A Fly Baby Annual

This posting from 1992 shows the work and expense that goes into maintaining a simple airplane like the Fly Baby.

Y'all know I *have* to post my yearly "Another expensive annual" report....:-)

The lead-in to this year's annual was unusual. Previously, the annual would just come up and we'd do it; no big deal.

This year, it was a bit different. I've already posted the tale of the Fly Baby losing rudder control while my partner was flying it. He'd just temporarily fixed it with a paperclip. I'd have to make a more permanent fix, preferably one that reduced the possibility of another failure.

For the first time, I was annualling an un-airworthy airplane!

One point I should make clear. I do not really "annual" the airplane. N500F was built in the old days of homebuilding; before such things as repairman certificates. The Fly Baby's annual must be performed by an A&P. Any A&P will do... they don't have to have Inspection Authorization.

My friend Ed does the offical annual. Northwest Airlines lost one heck of a mechanic when Ed got his engineering degree and went to work for Boeing. He's the ideal person to have inspect your airplane... a mechanic to his fingertips; an engineer to the last. Sherlock Holmes' powers of observation, Kelly Johnson's design ability.

It does make Fly Baby annuals interesting.

While the 'Baby doesn't require an IA, Ed and I have evolved into an A&P/IA relationship when it comes down to maintenance. Ed does the inspection, I do the work. This is deeper than a typical "owner-assisted" process... if a replacement part is necessary, I build it. Ed inspects and identifies the problems, I fix them, then he does the final check and signoff.

To reduce his "bitch list", I perform my own annual first. So a week ago Sunday I showed up at the airport with tools on hand.

First item of business was the rudder pedals. Normally, they're hell to get at on a Fly Baby. There's no cockpit door, and no forward inspection panels. You have to dive head-first into the cockpit and snake your body forward under the instrument panel. God help you if you forget a tool.

But N500F had a beautiful modifcation added during its rebuild ten years ago: A one-foot wide belly inspection panel running from behind the cockpit to the firewall.

You STILL can't go through the inspection panel and see the rudder pedals. But you can remove the seat, step carefully into the cockpit, drop your feet to the ground, then just bend forward at the waist to work in the legwell.

It looks kind of wild from outside. Until you bend over, your head and shoulders are in the same position as if you were seated, but your legs stick out underneath.

A better description? Every time a friend walks by the hangar, they yell: "Hey Ron! Yabba-dabba do!"

Ignoring the comedians, I removed the paperclip retaining the rudder turnbuckle clevis, then replaced the clevis pin with a clevis bolt and castellated nut. I turned the bolts so the end was outboard, so pants legs couldn't catch on the cotter pin.

While I was under there, I noticed the large cotter pin that kept the right rudder pedal from sliding free was chewed up. Didn't have a spare that big, so I hopped into the car and went to "Pep Boys Aerospace" for some replacements. Did both pedals just out of general principles.

Nut missing on the end of the pivot-bolt for the right rudder pedal; replace. The bolt seems a bit too short... I'll probably replace it with a longer one.

Checked the fuel lines while I was under the panel, all OK. Got my can of LPS-III and blasted everything moveable. Lubed the throttle, carb heat, and tail hook assemblies.

After climbing out of the cockpit, I checked the airframe. Not too much to do, actually... check the bracing wires and tangs, open up the elevator and aileron inspection panels and blast 'em with LPSIII.

There was a tear in the fabric under the left wingtip, from when the partner got caught in a taxiway under construction and a metal fence post ripped the tip. Cut out a patch the size of a big band-aid, clean the area with acetone, dab some Poly-Tac on it, slap the patch on, let it dry for a bit, then iron it. Two coats of silver dope and two of yellow, and that task's done.

The engine took a while, as usual. One of the clips holding the cooling shroud to the cylinders was broken; removed it and gave it to Ed to weld. Compression test- great. Four or five small cracks in the shroud and cowling to be stop-drilled. Disassemble and clean the gascolator.

The worst problem was a loose attachment for the throttle cable. The clamp wouldn't tighten any further. Made a shim from aluminum to use up the extra space.

Pulled the oil screen. Three or four flecks of metal in it; Ed says they look like bearing material. We'll track it over the oil changes.

Speaking of oil, I cleaned the oil off the belly using "Simple Green". I can't praise this stuff enough... in the past, I've tried conventional cleaners like 409 with poor luck. But Simple Green takes the grease right off with little effort.

As usual, I picked up the little stuff one leaves until the annual. Some of the fabric was pulling loose under the coaming; I Poly-Tacked it in place. One of the belly-pan nutplates was stripped, and was replaced. Two of the pop rivets in the seat had pulled out and were replaced by bolts.

The Fly Baby also got shook down: Tie a rope to the tailwheel, then lift the tail until the plane rests lightly on the prop hub. Good for getting all the garbage out of the tail cone.

One last item: The cable for the tailhook release had a lot of slack in it. Turns out there's no turnbuckle or anything to adjust it... in any case, the problem is too much slack in the sheath. I wrapped a couple of turns of safety wire around it and tied it forward to eliminate the slack.

When Ed came to inspect, he only came up with a couple of other things. I'd forgotten to lube the tailwheel. Some of the turnbuckles seem to be picking up corrosion and need a hit of LPSIII. He didn't like the amout of slack in the oil-temperature bulb wire, so I tie-wrapped the excess to the engine mount. After the usual amount of grousing and shaking his head, he finally signed off the logbook.

My favorite comment was the one he made on my throttle cable fix... "That's not the best way to do that... but it's no worse than the rest of the stupid system."

(Some may ask, "Then why don't you rework the system?" The answer is, it may not be the most elegant design, but it's been trouble-free for 32 years....)

So after about ten hours of work (over two weekends and one weeknight) the Fly Baby is legal for another year. The costs?

Two clevis bolts           $1.30
Two castle nuts              .41
Two little cotters           .12 (AN part)
Two big cotters              .14 (commerical part)
Fabric Repairs               .00 (equipment on-hand)
LPS-III                     3.50
Simple Green Cleaner        4.99

Total cost of Annual:     $10.46
(Not including my yearly Xmas gift for Ed, since he won't take any sort of payment for doing the annual.

Other than nonexistent labor costs, how do I get away so cheap?

  • No components that require periodic calibration... transponders, etc.
  • No components that require periodic replacement... e.g., ELT batteries
  • Dead-simple systems: No flaps, door latches, etc.
  • No electronics... no alternator belts, battery, starter, fuses, wiring, electric motors, lights, rheostats, lenses, radios, gyros, strobes, or rotating beacons.



    Oh, don't worry, I still end up spending a lot of money operating the thing. Autogas is up to $1.25 a gallon now... that works out to $6.25 an hour :-)!

    Comments? Contact Ron Wanttaja.

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