(Now we see the connection...the lack of structural connection described in May’s engineering safety article for this same aircraft.)

The submitter states, “This aircraft experienced a hard landing. During the landing the two top engine mount attach brackets failed behind the firewall, allowing the top half of the firewall to fail, pulling forward and down about 18 inches. (See the attached figure 19, items 7 and 6.) The part number 0513132-11 engine mount attach bracket fits onto the front of the hat channels (items 6 and 7). (This same part)--which has a hole in it for the engine mount bolt to go through—had failed some time ago on the pilot’s top side...(as evidenced by rust being found in the break surfaces of two pieces). The bracket on the co-pilot’s top side had an existing crack in the center third—at the bolt hole. Rust was also (evident on these crack surfaces).” ‘This aircraft had an STC’d (Supplemental Type Certificate) Continental IO-360 engine installed....” (SDRS data base records 17 entries on this particular part number.)

Part Total Time: 2,756.0 hours.