is limited to work that does not involve complex assembly  operations including the following:  9-11  • Updating self-contained, front instrument panel- mounted air traffic control (ATC) navigational  software databases (excluding those of automatic  flight control systems, transponders, and microwave  frequency DME), only if no disassembly of the unit is  required and pertinent instructions are provided; prior  to the unit’s intended use, an operational check must  be performed in accordance with applicable sections  of 14 CFR part 91.  • Replacing wheels and skis where no weight-and­ balance computation is involved; replacing any  cowling not requiring removal of the propeller or  disconnection of flight controls; replacing or cleaning  spark plugs and setting of spark plug gap clearance;  replacing any hose connection, except hydraulic  connections; however, prefabricated fuel lines may  be replaced.  • Replacing safety belts, seats or seat parts with  replacement parts approved for the aircraft, not  involving disassembly of any primary structure or  operating system, bulbs, reflectors, and lenses of  position and landing lights.  • Inspection and maintenance tasks prescribed and  specifically identified as preventive maintenance in  a primary category aircraft type certificate or STC  holder’s approved special inspection and preventive  maintenance program when accomplished on a  primary category aircraft.  • Removing and replacing self-contained, front  instrument panel-mounted navigation and  communication devices that employ tray-mounted  connectors which connect the unit when the unit  is installed into the instrument panel (excluding  automatic flight control systems, transponders, and  microwave frequency distance measuring equipment  (DME)). The approved unit must be designed to be  readily and repeatedly removed and replaced, and  pertinent instructions must be provided. Prior to the  unit’s intended use, an operational check must be  performed in accordance with the applicable sections  of 14 CFR part 91 on checking, removing, and  replacing magnetic chip detectors.  • Replenishing hydraulic fluid in the hydraulic  reservoir; refinishing decorative coating of fuselage,  balloon baskets, wings, tail group surfaces (excluding  balanced control surfaces), fairings, cowlings,  landing gear, cabin, or flight deck interior when  removal or disassembly of any primary structure  or operating system is not required; applying  preservative or protective material to components  where no disassembly of any primary structure or  operating system is involved and where such coating  is not prohibited or is not contrary to good practices;  repairing upholstery and decorative furnishings of the  cabin, flight deck, or balloon basket interior when the  repair does not require disassembly of any primary  structure or operating system or interfere with an  operating system or affect the primary structure of  the aircraft; making small, simple repairs to fairings,  nonstructural cover plates, cowlings, and small  patches and reinforcements not changing the contour  to interfere with proper air flow; replacing side  windows where that work does not interfere with the  structure or any operating system, such as controls,  electrical equipment, etc.  • Removal, installation, and repair of landing gear  tires and shock cords; servicing landing gear shock  struts by adding oil, air, or both; servicing gear wheel  bearings; replacing defective safety wiring or cotter  keys; lubrication not requiring disassembly other than  removal of nonstructural items, such as cover plates,  cowlings, and fairings; making simple fabric patches  not requiring rib stitching or the removal of structural  parts or control surfaces. In the case of balloons,  the making of small fabric repairs to envelopes  (as defined in, and in accordance with, the balloon  manufacturer’s instructions) not requiring load tape  repair or replacement.  •  Cleaning or replacing fuel and oil strainers or filter  elements; servicing batteries, cleaning balloon burner  pilot and main nozzles in accordance with the balloon  manufacturer’s instructions.  • The interchange of balloon baskets and burners on  envelopes when the basket or burner is designated as  interchangeable in the balloon type certificate data  and the baskets and burners are specifically designed  for quick removal and installation; adjustment  of nonstructural standard fasteners incidental to  operations.  • The installations of anti-misfueling devices to reduce  the diameter of fuel tank filler openings only if the  specific device has been made a part of the aircraft type  certificate data by the aircraft manufacturer, the aircraft  manufacturer has provided FAA-approved instructions  for installation of the specific device, and installation  does not involve the disassembly of the existing tank  filler opening; troubleshooting and repairing broken  circuits in landing light wiring circuits. 