PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   The Pacific: General Aviation & Questions (https://www.pprune.org/pacific-general-aviation-questions-91/)
-   -   Twin Otter (https://www.pprune.org/pacific-general-aviation-questions/253299-twin-otter.html)

Riding the Goat 22nd Nov 2006 10:01

Twin Otter
 
Hi,

I know this question was asked in some form about 12 months ago on here but I cann't find the thread.

Just wondering what peoples opinions are on the Twin Otter. Particularly interested in how it would compare in operating cost, payload, etc to a Metro and B1900 over short sectors of about 200-300nm or even less?

Also does anyone know the shortest landing/takeoff distance at max weight of the otter? (Sea level, ISA)

Lastly does anyone know of any good Twin Otters for sale in OZ or near by?

Yes, I know that there is talk of starting the production line again, as much as I would like a new aircraft unfortunately we need something soon.

Cheers,
The Goat.

international hog driver 22nd Nov 2006 14:48

Chk your PM's Mr Goat

hoggsnortrupert 22nd Nov 2006 15:24

Riding the Goat:
 
Don't you Aussies use sheep?
Check your PM's:
H/Snort:ok:

flyhardmo 23rd Nov 2006 06:40

Awesome Machine..Everyday we fly twotters at 4500' elev and isa +15 at max all up and the take off run with Flaps 10 is about 400-500m. We use 40PSI torque to stay within torque limits. with Flaps 20 it will be airborne in about 300m at those conditions. At Sea level with isa where you can use 50PSI at max with flaps 10 it will be airborne in about 300m, and with flaps 20 in <100m. These are not book figures just personal experience at sea level but with ISA +10.
Landing with full flap at max all up and braking you could pull it up in 200m..
An empty twotter touching down at <60kts we've stopped in less than 50m to avoid wildebeast crossing and ive taken off in about 30m at sea level fairly light ( well less than one and a half centre lines on the rwy).
As for operating costs its alright up to 200nm. It tends to get expensive after that unless its a runway that only the twotter can get in and out of.
Our company is looking at the B1900C for a 230nm route and the operating costs are similar on the book figures.
Why dont you go for a Caravan. Its a money maker, rugged, and also good short field performance.

podbreak 23rd Nov 2006 06:47

flyhardmo is right. Magnificent machine for what its made for. Shortfield performance will blow you away. Comparison with metros and 1900s aren't a good indicator, peas and carrots. Both do their different jobs very well. Metros aren't exactly STOL ac! PM me for nuts n bolts.:ok:

Torres 23rd Nov 2006 08:35

Goat. I'll go against the tide - why on earth are you considering a Twin Otter for a 200 nm to 300 nm flight sector? As you also mention the Metro and B1900, I assume airstrip dimensions are not a consideration?

The Twin Otter is a great machine - for the task it was designed for!!!

A Series 300 over a 250 nm sector, return fuel, 30 minutes plus 10% and the first leg payload is 720 kg.

One way fuel, 30 minutes plus 10% and the payload increases to 1,290 kg.

A Cessna 208B Caravan will beat a Twin Otter payload over the same sector.

Riding the Goat 24th Nov 2006 12:40

Thanks for the replies,

I guess the reason for the Twin Otter over the B1900 or Metro was that it may kill two birds with the one stone. As another of my threads suggests we are looking at replacing/upgrading from a C310/PA31 fleet. This is for several reasons, one being our clients are increasing their workforces and their workforces are getting heavier. The average miner is now about 90-100 kg without luggage or tools so the current fleet is getting very weight limited. Hence the need for a 15-20 seat aircraft. Over 200nm could you realistically put 19 people in an Otter? The second bird was an other client that may be increasing pax numbers into a location with a 650m strip, unfortunately this cann't be changed due to topography. Its currently serviced by Airvans so doing one load in one plane would be better then several loads.

We'll be getting proffesional advice before making the decision as it is a fairly big step. So I cann't provide exact details on the type, engines, etc other then to say if we went with the otter it would be a 300 series.

One of the main points of my post was to draw on any personal experiences flying these types. If pilots had a choice between Otter, B1900, Metro, King Air what would they choose? What personal opinion do people have on the flying characteristics, noise, pax comfort, etc on the Otter. Is it the payload machine that people make it out to be or only over really short flights?

The problem we have is the old single v's twin debate that so many customers seem to have. A Caravan would be good (theres a few cheap ones about at the moment) but we might go down the twin path instead. Does anyone have any experience operating both C208 and Otter? If so how do they compare on costs per hour?

Thanks again for the replies.
Goat Rider.

cunninglinguist 24th Nov 2006 12:52

Yep, what Torres said.
Have a few hundred hours in the ****, its noisy and slow but if you have to get 18 people into a 600m strip, I dont see you have alot of choice.
Certainly the Metro, King Air and Bandit are out of the running. ( not sure about Caravan )

Torres 24th Nov 2006 19:57


Over 200nm could you realistically put 19 people in an Otter?
Max TO 5,700 kg – MT 3,600 kg = 2,100 kg
2,100 – 160 kg two crew = 1,940 kg

200 nm at 130 kts + 5 mins = 1 hr 38 mins sector flight time
Fuel 1.63 hrs + 0.5 hrs + 10% = 2.3 hrs at 295 kg/hr = 680 kg minimum

1,940 kg – 680 kg fuel = 1,260 kg payload

Yes you can put 19 people in an Otter over 200 nm – provided their average weight is less than 66 kg each!

Direct Operating Cost (i.e. excluding annual costs – insurance, debt servicing costs etc), around $850 per hour.

Above is for a DHC6 Series 300. Don’t even think about a -20 powered Series 200.


Does anyone have any experience operating both C208 and Otter?
Yes, but how about you do the maths for your own operation? It's not that hard you know.........

Max TO 4,000 kg – MT 2,100 kg = 1,900 kg
(I forget the Max TO weight for a C208B with APE kit but it exceeds 4,000 kg.)
1,900 – 80 kg two crew = 1,820 kg

200 nm at 145 kts + 5 mins = 1 hr 28 mins sector flight time
Fuel 1.5 hrs + 0.5 hrs + 10% = 2.15 hrs at 160 kg/hr = 344 kg minimum

1,820 kg – 344 kg fuel = 1,476 kg payload. (May be a ZFW limitation?)

Direct Operating Cost (i.e. excluding annual costs – insurance, debt servicing costs etc), around $440 per hour.


If pilots had a choice…..
Erm….. Without putting too finer point on it – is that really a consideration?

Don’t discount an Embraer EMB110 Bandeirante. Cheap to buy, same MT and TO weight as a DHC6-300, same fuel burn, one hour sector flight time.

Disclaimer – all above from memory, no warranty expressed or implied – do your own maths!!! :} :}

Deepsea Racing Prawn 26th Nov 2006 00:07

Apologies for slight thread drift, but is the Bandit pressurised?

G.A. Boy 26th Nov 2006 00:21

No, the bandit isn't pressurised. The main problem with the bandit compared to the twin otter is the bandit's heavier empty weight with the same MTOW. I have found it varies around 200 KGs to as much as 300 KGs. Hence most operators only fit 12-15 seats on a bandit, however depends on trip length/fuel required.

turbantime 26th Nov 2006 00:27

What about a Dornier 228? They're used a fair bit around africa and have only just recently started entering oz. Haven't flown one myself but know people that have and they rate it very highly since it has good STOL performance and is marginally slower than a metro.

I think the name of the company in cairns is reefwatch?? They might be able to provide info....or get in contact with operators in africa or the carribean.

Torres 26th Nov 2006 00:39

Prawn. No, not pressurised!

GA Boy. True. But offset by lower sector fuel burn due to 50% higher cruise speed.

turban. It's a game man - or a goose - who would try to make money out of a Dornier 228 on anything other than the premium priced end of the air charter market.

NutLoose 27th Nov 2006 00:38

U know they are going to restart Otter Production?

Torres 27th Nov 2006 01:11

NutLoose. Do you know I've been hearing that the Twin Otter has been going back into production for the past 30 years??? Are new PT6A-27/-28 or -34 engines still available?

And if ever it did happen what do you think the price tag would be - maybe US$3.8 million plus? I can't see any Aussie operators forking out that much for an aircraft that in general, has very limited use and is not required in Australia? If any "new" Twin Otter had the same speed and weights as the "old" Twin Otter, I can't see it being a hot seller into anything but a very specialised market.

How many Aussie operators need to move 18 people over short sectors into short strips, often enough to service a Aus$5 million debt?

The Twin Otter was a great aircraft and a true legend in it's time, but I suspect that time has now come and gone.

Goat My Caravan payload figures may be very conservative. A C208B with the APE 3 kit installed has a max TO weight of 4,109 kg and max landing 4,081 kg. Should give a 1,500 kg payload over 200 nm - but you can do the maths!

tinpis 27th Nov 2006 01:11

*sigh* :hmm:

http://www.missionaryflights.org/05p.jpg
http://www.missionaryflights.org/09.jpg

Torres 27th Nov 2006 01:16


"The Twin Otter was a great aircraft and a true legend in it's time..."
And so were some of it's pilots of my acquaintance. Not that the last poster reminded me of that fact!!! :} :} :}

Nice hack, Tinpis. Especially with Pratt -67's and not Pratt 1830s!!! :E

tinpis 27th Nov 2006 01:42

Interesting site I wonder how much they cost?
Wouldnt be too much I expect the god botherers got em cheap :}

http://www.missionaryflights.org/Tur...CockpitNew.jpg

Torres 27th Nov 2006 01:58

Won't be too cheap Tinnie! Even a pair of used -67s has to be a megabuck plus ... and into a 60 year old air frame!

If only this Douglas aircraft had been built in greater numbers and survived..........

http://www.vrcurassow.com/2dvrc/sscuracao/wakago.jpg

It would have warranted a couple of turbines.......... :D

Sadly, not one DC5 survives! :{

tlf 27th Nov 2006 10:51

Maybe you could do the job with two Nomads, you'd be helping the employment situation as well with twice as many pilots needed :)


All times are GMT. The time now is 19:17.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.