Maintenance & Technical

Maintenance & Technical (123)

New paint, new interior and new Plexiglas make John D. Ruley’s 1975 Cessna 182P look and feel like a factory-fresh airplane. Sometimes, small problems can lead to more complex projects. This Skylane restoration started with a flat tire and fuel leak. The tire was a quick fix, and the fuel leak ended up being straightforward as well (leak at the filler neck). However, a check of the logs showed that N4696K’s fuel bladders were 20 years old—with an expected life of just 10 years. It was time for replacement. (For that story, see “Step-by-step Fuel Cell Replacement” in the January 2018 issue.) Once John Ruley and his four partners caught “upgrade fever,” they kept going. This month, the Skylane restoration continues with several cosmetic and safety upgrades. After N4696K’s fuel bladders were replaced in July and early August 2017, we once again had an airworthy aircraft, albeit one whose annual was coming due by the end of August. We elected to paint N4696K, redo the interior and replace the aged Plexiglas windshield and windows. The Plexiglas and glareshield would come first as part of the August annual. Great Lakes Aero Plastics delivered the Plexiglas parts early, which provided plenty of…
As an aircraft owner and pilot, you can legally perform some maintenance tasks, but you must adhere to strict guidelines when doing so. Steve Ells walks us through packing wheel bearings, while highlighting what’s important to stay legal. As most readers of Cessna Flyer know by now, all aircraft maintenance tasks must be overseen or performed by an appropriately-rated person. For maintenance tasks, this means an A&P mechanic—or a technician, as some like to be called these days—is frequently both performing and signing off on the work. This mechanic must (by regulation) have up-to-date versions of the appropriate manuals, bulletins, tools and equipment necessary to complete the tasks. However, there are also a number of maintenance tasks that owners may legally perform. These are termed preventive maintenance (PM) tasks. There’s a long list of them in Appendix A of FAR 43. What is considered preventive maintenance? Appendix A is titled, “Major Alterations, Major Repairs and Preventive Maintenance.” Paragraph (c) lists preventive maintenance tasks. Type “Appendix A of Part 43” into your favorite search engine (or find the link in Resources on Page 35. —Ed.). There is a surprisingly long list of tasks allowed. For instance, owners are permitted to remove…
Many single-engine aircraft rely on alternators to power aircraft systems, avionics and cockpit gadgets. A&P Jacqueline Shipe guides you through how alternators work and what to do when yours isn’t functioning correctly. Nowadays, with everything from glass cockpits to auxiliary power outlets for iPads and phone chargers, there are more demands on the average aircraft’s electrical system than ever before. Most General Aviation airplanes rely on an alternator to provide a steady, reliable source of electrical energy to power electrical components and recharge the battery. Electrical system components The main components in an average airplane’s electrical system are the battery, alternator, voltage regulator, bus bar and wiring. The battery provides stored power for starting the engine. It also provides a reserve of electrical power in case the alternator malfunctions in flight. The electrical bus bar provides a central point of power distribution to almost all electrical components (except the starter). The bus bar receives its power from the battery or alternator. Electrical components are connected to the bus bar through a circuit breaker or fuse. Electrical system specifications The electrical system on most airplanes is either a 14- or 28-volt system. 14-volt systems have 12-volt batteries. 28-volt systems utilize 24-volt…
A&P Jacqueline Shipe lists dissects the system and offers troubleshooting tips for Cessna’s retractable singles. In the late 1940s and through the decade of the 1950s, General Aviation began to really take off as airplane sales increased. The postwar economy was favorable for the production and sale of both single- and twin-engine models, and the “big three” in the aviation industry were Beechcraft, Piper and Cessna. It was 1947 when the Beechcraft Bonanza appeared on the aviation market. The Bonanza was the first retractable single-engine plane on the market that had a wide appeal to a large number of customers. Sales were good, and in the late 1950s, Piper also entered the single-engine retractable gear market with the debut of the Piper Comanche. Cessna enters the RG market Cessna wasn’t going to be left out, and in 1959, the Cessna 210 made its debut. Early 210s were essentially Cessna 182 frames with a stronger engine and a retractable gear system that was very complicated in its design. The main landing gear doors had their own actuators in addition to the gear actuators, along with an accumulator for the main gear doors. The hydraulic pump on the earliest models was engine-driven.…
A&P Jacqueline Shipe describes how to service wheel bearings in this article, the second in a DIY series for pilots who wish to take on preventive maintenance of their aircraft. FAR 43 Appendix A lists the preventive maintenance items owners may legally perform on their planes. This list is fairly long—and some of the items are a little involved for a person to perform the first time by themselves, while other tasks on the list are pretty straightforward. There are several preventive maintenance tasks pertaining to the landing gear, including tire changes, strut servicing and servicing the wheel bearings. (Last month, Shipe discussed the steps involved in changing an aircraft tire. See the June 2016 issue for more information. —Ed.) A tapered roller bearing with pits on the rollers caused by corrosion due to water. Bearings: small but mighty While cleaning and greasing wheel bearings doesn’t seem like too difficult a task, there are some guidelines that need to be followed. The failure of a wheel bearing can cause major damage to the wheel and can even allow the wheel assembly to slide off the axle. Wheel bearings are relatively small, but are incredibly strong. They have to support the…
In the third article in a DIY series for pilots, A&P Jacqueline Shipe goes through the steps an owner can take in order to properly service the struts on their aircraft. Among the preventive maintenance items listed in FAR 43 Appendix A that pilots may legally perform on an airplane that they own is strut servicing. The struts on any airplane serve a critical purpose. They provide the shock absorption necessary to prevent the airframe structure from enduring too much stress from the impact loads incurred on landings. Even taxi operations impose stress on an airframe every time the gear hits a bump or uneven surface. The strut absorbs the bulk of these loads and prevents them from being transmitted to the airframe. Overinflation or underinflation can affect the operation of the squat switch on this Cessna 210. Types of struts There are several different kinds of struts used for shock absorption. Over the years aircraft manufacturers have used different materials to limit the stress from the impact of landing. Some have used rubber biscuits, bungee cords and spring steel. The most common type found on most planes (and the only type used on fairly heavy planes from light twins…
Various things can cause nosegear shimmy. Here’s what to do. There’s nothing worse than completing a near-perfect landing and rollout only to have a sudden shimmy in the nosegear cause the whole front end of the airplane to vibrate. The shaking can be alarming to pilots who have never experienced it before, and can be worrisome for passengers. The vibration is also very hard on the airplane itself. A nosewheel shimmy is a rapid back-and-forth oscillation of the steerable part of the nosegear and wheel. It can be caused by a variety of problems, and it sometimes takes more than one trip to the shop to get the issue resolved. The nosegear has several points at which it pivots and rotates. These pivot points naturally wear over time, and excessive play in any one of them can cause the nose to shimmy. The photo is a close look at torque link bearings and bushings. Regular servicing these with clean grease helps prevent wear. The torque links (shown disassembled here) are made of aluminum castings. The torque links attach to a steerable nose collar on the top Cessna nosewheel design The nosewheel is turned left and right by means of a…
Jacqueline Shipe, A&P, explains the technology and preventive maintenance for aviation batteries in her sixth DIY article targeted to owner-pilots. The bulk of the items listed in FAR 43 Appendix A, paragraph (c) that an owner may legally perform on his or her owned aircraft are primarily maintenance tasks that have to be performed on a fairly regular basis. This is definitely true concerning aircraft battery maintenance, and “servicing or replacement of aircraft batteries” is included on the list of 31 preventive maintenance items. All batteries begin to degrade in performance from the moment they are placed in service. The constant chemical reactions that take place cause an ever-increasing lack of efficiency within the battery. This is especially true of batteries that are allowed to run down and remain in a low or depleted state. Lead-acid batteries are the type used in almost all General Aviation planes and are becoming more common for turbines employed in low-cyclic applications like medevac. (Turbine powered planes in high-cyclic applications (i.e., airliners) often have nickel cadmium or “NiCad” batteries installed. These batteries are costly, and the servicing requirements are much more complex than for the lead-acid batteries. NiCad batteries should only be serviced by…
Finding and repairing a broken circuit is the subject of this fourth installment of A&P Jacqueline Shipe’s DIY series. Among the many preventive maintenance items listed in FAR 43 Appendix A that a pilot may legally perform on his or her plane is “troubleshooting and repairing a broken landing light circuit.” This specific entry is the only reference to electrical circuit troubleshooting on the list. Most electrical circuits for lights or pitot heat, etc. are fairly straightforward, while a wiring harness for a unit like a panel-mounted GPS can be very complex. This article will focus on the tools and expertise required to successfully troubleshoot a landing light. Fig. 9-35: In this landing lights diagram, power comes from the bus bar to a 20-amp circuit breaker, which is a shared breaker for two separate landing light circuits. The number 14 indicates that the wire size for that section is 14 gauge. L1A and L2A indicate the wire numbers. Study the diagram On any electrical circuit, the best troubleshooting tool is always the current wiring diagram pertinent to the model and serial number of the airplane. Learning how to read a wiring or system schematic can help a pilot not only…
A look inside your aircraft’s vacuum system. An elliptically-shaped aluminum housing with the intake and exhaust ports in it. The rotating carbon vane assembly is housed inside. The air inlet for the vacuum pump. The outer vacuum pump housing has an air inlet port on the front of the pump, and an exhaust port on the rear. A rotor with carbon vanes extended, as they would be in operation. The vanes are free to slide inward and outward as the rotor spins. A carbon vane slid out to its maximum travel in its slot. The vanes are allowed to expand outward to their maximum extension at the widest points of the ellipse they travel in. When the earliest airplane gyroscopic instruments were introduced, the only available source for air pressure to spin them was an outside-mounted air venturi. The venturi accelerated the ram air pressure produced by forward flight through a narrowed opening. The instrument hoses were connected to the venturi at the point of lowest pressure, creating a vacuum that pulled a steady stream of air through the instruments. Although some VFR-only planes still use this arrangement, the trouble with this setup is that the amount of vacuum is…
Many Cessna aircraft depend on a carburetor. Cessna Flyer contributing editor and A&P Jacqueline Shipe explains the operation of this fairly simple— and very reliable—invention. One of the most recognized carburetor manufacturers for the GA fleet is Marvel-Schebler. The company has been around a long time, having its beginnings in the early 1900s when George Schebler and his friend Burt Pierce worked together to design the first carburetor using a tin can with a flap to regulate airflow. They both went on to patent their designs, with Pierce calling his carburetor the “Marvel.” Both the Marvel and the Schebler designs were successful and used on a variety of engine types. In the early days of General Motors, the two merged and became known as Marvel-Schebler Carburetor Co. (Author’s note: Burt Pierce also designed the still-popular Marvel Mystery Oil through Marvel Oil Co., which he founded in 1923.) In the beginning, the Marvel-Schebler Carburetor Co. made carburetors for cars, boats, tractors and airplanes. The company has since changed hands several times, being purchased and resold by Facet Aerospace Products, Zenith Fuel Systems, Precision Airmotive and the Tempest Group (who called it Volare Carburetors until it acquired the Marvel-Schebler trademark in 2010).…
Loss of control is a hot topic among the NTSB, FAA and other aviation organizations that promote aviation safety. Last year, the NTSB named the prevention of loss of control in flight in General Aviation as one of its “Most Wanted” transportation safety improvements. The NTSB report issued in 2015 stated that “between 2001 and 2011, over 40 percent of fixed wing GA fatal accidents occurred because pilots lost control of their airplanes.” This is unacceptable and mostly preventable. All pilots should be aware of the possibility of loss of control and take the time to review actions to prevent it. One way is to study flight manual procedures specific to the aircraft you fly. Another is to be aware of common situations that can contribute to loss of control. As a former air carrier pilot, air taxi pilot and mechanic with inspection authorization, I will focus this article on equipment and mechanical malfunctions that can also contribute to loss of control. Preflight actions As aircraft control systems, flight management systems and electronics have advanced to make the task of flying easier, it is still necessary to have sufficient skills not only to fly the aircraft but to do all…
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