Twin Otter X: open issues

[Ken Stallings 1]

In anticipation that this was the issue, I tried this also without success.

When I pulled back all the way on the throttle quadrant prop lever, I also used Track IR Pro and the mouse to "pull" back all the way on the VC prop lever.

What I observed is that visuall speaking my throttle quadrant lever was pulling back the lever in the VC all the way back also.

What you describe is exactly what is happening in the Cheyenne that Aerosoft sold for Digital Aviation. To feather the prop in the Cheyenne you have to pull the throttle quadrant prop lever full aft and then go in and use the mouse to "pull" the VC lever into the feather detent.

While I'm not thrilled with this it is an acceptable method.

But this isn't what I see with the Twin Otter.

Cheers,

Ken

[Ken Stallings 1]

I also tried to assign a keyboard command to the FS-X prop feather command that that did not work properly either. I tried two inflight feather operations to the left engine. On the first one with everything isolated, including the fuel cutoff switch engaged, the prop lever pulled full aft, and the keyboard command pressed, the prop did not feather for several minutes of flight. Far too long to be realistic and of practical use to a pilot experiencing a need to shut down an engine in flight.

Now, the first time, after flying a box pattern around the airport at 2,000 feet AGL, the prop suddenly feathered. I did nothing different. Clearly, the aircraft finally detected something that dropped the RPM.

However, I performed an inflight re-start and as I reported weeks ago, the number one engine went to full thrust, out of control, with the throttle pulled to idle. In actual flying, this would be considered a fuel control failure and a runaway engine. This would be a classic in flight condition calling for an immediate engine shutdown.

So, I performed the proper procedure again, throttle to idle, prop lever full aft to feather, and fuel mixture full aft to cutoff. I then hit the fuel shutoff switch and added the keyboard command for feather.

Nada, nothing. This time no matter how long I flew around the airport, the prop never feathered.

I did a single engine landing. Just as has always been the case, without making any changes to switches or levers after the plane touched down and airspeed bled down to below stall the left engine prop stopped turning -- a classic indication of windmilling prop.

Folks, I reported this in detail several weeks back. It is clear that Aerosoft has chosen against fixing this issue.

It is Aerosoft's decision, but I must say this decision disappoints me. Perhaps most customers could not care less, but I think for those who enjoy flying twin engine aircraft in a realistic manner, this inability to properly feather and shut down an engine in flight robs people of enjoyment.

I would urge Aerosoft in future to consider this an integral part of modeling a virtual aircraft, especially multi-engine aircraft. A proper shut down procedure should result in a feathered prop standing tall. An in-flight re-start should not result in a runaway engine, but rather a successful re-start. Anything less should be regarded as a plane not ready to emerge out of beta.

I sincerely hope Aerosoft chooses to adopt this policy for all future aircraft.

Ken

[JAL 0]

Hmmm...

Here's what I do: Throttle to 0, condition lever (mixture) to cut off, prop back to the stop. Then I press my key command. It is assigned to: Propeller (decrease RPM Quickly) make sure it is NOT on Propeller (low RPM). I should have been more specific about this in the last post I hope it is where we are doing things differently.

I do this and I get the prop on the dead engine to feather completely a few seconds after pressing the key.

Please try that and (fingers crossed) it should work for you.

I'm not sure about the restart at the moment. I don't have time to test, but I'll try later and see if I can figure something out.

John

[Ken Stallings 1]

In order to be correct, you pull throttle first, then prop lever, then mixture. The reason this order is vital is that you first pull the throttle to idle to ensure you are shutting down the correct engine.

You see, the prep step is to cob full power. So that when you pull the throttle of the problem engine (the one losing power) you can tell with an auditory sound reduction if you are pulling the wrong throttle. Also you reference engine instruments to ensure you are not pulling the wrong engine.

This is also backed up with the classic mantra, "Dead foot dead engine," which means that intuitively you have to apply rudder to counter the engine producing good thrust. If the right engine is producing good thrust, but the left not, then you have to apply right rudder to counter the asymetric thrust produced by the right engine. Ergo, the foot not pressing the rudder is the dead foot.

Took a long time to explain it, but in reality just a few seconds to recognize and execute.

Once the correct throttle is pulled to idle then you quickly pull the matching prop lever. Again, this is vital because of the lockout funtion of many props. If you wait too long, the prop pins will engage and prevent the blades feathering. At this point, you're screwed and have no alternative to the drag producing speed brake called a windmilling prop.

Only after these first steps do you take the final step needed to shut down the engine. You pull the mixture to idle cutoff. No fuel, no thrusties. Basic and unrelenting law of aviation -- no fuel and engine cuts off.

What autofeather is designed to do is if the engine experiences a catastrophic failure on takeoff (full thrust with greatest asymetric problems) then before the RPM can drop below the point of feather, the autofeather will feather the prop for you. But autofeather does NOT shut down the engine. So the prop will not stand tall.

So pilot procedure is precisely the same for autofeather. Apply full power, retract flaps from full, retract gear, retract flaps up on blue line, idenitfy (dead foot dead engine), verify (pull throttle and verify the right engine), feather (pull the prop condition lever full aft). Then pull the mixture to idle cutoff to shut down the engine, and clean up by moving the fuel cog away from the bad engine (either crossfeed or the other tank), close the cowl flap of the dead engine, turn off alternator for dead engine, and turn off magnetos for dead engine.

These final steps totally isolate all fuel feeds and electrical feeds to the bad engine. This is imperative if you shut down for overheat or fire. Of course as the Twin Otter has, some aircraft feature fire handles that do this automatically. It severs all fuel feeds and electrics feeds to and from the engine.

For the Aerosoft Twin Otter, if I want to "trick" the system, I just engage autofeather and pull the mixture lever to idle cutoff for the engine I want to shut down. Works every time to get a feathered and standing tall prop. Better yet, I get a good air re-start. But, it isn't right.

But I hope folks can understand why I am emphsizing this isn't the way it works for real. I respect that Aerosoft feels it has run out of time and has no financial interest in devoting more time to the Twin Otter. I just hope with this level of detail they can understand now why some folks feel it's important to get it accurate.

Cheers,

Ken

[JAL 0]

That was it! Thanks Ken! Now I see how I got the difference between the my new air file and the old one

I'm still a bit confused, but now I when I do the procedure: throttle to idle, prop back to the stop, key stroke, condition lever to cut off it doesn't work in the 1.10 version, but does work in my new air file.

Whew!

Restart seems to work fine although I'm really pressed for time now and I'd like to do this over and over about 20 times to make sure everything is working.

But so far so good.

Cheers,

John