The Fly Baby Maintenance Log

Let's help each other keep up with what problems to look out for with our flying aircraft. If you have a problem come up, please email me details and I'll add them here.

These reports aren't intended to point fingers at anyone. Rather, for safety's sake, we just want to spread the knowledge of what could go wrong with our aircraft. It'll help us find out if the same sort of problem crops up in more than one aircraft, too.

I'll start out with a couple of old ones:

Stick Weld Failure (~1989) - Ron Wanttaja

When performing the annual inspection of N500F, the A&P noticed a bit of play in the control stick. Checking the lower section, a failed weld was found. Stick was removed and the weld restored.

Tailwheel Horn Tear (~1988) - Ron Wanttaja

One arm of the horn bolted to the rudder spar for control of the tailwheel was found to have a large tear in it. The horn was removed, the tear was welded up, and reinforcement was added (this is documented on the Advice page)
Drew Fidoe reported the same sort of tear in the late '90s.

Wing Anchor Plate Failure (May 1999) - Scott Hinton

Fly Baby N96MG was lost when the forward left flying wire anchor plate broke. Aircraft was using solid tie rods instead of the standard cables, and it is suspected that vibrations in the wires fatigue-cracked the plate. Recommend solid wires (tie rods, streamlined flying wires, etc.) not be used.

Tailwheel Spring Mounting Bolt Failure (July 1999) - Ron Wanttaja

Upon landing, the tailwheel shimmied as the plane slowed down. Inspection of the tail wheel mounting spring found that the lower bolt (AN3) on the steel bracket used to attach the spring to the tail post had sheered off. Bracket was still held in place by upper bolt, but loss of lower bolt allowed entire spring and tailwheel to shift back and forth slightly. Bolt was easy to replace.
Two years later, I found the mounting holes badly worn, and made some changes. See below, and the Service Note.

Carbon Arcing in Case Magneto (July 1999) - Chris Horsten

"Flybaby C FRXL had a precuationary landing a few weeks back on take-off. The engine started to vibrate so the power was pulled back to idle and down it went. Fortuneatly, there is no damage and the problem can be traced to a CASE magneto. It seems they have a tendancy to build up carbon causing arcing and a firing of all plugs at the ame time - hence the vibration. You may want to alert others via the web page to check case mags often and clean them! Email me if you need more info."

Failure in front mounting area for tailwheel spring (July 2001) - Robert Giddens

"Tuesday evening I was flying my Baby and having a great time until I landed. The landing wasn't my smoothest, but not bad. As I was rolling out I could tell something was wrong with my tailwheel. I got out and saw that the front attaching bolt was attached to the spring, but not to the fuselage. The oak block inside the fuselage had split, letting the front of the spring drop. The break was not in a downward motion like I

thought it might be, but forward. So I put the tail over my shoulder and walked it back to my hangar.
"After looking it over and thinking there had to be a better way. I decided to rebuild it out of phenolic (partially since I had some of that and not a good supply of hardwood available). So I spent all of Wednesday morning performing surgery through the bottom of the plane and cutting, fitting and epoxying pieces of phenolic and wood. I also strengthened the way it was attached to the rest of the airframe. After letting it cure all night I got up early and repaired the fabric that I had cut away. With the weather this hot, I was able to glue, shrink, dope, silver and paint before 1:00 PM. I took her out after the sun was a little lower in the sky and it was a little cooler. All's well so far, I'll let you know in a couple of thousand hours if my phenolic attach point works or not.
"Is this a weak point in the FB or is it just me? If it is, how is everyone else repairing it? I would have asked the group first, but I couldn't stand the thought of her setting out there broken while I was in the air conditioning playing with my compooter."
[RJW Note: This is a new one on me. I haven't heard of this type of failure before, but until the last couple of years, the means didn't exist (e.g. email) to exchange this kind of information.]

Ovalling of tailpost holes for tailwheel bracket (May 2003) - Ron Wanttaja

The bracket that holds the tailwheel spring to the tail post sees a lot of strain. It's bolted to the tail post with 3/16" inch bolts (AN3). The lower bolt hole in the tail post tends to "oval" over time, getting the tailwheel spring a bit loose. This has been reported in at least three aircraft.

The solution is to drill the holes in the tail post to 3/8" and install some bushings, drilling the bushings out to match the bolts on the bracket. For more detail, see the Tailpost Problem Page.

Comments? Contact Ron Wanttaja .

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