20060622019059A

(-23) Inspector's statement: June 22, 2006, I went to investigate an accident at Lebanon, TN (M54) Cessna 182 rg s/n R18201911 N6124T. The pilot privacy data omitted was unable to get the landing gear into a locked position, due to total loss of system hydraulic fluid. As a result the pilot made a belly landing, without any injuries. The aircraft had substantial damage to the l/h horizontal stabilizer and elevator. We also found damage to the left wing some skin buckling, plus bow in the l/h flap and some damage to the belly from the gear area back. The aircraft was moved to a hangar and was put on jacks, the seats and floor inspection panels were removed to locate the origin of the hydraulic leak. After the reservoir was serviced the hydraulic system was pressurized, fluid was coming from the right gear hydraulic down line. Further investigating we found a NAS221-16 screw installed in and inspection panel, had penetrated the hydraulic down line. Complete loss of hydraulic fluid was the end result. It was noted while reviewing Cessna R182 & TR182 parts catalog pages 109 and 110 figure 37 that the floorboard access panel (37-23) had four different size screws installed. The following nas screw sizes are installed in the panel. 37-24 NAS221-12 screw 5 each. 37-25 NAS221-16 screw 10 each. 37-26 NAS221-14 screw 2 each. 37-27 NAS221-9 screw 1 each. This is a total of 18 screws in different places on the floor panel. We were unable to find in the Cessna maintenance manual any instruction that addressed the installation of the screws, I.e. where do the different sizes go. I believe this is a problem due to lack of information in Cessna 182 rg manual identifying appropriate location of screws in 37-23 panel, and Cessna should issue a safety bulletin to assure better understanding and uniformity. The aircraft had an annual inspection accomplished and returned to service by an i/a. a letter of investigation of pertinent FARS has been issued.