New SC Owner with Questions?

Hello all on ths fantastic site:
I purchased a 1963 SC last fall and have about 15 hrs in it now. I've noticed a few things.

1) I notice that on hard surface I have to taxi at a slight angle to maintain a straight line. I have 850x6 tires. The plane had a mishap from a privious owne when it went into a ditch and a wheel folded under. But the mechanic who repaired it said the "A frames were ok". I'm going to try to check tracking using straight edged lumber on the tires and see if any look off line. But how does one straighten misalingment?

2) Looks like all ADs are complied with and 337s for all changes and major work except a tow hook installation which we cannot find even entered in the logs we have. How would one go about getting that approved when we suspect the person who did it we guess about 7 years ago was not a mechanic. But the installation looks exactly according to AC 43-13 writeup.

3) The left wing was replaced due to the mishap mentioned. I notice in cruise , ie 2300rpm and 100 mph indicated, the left wing is heavy. I will be replaceing the right wing struts with AD free ones from Univair (the replaced left wing came with AD free struts). I guess that will be the time to maybe increase the washout on the right wing. Wonder if we should go thru a complete check of the rigging? I'm working with an IA who did the repairs.

But what fun flying anyway. I intend on flying out west this summer and do some backoountry camping. Also have a flying 1941 J3. And I'll keep reading posts here as I have for the last several months!

Thanks, Jim

Oldcuby,

Check the toe in toe out and if you have to straighten it, remove wheel and brake assembly and fabric etc. and heat the bottom of the landing gear where the axle meets the V. Put a big pipe on the end of the axle and straighten.

Getting the tow hook approved shouldn't be a problem as long as you have an IA who is willing to inspect the installation and sign it off as previously installed by persons unknown and meets the criteria as in AC43.13.

When you install the new struts definitely go through the entire rigging procedure including the tail.

Welcome to the site and enjoy your supercub.

cubsunlimited@verizon.net

Re: Alignment, sound advice in previous post (as always), but also take a close look at the tailwheel mounting pad, and alignment of the tailwheel springs: These frequently get tweaked in any incident leading to wing repair, and sometimes just groundloops not logged anywhere. It's possible the entire aft fuselage may be twisted a bit, I've seen (and flown) a few like that.

Re: Towhook installation, Schweizer Aircraft out of Elmira NY has multiple STC for this installation on Supercubs, but many have been done on Field Approvals, especially when they have release handle in a more useful location than down on the floor by the flap handle. Think big bellcrank, with the Oh-s**t knob near the throttle, where your hand is likely to be, and enough leverage to actually release under severe upload when 'Ham-Handed Hans' kites on you.

Don't forget the W&B change, as it's on a pretty long moment-arm. And heck, if You don't plan to tow with it, consider taking the durn thing off.

Just my thoughts. Thanks. Cubscout

Probably not the problem but check your tailwheel spring to see if its overly bent.... alot of steering issues come up when your tailwheel is tweaked in the down position... If it were me I would go one step further and buy a new pawnee tailspring..... As for the rigging.... I would have someone who knows how to rig a cub check it for you.... Its easy enough to get it straightenened out
Good luck

Due to past history purchasing aircraft, I have learned to try and find a mechanic that has never seen a plane to check it over before purchase. Hopefully one that I trust!

If the cub went in a ditch, bent a wing etc, there is a chance that the frame is less than strait. (in fact, it doesn't have to be in a crash for some frames). Measure from the outboard of the ailerons to the tail attach points and check for square.

But to get the wing heavy, suck down the rear fork on that wing a turn and give it a try.

Welcome to the greatest site for SC's (and PA-12s)

Good advice given, just the fact that the wing was replaced and new struts is enough to make the wing heavy, even if the rigging is per book. Original piper wings are lighter then the stamped rib, wings and likely the covering is heavier as well. The tail wheel/spring/rigging is likely the taxi problems. Very few Cubs that have actually been "used" have a perfectly straight anything., it would amaze you how bent they can be and still fly well. My best Cub was when finally taken out of service, over 6" off longitudinally and 3" laterally, from fitting in a jig and it was the "lightest feeling" best flying cub out of a 1/2 dozen or so I have owned.

Good Luck and if you get clear to the left coast this summer look us up,
We will be having another Snohomish fly-in in late July or early August.

Tim

Thanks to all for your comment. I see that "cubunltd" is not that far from me. I'll have to stop by when the wx permitts to see your cub restoration operations.
My struts are painted so next chance I get I'll get them installed. I do notice that the tailwheel spring is slightly cocked counter-clockwise looking from the rear. Wonder if that can be straightened with some washers. I'll look into new springs as one suggested. But we will go thru the full rigging procedures. I'll check to see if the left wing really matches the right.

I'll be happy if I could just get the plane rigged so that it feels like its taxiing straight and flys reasonably triimed in cruise.

I was in Mountana last summer for the first time and now can't wait to go back by plane. Bought Fly Idaho and the Big Sky guides along with SC videos. So hope to run into some of you folks along the way.
Thanks again and good to meet all.

Just a long shot, but do check your ailerons to make sure they are absolutely straight, and identical!

Hey Oldcuby,
Just let me know when you're coming. I'll be more than glad to show you around and check your Supercub out.

John

cubsunlimited@verizon.net

Further tests:
Went flying today in cold but very calm wx. The PA-18-150 flew straight and level at these settings:
2000rpm 80mph indicated
1800rpm 60mph
1700rpm 50mph and half-flaps.
In all cases, I could take hands and feet off controls after it settled down and see no tendency to drop that left wing. The ball remained mostly centered too.
But with 2300rpm and 100mph , the ball(T&B) moves right and the left wing starts down and with hands off, just gets worse. Holding right rudder does not hold the left wing up without excessive rudder thus moving the ball to the left of center!
Trying to think what could correct that. Maybe more on the right wing washout might still do it without upsetting trim and lower speeds and higher angle of attacks. Guess torque is a factor too. Will just have to experiment.
Jim

I would start over and have everything checked according to the book... This will give you peace of mind everything is true and correct and if it still doesn't fly straight it will give you a place to start from... just my thoughts... good luck

I sort of disagree with that. First, ASK YOURSELF "how am I going to USE this airplane?". NO airplane can ever be rigged to fly "hands off" at every speed possible to fly it. The "properly rigged" airplane flies straight and level "at normal cruise speed". Are you going to blast around "normally" at 100 mph in a Cub, or are you more likely to "pull 'er back some" and loaf around at 80 and a MUCH more affordable fuel burn? A "check" to make sure the rigging is SOMEWHERE around what the book calls for is fine. Great, even! But if you are going to hang there on a quiet evening with a big grin, surveying your expanded horizons, maybe that airplane is rigged PERFECTLY just the way it is! I wouldn't start twistin' stuff to start all over again until I was darn sure it isn't going to be 12 hours of flight time before I get it RIGHT BACK to the way it is now!

What are you using to determine you have to "taxi sideways"? Because the nose points off to the right of the runway centerline just a little bit? or does the durn thing dogtrack like a Blue Tick on the way home from an all-night hunt? The engine (and the cowl) IS slightly offset to the right, y'know... DOn't make work for yourself unless you HAVE TO.

Wingie,
I tend to agree with you about the trim in flight. Sorta getting used to holding slight right pressure on the stick when running 100mph. I was not expecting how well it flew at those other lower speeds.
On taxiing, the plane's nose has to be to the left slightly to stay on the centerline. If I taxi with the nose straight down the line on the taxiway, the plane drifts to the right. On landing I now crab slightly to the left on a 3 point touchdown to achieve a smoother touchdown (if I'm lucky!). I'll be checking everything along side the IA when we can schedule the replacement of my right side wing struts.
Wish all runways were grass.
Jim

OldCuby; Well, I had my say and I stand by the basic sentiment. But it sounds more and more like you need a Wrench that knows exactly what he's looking at to walk around your airplane at least once. Anybody can eventually find what's wrong, given enough time...but you need somebody that works around Cubs regular. If you're only a short Hop away from cubunltd, then he's probably your guy, and he HAS been doing Cubs a while now. Pointing considerably off to the LEFT on taxi probably means some kind of misalignment, and you ought to get that looked into. Having to "boot it around crooked" on touchdown sure ain't right! I herein formally recommend that you "seek professional help". Make arrangements to get the struts installed and the airplane rigged again at the same time. Happy flying!

I guess flying crooked is ok if that is what you are happy with..... I know that fighting an out of rig airplane can be a pain the #@@.... doesn't matter if its a PA-18, a PA-31 or a 747.... I for one want to know why it isn't behaving properly... sometimes it is just the way it is.... But isn't it nice to know why its not behaving rather than just going along with it....