Incident Overview
On August 23, 2013, at about 1034 eastern daylight time, a Cessna 152, registration N4922P, was substantially damaged during a landing at Easton/Newman Airport (ESN) in Easton, Maryland. The student pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed, and a visual flight rules flight plan was filed for the instructional flight conducted under Title 14 Code of Federal Regulations Part 91. The flight originated from Patuxent River Naval Air Station (NHK) in Patuxent River, Maryland, about 0955.
Pilot and Aircraft Information
The pilot held a student pilot certificate and a Federal Aviation Administration third-class medical certificate. She reported 29 total hours of flight experience, all in the accident airplane make and model. The Cessna 152 was manufactured in 1981 and equipped with a Lycoming O-235 series, 110 hp reciprocating engine. The aircraft's most recent 100-hour inspection was completed on July 20, 2013. At the time of the accident, the airframe had accumulated 10,839 total hours, and the engine had 1,770 hours since its most recent overhaul.
Sequence of Events
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 revealed no anomalies. During initial engine start-up, she reported that the rudder pedals "shook violently," but the shaking subsided at idle engine power. She departed and observed the rudder pedals shaking during the takeoff roll. While landing on runway 04 at ESN, she felt the main landing gear touch down, followed by the nose landing gear. The airplane then "bounced," and she saw the nose landing gear wheel rolling down the runway in front of the airplane. She 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 observed the airplane touch down, "porpoised," and then bounce twice before impacting the ground at what appeared to be a "steep angle." He also noted seeing an object depart the airplane during this sequence but could not recall exactly when.
Weather Conditions
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°C, dew point 20°C, and an altimeter setting of 30.04 inches of mercury.
Postaccident Examination
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, measuring 7/16 inches in diameter. The through bolt installed on the accident airplane was a steel alloy bolt measuring 5/16 inches in diameter. The bolt head was not recovered, so 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-inch bolt was installed or how many hours of operation the airplane had accrued since installation.
A steel alloy AN5-74 bolt (5/16 inches diameter) has a shear strength rating of 5,750 lbs, while the specified AN7-74 bolt (7/16 inches diameter) has a shear strength rating of 11,250 lbs.