What happened
On October 13, 2017, a single-engine Cessna 172S, registration HB-TDD, departed from Speck-Fehraltorf for a private flight to Wangen-Lachen. The flight was conducted under Visual Flight Rules (VFR) in favorable weather conditions with light winds.
During the approach to runway 26 at Wangen-Lachen, the pilot maintained a steady airspeed of 61 KIAS from 130 ft AGL down to 50 ft AGL. As the aircraft passed 135 meters before the runway threshold, a tablet computer mounted on the control column became loose and tilted downward, prompting the pilot to reach for it with his right hand. The aircraft crossed the threshold at 20 ft AGL and made a hard touchdown approximately 100 meters past the threshold.
Following the initial impact, the aircraft bounced and struck the runway twice more. The sequence of impacts eventually caused the nose gear to strike the ground, resulting in propeller tip damage. The pilot was able to use the brakes to slow the aircraft, exiting the runway 70 meters before the end. After a visual inspection, the pilot restarted the engine and completed the flight back to the origin.
The investigation
Investigators examined the flight data and pilot statements to reconstruct the approach and landing sequence. The investigation focused on the aircraft's weight, the approach speed, and the pilot's reaction to the cockpit distraction. The inspection of the aircraft revealed significant structural damage, including a deformed firewall near the nose gear attachment, buckled floorboards, and a shifted control column pivot that restricted elevator movement.
Findings
- The pilot utilized an inappropriate approach tactic for the 500-meter runway, characterized by an excessive approach speed for the actual landing weight.
- While the pilot maintained a stabilized descent angle, the airspeed was too high for the reduced weight, resulting in a pitch angle shallower than required.
- The aiming point was set approximately 90 meters behind the runway threshold, which contributed to a long landing.
- A cockpit distraction involving a poorly secured tablet computer occurred during a critical phase of the landing.
- The subsequent bounces led to a pilot-induced oscillation, culminating in the nose gear striking the runway.
- The pilot failed to initiate a go-around despite the high approach speed and the late touchdown.
Safety action
- The pilot continued the return flight despite discovering propeller damage, highlighting the risk that seemingly minor cockpit distractions can lead to significant structural damage that may only be identified during a thorough post-flight inspection.