Twin Otter, Plus and Minus Points Please
Thread Starter
Joined: Dec 1999
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From: UK
Twin Otter, Plus and Minus Points Please
What are the advantages and disadvantages of the Twotter in the utility/bush/tundra/arctic role?
What are its good points? Where does it not score well in its designed role? How far does it really go? How much does it really carry?
Real examples of loads, ranges, accessibility, maintainability etc much appreciated.
(Caravan 1 driver asking...)
What are its good points? Where does it not score well in its designed role? How far does it really go? How much does it really carry?
Real examples of loads, ranges, accessibility, maintainability etc much appreciated.
(Caravan 1 driver asking...)
Joined: Nov 2000
Posts: 92
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From: Wanaka
Pluses: Simple systems and airframe design, Reliability, good load carrier, rugged, great single engine performance, great strip performance both landing and takeoff.
Minuses: 155kt cruise, noisy but not as bad as a skyvan.
I have operated the Twin Otter, Skyvan, DO228 and the Nomad. They all have their pluses and minuses but the Twin Otter is definitely the best all rounder.
Basic wt in the 5600 lb to 6000 lb according to options. TOW 12500lb. Burns 600lb/hr @ sea level, 550lb/hr at 5000ft and 505 lb/hr at 10000ft.
The -300 will maintain over 10,000ft on one engine at ISA +15
I have flown the aircraft in ferry configurations at 18,500lb and it still goes OK
Minuses: 155kt cruise, noisy but not as bad as a skyvan.
I have operated the Twin Otter, Skyvan, DO228 and the Nomad. They all have their pluses and minuses but the Twin Otter is definitely the best all rounder.
Basic wt in the 5600 lb to 6000 lb according to options. TOW 12500lb. Burns 600lb/hr @ sea level, 550lb/hr at 5000ft and 505 lb/hr at 10000ft.
The -300 will maintain over 10,000ft on one engine at ISA +15
I have flown the aircraft in ferry configurations at 18,500lb and it still goes OK
the lunatic fringe
Joined: May 2001
Posts: 621
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From: Everywhere
It was designed to operate into short strips, and it does that wonderfully. It will stop on a dime.
With low approach speeds the radius of turn is tight. So great in the mountains.
In the bush you can put "Medium flotation gear" on it. Fat tires to you and me. With these on, you do not even need a runway.
The PT-6 has a free turbine, so is a cold starter, and very forgiving. Having operated it in the desert, into short mountain strips, and the beach. it is ideal for that job.
British Antarctic Survey has used them down south in for generations. Bradley Air Services used them in the high Arctic. It is simply the aeroplane for the difficult out of the way places.
The bad bits of the DHC-6 are. It is a handful in a crosswind, and has a slow cruise speed. That is about it.
I loved it. For all 3500 hours of it.
With low approach speeds the radius of turn is tight. So great in the mountains.
In the bush you can put "Medium flotation gear" on it. Fat tires to you and me. With these on, you do not even need a runway.
The PT-6 has a free turbine, so is a cold starter, and very forgiving. Having operated it in the desert, into short mountain strips, and the beach. it is ideal for that job.
British Antarctic Survey has used them down south in for generations. Bradley Air Services used them in the high Arctic. It is simply the aeroplane for the difficult out of the way places.
The bad bits of the DHC-6 are. It is a handful in a crosswind, and has a slow cruise speed. That is about it.
I loved it. For all 3500 hours of it.
Joined: Aug 2002
Posts: 181
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From: no fixed address
The Twin otter is the best designed aircraft I have flown when operating in the role that it is designed to do. It does its job very very well, with minimum fuss. As long as you arent trying to make it do a job outside its envelope, it "should" make you money.
I never had the luxury of anything bigger than the -200, so the old PT6-20 was what I operated with for 1600 hours. Great, simple engine, but a little underpowered at max weight especially on one. Another downside to this engine was finding engineers that knew how to coax the best out of 50's technology.
Some downsides.....
I found the forward and aft cargo areas very roomy, however the size of the doors limited the size of freight that you could carry. Many times I cursed the designer for not making the holes bigger.
The large beanbag like tyres were a bugger to balance (static balance - no worries, but dynamic balancing was the problem), so had a number of problems with nosewheel shimmy.
The lack of decent airflow when operating in the tropics was a problem, and a huge dislike of regular pax. Being Canadian, it was no problem to heat the inside, but cooling it without aircon was almost impossible with a full load of people.
Some upsides.....
Very high performance aircraft. Not in a speed sense, but in where you can put it down! Absolutely incredible, even with just using Flap 20 for landing. Not as good in a short field landing contest as the Nomad, but would rather be in the otter when trying to get out of a dodgy strip.
Can use it single crew or multi crew, depending on what rules you operate under.
Still my favourite machine.
I never had the luxury of anything bigger than the -200, so the old PT6-20 was what I operated with for 1600 hours. Great, simple engine, but a little underpowered at max weight especially on one. Another downside to this engine was finding engineers that knew how to coax the best out of 50's technology.
Some downsides.....
I found the forward and aft cargo areas very roomy, however the size of the doors limited the size of freight that you could carry. Many times I cursed the designer for not making the holes bigger.
The large beanbag like tyres were a bugger to balance (static balance - no worries, but dynamic balancing was the problem), so had a number of problems with nosewheel shimmy.
The lack of decent airflow when operating in the tropics was a problem, and a huge dislike of regular pax. Being Canadian, it was no problem to heat the inside, but cooling it without aircon was almost impossible with a full load of people.
Some upsides.....
Very high performance aircraft. Not in a speed sense, but in where you can put it down! Absolutely incredible, even with just using Flap 20 for landing. Not as good in a short field landing contest as the Nomad, but would rather be in the otter when trying to get out of a dodgy strip.
Can use it single crew or multi crew, depending on what rules you operate under.
Still my favourite machine.
Props are for boats!
Joined: Oct 2000
Posts: 994
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From: An Asian Hub
Ok have operated both -300 and -200. -300 is obviously the shinier one on performance with PT6A-27 engines. I remmember 2 performance senarios still to this day.After looking up performance tables.
MTOW, at sea level, 35 dec C, 20 degress flap, gives a 1350ft take off roll to 35 ft
And with 10 degrees flap, and same conidtions at MTOW, a 1750ft take off roll to 35ft.
Not bad at all.Those figures are in feet not metres by the way
MTOW, at sea level, 35 dec C, 20 degress flap, gives a 1350ft take off roll to 35 ft
And with 10 degrees flap, and same conidtions at MTOW, a 1750ft take off roll to 35ft.
Not bad at all.Those figures are in feet not metres by the way
Last edited by Sheep Guts; 15th May 2006 at 00:53.
