Easton, MD, USA
N4922P
CESSNA 152
The student pilot was landing at the first of two intended stops on the solo cross-country flight. She stated that she felt the main landing gear touch down on the runway first, followed by the nose landing gear. The airplane bounced, and the student pilot subsequently observed the airplane's nosewheel rolling down the runway in front of the airplane. The airplane settled back onto the runway and came to rest upright. The airplane sustained substantial damage to the engine firewall. An air traffic controller who observed the landing stated that the airplane touched down, porpoised, and bounced twice before impacting the runway at what appeared to be a steep angle. Postaccident examination revealed that the nosewheel exhibited impact damage to the rim. Postaccident examination of the nose landing gear assembly revealed that the landing gear through bolt had fractured in shear overload. Further examination revealed that the bolt measured 5/16 inch in diameter. However, the bolt manufacturer specified that a 7/16-inch-diameter bolt should be used. Review of maintenance records could not determine when the 5/16-inch bolt was installed or how many hours of operation the airplane had accrued since the installation. Additionally, the bolt head was not recovered, and it could not be determined if the 5/16-inch bolt installed on the airplane met standard aircraft specifications. Generally, a 5/16-inch bolt would be expected to have half of the shear strength rating of a 7/16-inch bolt.
On August 23, 2013, about 1034 eastern daylight time, a Cessna 152, N4922P, was substantially damaged during landing at Easton/Newman Airport (ESN), Easton, Maryland. The student pilot was not injured. Visual meteorological conditions prevailed, and a visual flight rules flight plan was filed for the flight, which originated from Patuxent River Naval Air Station (NHK), Patuxent River, Maryland, about 0955. The instructional flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The student pilot stated that she was conducting a solo cross-country flight, with ESN being the first of two planned stops before returning to NHK. A preflight inspection of the airplane revealed no anomalies. During initial engine start up, she stated that the rudder pedals "shook violently," but the shaking subsided at idle engine power. The student proceeded to depart, and stated that she observed the rudder pedals shaking during the takeoff roll. During landing on runway 04 at ESN, she felt the main landing gear touch down, followed by the nose landing gear. She reported that the airplane then "bounced," and subsequently observed the nose landing gear wheel rolling down the runway in front of the airplane. The student pulled back "hard" on the control yoke, and the airplane settled back onto the runway, resulting in substantial damage to the engine firewall. An air traffic controller at ESN stated that the accident airplane entered the airport traffic pattern on the downwind leg, and was cleared for a touch-and-go landing. He stated that the airplane touched down, "porpoised," and subsequently bounced twice before impacting the ground at what appeared to be a "steep angle." He also stated that he did observe an object depart the airplane during this sequence of events, but could not recall exactly when the departure occurred. The 1055 weather observation at ESN included wind from 360 degrees at 5 knots, 10 statute miles visibility, a broken cloud layer at 18,000 feet, an overcast cloud layer at 20,000 feet, temperature 25, dew point 20, and an altimeter setting of 30.04 inches of mercury. The pilot held a student pilot certificate and Federal Aviation Administration third-class medical certificate. She reported 29 total hours of flight experience, all of which were in the accident airplane make and model. The airplane was manufactured in 1981, and was equipped with a Lycoming O-235 series, 110 hp reciprocating engine. The airplane's most recent 100-hour inspection was completed on July 20, 2013. At the time of the accident, the airplane had accumulated 10,839 total hours in service, and the engine had accumulated 1,770 hours since its most recent overhaul. Postaccident examination revealed that the nosewheel had separated from the airplane, and exhibited impact damage to the rim. The nosewheel through bolt had fractured, and the fracture face exhibited a dull, grainy appearance and shear lip consistent with overload failure. The axle tube opening was elongated, consistent with impact force to the tube/through bolt assembly. Manufacturer's specifications indicated that the proper through bolt for the Cessna 152 was an AN7-74, which measured 7/16 inches in diameter. The through bolt installed on the accident airplane was a steel alloy bolt that measured 5/16 inches in diameter. The bolt head was not recovered, therefore, it could not be determined if the bolt was AN specification. Review of maintenance records revealed major repairs to the engine mount and nose gear assembly on three separate occasions, following hard landings in October 1981, August 1987, and September 1993; at 483 hours, 3,971 hours, and 5,601 hours, respectively. However, it could not be determined when the 5/16 inches bolt was installed, or how many hours of operation the airplane had accrued since the installation. A steel alloy AN5-74 bolt, which has a diameter of 5/16 inches, has a shear strength rating of 5,750 lbs. Comparatively, a steel alloy AN7-74 bolt with a diameter of 7/16 inches, the type specified by the manufacturer, has a shear strength rating of 11,250 lbs.
The use of an improper nose landing gear through bolt, which decreased the overall strength of the gear and resulted in overload failure during a hard landing. Contributing to the accident was the student pilot's inadequate landing flare, which resulted in the hard landing.
Source: NTSB Aviation Accident Database
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