Recommendations for twin turbine helicopter

[CommanderKeen]

I have been asked for my recommendations for a twin helicopter to replace our current EC130. At the moment it is theoretical only, the company may not replace the 130 with a twin, but I want to be prepared if they do. Basically our operations are as follows.

We operate private flights from Lubango, Angola, with an altitude of around 5800' and temperatures of 30 degrees Celsius (sometimes up to 35). The 130 has an auxillary fuel tank fitted giving us about 700 litres of fuel and a range of around 427nm. We manage 3 pax at full fuel at temperatures up to 30 degrees celsius. Most of the time we carry 2 to 4 pax for round trip flights up to 230/250nm. Occasionally they want to fill all the seats and do more than one flight or to do flights close to 400nm. Most of the places we land are unprepared with no fuel.

The company would most likely buy new and I was thinking of the latest versions of the following from Eurocopter: EC135, EC145 or Dauphin (most probably the 365N3+).

If there is anyone who flies any of these (or something else that may be suitable) who can give recommendations or realistic operational pax numbers vs range and cruise speeds at 5800' and 30 to 35 degrees celsius, please let me know. Any info or recommendations will be welcome.

Which would be suitable for single pilot VFR and which ones would need 2 pilots for SA and Angola even with VFR only?

The Dauphin may be ruled out as too big and too expensive, but I would appreciate info on it anyway.

[Evelyn Higginbottom]

I would have suggested the AS355N, performance wise, if it wasn't for your range requirement.

I'm betting that the EC145 will give you better hot and high performance than the EC135, better tail rotor authority too (the standard 145 not the T2).

[longbox]

Hi

Have you considered the Bell 429, I have around 200 hours on it now and I am also the Bell dealer for the UK, I would be happy to PM you some performance and brochure details

[Thomas coupling]

Nice one Longbox :D:D
Can't go wrong with the EC135 with a couple of P&W powerplants onboard.

[tottigol]

Longbox, it seems as if they actually want to carry a payload in addition to the fuel.
That excludes the 429 from the running.:E

[Savoia]

Rotorheads member JB-319 (http://www.pprune.org/members/194761-jb-319) flies the EC145 for the Gendarms in France, perhaps he could tell you something about the aircraft's performance.

[RVDT]

Another option.

AW 109E with Increased Gross Weight kit. MTOW 3000 kg.

5 cell fuel system = 835 litre. Does not intrude in the cabin or baggage space.

Range with no reserve ~ >500nm.

EEW ~ 2050 kg BOW ~ 2120 Fuel fuel ~2797 leaving 203 for your 3 pax.

The 135 and 145 do not have the legs unfortunately and the AUX tank options might make sense to someone but not me. Ballasting issues, C of G issues, no baggage space etc etc.

If you look at the N3 keep in mind the 2 x Arriel 2's are not the most efficient at going anywhere. 498 nm with AUX tank.

[Brilliant Stuff]

How reliable is the 109 nowadays?

[RVDT]

Like a Ferrari - the fastest way to where you will break down!

[CommanderKeen]

Thanks for the replies.

The 109s I know of operating in South Africa struggle with hot and high performance, so they will not be an option.

The Dauphin (365N3) is the only one that has a standard fuel tank range the same as our current 130 with auxiliary tank.

Some data I have seen on the newest version of the 135, the P3/T3 mentions an external auxiliary fuel tank, which I presume will eliminate the problems mentioned above with the previous versions. It is, however, difficult to get information on it.

I am a Eurocopter fan, so will probably try to stick with Eurocopter.

My basic assessment so far:

It looks like the EC135 will be borderline as to whether it will be able to carry the same passengers the same distance as the EC130. The EC145 should be able to take at least one more passenger for the same distance. The Dauphin (AS365N3) should be able to take three more passengers the same distance. This is all considering the same high altitude and high temperature.

[Evelyn Higginbottom]

CommanderKeen - I do believe the EC145 is the aircraft for you. It is available with an auxiliary fuel tank (which despite RVDT's disliking of it - and I understand the reasons why) is able to meet your range requirement.

The T2 has better overall hot/high performance but (and I am guessing here) I feel that the standard 145 with standard tail rotor will probably deliver better tail rotor authority for high altitude landings and take-offs.

If you don't want to go new, then used 145's are available for around 5m (USD).

[CommanderKeen]

Thanks Evelyn. I have also been leaning towards the 145.

[fatmanmedia]

what about the S-76D as an alternative.

Fats

[RVDT]

Commander,

The 117/145 is unfortunately NOT known for its tail authority.

The 135 has more control and loss of authority I have never heard of.

Do the weight and balance numbers for both of these aircraft with AUX tanks - not workable.

[Ian Corrigible]

The EC145 T2 shouldn't have any problems with LTA - it uses a fenestron larger than that on the EC155 (http://www.verticalmag.com/features/features_article/a-new-and-improved-fenestron-for-the-ec145-t2.html) and engines more powerful, but in a platform 25% lighter.

I/C

[RVDT]

but in a platform 25% lighter

What????? :confused:

[CommanderKeen]

EC155 MTOW: 4920kg
EC145 T2 Mtow: 3650kg

Hence EC145 T2 is 25% lighter than EC155.

According to the data I have, according to my weight and balance calculations, the EC135 should be able to do what our current 130 can do, even with the aux tank. The EC145 should be able to lift another person even with aux tank, hence my previous post.

[RVDT]

Didn't see the 155 dropped in there or the relevance for that matter.

As if size actually has anything to do with it as opposed to RPM or the length of the tailboom but hey.

Do your numbers without pax and full of fuel with AUX tanks and see what happens.

[Ian Corrigible]

RVDT,

The relevance was simply in terms of highlighting the size of the T2's fenestron, and - hopefully - its improved TR authority compared to some other fenestron-equipped designs. Size (GW) is relevant given the physical size of the anti-torque device, and the T2's much better installed power (and TGB rating), compared to the non-FADEC'd BK117 C2. Hence the reference to 25% lighter (but with the same power as the 155, and with a bigger blower).

Cheers,
I/C

[CommanderKeen]

RVDT: If I had the data I needed to do a proper weight and balance with the aux tanks in the EC135P2e/T2e (internal aux tank), EC135P3/T3 (external aux tank), EC145 and EC145T2 I would. I don't have all the data, only some of the basic weights to get a full fuel (main and aux) payload.

Perhaps you can share more info so I can do a proper weight and balance.

[Flyting]

Why not stop off at Eurocopter in Cape Town and sit with their pilot for an afternoon...

[CommanderKeen]

I would visit Eurocopter South Africa in person, but I am working in Angola. I will try to fit it in before I go on holiday in December.