SALT LAKE CITY, UT, USA
N4664S
CESSNA TR182
The pilot stated that the landing gear did not come down on final approach, and that he was unable to obtain a safe gear indication using either normal or emergency extension. The pilot reported that a 38-knot left crosswind component existed for the landing. The airplane's maximum demonstrated crosswind is 18 knots. The right main gear collapsed on landing roll and the aircraft departed the right side of the runway. A post-accident inspection revealed that a nylon wire tie securing the throttle cable had broken, and that a hole had been chafed in the hydraulic pressure outlet line between the main hydraulic power pack and the landing gear selector valve. The chafed hole was in the area of the unsecured throttle cable. The hydraulic line had been repaired in 1980 by splicing in an additional piece and was 1/2 inch longer than a new hydraulic line. A new hydraulic line, when installed, had adequate clearance with the throttle cable.
On October 27, 1995, approximately 1800 mountain daylight time (MDT), a Cessna TR182, N4664S, was substantially damaged when it departed the runway surface during landing roll at Salt Lake #2 Airport, Salt Lake City, Utah, following a hydraulic system failure and subsequent emergency landing gear extension attempt and gear collapse. Of the two occupants on board, neither the private pilot/owner nor the pilot-rated passenger were injured. The flight originated at Vernal, Utah, and was operated under 14 CFR 91. Visual meteorological conditions prevailed and no flight plan had been filed. The pilot reported: "Without any warning...the hydraulic pump that pressurizes the retraction mechanism began to whine loudly for 10-15 seconds. It stopped and then cycled again about two more times. Then it stopped...." "When I moved the lever to lower the gear on final approach to the [Salt Lake City] #2 airport the gear did not come down. Moreover, there were no annunciator lights showing the gear status lighted up for either 'up' or 'down' position. I then began to lower the gear by hand with the gear lever in the down position. The gear came down but quite sluggishly. After the left main gear arrived at what was probably its locked position (the 'down' light did not come on) I continued to pump the hand lever....I noticed that the hand pump did not give increasing resistance when the gear arrived at the final position but continued to allow the plunger to travel. I determined that to continue pumping might exhaust the remaining hydraulic fluid." "...I determined to make as smooth a landing as possible. I did so and there was hardly a bump. However, I felt a shove to the left and distinct upward bump from the right main gear as the plane moved for a small moment to the left. Then I became aware that the right main landing gear was collapsing and it quickly became evident that the right wing was going down and that a possible propeller strike was imminent. I determined that the best [action] to prevent both of these...was to place as much weight [sic] on the left main gear. To do so I turned right....Surveying the off runway dirt I determined that to proceed onto the dirt area off runway right would pose no threat to my passenger nor myself....As we came to a gentle stop the right wing tip...leaned over and made soft contact with the ground....The right main gear had returned to its housing...." A memo faxed to the NTSB investigator-in-charge from the FAA coordinator to the accident stated the following: "...An investigation...determined the throttle cable had [chafed] a hole in the P/N 2280001-13 hydraulic pressure line resulting in a [loss] of all the hydraulic fluid. The P/N 2280001-13 line runs from pressure outlet of the hydraulic power pack to the landing gear selector valve. The [chafing] occurred just aft of the firewall at the point where the throttle cable passes through the firewall." "The hydraulic line had been repaired by splicing back in 1980 and [possibly] was routed different than original[;] also the throttle cable had been tied to the hydraulic line with nylon wire ties to prevent [chafing] but one of the nylon ties had broken, probably from old age." The investigator-in-charge discussed the hydraulic line findings in a telephone conversation with a mechanic from Alta Aircraft Maintenance, Salt Lake City, Utah, on March 27, 1996. This mechanic performed the repairs to the aircraft after the accident. The mechanic stated that "when the airplane was brand new", the chafed line had been repaired by splicing in an additional piece, and that the repaired line was about 1/2 inch longer than a new Cessna hydraulic line. He stated that the new hydraulic line, when installed, provided adequate clearance from the throttle cable. The mechanic furnished a copy of an entry from the aircraft logbook, dated October 1980, which read: "Repaired hyd line (pump, ld gear, to handle) by cutting and installing fitting AN 886-20...." The pilot reported that the wind at the time of the accident was from 270 degrees magnetic at 40 knots. In a landing to the north (runway 34 according to the Airport/Facility Directory) at Salt Lake City #2, as reported by the pilot, winds from 270 degrees magnetic at 40 knots would produce a 38-knot crosswind component for the landing. The 1979 Cessna model R182 information handbook gives the maximum demonstrated crosswind velocity for landing as 18 knots.
maintenance personnel improperly installed a landing gear system hydraulic line and the throttle cable which resulted in chaffing and subsequent loss of hydraulic fluid disabling the landing gear extention systems.
Source: NTSB Aviation Accident Database
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