The Annual Inspection

From Bondline

Introduction

This is part one (1) of a three (3) part article about Mike (and his '76 AA5A).

1. The Annual Inspection
2. The Replies
3. What I've Learned

Part 1: The Annual Inspection

My Cheetah is the first airplane I've owned and we just went through our first annual together. I thought I'd share my experience and I'm also looking for some "sage advice" on what I should expect in an airplanes condition after it has completed an annual. I have found a number of problems since the airplane was returned to service by the shop (which came recommended by a number of individuals as one that knows Grummans...more on that below).

In addition to the basic annual, my squawk list included

• A throttle cable that was starting to get stiff
• A check of the charging system since a battery recently died (it was unknown age and was a really tired battery)
• Replacement of the aileron bearings/bushings as part of the 100 hour AD (recommended from previous AD compliance)
• Upgrading to the Boom Beam HID landing light (a x-mas gift from my wife - ain't she great).
• I had also told them I wanted the wobble check done since it had been over 500 hours since the top overhaul.

I had taken off 3 days from work in order to "owner assist" (mostly just help with the access panels and watch and learn).

On the first day of the annual, my skills with a Philips head screwdriver served me well as I removed most of the access panels, the wing tips and, with help, the cowl while the A&P spent a fair amount of the time looking at the HID light STC instructions and doing other prep work. We then went to work on the landing gear, finding that new brakes and discs were needed, cleaning and repacking the bearings. I'm thinking at this point that every airplane owner should definitely do this.

Day two was where it got interesting. Brake parts were on back order and most progress seemed to grind to a halt. The A&P decided that the tasks for the day were to install the HID landing light harness/control and replace the wind-sheared ELT antenna. Since the ELT antenna sits partially inside the vertical fin, the A&P decided he'd have to drill out the pop rivets that hold it to the bottom mounting. Since there are screws at the back of the fin and drilling out all those rivets sounded excessive, I asked if he would call Fletchair and see if there was a trick to this. He declined. Of course, after drilling out the rivets and lifting the fin off of the mount he found the clips that would have allowed removal by just removing the screws and sliding forward a few inches (yes *I* later looked this up in *their* copy of the maintenance manual - 53-0 p202). This, along with a prior incident explaining to them how the aileron AD was supposed to be done (Thanks Bob Steward & Barry), and I start to wonder about the "Grumman experience" of this shop.

Since parts were on back order, I went back to my job for a couple days and did not show back up at the shop until the day the parts were supposed to arrive. When I got there, I found that they had "done the rest" of the inspection and replaced most of the access covers and the lower cowl. So much for learning the rest of that process. All that was left was to finish the brake work and install the throttle cable. I was told that they had another plane coming in and needed to get mine wrapped up. So, the A&P finished the work (brakes and throttle cable) and I reinstalled the wheel fairings. I asked about the results of the wobble check and they said they didn't have the fixture but would order one if I wanted to reschedule another appointment. Hmm ... I've only had this scheduled with them for over a month and I specifically asked about this check ... oh well.

In hindsight I wish I had been there the entire time my plane was at the shop. After the A&P approved the plane for return to service, I found the following squawks that did not exist prior to the annual:

• The elevator would stick at about "neutral" - the problem was a interference by a mis-positioned throttle cable clamp.
• The elevator would make a noise when full left aileron was applied - A scat tube had moved into the control path.
• The flap fuse was blown and replacement caused immediate fuse failure - A&P said he checked the flaps and they were fine, but the limit switches may now be out of adjustment and the mechanism was jammed in the up position.
• The right brake intermittently loses effectiveness - Cured by bleeding the brakes.
• The wheels or brakes make rubbing noises as if a brake is sticking a little and the disc is warped. - This turned out to be a bent wheel fairing bracket. Fixed by my *new* shop.
• Fuel was leaking out of the carburetor return hose fitting @ ~4gph(1) They rechecked and tightened the fitting.
• My Nav2 radio no longer worked – New mechanic found that the plug had been knocked loose. Now fixed.
• Trim around the rear seat belt mounts had been broken (yeah, I know a nit pick and brittle plastic - guess I'll try that MEK and dissolved plastic trick I've been reading about. Of course the guys that replaced all the side window plastic a year earlier managed to do it without breaking the plastic)
• The updated W&B, required by the STC, was not placed in the plane (only copy was in their file).

This, unfortunately, was discovered in-flight by my fuel totalizer which was showing an unusual 13GPH consumption rate for my HC Cheetah. Looking inside with the electric pump on, there was an obvious stream (fountain?) of 100LL coming from the fitting. I have since modified my pre-flight checklist to include pressurizing the fuel system before the external walkaround and to check for fuel leak/smell around the cowl.

Now, I understand that my Cheetah's 30th birthday is this year and I would expect that things could potentially fail just after an annual. And I know that problems are why we regularly practice emergency procedures. But to have such a large number, and specifically items that they should have inspected or they touched during the course of their work, be problems immediately after the annual seems to be to be outside the range of normal coincidence. I have since received a copy of the checklist they use for annual inspections and have tried to compare it to the one in the maintenance manual. The one they use is a general checklist and so it includes items not on our planes (such as retractable landing gear checks) but does not include items specific to our cats (like skin bonding issues, canopy issues, etc.). And items on their checklist, like "Flight controls free and correct", do not appear to have been performed after all work was completed. I've founds checks in the inspection checklist in the Grumman Maintenance Manual that should have found all the above problems if done in an appropriate sequence.

So I'm now a little concerned that this annual was not done to the level of detail that I would expect from an inspection designed to verify the operational safety of an aircraft. To their credit, they have been good at working with me to fix the issues.

But like I said, I'm kind of new to this process so I'd like to hear from some of you veteran owners and mechanics out there. On a scale of "Oh, stop your whining" to "Go quickly and find another shop," where do you think this experience belongs?

The Rest of the Story

Next: The Replies

Last: What I've Learned