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There comes a time in every pilot's life, usually during a weak moment, that the idea of owning an airplane is seriously entertained.

Once the pilot embraces this exciting image in the mind's eye of flying his or her own machine, the notion grows and grows until it becomes an all consuming passion. I base this observation on my own personal experience

To the best of my knowledge there is no known cure for this reverie. The addiction must run its course. Sadly, too many pilots buy airplanes to make a dream come true and wind up living with a winged nightmare nicknamed, "Jason" or the "Orphan" as mentioned in previous article.

Therefore in the interest of all mankind, my goal in writing this less than perfect article is to make pilots aware of what they should look for during a pre-buy inspection of your basic two- or four-place aircraft of 200 horsepower or less.

Once the decision has been made on what make and model dream machine you wish to purchase, the next logical step is to research that aircraft.

First, get as much information as possible on the aircraft's capabilities and performance. Some obvious sources are the aircraft's flight manual, trade magazine articles, or bumming rides in identical make and model aircraft.

Another information source you can check is the Internet The Internet is a well-spring of knowledge, and even the briefest search for web sites dedicated to a particular aircraft type will pull up web pages such as Cessna 170 Society, Beech Bonanza, Mooney, etc. These web sites can answer your questions on maintenance costs, availability of parts, the aircraft's good points or nasty habits, or any recurrent or pending Airworthiness Directives on the aircraft, engine, or appliances.

The next bit of information is very important! If you have access to the Internet, you can search on the FAA website for a copy of the FAA Type Certificate of the aircraft you are interested in at URL: fsdo/Bhm under the Airworthiness entry. If you don't have Internet access, buy or beg from your FBO or mechanic. The type certificate is the birth certificate of the airplane. It lists the applicable engines and propellers, speeds, gross weight, empty weight, etc. It also tells you what FAA regulation the aircraft was built to. Why? This might seem as boring as watching a glass of water, but what rule the aircraft was built to is a very important piece of information.

For example, Type Certificate (TC) A30CE is for the Beech (now Raytheon Aircraft Company) Model 77 Skipper, a two-place trainer. The TC identifies the certification bases of the aircraft as Part 23 of the Federal Aviation Regulations. Part 23 is the latest certification regulations for general aviation airplanes and includes in those regulations mandatory retirement times. Note 3 in the Skipper's TC explains that these retirement times are contained in the Pilot's Operation Handbook and FAA Approved Flight Manual. What does this all mean? In the case of the Skipper, this means airframe carry through structures have a limited life and require mandatory replacement at 12,000 hours.

Now take a look at a Cessna 150 type certificate. The C150 is a similar two-seat aircraft like the Skipper, but it does not have mandatory replacement times because it was built under the older Civil Aeronautics Regulations (CAR) 3 regulations. So it is important to the buyer to determine what is the certification bases of the aircraft before you buy, because the certification rules will determine future maintenance costs. Now, just a word or two about the aircraft's Flight Manual. If the TC, requires a FAA Approved Flight Manual like our Beech Skipper, the Flight Manual must have the latest manual "revision" installed. A FAA Approved Flight Manual is part of the Type Design of the airplane, and an out-of-date manual does not meet type design requirements so the aircraft is technically unairworthy. A mechanic can check what the latest flight manual revision number should be.

Okay, now we can get down to business. Since we have read the Flight Manual and the TC and other information, we now have a good idea of the aircraft's capability. So now is the time to take a look at the airplane. Get a pencil and paper, a mechanic's inspection mirror, a 10-power magnifying glass, and an explosion proof flashlight. Now before we rush off and look at the aircraft, we have to answer the question what are we looking for? The quick and dirty answer is; we are looking to see if the aircraft is airworthy. What is airworthy? Airworthy is when the aircraft meets its type design or properly altered condition and is in the condition for safe operation. The TC, I asked you to pick up, should list all of the required equipment and approved engines and propellers. The aircraft paperwork should contain a history of all major alterations listed on individual FAA Form 337, Major Repair and Alteration. Until we get serious about a particular airplane I recommend that you hold off delving into the Form 337 paperwork review until we first determine if the aircraft is in a condition for safe operation.

The pre-buy inspection is very similar to, but is much more detailed than, a pre-flight inspection. You must examine the aircraft from all sidesóinside and out, and top to bottom. A good rule of thumb is to figure that it will take you a good two hours for each aircraft that you look at on the ground and another two hours for the test flight.

Next, assuming it is a U.S. registered aircraft, open the aircraft's door and check and see if there is a current U.S. registration and airworthiness certificate. Check the "N" numbers on both certificates and make sure they match each other and the "N" number on the aircraft. Also copy down the owner's name and address and the aircraft's serial number that is on both certificates, you will need this information later. If the flight manual is handy, check the equipment list against the required equipment on the TC.

Next check the flight manual and see if the weight and balance is correct. If the aircraft has a new radio package and a weight and balance form has the color of old teeth, you can be sure that nobody has computed the empty weight center of gravity (CG) lately. I have had owners tell me that the new radios are 10 to 12 pounds lighter than the old vacuum tube/power supply driven NARCO Mark 12 radios which were pretty much the general aviation (GA) standard in the late sixties and early seventies. So what is the problem? The problem is the instrument panel on most GA airplanes have a forward CG. If you remove fat radios and replace them with light-weight ones, the CG always goes aft! How far aft depends on the airplane. Since an aft CG is the worst case scenario to load an airplane, the current weight and balance must be dead accurate. If the paperwork doesn't match or is missing or just looks funny, don't waste your time with this one. Go to the next aircraft on your list.

Finally we get to look at something other than paper, so the first thing you should look at is the door! A let down you say! Not really, a door can tell you a lot about the airplane. If it is hard to shut then maybe the door is warped from wind damage or the fuselage is twisted from high "G" loading or hard landings and the door will not align up properly. Check if there is a larger than normal door seal on the door. If there is a fat door seal on the door frame, it is almost a promise that the door leaks rain water or has a wind noise at cruise. Next check the window. On most unpressurized aircraft the Plexiglasô windows carry no structural load. You should be very concerned about how clear the windows are from both a safety and an economic point of view.

Most of these aircraft that you will be looking at are parked out in the weather, year round. UV radiation from the sun will take its toll over time and the windows will yellow and begin to craze. Crazing is voids formed by a separation of the layers of plastic in the window. The voids in turn cause refraction of the light which the pilot sees as a sparking or sun devils when you are looking into the direction of the sun. This reduction in visibility can be a major problem when flying in busy airport areas.

Replacement Plexiglasô windows run about $100 for the side window, and pick a number from $200 on up to replace the windshield. While we are still in the cabin, check the aircraft seats. After a cosmetic review, you should very carefully check the seat belts. Both the shoulder harness and lap belt should have a Technical Standard Order (TSO) marking on them. TSO means the webbing is aircraft quality. Also check the seat attach points and hardware with your mirror. Check the seat rail holes. This is where the seat pins engage the rails and lock your seat in a comfortable position. If the seat rail holes are elongated or appear to be scooped out the rails are bad. If the rails are bad, the seat will not stay put on take-off which will provide the pilot with a very interesting ride. Figure $1,000 for new rails and labor.

After the seats take a look at what is under the carpet. If the carpet is damp or wet with water then you confirmed that the cabin is not weather proof. If you find red hydraulic fluid on or under the carpet, it is a sure sign that the toe/handbrake is leaking. If you spot a white power on the floor's sheet metal that white power is probably surface corrosion which is again a good indication that the doors or windows are leaking.

Now take a look at the instrument panel. The panel contents is approximately 1/6 of the total cost of the aircraft. First, make sure the instruments are securely attached. Check under the panel for loose wires and vacuum hoses that may bind up the movement of the flight controls. Now look at your old friend the airspeed indicator. Check and see if the marking on the airspeed indicator agree with the speeds listed in the Flight Manual. It is not unusual to find an airspeed indicator that is for a Cessna 172 in a Cessna 150. The instruments are identical, except for the airspeed markings. Now check and see if the stand-by wet compass look serviceable and has a compass correction card filled out. If the card is missing or has no heading corrections on it, you are also looking at four hours of labor for two mechanics to take the aircraft out and "swing the compass" to make the aircraft VFR legal.

Take a look at the gyro instruments. Most pilots are aware of how to check a gyro for precession in flight. But here is a little tip on ow to tell if the instruments are having problems just sitting there. Check if you see a haze surrounding or partially surrounding the glass of either instrument. The haze is really dirt that is on the bezel glass and inside the gyro that has been sucked into the instrument because the "O" ring seal between the glass and the gyro instrument has been breached. The dirt is being sucked into the instrument because it is easier to get air from a breach in the seal then get filtered air from the instrument regulator. Haze will tell you the gyro instrument(s) are not long for this world. Overhaul cost vary, but you can figure on overhaul costs starting at $350 for the directional gyro (DG) and $450 for the artificial horizon. Altimeters are easy to check. Make sure, after you dial in the local barometric reading in the Kollman's window, that the indicated altitude matches the field elevation. You can also check if the altitude select knob moves the hands without sticking or binding. An altimeter overhaul costs approximately $150 to $300 depending on type.Next instrument to check is our good friend the rate of climb or if you are a card carrying pessimist, the rate of decent instrument.

Many of these instruments tend to read plus or minus 50 to 100 feet. While many fly with instrument reading a 50 foot rate of climb on the ramp, not many of us would want to rely on a non-calibrated rate of climb during a instrument check ride with the FAA. Calibration by an instrument repair station usually costs around $100, plus or minus $20. The turn coordinator (TC), or the older turn and bank indicator, usually is an electrical driven gyro which shows the degree of bank the aircraft is in either with a pointer or an stylized airplane. A glass tube with a free floating ball inside shows if the aircraft is in a coordinated turn. To check the TC instrument on the ground, turn on the master switch and just listen! If the gyro sounds like a tin can filled with marbles, the gyro bearings are going bad and a replacement instruments will cost in the $250 plus range or more than double the base price depending if the gyro has a wing leveler electrical pick off installed.Next item you can check is the emergency locator transmitters (ELT). If you have a remote ELT switch in the cabin, by regulation you must wait until five minutes after the hour to activate the ELTóunless you want the Civil Air Patrol and airport "ELT" police driving up to your airplane.

Turn on a radio and listen for the emergency signal on 121.5 MHz. If you have a strong signal the next thing that you should check is compliance with FAR ß 91.207, the annual ELT inspection. This is separate from the FAR ß 91.409, annual inspection requirement. So make a mental note to check the log book entry for the ELT inspection. Now it is time to further explore the radio package in the airplane. If you have more than two radios, then the mark of a good avionics installation is an avionics audio panel and an avionics on/off switch. The best you can do on the ground to check the radios is call the ground control or UNICOM. Obviously, the best way to check the radios and navigation aids is during the flight test.Next in line is the lower instrument panel. If the battery is up to it, check the landing and taxi lights, position and rotating beacon or strobe. Check the interior and panel lights. Make sure the circuit breakers or fuses are properly marked and operable. Exercise the flaps and trim(s) and check for smooth operation and that they work as advertised. Next, check the fuel gages. You might be surprised to know that by FAA regulations applicable to both CAR 3 and FAR 23 aircraft the fuel gauges need only to be accurate when reading empty.

So write down the fuel gauge readings and later visually check the fuel level in the tanks. Use a fuel tank dip stick, if necessary, to ensure accuracy. There is another instrument that most pilots rarely pay close attention to. It is the engine tachometer. Its only purpose in life is to read the engine RPM. An interesting thing about this instrument in your basic GA airplane is there is no direct mechanical connection between the tach needle and the engine. The needle moves because the tack cable spins a metal drum inside the tack head setting up a magnetic field which turns the needle. We found that most old tachs read lower than the actual RPM of the engine! This low tach reading can cause some serious problems! For example, on GA airplanes with fixed pitched propellers, engine power settings are set according to tach readings. If the tach is reading lower RPM than actual engine RPM, more fuel is being used. Now couple that piece of information, with a long cross country, with higher then forecast headwinds, and with fuel gauges that are only accurate when empty, it is then not hard to see why so many pilots run out of fuel on final.Something to keep in mind is the fact mechanics use the tach reading when setting the propeller governor for constant speed propellers.

If the tach is used as a reference and the tach read low, then the governor setting would allow a higher RPM than specified when either the propeller or governor is replaced. The higher RPM will allow the engine to over-speed on take-off which would contribute to excessive vibration and premature wear to the engine. One of the things you should check before flight is the magneto switch for a hot mag, so make sure during run up that the engine can be shut down with the magneto switch.

Another item pilots tend to forget, except on really cold days, is the primer. The hand operated primer on most small GA aircraft rarely cause problems. However, if the engine runs badly and lopes at idle but the mag check at 1700 RPM is great, chances are, even if the primer is locked, one or more of the "O" rings on the primer piston is leaking and allowing fuel to be sucked into the engine on the intake stroke. This extra fuel enriches the intake fuel/air ratio which makes for a rough idle and little or no mag drop when you check the magnetos. Another indication of a very rich mixture is a black sooty exhaust in the pipe and on the fuselage aft of the exhaust pipe.

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