landing as short as possible

[PACERGUY]

The issue is you have a adjustable stabilator not just a trim tab on the tail. The stabilator if trimmed nose down is lifting the tail while you are trying to flair with the elevator that is why it feels you are running out of elevator (if fuselage is straight). Go up to safe altitude for a stall and set the plane up for slow flight. Say 2000 rpm and full flaps. Now dial in your trim for no pressure on the yoke at landing speed, say 55 mph. Note the trim setting as a starting point. As you approach with that setting on final you will most likely need forward yoke pressure to maintain your airspeed on final, this will give you the feedback you like it is just forward pressure not back pressure. As you slow to flare you will come to the no pressure point your airspeed should be about what you had altitude now add some back pressure as needed. You can dial this in over time to stall speed so you know if you are pulling back you will stall. This helps in keeping your eyes outside so you do not have to look at airspeed. This topic is debated on the cub site because some prefer the feel of pulling the stick and like to trim nose down to help roll onto a wheel landing. The problem with a cub is hard braking will put it on the nose pretty easy, pacers are more forgiving. I think you will find proper stabilator adjustment will solve you problem. I would not make radical trim changes just dial it in over several landings.
DENNY

[TxAgfisher]

PacerGuy, that is interesting. Is that something I can physically see on the tail feathers? I don't recall seeing anything but again it's a new airplane for me.

Edit to clarify - are you referring to the horizontal stabilizer or something else?

[PACERGUY]

Yes the horizontal stabilizer, Sorry I used the wrong terminology a stabilator is a combined horizontal stabilizer and elevator that moves as a unit( this is the inferior trim tab found on many aircraft). In any case go look at it. the front of the horizontal stabilizer has quite a bit of movement as you trim and when used properly will help a lot in both takeoff and landing. Pacers and cubs are pretty forgiving overall with whatever you dial in. Not so much in the Cessna 180/185. If I really want a soft landing in the cub I just roll my trim back on short final to the speed I want and float on in. If I am going to hammer the brakes I am full nose up trim in case the tail comes up. as TomCam12 points out more nose down trim lets you roll on the mains with no effort but, be careful how hard you brake. Doing the forward pressure on the yoke thing is also hard to get used to sometimes. Just play with it I bet you won't need any gap seals or other mods once you figure it out. Keep us posted on how it works.
DENNY

[flynfish]

PacerGuy, that is interesting. Is that something I can physically see on the tail feathers? I don't recall seeing anything but again it's a new airplane for me.

Edit to clarify - are you referring to the horizontal stabilizer or something else?

What you can see on the outside is the little slot that I've circled in the photo. The front of the Horizontal stabilizer moves up and down in that slot driven by a jackscrew assembly that is rotated by the trim handle. Unlike the trim on a cessna or other that adjusts a tab on the trailing edge of the elevator. You can see a drawing of the jackscrew assembly in the first post of this thread. There is a photo further down the thread.

IMG_2782_Marked.jpg

[TxAgfisher]

So the AOA in a sense changes instead of using a trim tab?

[CamTom12]

No, just reduced authority with a tab.

[PACERGUY]

CamTom12
I think he means the AOA of the horizontal stabilizer, not the wing. Adjustable decalage would be a better discribtion.
DENNY

[flynfish]

So the AOA in a sense changes instead of using a trim tab?

Yes, the AOA of the stabilator increases or decreases which decreases or increases downforce on the tail. Which effectively cancels out any work the elevators need to do (hand trimming) in maintaining that same down/up force. There is limited travel (+24deg, -12deg)in the elevators. If I use 5deg in either direction by hand trimming in the approach, Ive lost that much control movement in the round-out/flare. My preference is to trim to neutral with any throttle change of flap movement. My first few dozen landings in the Pacer were a bit uncomfortable as the elevators felt "twitchy" at slow speeds compared to other aircraft.

[Gilbert Pierce]

Never flew a ShortWing other than the Vag that needed full back stick to land at any gross weight.
Are your elevator bungee springs still attached? Removing them reduces the longitudal stability and are required by the FAA to pass certification.

[CamTom12]

Yes, the AOA of the stabilator increases or decreases which decreases or increases downforce on the tail.

Seems like a minor correction but there's importance in the semantics. Moving the front of the trimmable horizontal stabilizer changes its Angle of Incidence. The Angle of Attack is affected by a few other factors.