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Light Twin Comparison

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Old 18th Nov 2004, 03:50
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Cool Light Twin Comparison

Which light twin helicopter is the prefered one out there and why?How does the A109 power compare to the likes of the EC135, AS355 and Bell 427?
What other light twins are there out there?

Just Curious

DC
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Old 18th Nov 2004, 10:53
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Hi DC. Before you look to see which is our choice of twin you really need to look at your requirements as far as;-
1. the number of passengers
2. typical sector distances
3. the area in which you operate
4. are your passengers all able to climb into and get out of the skidded versions
5. where your maintenance base is situated and who the engineers are
6. the availability of refuelling stops
7. would your passengers be happy to make refuelling stops
8. are there noise sensitive neighbour/places at your landing sites

the list is not exhaustive so once you know some or all the answers THEN you will probably come up with the answer.

The 109 with the increased MAUM is certainly very attractive sleek and easy for passengers to get in/out. The S version should do well.
The 135 is good but has short range and is quieter than the 109
The 355 is very nice for 3/4 passengers and has a good range
The 900 has a superb passenger cabin but very short range but beefy engines and a confortable ride and is quiet.

So what will meet your requirements?
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Old 18th Nov 2004, 16:19
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The U.S. Army currently has a draft RFP for 300 - 600 Light Utility Helicopters so we will certainly see what the Army thinks.
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Old 18th Nov 2004, 18:01
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The U.S. Army currently has a draft RFP for 300 - 600 Light Utility Helicopters so we will certainly see what the Army thinks.........

I thought that that Light Utility programme was for single engine types .... Bell 407 EC120 MD500 sort of size.... Or is there another contract in the offing?
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Old 18th Nov 2004, 20:12
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There are two draft RFP's outstanding. One is for an ARH (Armed Reconnaissance Helicopter) which has also been referred to as the LRH (Light Reconnaissance Helicopter). The second is for a LUH (Light Utility Helicopter) which, as of the last draft publicly available, not required to be a twin but most of the "likely" aircraft are twins.

I do not have a direct link but I would assume Mr. Lappos or others would have a link to the draft RFP's.
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Old 18th Nov 2004, 20:53
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Dynamic Component:

If it is a VIP aircraft you are looking for that is Single Pilot IFR, can carry 7 pax and has the right image then there is no comparison between the 109 Power and the other types mentioned.

The 135 is the dominant utility airframe in the UK but as Head Turner mentioned is a bit short on legs. Otherwise a capable and quiet machine.

The 355 and 427 are old technology but are relatively inexpensive to buy and maintain.

As always with a vague question of this nature it is very difficult to provide a definitive response.
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Old 19th Nov 2004, 02:05
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Only looking at this stage.

Lets say it would have to be able to do utility(Lifting) and cart VIPs around.
What is the endurance like in the 109E and can it lift much?

I think noise is a issue everywhere in the world now(unless you live in the dessert).

DC
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Old 19th Nov 2004, 09:13
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I do not have a direct link but I would assume Mr. Lappos or others would have a link to the draft RFP's.
Yes:

https://arh.redstone.army.mil/rfp.asp

https://wwwproc.redstone.army.mil/ac..._business.html
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Old 19th Nov 2004, 12:04
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I read a review of the A119 in "Flyer" recently. Single engine derivative of the A109. The review machine was used for utility/VIP work as well. The reviewer was very complimentary, considering it ideally suited to the task.
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Old 19th Nov 2004, 12:21
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SPIFR 109E with 7 pax????

Add IFR reserves with 7 pax and you are probably going the sum total of 'NOWHERE".
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Old 19th Nov 2004, 15:05
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Eurobolkow posted...

The 355 and 427 are old technology but are relatively inexpensive to buy and maintain.

I concur with the 355 [the 109 and others] as being 'old technology' but not the 427 .... it barely exists it is so 'new.' And of course it will have to be a JAR27 build standard will it not.

Did you mean the 407?
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Old 20th Nov 2004, 10:26
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Depends on your requirements, but as a business acft AS355N has strong package of reasonable speed - 130kts, good range - realistic 350nm, and very good payload - full fuel + 4/5 POB, so IFR range pretty good with 4 pax.

Add reasonable running costs, great reliability, a very comfortable, fairly quiet ride for 4 pax, ability to take 6 if needed, and it is hard to beat as the inevitable compromise if you're paying your own bills!
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Old 20th Nov 2004, 13:00
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https://wwwproc.redstone.army.mil/ac...ib/perspec.doc

The solicitation mentioned above leads to this performance spec doc .
No ref to twin engines but requires dual hydraulics ( do oh-58D or OH6 have this now ?) and capability of single pilot IFR ops.

they are looking for a Commercial off the shelf solution.

is there another single besides ec130 and bell 210 that have dual hydraulics ?

Last edited by widgeon; 20th Nov 2004 at 13:26.
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Old 20th Nov 2004, 17:25
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Giovanni Cento Nove wrote:

SPIFR 109E with 7 pax????

Add IFR reserves with 7 pax and you are probably going the sum total of 'NOWHERE".

Perfectly true, but for another reason as well.
Try putting seven pax into a VIP fit 109E and see where the CofG is. It just can't be done with a standard VIP machine. Your fuel load is so low as to make it unusable, but more importantly the CofG position is well outside limits, by a large margin. Getting rid of the front LHS pax will bring it into limits, but again as Giovanni says, no fuel to go anywhere.
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Old 21st Nov 2004, 01:40
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I have 0 time in them, but how about a BO 105? The visibility is good, Passenger comfort is OK , aicraft speed is OK.
Its probably more of a utility aircraft, put if the interior is ok I guess it could do as a semi-VIP aircraft?
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Old 22nd Nov 2004, 10:47
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Re A109E - note that there is now a mod for increasing the MAUM which ought to give some range when full IFR flight prevails.
Sensibly, the passenger load in a 109 would be 5 pax and pilot for an IFR flight with more or less 860 litres of fuel and the u/c mod the range and reserves should be as good as any other twin in IFR configuration.
I notice that nobody has mentioned the MD902 - why?
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Old 22nd Nov 2004, 11:13
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Head Turner,

Apart from your own early mention of the 900, there's been no talk of the MD offering. It's perfectly capable of the USL ops you describe - our company intranet has some good pics of the recent JATE trials with all configurations up to 80 ft strop. Your own observations about the superb cabin hold true for pax comfort and visibility. Build quality is not so robust as the Eurocopter models, and as has been said in previous threads the NOTAR takes away payload equivalent to one pax.

Based solely on my limited experience (902, current 135 and a few cabbies in early 109s - the 212/412 probably doesn't count as they're a bit larger), I'd prefer the 902 over the rest so long as yaw control and long range weren't an issue. The 135 is well built, loads of yaw authority but a tiny cabin and - to use a phrase beloved of an instructor I know - the pilot was definitely not in the office that week when they put the cockpit together. The learning curve on the CPDS and AP is steep; it's nowhere near as intuitive as the 902. Why they need separate FADEC switches only Eurocopter can say, and for a lesson on twist-grip throttles take a look at how MD and Bell do them. Haven't operated the 214ST, but those throttles look fascinating...

If 7 pax IFR is what people are looking for, I assume the 145 would be under consideration too.
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Old 22nd Nov 2004, 13:32
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PA News: Apologies for that mistake I did indeed mean the 407 and not the 427 as you rightly point out.

As for the other comments on the 7 pax lack of range issue for the 109E the new modification should go some way to alleviating that problem and the Grand will go further again.

The same issue exists for most of the light twins available currently but at least with the 109 you will be 'going nowhere fast'

From a previous post can anyone confirm whether a 355N can full fuel and 5 pax?? If so what is 'full fuel' on an N?
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Old 22nd Nov 2004, 15:15
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A standard IFR 355N, no floats & bags, 5 pax @ 85kgs each leaves 70% fuel (345 kgs) split 15% fwd/45% aft, plus 50 kgs of ballast in the rear boot to bring the CofG into limits.

Full fuel on an N, 100% is 577 kgs.
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Old 23rd Nov 2004, 08:41
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Mr Selfish

Not sure what acft C of G Kalif is working on, but from experience a std IFR AS355N (no floats/air cond/EFIS) can take 6 x 85kg persons and 75% fuel (100% = 577kg) with no baggage, or 5 x 85kg persons and 90% fuel. Using EEW 1650kg, MTOW 2600kg. All within C of G.

Reckon on 235 litres/hour at 2000 ft ASL, 210 litres/hour at 5000ft ASL.

Last edited by rotorspeed; 23rd Nov 2004 at 09:53.
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