DO YOU THOROUGHLY CHECK YOUR HELICOPTER BEFORE EACH FLIGHT?

Let’s check our blades thoroughly before every flight!

An observant and quick-thinking helicopter pilot probably saved his life by making the decision to land immediately when he noticed the vibration.

A post-occurrence inspection of the Robinson R22 Beta found a crack in one main rotor blade that had spread almost completely through its cross-section.

The incident occurred in December 2016 in Australia during a cattle drive.

An Australian Transport Safety Bureau (ATSB) investigation confirmed a large crack from the trailing edge of the blade through both the upper and lower skins, stopping just short of the leading edge spar.

The examination did not identify any initiating or contributing defects, such as pitting corrosion, external damage, deformation or metallurgical anomalies in the blades.
However, the helicopter’s flight records showed that in December 2014, a hard landing occurred with a suspected main rotor overspeed resulting in a loss of control of the tail rotor.

The incident required the blades to be dismantled and inspected. After the blades were inspected and the spindles repaired, the blades were returned to service. Both blades were operated for a further 778 hours before failure, giving a total of 1747.7 flight hours, well below their life expectancy of 2200 hours.

The ATSB said it was likely that the hard landing had the effect of overloading the rotor system, and combined with the use of herding cattle on a farm, fatigue damage that could not be detected during the blade inspection.
The damage was not determined during the investigation and it could not be concluded that the type of operation or previous incident was a contributing factor to the blade fracture.
The Commission was also unable to determine whether early signs of cracking could have been detected during the helicopter’s final 100-hour inspection or during the daily pre-flight inspection, as several factors could have made it more difficult to detect the initiation of the cracking process during the helicopter’s daily inspections.

If the pilot had chosen to continue flying the helicopter, there is a high probability that he would have lost control during the flight due to the further change in the shape of the airfoil profile.

The factory and Civil Aviation Safety Authority’s response to the incident was immediate. Eight days after the incident, Robinson Helicopter Company issued a safety alert recommending close visual inspections of the trailing edges of the blades during daily pre-flight inspections, and the Civil Aviation Safety Authority of Australia (CASA) issued Airworthiness Bulletin 62-006 – Main Rotor Blade Cracking (Appendix B) nine days after the incident.
In February 2017, Robinson made a minor redesign of the main rotor blades.