AS355N versus EC135
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AS355N versus EC135
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
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
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?
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?
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
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
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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.
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.
Last edited by NickLappos; 22nd Jul 2005 at 16:02.
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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.
Nick,
Seems the fixed winged influence is getting to you? Must be all that golfing or something?
Seems the fixed winged influence is getting to you? Must be all that golfing or something?
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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.
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.
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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
Eurobolkow, we are unfortunately limited by the local support available only for Eurocopter and Bell aircrafts
Regards
WLM
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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
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
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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
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
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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
ask to speak with mike or matt at helilynx
dr
www.helilynx.com
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Power-by-the-Hour
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.
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AS 355N v EC 135
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.
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.
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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
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
Helitech'05
Hi!
Any Ppruner going to the event http://www.helitech.co.uk/ ?
Any flight display in helitech?
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
Any Ppruner going to the event http://www.helitech.co.uk/ ?
Any flight display in helitech?
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