Boeing 737: While climbing through 23,000 feet, the crew experienced a rapid depressurization and loss of cabin pressure. Oxygen masks were donned by the flight crew. The crew manually closed the outflow valve, however, the aircraft would not pressurize. The crew requested a descent and return to base. No emergency was declared. The aircraft landed without incident. Maintenance inspection revealed the upper beacon assembly light missing, with no damage in the hole or the airframe. The beacon assembly was replaced and the aircraft ground checked serviceable. The aircraft was returned to service with no further incidents to report. Note: the part history shows that the upper anti-collision light assembly was replaced during a C1-3 check at a third-party vendor per a non-routine discrepancy form. [ This SDR provided by AlgoPlus Consulting, www.algoplusaviation.com. ]

Cessna 421B: An annual inspection found the aft bulkhead (P/N 0823400-63) of the left wing’s tip-tank assembly (P/N 5092300-17) horizontally cracked through, as measured from the approximate center of the inboard lightening hole to the bulkhead inboard edge. The technician wrote, “it may possibly have been caused by previous ground mishandling or a hangar rash-type incident.” (SDRS data includes two additional, almost identical reports of cracks in the same part.) Part total time: 6,881.4 hours.

Cessna 441: A mechanic described finding this aircraft’s righthand aft elevator cable (P/N 5815103-6CR) significantly frayed “through four of the seven strands. Failure was imminent. No signs of wear seen on the previous inspection [500 hours earlier]. It should probably be inspected every 300 hours instead of the factory inspection schedule of 600 hours.” (Fuselage station number is 290. An attached note from the Flight Standards District Office in Wichita, Kansas, further described the submitter’s speculation: “...the corrosion-resistant stainless steel cables seem to be more brittle than the standard steel cables.”) Part total time: 4,000 hours.

Bell 407: A pilot found the tailskid (P/N 206-020-110-103) to be loose during a preflight inspection. “Upon closer examination, the tail skid pulled out from the fin assembly. The tailskid had cracked completely around and through at the attachment bolthole.” This crack propagation appeared slow. One occurrence of a hard landing four years and more than 2,700 hours prior to this defect. The SDR database records another three occurrences of cracked tailskids at this same location.