Helicopter
Flight Crew Commercial; Flight Crew Instrument; Flight Crew Rotorcraft; Flight Crew Flight Instructor
Flight Crew Total 1100
Confusion; Communication Breakdown
Conflict Airborne Conflict; Inflight Event / Encounter Other / Unknown
Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Human Factors
I was beginning a tour of the Hoover Dam and there is a spot where numerous tour operators converge from different angles to generally follow the same 'S Turn' around the Hoover Dam. The agreed upon altitude is 3;000 ft and there are two rock peaks that mark the convergence point. I was heading toward those two peaks when I suddenly noticed a helicopter to my left at about 500 ft away. He made a call to me to ask if I saw him; but it caught me by surprise and I did not reply. I was focused on making a gentle left turn to give him space to enter the S-turn ahead of me. I did a fairly tight left 360 and fell in behind him. He was very upset over the radio and I incorrectly did not get back to him on the CTAF.
A helicopter pilot was beginning a tour of the Hoover Dam when he caught sight of another Helicopter about 500 feet away.  Aircraft Y pilot asked Aircraft X pilot if he saw him but the Aircraft X pilot stated that he was surprised and did not respond.  Aircraft X did a 360-turn to allow Aircraft Y to precede him and reported that he incorrectly did not get back to him on the CTAF.