CEN19LA059

The private pilot reported that, after takeoff for the cross-country, personal flight, he attempted to retract the landing gear and noticed that the gear motor continued to operate longer than normal and that the sound had become abnormal toward the end of the retraction sequence. The pilot subsequently saw that the right main landing gear (MLG) had not fully retracted and was hanging about 45° rearward. He could not see the left MLG. The pilot attempted to address the gear issue for more than 20 minutes by completing the emergency procedures checklist; however, although the nose landing gear (NLG) had extended, the MLG did not respond, so the pilot continued to the destination airport. Before landing, the pilot again attempted to extend the landing gear. During a flyby, an air traffic controller confirmed that both MLG were not extended. The pilot subsequently conducted an emergency landing with the NLG extended and both MLG partially extended. Upon landing, the airplane spun about 180° and then came to rest on the runway, sustaining substantial damage to the right horizontal stabilizer and elevator. During postaccident examination of the airplane, the NLG well was found partially covered in red hydraulic fluid, no hydraulic fluid was found on the reservoir dipstick, and an NLG actuator hydraulic hose was found damaged. During a functional test of the hydraulic system, the emergency gear extension handle was actuated in an attempt to extend the MLG; however, after 10 to 12 pumps, hydraulic fluid sprayed from the damaged hose; the system could not build pressure, and the MLG would not extend. The damaged hose was replaced, the emergency gear extension handle was actuated, and the MLG extended and locked normally. According to a service bulletin issued 17 years before the accident and based on the maintenance criteria for the hydraulic hose part number, the hose should have been replaced with an updated hose. However, about 13 years before the accident, the hydraulic hose was replaced with the original part number rather than with the updated part number. The hydraulic hose failed during the accident flight when the pilot attempted to retract the landing gear after takeoff. It is likely that, during annual inspections subsequent to the hose replacement, the hose was treated as an "on-condition" part since it had not been replaced with the new hose. It is likely that most of the hydraulic fluid was pumped out of the damaged hose during the pilot's troubleshooting attempts, which led to a loss of hydraulic system pressure and prevented the MLG from fully extending or retracting and resulted in a gear-up landing.

On January 6, 2019, about 1640 eastern standard time, a Cessna T210 airplane, N1237M, experienced an unsafe landing gear indication and landed with the gear partially extended at Bishop International Airport (FNT), Flint, Michigan. The private pilot and 3 passengers were not injured, and the airplane sustained substantial damage. The airplane was registered to Fly Happy LLC and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed at the time of the accident and a flight plan was not filed. The flight originated from Clare Municipal Airport (48D), Clare, Michigan, about 1600, and was destined for FNT. The pilot reported that after departure from 48D he raised the landing gear handle and the gear motor continued to operate longer than normal with an abnormal sound toward the end of the retract sequence. The right main gear did not fully retract and hung about 45° rearward; the left main gear was not visible from the pilot's vantage. The pilot troubleshot the issue for 20 to 25 minutes by completing the emergency procedure checklists, but the landing gear did not respond. At some point during the pilot's troubleshooting, the nose landing gear fully extended. The pilot continued the flight to FNT and declared an emergency with air traffic control (ATC). Before landing the pilot attempted to extend the landing gear but was only able to get the nose gear to extend. During a flyby ATC confirmed that both main landing gear were not extended. During the emergency landing at FNT, the nose gear remained extended and the two main gear were partially retracted. The airplane spun about 180° and came to rest on the runway (figure 1). Figure 1. Accident airplane on runwayThe responding Federal Aviation Administration (FAA) inspector completed a postaccident examination of the airplane and provided oversight for a functional test of the landing gear system. The examination revealed the nose gear well partially covered in red hydraulic fluid, no hydraulic fluid observed on the corresponding dipstick, and a damaged nose gear door actuator hydraulic hose, part number (p/n) S2178-4-0095A (figure 2). Figure 2. Damaged hydraulic hose To facilitate a functional test of the hydraulic system, the airplane was raised on jack stands and about 16 ounces of hydraulic fluid was added to the hydraulic reservoir. The emergency gear extension handle was actuated in attempt to extend the main landing gear before preforming the full functional test. After 10 to 12 pumps, hydraulic fluid sprayed from the damaged hydraulic hose. There was no resistance felt from the emergency handle during actuation. The hydraulic system was unable to build pressure so the functional test was terminated. The damaged hose was replaced with a new hose and the functional test was resumed. With the new hose installed, the emergency handle was actuated and the main landing gear extended and lockedwithout anomaly. A review of the airplane's maintenance records revealed that the last annual inspection was completed on September 9, 2018, at 3,840.2 hours total airframe time. The airplane accumulated 32.8 hours since the annual inspection with no hydraulic hose or landing gear discrepancies noted. The nose gear door actuator hose was first replaced in October 1977, and then replaced again on April 4, 1996, at 2,059.2 hours total time. The airplane had accumulated 1,813.4 hours total time since the hydraulic hose was replaced. The airplane manufacturer's inspection guidelines are to perform a functional test and inspect the landing gear system every 200 hours. The maintenance manual states, "Each 5 years, overhaul all retraction and brake system components. Check for wear and replace all rubber packings and backups and hydraulic hoses." This maintenance requirement applied to this airplane. Additional guidance associated with the inspection was Cessna service newsletter, SNL85-54, issued during November 1985, which changed the 5-year overhaul/replacement requirement to an "on condition" overhaul/replacement interval based on part numbers involved. The damaged hose, p/n S2178-4-0095A, was considered an "on condition" component and could be replaced based on its condition at the time of maintenance. In 1992, the airplane manufacturer released Cessna service bulletin, SEB92-8, that called for the replacement of all S2178-4 hydraulic hoses with p/n S2888-4-0095. According to available maintenance documentation, the airplane was never equipped with the updated hydraulic hose.