Aviation Accident Summaries

Aviation Accident Summary WPR18LA058

San Bernardino, CA, USA

Aircraft #1

N222AT

CESSNA 210

Analysis

The airplane was at a maintenance facility for an annual inspection, which had not been completed, and the airplane had not been returned to an airworthy condition. Despite this, the private pilot picked up his airplane from the maintenance facility to fly it to his base airport. While in the traffic pattern, the pilot lowered the main landing gear (MLG) but noted that the left MLG was not fully extended. The pilot attempted to manually extend the MLG to no avail and subsequently landed the airplane with the left MLG retracted. Postaccident examination of the left MLG revealed that the saddle assembly had fractured. The assembly was removed for metallurgical examination, which revealed that the saddle fracture surfaces exhibited features consistent with fatigue. An airworthiness directive (AD) required that the MLG saddles be inspected for cracks using the dye-penetrant procedure as part of the annual inspection. The mechanic who was conducting the annual inspection reported that he had not inspected the landing gear before the pilot took the airplane and that he had informed the pilot that the annual inspection was not complete and that he was not signing the airplane off as airworthy. It is likely that, if the AD had been complied with and the pilot had not taken the airplane before the annual inspection was complete, the preexisting crack would likely have been identified during the inspection of the MLG saddles.

Factual Information

HISTORY OF FLIGHT On December 29, 2017, about 2030 Pacific standard time, a Cessna 210J airplane, N222AT, experienced a left main landing gear collapse during landing at San Bernardino International Airport (SBD) San Bernardino, California. The private pilot was not injured. The airplane sustained substantial damage to the empennage. The airplane was registered to Sierra 1 Tech Inc., San Bernardino, California, and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed for the flight, which originated from Chino Airport (CNO), Chino, California, about 1915. According to the pilot, he picked up the airplane from a maintenance facility to return to his base airport at SBD. Lock actuator seals were on order and he would bring the airplane back when they arrived the following week. When inbound for landing to SBD, the pilot lowered the landing gear and noted that the left main gear was not completely down. The pilot informed the tower controller of the situation. Despite multiple attempts, the pilot was unable to hydraulically or manually extend the landing gear to the down and locked position. During the landing, the left main landing gear collapsed, and the left horizontal stabilizer struck the ground. The airplane subsequently spun left and skidded to a full stop on the runway. A postaccident examination of the left main landing gear revealed that the saddle assembly (part number 1241423-1) had fractured. The mechanic at the maintenance facility where the pilot had picked the airplane up from, reported that the airplane was at his facility for two days during the last week of December and that the annual inspection was almost complete except for inspecting the landing gear and fixing some hydraulic system leaks. The mechanic had informed the pilot that new seals needed to be ordered and the annual inspection was placed on hold. The airplane remained on jacks and the access panels were left off. On December 29, around lunch time, the pilot arrived at the maintenance facility and told the mechanic that he needed the airplane that day. The mechanic informed the pilot that the annual inspection was not complete, and he would not be signing the airplane off as airworthy. The mechanic left for lunch, and when he returned, the pilot had re-installed all the removed panels, and down-jacked the airplane. It had been pulled outside and the pilot was attempting to start the engine. When confronted, the pilot was insistent on taking the airplane. The engine was subsequently started, and the pilot taxied out and eventually took off. The mechanic reported that on January 3, 2018, the pilot arrived at the maintenance facility and asked for the annual inspection to be signed off. The pilot told the mechanic that personnel at SBD airport needed to see proof of an annual inspection signoff prior to him being able to taxi. The pilot stated that as soon as he received the annual inspection signoff he would return the airplane to the mechanics shop, so the annual inspection could be completed. The mechanic complied with the pilot's request and provided the annual signoff dated January 3, 2018, because that was the day the pilot was bringing the airplane back, and that the pilot reported that he had performed landings and checks and found the airplane safe to fly back to his business. It was not until later in the week that the mechanic learned of the accident on December 29. AIRCRAFT INFORMATION A review of the airframe maintenance records, revealed that an annual inspection was completed on September 16, 2016, at a total time of 4,550.65 hours. The entry indicated that Airworthiness Directive (AD) 76-14-07 Gear Saddles had been complied with. A lined piece of paper, separate from the logbooks, was also provided. The page identified three stamped statements. Each statement identified the date of January 3, 2018. No Tach time was identified. The three statements identified the mechanics name and maintenance certificate number, as well as his signature that reported that the "Aircraft", "Engine", and "Propeller" "has been inspected in accordance with an Annual inspection and was determined to be in an airworthy condition at this time." No entries were identified that indicated if AD's had been complied with. TEST AND RESEARCH The landing gear saddle assembly was removed from the airplane and sent to the NTSB Materials Laboratory in Washington, D.C. for metallurgical examination. According to the engineer's factual report, the saddle fracture surfaces exhibited features consistent with fatigue. ADDITIONAL INFORMATION Amendment 39-5124, dated August 28, 1985, to Airworthiness Directive (AD) 76-14-07 R2 CESSNA, regarding Cessna Models 210 – 210J (Serial numbers 57001 thru 57575, 21057576 thru 21059199), with 1,025 hours' time in service, and each 25 hours subsequent, require inspection of main landing gear saddles, part numbers 1241423-1 and 1241423-2, for cracks using dye penetrant procedures outlined in paragraph E of the AD. Cracked saddles require replacement prior to further flight. The AD further states that within 100 hours time in service after August 16, 1976, or prior to April 1, 1977, whichever occurs later, landing gear saddles are to be replaced with improved saddles of the same part number, in accordance with Cessna Service Letter SE 75-26, dated December 5, 1975. The improved landing gear saddles are to be inspected for cracks at each annual inspection using the dye penetrant procedure. Examination of the airplane's Airworthiness Directives Compliance Log showed that new landing gear saddles (same part number, 1241423-1 and 1241423-2) were installed on April 1, 1977 at 2,860.7 hours. The last time the AD was complied with was on September 16, 2016 at 4,550.65 hours. According to photos obtained from the FAA, at the time of the accident the airplane had accumulated a total time of 4,808.97 hours. At this time the landing gear saddles had been in service for 1,948.27 hours.

Probable Cause and Findings

The fatigue failure of the left main landing gear (MLG) saddle, which resulted in the pilot's inability to extend the left MLG. Contributing to the accident was the pilot's improper decision to fly the airplane before the annual inspection was completed and the airplane returned to service in an airworthy condition.

 

Source: NTSB Aviation Accident Database

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