Incident Details
On August 19, 2010, at 18:00 UTC, a Piper PA-44/180T, registration CS-DGN, operated by Nortávia – Transportes Aéreos, SA, was scheduled for a training flight from Aeródromo Municipal da Maia, Vilar da Luz. During the pre-flight exterior inspection by the student pilot, deep cuts were found on the left main landing gear tire, prompting its replacement. After the tire change, the right-hand side door could not be closed, and a deformation of the fuselage was observed. The aircraft was removed from service for a detailed inspection.
Hard Landing
The investigation into the aircraft's history revealed that the previous day, the same aircraft had conducted a navigation training flight from Vilar da Luz to Viseu and back. No anomalies were recorded in the technical log or flight report. However, it was later determined that during the landing back at base, the pilot allowed the airspeed to decrease very close to stall speed, while the approach was flown with an excessively high descent rate and a late flare. This resulted in a violent impact with the runway.
Damage Found
The maintenance team conducted a thorough inspection per the aircraft maintenance manual. The left tire showed cuts from the brake disc, consistent with the abnormal landing attitude. The fuselage exhibited significant deformation on the right side above the wing leading edge, preventing door closure, and on the left side. The belly skin was heavily distorted, with many sheared or missing rivets. Structural longerons in the wheel well were deformed, and rivets were pulled. Both wings near the fuselage attachment showed significant deformation. Rub marks were found on the right engine propeller tips.
Investigation
The Portuguese Aviation Accident Prevention and Investigation Office (GPIAA) classified this as a serious incident per ICAO Annex 13 and opened an investigation. The investigation noted that the instructor pilot did not perceive the speed decay and high descent rate in time, partly due to expecting normal student performance, and when he attempted to intervene, he could not avoid the hard impact. The aircraft's T-tail configuration, differing from the low-tail aircraft the operator mainly used, may have influenced the pilot's instinctive reaction. No hard landing entry was made in the technical log or report, and no oral notification was given to maintenance.
Probable Cause
The aircraft made an extremely hard landing due to an unstabilized approach in terms of speed and descent rate, without timely corrective measures, combined with a flare that was too late and too low, aggravated by an excessively nose-high attitude and the particular reaction of this type of aircraft.