diff. braking - only an issue when in ME chosen "takeoff from ramp" - "takeoff from RWY" goes well

[wernst]

Differential braking during taxi and takeoff is still an issue.

But I have found that, oddly enough, this problem only exists when you taxi from ramp to the runway and then take off. If you build a mission in ME and choose the option "takeoff from RWY", then the take off run is easy controllable. The Mossi keeps almost straight on the center line of the RWY - without any diff brake control. As soon as the rudder has enough wind the plane can be steered with the pedals alone. It seems as if the position of the tailwheel in the "takeoff from RWY" mode is exactly aligned and is somehow fixed in this position during the TO run. 

In "takeoff from ramp" mode rolling to the runway leaves the tailwheel in a random position when arriving at the RWY takeoff position, even when you try to carefully center the plane. As result the random tailwheel alignment leads to continuous direction corrections during the TO run -  compensation  is possible with less than moderate success. 

The diff. braking system can be relatively well used for steering while taxiing. But for takeoff it strongly depends on which option you have choosen in the ME: "takeoff from ramp" or "takeoff from RWY".

TO assist alway kept to "0".

Edited November 12, 2021 by wernst

[razo+r]

Not sure what to say. I mean, the brake system is not an issue. With enough practise, you can come out of a 90 degree turn on the ground and directly accelerate without an issue of keeping the aircraft straight with brakes at the beginning of the run. 

I also dont have any issues keeping it straight after startup and holding short on the runway and then taking off. And I also have my brakes mapped to the paddle switch. 

And by the way, it does not leave it in a random position, it will stay in the position of your last direction of travel when stopping. You can use this to anticipate the direction of travel already before you add power. 

So what about you doing a video for us to show us a potential mistake in your takeoff procedure, or more practise? 

[wernst]

29 minutes ago, razo+r said:

So what about you doing a video for us to show us a potential mistake in your takeoff procedure, or more practise? 

There are no potential mistakes in my takeoff procedure . . . provided I have in ME chosen "takeoff from RWY". In this case TO is alway easy and successful.  

Regardless of "random" or "last direction of travel", the tailwheel in "takeoff from RWY" mode is alway in a position for easy takeoffs. Why is this different to "take off from ramp"?   

Edited November 12, 2021 by wernst

[Basco1]

Mmm.....As razo+r,no problems here either,all working ok.......it's got to be how you set yourself up on the runway,suggest you line up straight and make a point of pulling forward a little bit just to ensure the tail wheel is straight.

I always start from the ramp or parked position using ME because I like to start from cold......and once I have taxi'd and have turned on to the main runway I always get myself straight by just pulling forward a little to ensure the tailwheel and the aircraft are lined up straight before my off.

[razo+r]

48 minutes ago, wernst said:

There are no potential mistakes in my takeoff procedure . . . provided I have in ME chosen "takeoff from RWY". In this case TO is alway easy and successful.  

 

If there werent any potential mistakes, then you wouldnt have any issues taking off, would you? 

 

48 minutes ago, wernst said:

Regardless of "random" or "last direction of travel", the tailwheel in "takeoff from RWY" mode is alway in a position for easy takeoffs. Why is this different to "take off from ramp"?   

 

Because with takeoff from runway, the plane is placed on the runway and TW is set straight. When you start from ramp, you drive around and turn the TW depending on the turns you take and potentially keep it in a turned position on the Runway. 

Edited November 12, 2021 by razo+r

[Bozon]

@wernst

I can’t see the effect you are describing.

When you turn to align the plane with the runway and stop, the tailwheel stays at the last angle - on a tight turn this could be a very large angle, closer to 90 degrees than to 0. If you start the takeoff run from this position, the first thing that will happen is that the tail will continue to turn in the direction it did just before you stopped. You will start your run already swinging from side to side.

To prevent this, what you are supposed to do is to continue straight (not touching the breaks) for a few meters after you aligned yourself with the runway and the break to a stop with even pedals (so no diff. braking at the last moment). The you end up ready fir t/o with the tail wheel aligned.

Personally, I start the t/o run by gently rolling down the runway steering with the breaks and increasing power gradually as I see that the plane keeps a straight course. Very quickly the rudder starts to respond and then I can go full power. It might not be the shortest possible t/o run, but it is very easy.

[grafspee]

I noticed it too, the last position of TW determine to which side Moosie would turn in initial take off roll, so more straight TW will be the less work during take off is needed.

Problem with TW is when you taxi to runway, you can't straight TW perfectly if you spawn on runway TW is perfect straight.