What aircraft was involved and where did it happen?

The accident on 2018-03-31 involved a Robin DR400 120 cv, hélice 56’’, registration F-GIKQ, at Saint Chamond, FR.

What was the probable cause of the accident?

The accident was caused by the decision to execute a touch-and-go maneuver on a runway that was too short for the aircraft's performance requirements, exacerbated by an unpaved, heavy surface and an uphill gradient.

Fatal Runway Excursion During Touch-and-Go at Saint Chamond

A training flight involving a Robin DR400 ended in a fatal collision with trees and a highway sign after an insufficient runway length led to a failed takeoff attempt.

What happened

On March 31, 2018, a Robin DR400 120 cv, registration F-GIKQ, was performing a training flight from Lyon Corbas toward Saint Chamond l’Horme. The flight involved a pilot and an instructor. Upon arriving at Saint Chamond, the crew entered a left-hand circuit for the unpaved runway 28.

During the approach, the crew initiated a touch-and-go maneuver. The aircraft touched down near the midpoint of the runway, but during the subsequent takeoff roll, the aircraft exited the runway longitudinally. The aircraft continued to accelerate along a downward slope, crossing a hill at the end of the runway. The aircraft then lifted off with a high pitch attitude but failed to gain sufficient altitude, ultimately striking a row of trees and a highway sign before crashing into the ground near a motorway barrier.

Two fatalities occurred as a result of the impact, and the aircraft was destroyed.

The investigation

The BEA examined the wreckage, the airfield, and the operational procedures of the Lyon Corbas aero club. Technical analysis of the engine and fuel system showed no mechanical failures or fuel contamination. The investigation focused on the performance capabilities of the F-GIKQ specifically, as it was equipped with a Sensenich 56’’ large-pitch propeller, which significantly alters takeoff and landing distances.

Investigators also reviewed the club's operating manual and a specific warning sheet regarding this aircraft's performance. The investigation found that the aircraft's weight was approximately 770 kg (without fuel). The airfield's runway 28 was unpaved, uphill (1.4% gradient), and had a limited usable length of 653 meters due to a displaced threshold.

Findings

The primary cause was the crew's decision to perform a touch-and-go maneuver with an aircraft whose performance capabilities were insufficient for the specific runway conditions.
The aircraft's takeoff distance was significantly increased by the use of the 56’’ propeller, the uphill gradient, and the heavy, soft nature of the unpaved surface.
An improvised change of aircraft and destination likely prevented the crew from recalculating necessary performance margins, especially considering the lower power of the 120 cv engine compared to the aircraft originally intended for the flight.
A specific warning sheet regarding the propeller's impact on performance was stored in a folder at the back of the logbook rather than being prominently displayed, meaning the crew was likely unaware of the specific restrictions for F-GIKQ.