Incident Overview
On 3 June 2020, a Bell 407 GXP helicopter, registered SP-MGS, was involved in an incident at Katowice Muchowiec Airport (EPKM). The helicopter was operated privately and was being flown by a professional helicopter pilot holding a CPL(H) license with a Bell 407 type rating. A helicopter examiner was also on board. The incident occurred during a training flight in visual meteorological conditions (VMC) during daytime.
Sequence of Events
After completing examination flights, the pilot and examiner repositioned the helicopter from the Ferrari helipad in Katowice to EPKM. The pilot intended to perform several training circuits with landings. During the third circuit, the concrete runway (RWY 05L) was occupied by a landing and taxiing Extra 300 aircraft. The pilot therefore approached the parallel grass runway (RWY 05R), which was designated for glider operations only per a NOTAM effective from 15 May 2020. The helicopter descended to a hover in preparation for a low-level flight to the apron. However, the helicopter flew too close to cloth starting markers laid on the grass. The rotor downwash lifted the markers, which were secured by metal pegs, and they struck the main rotor. The pilot felt strong vibrations on the cyclic control and decided to land immediately, which was accomplished without difficulty. After shutting down and exiting, the occupants observed that one of the main rotor blades was significantly damaged.
Findings
The investigation analyzed video footage from an industrial camera installed at the local aeroclub building. Frame-by-frame analysis showed that the helicopter approached to a hover about 20 seconds after the preceding aircraft vacated RWY 05L. The pilot used the parallel grass strip as a reference plane, likely unaware of the cloth markers' exact location. The markers were lifted by rotor wash, and the attached metal pegs contributed to the severity of the damage. The pilots had their seat belts properly fastened and sustained no injuries. The helicopter had a valid permit to fly and was insured.
Cause
The incident was caused by the helicopter flying at too low an altitude over the cloth starting markers laid on the grass, resulting in them being lifted and colliding with the rotor. No contributing factors were identified, and no safety recommendations were issued.