Beech Model 58 Baron Burned Circuit Breaker Switch The pilot reported a burning smell in the cabin. Inspection revealed the taxi light circuit breaker switch had burned internal components. This switch (p/n 35-380132-105) is the improved model required by AD 2008-13-07. Unfortunately, when these switches overheat, it can be impossible to determine if the insulators had been installed improperly, or installed at all. This was the second post-AD switch failure in this fleet. Part Total Time: (unknown) Cessna 172S Loosened Seat Lock Attach Screws The pilots seat would not lock into position. A maintenance technician found the attachment screws of the left and right seat stop pins had backed out, allowing them to be detached and ineffective. A check of other examples in the fleet found six additional aircraft with loose attachment screws (p/n MS35207256). All loose screws were removed, inspected and reinstalled with Loctite 242 per the manufacturers suggestion. Part Total Time: 1797.0 hours Piper PA-28-180 Failed Landing Gear Strut The right main landing gear lower strut fell off during takeoff. The student pilot flew to his destination and landed, resulting in damage to the upper landing gear strut (p/n: 6531904). When the lower strut departed the upper housing, it struck and damaged the flap skin. The right main landing gear upper torque link mounting ears broke off the cylinder, allowing the lower gear leg to fall out of the upper cylinder and depart the aircraft. The upper torque link attach point is covered by a fairing, preventing the pilot from seeing any defects during preflight. Part Total Time: (unknown) ECI Cylinder AEC631397 Separated Cylinder Head While the Cessna 414 powered by TCM TSIO-520-NB engines was in flight at cruise power, manifold pressure was lost, accompanied by engine roughness. The engine was shut down. A normal landing was made at the intended destination. Inspection revealed the number two cylinder head had separated. No structural damage occurred. Part Total Time: 1163.0 hours Lycoming LTIO-540-J2BD Improper Rocker Cover Installation The Piper PA-31-350s right engine was written up for a large oil leak. Inspection revealed the number three cylinder (p/n LW-12966) had an incorrectly installed gasket (p/n 66732) under the rocker shaft cover (p/n 72710). This engine was factory-remanufactured with only 44.7 hours time in service. Part Total Time: 44.7 hours