FSX-MS Aerosoft Twin Otter Extended

[flapsdown 45]

Other than there is a ground friction problem built in to both FSX and P3d, the Twotter is still a hair different.

 

I did not really see much if any difference with the TwotterX's taxi behavior in its initial release compared to any other FSX turboprop, they all have a general tendancy to over-surge after a throttle application, and most have so much "get up and go" that you had to look to your brakes first and then perhaps reverse thrust to manage the speed - unlike say the RealAir DukeV2, which is incredibly manageable by just manipulating the low/high idle power settings.

 

Once in the air, the TwotterX did (and still does), represent a much better than "FSX default" operating behavior experience, that is close to, but not quite in RealAir territory. However, the amount of power required regardless of gross-weight to unstick it in later releases is pretty absurd. Again, this may be some anomoly related strictly to a change in my installation...

 

[andymartin 1]

Im using orbx airports and  dont have any ground sticking issues.   There is a long lag, true to the real aircraft, between applying power and the engines responding, so you can end up giving it too much welly to get it moving.  Small adjustments i think is the way to go.

My 2 issues are the data charts, which seem wildly inaccurate.   And the autopilot.

The charts state rotate at 65 kts average weight aircraft, flaps 20.  I find this impossible,  Even with maximum up trim it wont rotate much under 75.   It then rapidly increases speed even though the charts state climb at 85.  I can eventually achieve 85 after flaps up and throttling back, still seems a very nose high attitude.

Landing at anything under 80 flaps 2 without getting a seriously nose high touchdown seems impossible too.   Im landing at 80, 11-15 hg, flaps 20 or 30 and can get a decent shallow flare at touchdown.

The worst thing for me is the autopilot.  When climbing out, after trimming, i set the ias on the autopilot and instead of climbing at a steady rate it bucks the nose up and down.    After leveling out and trimming i set the altitude hold and the aircraft immediately dives.   When i take control and level out and select altitude select again, the autopilot is fine, but it always takes 2 attempts.    It seems that the trim is critical in the twin otter before engaging autopilot?   

 

Having said all that, i love this aircraft,  perfect for short flights and a challenge to manage the engines and props.  

 

Thanks for the helpful advice

Andy

[vc10man 732]

 

 

i set the IAS on the autopilot and instead of climbing at a steady rate it bucks the nose up and down. After levelling out and trimming i set the altitude hold and the aircraft immediately dives.

I had the same in my short flight to Liverpool yesterday, so I switched it off and controlled the speed from, my joystick throttle.

[flapsdown 45]

 

 

 Small adjustments i think is the way to go.

 

Wish that were the case for what I have been seeing, but for me it is not - I am actually starting to look into whether or not I have some kind of brake pedal sensitivity or null zone issue when I load the plane, as I can run up the engines quickly or gradually and it makes no difference at all, the Twotter will just sit there like its tied to ground (regardless of gross weight)  - eventually at high enough power settings it will break away and then start to accelerate like a scalded dog - Interestingly, when the A2A 172 first came out, many people were having the same sort of brake/stuck issues, and eventually A2A was able to deliver a fix - that won't happen here as Aerosoft has moved on in regards to this plane quite a while a ago, so I will just have to keep tweaking I guess...

[Aeromaestro 1]

Im using orbx airports and  dont have any ground sticking issues.   There is a long lag, true to the real aircraft, between applying power and the engines responding, so you can end up giving it too much welly to get it moving.  Small adjustments i think is the way to go.

My 2 issues are the data charts, which seem wildly inaccurate.   And the autopilot.

The charts state rotate at 65 kts average weight aircraft, flaps 20.  I find this impossible,  Even with maximum up trim it wont rotate much under 75.   It then rapidly increases speed even though the charts state climb at 85.  I can eventually achieve 85 after flaps up and throttling back, still seems a very nose high attitude.

Landing at anything under 80 flaps 2 without getting a seriously nose high touchdown seems impossible too.   Im landing at 80, 11-15 hg, flaps 20 or 30 and can get a decent shallow flare at touchdown.

The worst thing for me is the autopilot.  When climbing out, after trimming, i set the ias on the autopilot and instead of climbing at a steady rate it bucks the nose up and down.    After leveling out and trimming i set the altitude hold and the aircraft immediately dives.   When i take control and level out and select altitude select again, the autopilot is fine, but it always takes 2 attempts.    It seems that the trim is critical in the twin otter before engaging autopilot?   

 

Having said all that, i love this aircraft,  perfect for short flights and a challenge to manage the engines and props.  

 

Thanks for the helpful advice

Andy

Hey Andy,

 

You are very much correct. As a Twotter pilot, I find this bird flies very wrong, especially in takeoff and landing configurations. In the real bird, I'm flying a visual approach at flaps 20 and 76 knots and I'm flying with a serious nose down attitude. The original Twotter flies exactly like this. The Extended flies at that speed in a nose level attitude or a nose up one depending on landing weight. Flaps 10 on takeoff in the real bird if I'm lightly or moderately loaded, sees me off the ground at 60 knots. Flaps 20 and I basically "helicopter" off the ground (no rotation and the thing flies itself off the ground in a nose level attitude). Full flap landings and I can fly at 50 knots and below STILL WITH A SERIOUS NOSE DOWN ATTITUDE! To get her on the ground, pull the power off, wait for her to start sinking then flare her out. Drop on the numbers and stop 100 ft after that(with a nice headwind). Do not try that with the Extended. Thing wants to land like a 747. The original Twotter replicates that perfectly. My opinion, take the FDE of the original Twotter, adapt it to work with the Extended. I still fly the original Twotter. Have the extended but don't touch it. Going into St Barths with that...? Doable....but takes the whole runway.... Riiiiiight.... Ama stick with the original.

 

Cheers.

[andymartin 1]

Hi Aeromaestro,   many thanks, that is really interesting to hear from a real pilot.    Ive never been in a real twotter(maybe one day)  but the extended just didnt seem accurate, especially when i compared the data charts and also videos on you tube of take off and landings. 

Maybe i will go back to the original aircraft and stick with that !

 

Thanks again

Andy

[vc10man 732]

Me too, back to the original.

 

Waste of money, the Extended.

[andymartin 1]

back to the original now,  although it wont even start for me now!

[Aeromaestro 1]

Hey guys,

 

For what it's worth, the Extended is a masterpiece of flightsim engineering. It's just really lacking in flight characteristics. If Bernt Stolle or someone of his calibre had a go at an alternative FDE for it, it probably would be a marriage made in FSX heaven. I personally wish someone could take FDE and .air files from the Twotter X and merge it with the Extended. Awesomeness it would be...

 

 

Cheers

[Paul Golding 92]

Having seen this thread yesterday, I had to take the Twotter Extended for a ride last night to see what all the fuss was about.

 

As far getting it to start rolling goes, maybe I'm just used to it, but I have no big issue with applying power, waiting for the engine to supply it and once rolling reducing the power to taxi.  Just how much power should be needed and how quickly it appears after moving the throttles.....I have no idea.

 

Similarly, the take-off and landing speeds 'seem' fine to me but I probably need to be a little more precise in terms of looking at weights and speeds..........on the other hand, is that how this kind of aircraft is really flown?

 

The autopilot did everything I expected it to including holding altitude.  In fact I found it enjoyable using IAS mode to hold speed together with the required climb or descent for any given power setting.  I can't help wondering if others are using the AP as it was designed to be used.  If anyone has an issue with say alt hold and would post their fuel/weights etc here, I'd love to try and recreate the problem.

 

That said, I certainly agree with you Aeromaestro about the speed/flap/pitch issue, it's almost like there's a lack of lift from the flap settings.  The fact that very little control input is needed to stay on a glideslope also points to this; I'd expect quite a bit of lift from each step of flap together with needing to push the nose down to avoid any ballooning effect.  That of course is not a big deal to fix on its own, however, the knock-on effects might come out elsewhere. 

 

That said, the aircraft was modelled on a specific aircraft the developers had access to, and the beta team included real world Twotter pilots, so maybe they don't all fly the same?

[Aeromaestro 1]

True, Paul. Most frustrating when trying to get into St Barths or Saba or any Rwy just as short and I have to fly it like I fly my Majestic Q4. Usually end up using all the Rwy. Used to irk the crap outta me. Now it's just plain hilarious. The original Twotter X flies just perfectly like the real thing.

 

 

Cheers.

[Paul Golding 92]

Maybe I was just light last night, but I flew into EGKH runway 03/21 and easily stopped in less than half of it; I only just looked it up and that runway is 1750'.  Again, not very precise as I don't know what weight I was at, didn't touchdown in the right place and didn't bother with reversers.

[Aeromaestro 1]

Maybe I was just light last night, but I flew into EGKH runway 03/21 and easily stopped in less than half of it; I only just looked it up and that runway is 1750'. Again, not very precise as I don't know what weight I was at, didn't touchdown in the right place and didn't bother with reversers.

Were you flying the final approach with a nose up attitude or nose down one? I figure to get into that short of a Rwy with no reversers and stop in half the rwy, you must've been dragging it in at about 50 knots and full flap. That config in the Extended equates to a nose up attitude or nose level attitude depending on weight. In the real world, you'd be staring down at the ground from a rather high perch, created by a significant nose down attitude. If you got both the Twotter X and the Extended, fly the same approach using both with the same weight and balance. Tell me what you see.

 

 

Cheers

[Paul Golding 92]

Were you flying the final approach with a nose up attitude or nose down one? I figure to get into that short of a Rwy with no reversers and stop in half the rwy, you must've been dragging it in at about 50 knots and full flap. That config in the Extended equates to a nose up attitude or nose level attitude depending on weight. In the real world, you'd be staring down at the ground from a rather high perch, created by a significant nose down attitude. If you got both the Twotter X and the Extended, fly the same approach using both with the same weight and balance. Tell me what you see.

 

 

Cheers

It was very definitely not nose down.

 

Try this.  Go to the Aerosoft_DHC6_300_WHEEL folder and open the aircraft.cfg file (after putting a copy somewhere safe) and go down to the [FLAPS.0] section; adjust the lines lift_scalar and pitch_scalar from 1.0 to 1.5 and give it a go.

 

At max weight with flaps 20 and neutral trim I was off the ground close to the numbers using maybe 1500' of runway (too long/to short?) and the approach was again close to the numbers and with a very noticeable nose down attitude.

[flapsdown 45]

Turns out my "stuck" issue is somehow related to the Twotter being the first aircraft I load going into FSX - if I use anything else first before selecting the Twotter for a flight, I do not have the "stuck" problem, and it does appear to be somehow related to the initial state of the brakes - kind of odd, but since I found a work-around I can't really complain