There's nothing like that yearly annual inspection to get the bloodflow going. Visions of particles of metal lurking in the oil filter, valve lifters destroying themselves as they eat away at the surface of the cam lobes, cracked cylinder heads, diminishing compression, little spidery lines tracing their way around the engine case, revealing their location by just the tiniest oil seepage...it's all waiting. That's especially true if it's been a year since anyone has looked under the cowling. Don't let that happen. Even if one has no desire to actually work on the plane, at least the details of a good inspection process should be learned. Though it's never pleasant to learn that one's aircraft needs repair, the earlier a problem is detected, usually the less expense is incurred in correcting the fault. The FAR's, or to be more correct, CFR Title 14 Part 43 Appendix "A" specifies many tasks that can be legally accomplished by the maintenance savvy owner/operator whose plane flies under Part 91 rules. A combination of inspection and owner performed legal maintenance can help ease the onerous burden of affording an aircraft.
Let's look at some of the tools that can make life easier for the aircraft owner who wants to inspect his aircraft. First in line is a set of jacks. Without be The outer stabilizer for the jack was formed from 1/2 square steel support that fits into a triangulated base. Scrap metal was used to make the device--it's always nice to have a heap of scrap metal out back--and welding time was less than an hour for both sets of supports. Of course, were the retraction test to be performed on a high wing aircraft, the support system would have to be somewhat more complex. Plans are already in motion to construct a base that will support these jacks so they can be used to raise a Cessna 172 RG for its retraction test. For other tasks, such as simply removing wheels, it's not necessary to use wing jacks. In fact, a simple scissors jacs placed under the gear is much more stable, very easy to use, cheap to purchase and, once the wheel and brake assembly has been removed, a suitable support can be place under the axle and the jack can be moved to the next wheel. It's a violation of the rules of common sense to allow any aircraft to spend more time on wing jacks than is absolutely necessary. As sturdy as the devices might be and as well constructed as they might be, even a set of Meyers professional stands can be dangerous. Seeing a plane slip off it's supports and watching the top of a jack as it goes through the wing is something few pilots, mechanics or ever casual bystanders would care to see.
Above are three photos of a safe method for removing aircraft wheels and leaving the plane on blocks. A hydraulic scissors jack cost less that $20 and fits even inside the narrow space between the landing gear door and gear truss of a Mooney. In the photo on the right, it's apparent that the brake caliper has been removed. After raising the plane and letting the air out of the tire--releasing pressure is a necessary safety step before taking off the axle nut--the caliper must be removed. In the case of Mooneys which have the caliper STC'ed from the upper rear to lower front position, the caliper must be removed in order to gain access for the jack. OK, let's examine just what an "Annual Inspection" comprises. The terms "Annual or 100 Hour Inspection" are explained in Title 14 CFR Part 43 Appendix "D," or, as it's more commonly known, in Part 43 of the FAR's. Here's what Appendix "D" says: a. Each person performing an annual or 100 hour inspection shall, before that inspection, remove or open all necessary inspection plates, access doors, fairing, and cowling. He shall thoroughly clean the aircraft and aircraft engine.
43xD.j Each person performing an annual or 100 hour inspection shall inspect (where applicable) each installed miscellaneous item that is not otherwise covered by this listing for improper installation and improper operation. What's the difference between a 100 hour inspection and an annual? An annual inspection is performed by an Airframe and Powerplant mechanic with Inspection Authorization, someone who is commonly referred to as an "A&P IA" or simply an "IA," and said individual signs the inspection off as an annual. A 100 hour inpection follows the same guidelines as an annual but it may be performed by an A&P without IA, though in this case, the inspection does not start the clock running as an annual. Photographs inserted in the section above are of the freshly cleaned belly of 5529Q, top looking from under the airplane forward and lower photo from the gear doors back. "Clean" is like incest and nepotism, it's a relative term. Many aircraft are returned to service with no more than a cursory spray of degreaser and a rinse plus the occasional lackadaisical wipe with a cloth. This practice is not, per se, illegal but it isn't good practice. Without a thorough cleansing, it's difficult for a mechanic--or anyone else-- to see whether or not an assembly might need attention. However...as most A&Ps will attest to...few owners will spend the money to really clean their aircraft properly nor will they expend the time and effort necessary to do the job well themselves. |
An example of just what can happen to a sadly neglected airplane is illustrated in this photo of the left wing main spar of a Piper Cherokee 140. The little bird had corrosion, only an owner who failed the vision portion of the aviation medical exam could deny that fact. Still, this particular pilot believed that a few shots of ACF 50 and some judicious work by a mechanic would whisk away all signs of oxidation. Add a little bit of paint and that plane will look good as new. However, a surprise was waiting. Both fuel tanks were leaking. The right tank was pulled, the surrounding area was cleaned and no real lasting damage was found. The left tank revealed a trail of tiny metal particles along the lower front edge of the main spar. Some careful examination yielded the source of the shavings. The upper front horizontal edge of the spar--marked by the two black arrows--had corroded so badly that it had begun to exfoliate. Aluminum was peeling away like the layers of a dinner biscuit. Piper aircraft was contacted and asked whether the damaged area could be treated, whether the oxidized metal could be ground away. After all, most of the stress in a spar is in the web, not on the outer edges. No way. It's new spar time. Estimated costs: around $15,000. The real shame is that this damage could have been prevented. It did not occur because of stress. Rather, the causal factor was neglect. Only the removal of a faulty fuel tank revealed just how far neglect and denial had allowed this situation to go. What was surprising to me was a glance inside the cockpit of the plane. A panel-mounted IFR approved King GPS was mounted just above a KX-155A radio. Thousands of dollars had been poured into avionics while the basic structure of the aircraft was being ignored. 
ing able to lift the tires off the floor of the hangar, it's really difficult to determine whether the wheels are turning smoothly, whether the brakes are binding, or, in the case of a retractable gear aircraft, whether there are any hitches in the way the plane gets its wheels tucked up inside. Many pilots think of raising the plane as a daunting task and one they'd rather not tackle by themselves. After all, even for a low wing plane, a set of jacks can run into the $500 and up range. Well, not really. Illustrated is one of a set of two wing jacks the author constructed for his Mooney. The constituent parts cost less than $100 for both jacks. A pair of 24" rams ($39 each...NEW!) came from Harbor Freight. These are mounted on a pair of 15" Chevrolet rims using five 1/2" bolts on the base and an outer tripod system for added stability. First time out this year, they worked great. The tail was held down using a web around the empenage in conjuction with a strap through the tail eyebolt anchored to a 150 pound weight. Alternatively, a prop support can be used as is illustrated in the Mooney service manual. The padded stap around the empenage provides additional security for those who are concerned that the tail tie could come lose (such as me...) and the strap through the tail tie takes some of the pressure of the upper portion of the tail section of the plane. 
(1) Generally - for uncleanliness and loose equipment that might foul the controls.
and center section assembly for poor general condition, fabric or skin deterioration, distortion, evidence of failure, and insecurity of attachment.