Simviation Forums

I have been an avid user of FS9 for many years and recently moved over to FSX SE. Interestingly a problem still persists in that a number of freeware aircraft when
selected actually move forward when activation begins. This can be for both apron start or active runway, and in some instances the aircraft gathers speed when taxing.
I have ensured calibration on the joystick (Thrustmaster) is correct. Has anyone experienced this? Also is the aircraft speed determined through the aircraft cfg and if
so can it be altered.
Thanks ROY

You don't say which aircraft you normally fly. One difference between FSX & FS9 is that in FSX Free Flight the aircraft loads without the parking brakes applied. You could always save a flight with brakes applied & make it the default flight. This might well fix your problem.

Thank you for the reply. There are numerous aircraft, both civil and military. Yes you are correct fsx does load without parking, yet most aircraft are stationery. An example
is I have two ATR 72 down loaded from separate sources. As soon as one of the aircraft is loaded I have to manually apply full parking mode. I was wondering how the aircraft configuration is applied in reference to the aircraft cfg. possibly contact points or something similar.

roymonty wrote:I have two ATR 72 down loaded from separate sources. As soon as one of the aircraft is loaded I have to manually apply full parking mode.

I suspected the problem might be with turboprops. I have no experience with them myself but understand the power controls are different from those on piston engined props. To make taxying easier you might try moving the 'Condition' levers to the Low Idle position.
See this article --> http://www.skybrary.aero/index.php/Condition_Lever

I was wondering how the aircraft configuration is applied in reference to the aircraft cfg. possibly contact points or something similar.

The Aircraft.cfg Contact Points entries define the landing gear & scrape points & have no effect on power.

Hope I'm not preaching to the converted.

Thanks for your assistance. In the meantime I have been experimenting with another aircraft - Mirage 2000. Again I use two versions, and noticed in the aircraft cfg file
for the static aircraft differed from the moving Mirage. In the section JET ENGINE there is a scalar rating. I have adjusted the cfg file to match the static aircraft and
on this particular aircraft it seems to have worked. Will now try others.

IMPORTANT if anyone wishes to try this, as always, please take a copy or backup files.

Regards ROY

Hi,
It shouldn't be necessary to modify the cfgs. This sounds like the default flight was saved with either some amount of forward motion or revved up engines. I suggest re-saving the default flight with every thing stopped and see what happens.
Jim F.

jandjfrench wrote:Hi,
It shouldn't be necessary to modify the cfgs. This sounds like the default flight was saved with either some amount of forward motion or revved up engines. I suggest re-saving the default flight with every thing stopped and see what happens.
Jim F.

Yes, this should be the origin of the problem.

The best way to prevent this is to set up your default flight as cold and dark. Nothing running and no power at all.
On turboprops there is a setting for the propellers. I do not know if you have ever seen a real world turbo prop sitting on the ramp you will notice the propellers are in a feathered position. In the real world aircraft after starting the engines the pilot sets the pitch of the props accordingly. The problem with FSX is most freeware turboprops this lever does not have a lot of effect on taxi speeds. The default King Air is a great example that aircraft taxi speed is way to fast. Setting the pitch all the way to minimum has no effect at all. I installed a auto taxi gauge into the aircraft so now it will not try to take off going down the taxi way.
Now there is probably an adjustment you could make in the aircraft cfg file. But I do not like to change anything in this file since I do not know which setting to change or which way to go with the setting higher or lower.
I am not a aircraft designer so I do not change things that I do not understand
And a lot of freeware aircraft out there are not designed well at all. They may look great but fly like a rock or taxi like a SST or both.
One does not have that problem with payware these people are engineers and actually know what they are doing.The planes they make look great and fly like the real thing.
Mind you there are some great freeware designers out there ALROT is one of them but unfortunately others are not that good at it. So choose wisely my friend.

The main constraint is that most turbo prop aircraft do not properly model BETA mode for propellers. With engines running in parking, the pilot will normally beta the props. This is a state of zero thrust. You can try applying a little bit of reverse to counter the constant forward thrust to simulate beta.

The other solution, as already mentioned, is to to set condition to low idle. This reduces the power output to the propellers. Taxi in low idle with your props set to as fine as you can. When you pull into the runway, push your condition lever to full power and set power for takeoff.

Prop control is for use in flight. you want to angle the prop blades for the most efficient cut into the air. If you leave them at fine while in flight, you are creating more drag than thrust.

With jet engines, there's not much you can do. Jets produce thrust, even at idle power. Set parking brake when parked.

I don't recommend messing around with power scalers. This could mess with your power for phases of flight too.

Save a state with parking brakes applied, or cold and dark, as you see fit.

I never had too much trouble controlling a Turbine Prop aircraft on the ground, using the Condition Lever(s).

My difficulty was/is always trying the reduce speed quickly when attempting to land!... ...!

Shut off the throttle on a Piston Prop aircraft and its like putting the brakes on!.... ....

...on a Turbine Prop aircraft.....nuffin' appens!.... ....!

Paul.....in no condition to slow down.... ....!

My definition..... ...>>>
Turbine Prop: An aircraft fitted with a Turbine Engine.
Turbo Prop: An aircraft fitted with a Turbo-charged Piston Engine. (Beech Baron TC).
...... ... ...!

Fozzer wrote:My definition..... ...>>>
Turbine Prop: An aircraft fitted with a Turbine Engine.
Turbo Prop: An aircraft fitted with a Turbo-charged Piston Engine. (Beech Baron TC).
...... ... ...!

Sorry Paul. Your definition is wrong. https://en.wikipedia.org/wiki/Turboprop

We've been here before. Please don't confuse the issue.

Hagar wrote:

Fozzer wrote:My definition..... ...>>>
Turbine Prop: An aircraft fitted with a Turbine Engine.
Turbo Prop: An aircraft fitted with a Turbo-charged Piston Engine. (Beech Baron TC).
...... ... ...!

Sorry Paul. Your definition is wrong. https://en.wikipedia.org/wiki/Turboprop

We've been here before. Please don't confuse the issue.

....its WAR!.... ....!

Paul....in a nice sort of way, on a pleasant sunny day.... ...!

One of my greatest Flight Sim Delights is poking Doug with a pointed stick...and see what 'appens!.... ... ...!

Power management on turbo props takes spme planning. The engines take time to react to power adjustments. On landings you want to be stabilized in decent profile and power setting well before reaching the runway. Trim becomes very important for minor speed adjustments. Vertical speed is then managed more with engine power, rather than control surfaces. And if you start dropping too fast, you might get a bit of a scare when you add power...and those few seconds for the engines to react seem like an eternity.

The problem with the default turboprops is this.
Everyone knows that any prop driven aircraft will try to pull in the direction that the prop is turning. On a two engine aircraft the props should turn in opposite directions which should mean that they cancel each other out and should not pull to much in any one direction. Not the case with the default King Air 350 this plane is all over the taxiway and runway. The Beechcraft Baron is not that much better it has the same problem but not as much pronounced
As for my definition of Turboprop I always thought it was just that a turbine with a prop attached.
Where a turbojet was a jet engine with a prop attached the difference is obvious from the outside all turboprops have exhaust pipes that are just behind the prop where a turbo jet does not and looks more like a true jet engine
A good example of a turbojet is the C130 or the P3 they booth use a JT50 I believe
Another quick way to tell the difference is when you shut a turboprop down the prop will automatically go into a feathered position and when you shut down a turbo jet the prop will free spin for some time.
While in the military I worked on the flight line of VW4 also known as the Hurricane hunters which is why you see my squadron patch as my avatar. It used to amaze me that when in ground idle you could light a match behind the spinning prop and it would hardly blow it out. Which was one of the reasons it was so dangerous at night. You can not see the spinning prop and all you hear is a constant roar and the fact that there is hardly any wind behind the prop forget where you are at and make the wrong turn and it might be your last.
If you have ever worked on a flight line the one place you never walk is in the prop arc of any engines. It is not good for ones health.

Every one should know that one of the most dangerous places to work is on the flight line of a aircraft carrier. Most people do not have a clue as to how dangerous that really is.
My hat is off for those who do this for a living. It is not a place for the absent minded person. All it takes is to get blown off the flight deck and your odds of surviving it are slim.
If the 60 to 70 foot fall does not kill you than the screws will. The main reason you will see nets on certain places of a flight deck of an aircraft carrier.