Incident Overview
On January 6, 2019, about 1640 eastern standard time, a Cessna T210 airplane, registration N1237M, experienced an unsafe landing gear indication and landed with the gear partially extended at Bishop International Airport (FNT) in Flint, Michigan. The private pilot and three passengers were not injured, but the airplane sustained substantial damage. The airplane was registered to Fly Happy LLC and operated by the pilot under Title 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed at the time, and no flight plan was filed. The flight originated from Clare Municipal Airport (48D) in Clare, Michigan, about 1600, and was destined for FNT.
Pilot Actions
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 landing gear did not fully retract and hung about 45° rearward; the left main gear was not visible from the pilot's vantage. The pilot troubleshooted the issue for 20 to 25 minutes by completing emergency procedure checklists, but the landing gear did not respond. During the troubleshooting, the nose landing gear fully extended. The pilot continued 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 while the two main gear were partially retracted. The airplane spun about 180° and came to rest on the runway.
Post-Accident Examination and Functional Test
The 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 that the nose gear well was partially covered in red hydraulic fluid, no hydraulic fluid was observed on the corresponding dipstick, and a nose gear door actuator hydraulic hose, part number (p/n) S2178-4-0095A, was damaged.
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 an attempt to extend the main landing gear before performing 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 locked without anomaly.
Maintenance Records Review
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 require a functional test and inspection of 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 in November 1985, which changed the 5-year overhaul/replacement requirement to an "on condition" 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, which 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.