.

[WLM]

Thank you all for the excellent feedback. Yes I think the AS355 wouldl be sufficient for our need. I have been given a published hourly running cost of USD280 excluding fuel & labour. Is it close to actual ops figures?
Eurobolkow, we are unfortunately limited by the local support available only for Eurocopter and Bell aircrafts
Regards
WLM :D

[paco]

For support, I would always expect Bell to be better

Phil

[BigMike]

Have you looked at the 427?

[WLM]

Hi Paco & Bigmike
Don't get me wrong I am a big fan of Bell aircrafts, but we have had a few fatal accidents in the last 18 months over here, leaving intending purchasers on the edge.
Eurocopter on the other hand has no bad record. I know I know, we cannot base our beliefs on that only, but trying to convince emotional people and bean counters is not easy :(
So it's back to the AS355, and I ' m a Frog anyway, so it's about time I flew something EC :p

[BigMike]

Understand. Have not flown the 135 but but it looks to be a nice machine. Hard to beat the Squirrel as a good all-rounder though.

Cheers BigMike

[paco]

Yeah, bean counters - been there, done that! Just wait until a major part goes away for servicing and you are on the ground waiting..... For that reason alone, I would prefer the F1 because at least the engines are out of the stranglehold.

One tip I can offer - if you send anything away to Canada/USA, keep track of it yourself, as if the security people have a question they are not allowed to initiate calls. It's only when you begin to wonder where it is that you find it's been sitting in a warehouse for a week!

Phil

[chopperdr]

sir: if your serious on the twinstar then would strongly suggest you contact heli-lynx in ontario canada. they have the 355fx stc,which very effectively addresses problem maitenance areas of the 355, mostly electrical. in addition the use of squirrel cheeks will get your luggage capacity very close to the 135. also i would talk to actual operators of both airframes, i think you will find lower doc's on the 355.
ask to speak with mike or matt at helilynx
dr

www.helilynx.com

[Hidden Agenda]

I would suggest a thorough investigation into the benefits of going on to a power-by-the-hour program (or whatever EC calls it) for as many of the components as you can. It will increase your operating costs a little but give EC & Turbomeca an incentive to provide you with better support. Gives you much more predictable costs too, which your accountants will like.

[Weasel Watcher]

As far as corporate transport is concerned the EC 135 is far from ideal. The rear seats are cramped in headroom and claustrophobic. There is a significant cabin attitude change from sitting on the ground to flying at normal cruise speed which further exacerbates passenger discomfort.

The quality of the ride in the cabin is hard, resulting from the rotor head design and a very responsive autopilot. Complaints from passengers about queasiness are commonplace and projectile vomitting is not unheard of.

The autopilot is superb on the other hand, especially for IFR operations, although the airframe does appear to fly one wing low and out of balance when all the indications are suitably in line.

The 355 however has none of these vices and if one was forced to find fault it would have to be a comment on the speed. A fully IFR equipped, flotation fitted heavy 355N will struggle to make 120 knots in temperate climes.

Where the guy in the back is all important in terms of comfort and ease the 355 wins over the 135 every time.

[WLM]

Thanks for the excellent feedback guys. Unfortunately, we have received news of another Bell 206 L4 crash yesterday morning. So my principal is gone quiet about upgrading right now :(
Trying to explain the advantages of twins, etc, but the subject of helis is a little touchy...:{
Anyway, keep the info coming please. Very interesting to hear about the passenger discomfort in the EC135. I also feel the rear passengers are slightly isolated from the pilot, where it's all a big family in the AS355..
Cheers
WLM

[Friendly Black Dog]

Selfish...YOU WISH! FBD.:ok:

[Aser]

Hi!
Any Ppruner going to the event http://www.helitech.co.uk/ ?
Any flight display in helitech?:confused:
Did you register on the website and still waiting any kind of confirmation?
Is it a free event for a professional/non-professional ?

Best regards.
Aser

[helmet fire]

Recently, I have been pondering the attributes, and pros and cons of the EC 135 for corporate work. no i am not going to buy one. no I am not going to operate one. Just interested, and like to be informed.

I have done a bit of a search here on pprune in relation to the above, and it seems that the general feeling was/is:
The EC135 is the a great aircraft, with all the modern technology, but may not be suited to corporate work.
The AS355N is more suited to corporate work due cost and rotor head.
The Augusta series would win hands down for corporate work if only they were a little more reliable and less noisy.

Is that a fair summation?
Is the EC135 rotor head really that bad for corporate work? Is it anything like the BK117 head?
Is the EC135 too squeezy in the back? Is it more roomy than the 109s?
What is the 355N like? Does it do the job? Is it slow, old and noisy?
Are the 109 series really that unreliable? Are they that squeezy?
Are there any other competitors in this class worth a look (twins)?

[Mark Six]

Check your pm's
MS

[BigMike]

Yes there is, the Bell 427. VIP flying is the role it is most suited for I think. Quite a nice ride, enough room in the back cabin with good vis through the large windows, rear cabin seperate from the pilot, FADEC, P&W engines, about 125-130kts cruise, skids for off airfield landings, Bell customer support.
Piloting wise, they are a nice responsive helicopter with a bit of speed.

Cheers BigMike

[helmet fire]

thanks big mike. Hadn't considered that. Do they have less issues than the 407s? IE, nice aircraft to fly, but a few reliability issues. Do they come SPIFR or do you have to go to the 429 for that?

[BigMike]

Don't know much about the 407 other than what the guys who have flown it told me, A LOT of power!
The 427 is very realiable. The only issues my company has had, have been avionic related, IIDS display sometimes playing up, and the occassional small things when the aircraft first came out, from what I have been told.

If you PM me, I can put you in touch with the Engineering guys here, and they might be able to answer those questions better.

And to answer your other question: They are VFR/NVFR. Bell were originally going to certify it latter as SPIFR I believe. They are now concentrating on the 429 I guess, which according to the specs should be quite good.

Cheers BigMike

*The 427 is also certified Cat A.

[JimL]

BigMike,

You might need to check that the B427 is certificated in Category A; to my knowledge it is not - hence one of the imperatives for the work on the B429.

Certification in Category A in accordance with Appendix C of FAR/JAR 27 goes well beyond the requirement for performance data; this was exhaustively discussed in a recent thread that can be found here (http://www.pprune.org/forums/showthread.php?s=&postid=1846852#post1846852). Performance data in the RFM is not evidence of certification in Category A as Nick Lappos pointed out in the same thread.

You will also be aware that operations in PC1 or PC2 in compliance with JAR-OPS 3 requires certification in Category A. As the B427 was certificated after the introduction of Appendix C to FAR 27, it cannot take advantage of the alleviation contained in IEM OPS 3.480(a)(1) and (a)(2) which was introduced to cover helicopters certificated before the advent of that Appendix.

Jim

[NickLappos]

JimL is right on, and even more so, the certification rigor for a Part 27 aircraft (Normal Catagory Rotorcraft) is much lower than that for a Part 29 (Airline Transport Rotorcraft). Fire protection, crash safety, duplication of systems, etc all favor the Part 29 aircraft.

The difference is like that of a Beechcraft to a Boeing, literally.

The 427 is the Normal catagory aircraft, and is quite a bit less than a Part 29 aircraft, especially regarding safety.

The EC 135 is a hybrid, with its twin engine installation the only system meeting Part 29

The 155 is purely a Part 29 aircraft.

Comparing the three is not easy, they are an apple, a tangerine (hybrid) and an orange.

[EESDL]

Looking at replacing company's mount (355-F1) with another aircraft that is certified SPIFR and AOC. UK/near Europe Charter.
Obvious choice would be 355N as I've heard unfavourable accounts of ride comfort for the corporate/vip role in the back of a 135.
All ears though, as my knowledge of the market is limited at the moment.

[Droopy]

I've operated both, though not in the corporate role. What follows is based on an IFR version, which I assume you'd have for the corporate role. In no particular order:-

EC135

Avionics, autopilot, maintenance downtime, cabin size, seating capacity, sloping ground capability, build quality, noise, speed.


AS355N

Initial cost, ease of pilot inspection in the field [just], ride quality [the 135 isn't terrible, just rather harder], fuel endurance.

The 135 has a greater payload but also a greater fuel burn so a lot depends on whether you'd need the extra seats at the expense of range.

The 109 is a lovely aircraft but is, as you say, squeezy [only been in one, never flown it] Although the 135 high density seating isn't luxurious, the higher cabin roof gives it a much bigger feeling.

Difficult to comment further without a specific role to analyse, which seems to be the case.

[BigMike]

JimL, Nick, fair enough. The guys here have told me they had it certified ("cleared" might be a better word)for Cat A procedures? They had a Bell Factory pilot come out for the training on aproaches and departures, when the Czech CAA raised this issue sometime ago. Is this a Czech thing only? Put it this way, the 427 is allowed to conduct HEMS flights under JAR OPS-3 in Czech, does it have to be Cat A for that? I am new to the Euro rules and currently wading through the paperwork for a licence validation (another story in itself) This is my first time flying twins so this is all new to me. I'm sure you are better qualified to comment on this than me.

BM

Nice helicopter to fly though.

[rotorspeed]

This topic has been done before! My previous comments and views were as follows

Firstly 355N is quite different from 355F; significantly more power, faster (130kts low skids no floats), much better Class 1 performance, much more reliable (engines), very quick to start and go, 1 min shutdown v 2 mins on the Fs.

Advantages 355N are mainly much better range than 135 (3 hours endurance v 2.30) , better ride comfort (135 is more fidgety esp in turbulence), better pax seat comfort and view, pilot/pax communication, ability to pick up/drop rear pax through big pilot door rotors running safely, lower price and hence insurance costs.

Advantages 135 are lower operational costs and downtime from maintenance, speed (probably 7 kts faster spec for spec), Cat A performance, baggage space, cabin volume, quieter outside, better quality avionics, generally more solid, more modern systems, better crash-worthiness.

Both excellent, popular aircraft with different role strengths.

[JimL]

BigMike,

The operational standards applying to the Czech Republic is a matter for the Czech Authority; however, being a signatory to Cyprus Convention, the State could be audited by the JAA Operational Standardisation Team and found to be non-compliant (on this issue). The flexibility of implementation (currently being exercised by the Czech Republic and other States) will have to be addressed when European operational standards are unified under EASA - at which time all States will be brought into compliance.

In answer to your question; to operate in PC1 or PC2 in compliance with JAR-OPS 3, the helicopter must have been certificated in Category A. It could be compliant by operating in PC3 - in a non-hostile environment - but that could present problems for a HEMS operator.

The B427 never has, and never will be, certificated in Category A (it is a matter of the design and build standard - Bell took that decision when the helicopter came off the drawing board) - that will have to await the B429; and while we are on the subject the same applies to the B206L4T and the MD900.

If it had not been for your claim about the B427, I for one, would have remained silent on the issue even though the facts were known.

Jim

[BigMike]

Thanks for clearing that up. Interesting how everyone has there own interpretation when it's meant to be a common Authority.

BM

[EESDL]

OK, so need to get out of Battersea (helipad), Perf A, AOC, 5 on board with 90 minutes fuel - who wins?

Edited to indicate to our distant cousins that Batters is a helipad

[Dynamic Component]

The S76:ok: :E
What about the new Agusta Grand??

[Jez]

I have flown both types but mostly the AS355N and the AS355N wins my vote.

One word of warning with corprate machines - don't put too much stuff in them which makes them too Heavy!!!! :{

[JimL]

EESDL,

You may have to choose another example - one of the elements of a Category A procedure is the size of the FATO; it is unlikely that there will be many helicopters that can meet the size constraints of Battersea.

Having said that, it might be possible to find a helicopter which can operate in PC1 (not Category A) from Battersea under the revised rules of NPA-38 (in the circumstances where a rejected take-off is not required); in the class of helicopter (that it appears) you are considering it is likely that the Grande will be one. Depending on the day, the latest marks of the EC135 might also be candidates.

Jim

[EESDL]

Best I tell my Boss and his clients to bring their umbrellas!
Let's hope it is not a 'leaker' like its' forebearers.

Comment not made from any prejudice but from talking to 109 pilots and operators. Like I said earlier - I'm all ears.

Have no particular bent towards the AS355 either, gutless and full of limits above 15 deg celius and 2 pax! (F1 that is).

Have looked at the S76 and, although it's seen by most as the corporate workhorse, its too big for our needs, doesn't have skids and has silly running costs.

Lots of muddy site inspections, so skids essential as far as I can determine.

5 pax max. Typical work can vary between taking Boss to near europe or 5 business men to the big smoke (1.3hrs from our base).

[rotorspeed]

EESDL

Your Battersea example: no prob in 355N.

Say EOW 1670 kg (IFR but no floats), 90 mins fuel at 3kg/min = 270 kg, say 20% reserve = 40 mins x 3 kg = 120 kg, say 5 pax x 90kg = 450 kg. Total weight 2510kg, max Group A TOW 2540 kg.

Don't know about 135 but would guess would do it too.

[tecpilot]

Your Battersea example: no prob in EC 135 P2 :)
don't know Battersea?

Say EOW 1850kg (IFR but no floats), 90 mins fuel at 3kg/min = 270 kg, say 20% reserve = 40 mins x 3 kg = 120 kg, say 5 pax x 90kg = 450 kg. Total weight 2690kg, max Group A TOW 2835 kg up to more than 30°C, means much more possible payload than on a AS 355.

Also much more bagagge room on EC 135 than on AS 355 and the EC 135 is in my view the more modern and innovative a/c. Full Cat "A", including automatic enhanced rotorspeed by "Cat A" switch and better OEI performance.
Engines without cooling time, can be immediately stopped after touch down. Maintenance costs are much lower on the EC 135. First date at 400h and many components "on condition", doesnt' have 50h or 100h checks. With the "fenestron" lower ground risk than the conventional tailrotor on the AS.
The EC 135 seems to be more expensive in buying, but i don't know actual AS 355N prices.

But just my view!!!

[212man]

Save a few more pennies and get a 155; you know it makes sense;)

[Eurobolkow]

The honest answer is that neither the 355N nor the 135 are ideal ships for corporate operations and once again the more pertinent question is not which EC aircraft is better for these ops but rather can they even hold a candle to the new Agusta Grand.

[EESDL]

You're not wrong the 155 and Grande look great aircraft (Sloane sending spec) but I'm looking for something that is a similiar size to 135/355.

[Eurobolkow]

I'm open to correction on this one from anyone with a better knowledge than I, but isnt the AB139 the EC155 rival and thus the Grande and Power are 145 and 135 rivals respectively?

[spinwing]

Cripes ...... the AB139 and the EC155 can't really be compared ...

On paper the AB 139 leaves the EC 155 way behind ....

BUT ... it is also bigger and more expensive to operate (two pilots) etc ?????

Of course "time will tell" ..........




;) ;)

[Oogle]

The AS355N wins my vote. :ok:

[BOBAKAT]

Hi,

And today.... what about the hourly operating cost EC355NP/EC 135P2i ?