H9 33% Pawnee Tug Conversion

[stevekremer]

Got the tailwheel mounted and connected. Went with the Whiterose Engineering Tailwheel.



Steve K

[stevekremer]

Well, here it is. Done! Not really, need to balance, set throws, and do a littl programming. Thanks to all that guided me through this.

Steve K

[stevekremer]

Took the Pawnee for Maiden. Flew well and towed Kevin's 233 at Harris Hill. Cool.

Steve K

[lenb]

Look at you two!!!!!
Hard to believe only 3 years ago you just got serious about aerotowing. Very cool.

Way to go guys!


Len

[Xroadie]

We test flew the Pawnee that I assembled for a friend Saturday. It flew great, what an easy flying model, zero trim changes needed on the test flight...or subsequent flights. With the DA100 it took off at less than half throttle and at full throttle attained a steady climb angle. No elevator compensation needed with flaps deployed. Can't wait to tow with it!!

Pete

[Steve P]

Congrats, Pete!

[Swiss1]

Well done Pete
Jeremy and Ben
SCCAAA TT TN

[stevekremer]

Doing some work on the Pawnee, thought I would post pictures. Also wanted to show the new realistic pilot I got. Steve K

[JimD]

I like the shout out to Horizon Hobby with the N number also! 👍

[Sinkhappens86]

Enough full size stuff on here... back to business. Making some progress on the newest Pawnee. Wings are 99% complete, landing gear reinforcements are done. Waiting on some more packages to arrive in the mail to really make some more progress on it.

Going with Jim's plan to put the release closer to the CG, mounted on either side and using a bridle to connect it to the tow line. Still not totally sure how to go about reinforcing the spot for the release. Any thoughts?

[JimD]

Looking at your last picture above, I would put a 3/8" basswood stick across the fuselage at the intersection of the former and stringer under the door. Then add plywood triangles between the basswood stick and the stringer aft of the former. Tow release would be located just in front of the basswood stick. Forces created by the pull on the tow line should be countered by this added structure...IMHO. 😎

[AGriffith]

I gotta ask, if the tow point behind the canopy has worked for hundreds of tows, why do you feel the need to do a bridle? I had I don't know how many tows on mine, Marc Simmons another who knows how many hundreds, and all the ones that Horizon has been using.

[lenb]

Hi Andy,
I'm usually the same way, if it works why reinvent the wheel, however on this one the tow position is really in the wrong location. Its something like 22" behind the CG. Numerous times at the Horizon event if a big sailplane got too high on the tug it will pull the tail up and the tug is pretty much out of control. I've seen it happen quite a few times, so this is an attempt to see what can be done and perhaps improve and already good tow plane.

Missed you at Horizon this year!!!

Len

[jgallacher]

I have a Legacy Turbo Duster (low wing) and I am using a bridle on it. The only problem I had was the ends of the bridle slapped the under side of the elevator when I would drop the line before landing. A couple of times I had the line catch on the elevator servo which is proud of the side of the fuse. The fix was to add a length of Ny-Rod outer sleeve over each half of the bridle. The Ny-Rod sleeve extends back over the elevator. Now when I release the line the ends of the bridle go straight up as the elevator drives under the bridle ends.
Jim

[JimD]

I have experimented with placing the tow point in a more aft position on a Hangar 9 Decathlon. With small to medium size (Blanik and ASW20) sailplanes, this was not a problem...maybe even better than a more forward placement like on the TopModel 3.2m Porter. BUT, as the sailplanes got larger (6.6m Arcus and Duo Discus) keeping the sailplane in just the right position behind the tow plane became increasingly necessary. This became extreme when we tried towing the 8.0m sailplanes. Tow plane and sailplane could get radically out of shape in the blink of an eye!

When I moved the tow release further forward on the Decathlon, things improved remarkably with the big sailplanes. Having had this experience, and watching many Pawnee tows, I think the Pawnee would do a much better job towing the big stuff with this more forward placement. As I said, the smaller to medium size sailplanes were no problem and hence I agree with Andy that the Pawnee has been a great tow plane...but sailplanes keep getting bigger and that is placing more of a challenge on the tow pilots and their planes.

[AGriffith]

Gotcha, all good points.

[Sinkhappens86]

Does anyone have a photo of the Ohio Superstar 1/3 scale tailwheel installed?