Eurocopter AS 350/355/EC130 - Astar/Twinstar/Ecureuil
Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Flight Crew Last 90 Days 75; Flight Crew Total 3151; Flight Crew Type 544
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Departure Airport; Flight Crew Landed As Precaution; General Flight Cancelled / Delayed
Aircraft
I was assigned as the pilot (Captain) to conduct a maintenance test flight for the purpose of tracking and balancing a rotor system on an AS-350B2. The aircraft was recently (within the last 24 hours) fitted with a new main rotor system. Before the aircraft could be returned to service; it was required that a track and balance be performed. I conducted a thorough preflight of the aircraft to include systems; structural and components. Multiple starts; hover and flight checks ensued. A flight was conducted and the equipment used by the Mechanic to determine accuracy of the track and balance indicated a required adjustment to the rotor system. The Mechanic stepped out of the aircraft after shutdown and made his adjustments to the pitch change links. After he was completed; he informed me we were ready for the next test run and he placed his tools inside the aircraft. The aircraft was subsequently started and the procedures commenced. As I advanced the Fuel Flow Control Lever (throttle) from idle to flight idle; a 'clinking' sound was observed by me. Thinking it was a tool rattling in the tool kit and not observing any indications to the contrary; I commenced flight to a hover of approximately 5 FT while the first test was completed. After about 20 seconds the Mechanic asked to depart and set a cruise speed of 80 KTS for the next segment of the test. A standard departure from the location was used as we took flight. At approximately 60 KTS the Mechanic instructed me to return as the Micro-Vib II indicated the need for an additional adjustment. I returned to the landing zone safely. While the Mechanic was making the necessary adjustments it was observed that one of the main rotor blades had a depression 2/3 of the way down the blade from the root on the leading edge and a deformed trim tab on the trailing edge.
AS-350 pilot on a post maintenance test flight heard a clicking noise and onboard Mechanic detected vibration in cruise flight. Pilot returned to base and a depression in the blade and a deformation in the trim tab of the main rotor was discovered.