19990826042879A

(-23) Pilot air taxiing to helipad decided he did not want his tail rotor protruding into the taxi way where it might create an obstacle. Pilot turned the a/c 180 degrees over the helipad and started to set down when the tail rotor hit the low fence behind him. The tail rotor disintegrated causing a loss of control. Pilot landed upright on helipad without injuries to himself or pax. (.19) on August 26, 1999, at 1333 hours pacific daylight time, an aerospatiale AS350B3, N5224R, collided with a fence while landing at the Long Beach, California, airport. The helicopter, operated by American Eurocopter, grand prairie, Texas, was substantially damaged. The commercial pilot and commercial rated passenger were not injured. The local area business flight was conducted under the provisions of 14 CFR part 91 and originated from the van nuys, California, airport, about 1235, and made a planned stop at a private heliport in los angeles before continuing to Long Beach. Visual meteorological conditions prevailed and no flight plan was filed. In a written statement, the pilot reported that he had planned to park the helicopter on a pad in front of a fixed-base operator (FBO). He reported that the air traffic controller directed him to land on runway 7 and air taxi to the FBO. Upon reaching the fbo's ramp, a linesman directed the pilot toward the center of three helipads next to a small fence that bordered the western perimeter of the ramp. All three pads were empty. The pilot reported that as he approached the pad he became concerned that his tail rotor was exposed to a taxiway which was out of his view. Additionally, there were two alrge semi-tractor trailers parked south of the helipad which the pilot flet would obstruct the view of any a/c taxiing out of the south and hangar. Because of these obstrcutions, the pilot initiated a left pedal turn over the pad to bring the nose of the helicopter around to face the taxiway. The pilot reported that he looked to the linesman for further guidance. The linesman made a "hands down motion" and started to walk away. The pilot stated that he interpreted the linesman's signal to mean that he was clear to touchdown. As he landed, he felt a slight impact followed by a seriesof vibrations. The nose of the helicopter began to yaw left. The pilot reported that he immediately lowered the collective and reduced the power; he had no tail rotor control at that time. The pilot instructed his passenger to remain in the helicopter until he could ensure that the area was clear. He performed a normal engine shutdown. As he exited the helicopter, he discovered that the tail rotor had struck the short chain link fence behind the aircraft. The tail rotor blades were destroyed and about 3 inches of the blade tips were broken off. One piece impacted the exhaust stack and went into the engine. The tailboom was buckled. A representative from American Eurocopter submitted a drawing of the helipad displaying the measurements of the perimeter and the pad's location in relation to the fence. The pad, as defined by the painted border strips, was 36 feet by 35 feet, which would generate a radius comparable to approx. 17 1/2 feet. The distance from the center of the "h" to the fence line was shown as 23 feet, and the distance from the nearest pad border of the helipad to the fence was 5 1/2 feet. According to American Eurocopter, the main rotor diameter of the AS350B3 helicopter is 35 feet and the distance from the center of the main rotor mast to the end of the tail stinger is just over 23 feet. The parking space dimensions were reviewed for compliance with federal aviation administration (FAA) advisory circular (ac) 150/5390-2A, issued in 1994. The application of the measurements to the FAA criteria revealed that the fence, at 23 feet from the center point of the helicopter parking space, was within the tail rotor clearance area. Pertinent portions of the advisory circular and the helicopter dimensions are appended to this file.