N740SPCessna 172S · 2000

The student pilot was on a solo instructional flight in the airport traffic pattern. She approached the runway and described that the airplane touched down on both main landing gear and that the nosewheel touched down almost immediately thereafter. The airplane then bounced three times, which each bounce being harder than the last. After the last bounce, the pilot taxied off the runway uneventfully. The underside of the airplane’s fuselage was substantially damaged during the accident sequence. The pilot reported that there were no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.

During a 50 hour maintenance inspection, an airframe and power plant mechanic discovered that the airplane's firewall was substantially damaged. The operator was not able to determine when the accident flight occurred or the pilot responsible.

The airplane's last maintenance inspection occurred about three months prior to the discovery. Numerous pilots flew the airplane during that period, none of which reported an event that would result in damage to the airplane.

According to the student pilot, he was fast on the approach and touched down on the main landing gear, bounced, then released back pressure on the yoke. The airplane started to porpoise uncontrollably and the nose landing gear broke off. The airplane departed the runway to the right and came to rest inverted in the grass. Examination of the airplane by an FAA inspector revealed that the airplane sustained substantial damage to the firewall, vertical stabilizer, and to the rudder. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.