Twin Otter X: open issues

[WF442 1]

I guess i`ll just have to get used to flying the twin otter the way it`s supposed to be flown. Haven`t experienced this behaviour in a FS plane before. Kudos to Aerosoft for making something rather new in this field.

[Aerosoft Team [Inactive Account] 51558]

I guess i`ll just have to get used to flying the twin otter the way it`s supposed to be flown. Haven`t experienced this behaviour in a FS plane before. Kudos to Aerosoft for making something rather new in this field.

Hold on, hold on, the jury is still out on this this. As we got the aircraft now we let FSX decide what happens. We got the thrust vectors where they should be, but that does not alway mean the aircraft behaves as Newton told us it should. It is well known that a Super Cub defies Newton on every landing and that helicopters are not able fly, they just beat the air into submission.

In the end, we build them as you like them, so fly some more and give me your comments.

[flyfalcon 1]

You are either running low on graphics memory or you got the Global texture resolution set to something else but Very High.

No , doesn`t work

[Private-Cowboy 3]

No , doesn`t work

I had that too, for me the solution was getting into windowed mode (Alt-Return) and then back out to full screen and the texture were razor sharp again. Have not seen that yet on other addons but that is what fixed it for me.

I had another issue with the sound. I opened and closed the doors (boarding imaginary people) and the door sound would loop forever and would not stop. I need to open and close the doors again to stop the sound. That is prolly my system but maybe its of interest to you.

[flyfalcon 1]

I had that too, for me the solution was getting into windowed mode (Alt-Return) and then back out to full screen and the texture were razor sharp again. Have not seen that yet on other addons but that is what fixed it for me.

I had another issue with the sound. I opened and closed the doors (boarding imaginary people) and the door sound would loop forever and would not stop. I need to open and close the doors again to stop the sound. That is prolly my system but maybe its of interest to you.

Yes but anyway that should be a fixed

Hope it is possible ! :wink:

[Private-Cowboy 3]

May I ask what spec you're on. I just noticed the texture format is 32bit on most textures resulting in a whopping 70MB per plane. That may be too much for some GPU with the result you and I are seeing. I'd try to convert them to DXT3 or DXT5 with the ACES image tool. It would cut the size down to 35MB per plane if not less. It would help the issue for sure.

[flyfalcon 1]

Hi,

My system:

Intel Pentium 4 CPU , 3.4 GHz

1GB RAM (-Is that the problem?-)

ATI Radeon X1950XT

The Twin Otter is the first plane where that happens ...

[sry for the bad english]

[Private-Cowboy 3]

Its also the first plane for me where that happens. And my specs are similar, more powerful CPU and twice the RAM but less powerful GPU. My best guess is that the 32bit texture format is just too much. I'll try to convert it to DXT3/5 and see if it helps. It should take a lot of load of the graphics memory.

[Finn 873]

Regarding the pitch wit power change:

Be aware that You don´t pull Your hardware throttle all the way back for the descend or approach. Doing so will put Your propellers into beta range, something De havilland (in the realworld) doesn´t approve. The same goes for taking the propellers into reverse inflight.

Whilst on the ground: move the power levers forward until the two blue beta range lights go out. At that position You are in flight idle, note the position of the hardware throttle, cause that is the minimum You want to pull the power levers back to during descent and approach.

On the real twotter there is a detent at flight idle, something not present on most controller setups for FS.

If You are in beta range, the propellers doesn´t produce much thrust, but inflight they will produce a lot of drag. This combined with the low center of gravity and inertia of the airframe ,will make the aircraft pitch up even more than if just being in flight idle.

Well.. Too bad that it`s virtually unflyable with the pitch issue.. I had high hopes for this one.

This is in my view an large overstatement, the twotter is very controllable. I have landed perfectly numerous times at Lukla, as well as making a couple of very short landings with no problem. Offcourse You have to be aware of the pitch movement, but that is just part of the fun :-)

Flying the twotter has to be learned.

Wothan

[gwolb 0]

I can not bring up any other the other panels when using Shift -3 or 4. Shift 2 brings up the gps, but not able to display the radio stack or AF display. Some planes dont have this many options, is this all in the VC view on purpose? thanks.

[azflyboy 1]

Is there any chance of getting some cruise performance data? I notice that there is takeoff, climb, and landing data, but no information for power settings and airspeeds for cruise flight.

Also, there seems to be a slight bug with the GPS. Most of the modes work correctly, but the "other" pages seem to calculate endurance, range, and fuel flow incorrectly. From what I can tell, the GPS uses the correct value for the amount of fuel on board the aircraft, but it only uses the fuel flow data for one engine, which leads to the unit listing the range and endurance as twice what they should be and a fuel flow and fuel used about 50% lower than they should be.

[Finn 873]

Regarding the 2D popups:

Pressing shift+2 should bring up the hole radiostack including the GPS.

The Autofeather lights section should have been deleted from the panel.cfg, since it is placed in the VC. It is simply a leftover from the beta testing phase.

Wothan

[Aerosoft Team [Inactive Account] 51558]

I can not bring up any other the other panels when using Shift -3 or 4. Shift 2 brings up the gps, but not able to display the radio stack or AF display. Some planes dont have this many options, is this all in the VC view on purpose? thanks.

We only have a 2d panel for the advanced radios. no other 2d panels were needed in our opinion.

[Aerosoft Team [Inactive Account] 51558]

Is there any chance of getting some cruise performance data? I notice that there is takeoff, climb, and landing data, but no information for power settings and airspeeds for cruise flight.

Also, there seems to be a slight bug with the GPS. Most of the modes work correctly, but the "other" pages seem to calculate endurance, range, and fuel flow incorrectly. From what I can tell, the GPS uses the correct value for the amount of fuel on board the aircraft, but it only uses the fuel flow data for one engine, which leads to the unit listing the range and endurance as twice what they should be and a fuel flow and fuel used about 50% lower than they should be.

I'll dig up some cruise data.

I'll also discuss the gps issue, that's a new one for me.

[flyfalcon 1]

Its also the first plane for me where that happens. And my specs are similar, more powerful CPU and twice the RAM but less powerful GPU. My best guess is that the 32bit texture format is just too much. I'll try to convert it to DXT3/5 and see if it helps. It should take a lot of load of the graphics memory.

Would be great if it works , keep me up to date

[WF442 1]

Regarding the pitch wit power change:

Be aware that You don´t pull Your hardware throttle all the way back for the descend or approach. Doing so will put Your propellers into beta range, something De havilland (in the realworld) doesn´t approve. The same goes for taking the propellers into reverse inflight.

Whilst on the ground: move the power levers forward until the two blue beta range lights go out. At that position You are in flight idle, note the position of the hardware throttle, cause that is the minimum You want to pull the power levers back to during descent and approach.

I guess you meant "the maximum you want to pull the power levers back"

And how is that going to work if the beta light stay on until i hit 80% of full power? Kinda difficult to fly the bird on approach with 80% power and props in full forward.. :wink:

I`ll just keep on trying to control the beast.

[Finn 873]

Yes the 80 % power is too much.

I guess Aerosoft needs to look into that.

I have some diagrams about the relationship between power lever movement and various lighs announcement.

According to those 50 % is more correct, allthough it still sonds rather high, but those diagrams are from a real world twotter handbook.

Wothan

[kingfish42 0]

I tried to find the glideslope "needle" again with no luck. The autopilot will perform a coupled approach, but no luck on the glideslope needle. Please advise.

Also, sound picky; but the beta range lights directly in front of the pilot are labled with "R" (presumably right) on the left side and "L" (presumably left) on the right side. I know this aircraft was designed before the advent of good layouts, but I doubt the designers would be that lax.

Also, no marker beacon lights. The audio for them works, but I couldn't see the lights on the panel, at least not in the pilot's view.

???

kingfish

[Finn 873]

There are no glide slope needle in the twotter.

Wothan

[Stefan Hoffmann 4160]

I land my TWOTTER with almost no power and 30 Percent flaps.

The airspeed should not fall below 68 Knots IAS. Keep in mind that

the airfoil has an difference angle of 2.5 degrees to the fuselage of this bird.

So when coming the pilot is look'in everytime a little downwards of the flightpath.

Also the glidepath should not be to narrow. This will bring the otters downside iton the airstream and you will have to pull to keep altitude and push the

throttle because you are losing even more speed. So sink in more you would , reduce throttle to your needed minimum bring up the flaps and break with them, flare with finger tip feeling because the TWOTTER will come up from alone.

I wonder why all the other folks not have the problem?!

I guess its the technique. If find the twotter is really easy to land, almost on a stamp!

[Aerosoft Team [Inactive Account] 51558]

I tried to find the glideslope "needle" again with no luck. The autopilot will perform a coupled approach, but no luck on the glideslope needle. Please advise.

Also, sound picky; but the beta range lights directly in front of the pilot are labled with "R" (presumably right) on the left side and "L" (presumably left) on the right side. I know this aircraft was designed before the advent of good layouts, but I doubt the designers would be that lax.

Also, no marker beacon lights. The audio for them works, but I couldn't see the lights on the panel, at least not in the pilot's view.

???

kingfish

Not every HSI has a glideslope option, ours does not, better get your descending skills ready. The AP was added with slightly more functions than it should have, that's explained elsewhere in the forum. Basically most Twin Otters do not have full ILS equipment.

The beta range lights will be changed, it's one of those issues that were corrected in the beta cycles but crept back in.

We could add marker beacon lights, but a quick look in the images we made for this project shows that most were removed or disabled, we'll think about it.

[Stefan Hoffmann 4160]

There are no glide slope needle in the twotter.

Wothan

For what a glide slope needle. LOL?!

This thing falls from the sky short time before standing still and you not

even have to flare her up much at final touchdown, she does it herself.

But you have to look at the speed. Dont drop her below 68 knots IAS while

landing and flare, that not a good technique.

Remember that your pull her up too near 80 Knots for takeoof!

So below 70 Knots she will not stall, but you will with each lost knots remarkably lose control.

If there is some wind against your nose, you can surely go slower.

Yes wind also an thing you should not underestimate, especially when it comes from the rear when landing.

[pbearsailor 9]

I flew one for 2000 hours in Samoa into some pretty short strips.

If you flew by the manual, it called for some really slow speeds on final with lots of power. One guy that flew with us tended to do it that way, made the co pilots nervous, but the rest of us tended to use a little more airspeed and less power. Personally, I'd use 30 flaps instead of full as it was less drag and easier to do a go around out of if necessary. I'd start my flare a bit high to bleed the bit of excess speed. Another guy was a believer in "cracking beta", or going over the gate with the power levers in the flare, but I'm just not comfy with beta or reverse in the air. Still another captain had the copilots flip up the flaps in the flare to make the plane settle. He had nearly 10,000 hours in Twin Otters and it worked for him.

Prop reverse was far far more important than brakes. The plane has so much lift, that it's really hard to get a lot of weight on the wheels until you're going very slow, so too much brake leads to locked brakes, sliding tires, and blown tires. Seen a few of those.

On our virtual Otter, I agree with some of the posts about the pitch up with power reduction. Just did NOT see this in the real plane, particularly down in the low power range, like in landing flare. I'd just try to hold the nose wheel a couple of feet high and let the mains settle as the speed bled off. No quirks in the way the Otter handled, she was totally honest.

cheers,

steve

[pbearsailor 9]

We could add marker beacon lights, but a quick look in the images we made for this project shows that most were removed or disabled, we'll think about it.

There are quite a few ILS/LOC procedures around that depend on the outer marker fix. It's not an issue if you have a glideslope (wish the Otter did) as your glideslope intercept will substitute for knowing where the marker is. If you don't have a glideslope, like in the Twin Otter, then all ILS approaches become LOC approaches and the outer marker becomes your crucial final approach fix. If you are flying an approach with only marker beacons and not an intersection or NDB at the same location, you'd be out of luck with the Twin Otter and couldn't do the approach.

I'd really like a glideslope, but if we can't, it seems the plane really should have marker beacon lights.

cheers,

steve

[Aerosoft Team [Inactive Account] 51558]

I flew one for 2000 hours in Samoa into some pretty short strips.

If you flew by the manual, it called for some really slow speeds on final with lots of power. One guy that flew with us tended to do it that way, made the co pilots nervous, but the rest of us tended to use a little more airspeed and less power. Personally, I'd use 30 flaps instead of full as it was less drag and easier to do a go around out of if necessary. I'd start my flare a bit high to bleed the bit of excess speed. Another guy was a believer in "cracking beta", or going over the gate with the power levers in the flare, but I'm just not comfy with beta or reverse in the air. Still another captain had the copilots flip up the flaps in the flare to make the plane settle. He had nearly 10,000 hours in Twin Otters and it worked for him.

Prop reverse was far far more important than brakes. The plane has so much lift, that it's really hard to get a lot of weight on the wheels until you're going very slow, so too much brake leads to locked brakes, sliding tires, and blown tires. Seen a few of those.

On our virtual Otter, I agree with some of the posts about the pitch up with power reduction. Just did NOT see this in the real plane, particularly down in the low power range, like in landing flare. I'd just try to hold the nose wheel a couple of feet high and let the mains settle as the speed bled off. No quirks in the way the Otter handled, she was totally honest.

cheers,

steve

Thanks Steve for the comments. I really value your input on the flight model. We are not totally sure how to model that as we put the engine trust vectors right where they should be and let FSX handle it from there.

Could you do me a favor, fly some speeds and see if we can dampen all the whole pitch movements? If we can do that it would allow us a way out of the problem without having to move the engines around (that leads to all other kinds of problems.