It was this day in Aviation History that a future Sud-Aviation SA 316B Alouette III student pilot had been working hard for. The day of his Practical Exam on the Alouette III. With the necessary training completed, he was ready for the flight. The external preflight inspection was completed and the necessary checklists were completed, soon afterwards the helicopter lifted off from Rotterdam Airport (the Netherlands). Onboard the candidate and the examiner.
The aircraft after the failed autorotation (© www.hdekker.info)
After several examination manoeuvres were completed the next manoeuvre that had to be demonstrated was an autorotation from a hover, at an altitude of 1000 feet (~300 meters). The FAA's FAASTeam describes automation as follows;
"Autorotation is the state of flight where the main rotor system is being turned by the force of the relative wind rather than engine power. It is the means by which a helicopter can be landed safely in the event of an engine failure. In this case, the potential energy of altitude is converted to kinetic energy during the descent and touchdown. All helicopters must have this capability in order to be certified. Autorotation is possible owing to a freewheeling unit, which allows the main rotor to continue turning even if the engine is not running. In normal powered flight, air is drawn into the main rotor system from above and exhausted downward. During autorotation, airflow enters the rotor disc from below as the helicopter descends"
During Autorotation, the upward airflow of relative wind permits the main rotor blades to rotate at their normal speed. (Source: https://www.faasafety.gov)
The helicopter was brought into a hover and the autorotation was initiated. Due to the fact that the pilot did not use the technique as instructed the vertical speed increased substantially, while at the same time the helicopter started to roll to the left. Just before the aircraft would have slammed into the ground the examiner took over control of the helicopter and managed to arrest the descent. however, it was too late. The helicopter slammed into the ground causing the nosewheel assembly to break off. The tail boom was found fractured at the mounting point between the tail boom and the fuselage. Ps.1 --> It is unknown if the candidate passed his exam
Ps2 --> It is unknown if the aircraft was repaired