N357NT

HISTORY OF FLIGHT

On September 11, 2002, at 1700 mountain standard time, an Aerospatiale AS350BA, N357NT, experienced a hydraulic failure during cruise flight and landed hard while making a precautionary landing at the Grand Canyon West Airport (1G4), Peach Springs, Arizona. Heli-USA Airways, Inc., operated the helicopter under the provisions of 14 CFR Part 135 as a tour flight. The helicopter sustained substantial damage. The pilot and five passengers were not injured. A sixth passenger sustained minor injuries. Day visual meteorological conditions prevailed for the tour flight over the Grand Canyon, and a company visual flight rules (VFR) flight plan had been filed. The flight departed the McCarran International Airport (LAS), Las Vegas, Nevada, about 1600. The flight was returning to LAS when the hydraulic failure occurred.

According to the operator, the flight was returning to LAS when the helicopter had a "complete" hydraulic failure. The pilot was in the vicinity of Peach Springs Airport, and made the decision to make a precautionary landing. The helicopter landed hard, the main rotor blades flexed down and cut off the tail boom.

According to the pilot's written statement, the flight to the Grand Canyon was uneventful. He made a radio call indicating that he was crossing the Grand Wash Cliffs area heading towards the Bat Towers. Five miles before entering the canyon he heard an aural alarm and saw that the hydraulic light was illuminated on the caution panel indicating a hydraulic failure. The airspeed was at 100 knots so he slowed the helicopter down between 40 to 60 knots per the recommended procedures, and turned off the caution horn using the button on the systems control console.

After turning the helicopter towards the Peach Springs Airport, he depressed the hydraulic cutoff button on the collective control. During the approach he reported making his radio calls to the airport traffic, as well as coordinating with a sister ship to transport his passengers back to the operator's facility after landing.

The pilot informed his passengers of the mechanical problems and noted no additional issues with the flight to the airport. He indicated that the hydraulic off indications were "felt" in the flight controls, and intended to do a run on landing in the new concrete landing/parking ramp area on the field. He reported that everything was normal until the helicopter was about 25 feet short of the ramp area. As he continued the approach, the flight controls increased in stiffness. He noted the airspeed was now 30 knots, and about 10 feet before the ramp at an altitude of 15 to 25 feet above ground level (agl). The nose pitched down, and the helicopter started to rotate. He pulled back on the cyclic enough to get the nose back up, which slowed the helicopter more but increased the rotation speed. The pilot thought they made two complete rotations, and reported that the flight controls were not responding. In order to slow or stop the rotation of the helicopter, he "cut off" the engine. The rotation slowed, and the helicopter started to settle to the ground. The pilot attempted to keep the helicopter in a level attitude, and it impacted in a near vertical descent from about 10 to 20 feet agl. The helicopter came to rest facing 180 degrees from its original direction of travel.

The pilot reported that one of the passenger's feet had become trapped under the helicopter during the accident sequence. Airport personnel and pilot's from other companies assisted with pushing the helicopter up in order to remove the passenger's foot; there were no other injuries.

In an interview with the National Transportation Safety Board investigator-in-charge (IIC), the pilot reported that the flight was about 3 minutes from the airport when he heard the aural caution horn and saw the hydraulic light illuminate. He also recalled that the passenger seated behind him was over 6 feet tall. The passenger's foot had been extended all of the way forward, resting by the pilot's side door, and had become trapped during the accident sequence. The pilot reported that the helicopter made two full revolutions to the right, and he had in full left pedal. He also reported that he had landed with a 4-knot tailwind.

A witness to the accident (a company helicopter tour pilot) submitted a written statement to the Federal Aviation Administration (FAA). He reported that he was at 1G4 refueling his helicopter when he heard the accident pilot radio and that he had experienced a complete hydraulic failure. The witness asked where the accident pilot intended to land the helicopter, to which the pilot replied that he was headed for the large parking apron located on the northeast side of the runway.

The witness reported that the helicopter was heading in a southerly direction. He observed the helicopter approach the landing area and said it was a little fast, between 40-55 knots. As the helicopter made its final approach to the parking apron, it was still a little bit high. The helicopter started to pitch up with a slow roll to the left. The witness reported that the helicopter's nose pitched down, all the while doing a complete 360-degree turn to the left. He estimated the helicopter's altitude between 30-50 feet. The witness began yelling on the radio for the accident pilot to get the nose of the helicopter up and not let it strike the ground in a nose down attitude. After completing the 360-degree turn, the witness reported that the helicopter had lost altitude in the left turn, the nose was slowly starting to pitch back to level flight, and the main rotor blades were starting to slow down. He reported that he could see the main rotor blades starting to cone in an upward direction, an indication to him that the main rotor blades were starting to slow down.

The helicopter impacted the ground in a level attitude, and was covered by a large dust cloud. The witness could not see anything for about 10-15 seconds. He shut down the engine of his helicopter and ran towards the accident helicopter. When he was able to see the helicopter again, he noted that the tailboom had separated and was lying near the right side of the fuselage. He then assisted with the welfare of the passengers on the accident helicopter.

PERSONNEL INFORMATION

A review of the FAA airman records revealed that the pilot held a commercial pilot certificate with helicopter and instrument helicopter ratings. The pilot also held a mechanic certificate with ratings for airframe and powerplant.

The pilot held a second-class medical certificate issued on August 28, 2002. It had no limitations or waivers.

The pilot reported his total flight time as 4,025 hours, with 1,785 hours in the accident make and model. He had logged 134 hours in the last 90 days, and 21.6 hours in the last 30 days. According to personnel records obtained from the operator, the pilot had flown 2.3 hours on the day of the accident.

The operator had employed the pilot since 2000. At the time of the accident he was the Assistant Director of Operations, as well as a company flight instructor and mechanic.

AIRCRAFT INFORMATION

The helicopter, serial number 1549, was originally issued a standard airworthiness certificate in 1987, as an Aerospatiale AS350B, but was converted to a BA and issued a standard airworthiness certificate on May 9, 2000. A review of the helicopter's daily flight logbook revealed a total airframe time of 8,387.7 hours at the last 100-hour inspection, completed on August 28, 2002. The airframe total time at the time of the accident was 8,451.7 hours.

A Turbomeca Arriel 1B engine, serial number 4474, was installed on the helicopter. The engine total time was 8,824.5 hours at the last 100-hour inspection dated August 28, 2002. The engine had accrued 2,830.7 hours since overhaul, and 74.6 hours since the last 100-hour inspection.

A review of the operator's maintenance work order for the helicopter (number 08270215491, dated August 28, 2002, revealed that under the Discrepancy heading, the hydraulic pump bearing was due for replacement. The operator's corrective action by maintenance personnel indicated, "replaced hyd[raulic] pump assembly TSN 0, 28Aug02." The serviceable tag issued for the hydraulic pump assembly, serial number 10318827, contained the following information, "inspected, cleaned filter, new O rings installed on connections, inspected coupling, new pump assembled."

According to the operator, the helicopter had 88.44 gallons (62 percent) of Jet-A fuel on board prior to departure from LAS. Examination of the maintenance and flight department records revealed no unresolved maintenance discrepancies against the helicopter prior to departure.

For a hydraulics failure, the operator's FAA approved AS350 flight manual states in part, "calmly reduce collective pitch and adjust the airspeed to between 40 and 60 knots (74 to 111 km/hr) in level flight. Cut off the hydraulic pressure, using collective lever pushbutton. Make a flat approach over a clear landing area and land with slight forward speed."

AIRPORT INFORMATION

The Airport/ Facility Directory, Southwest U. S., indicated Grand Canyon West Airport (1G4) runway 17/35 was 5,058 feet long and 60 feet wide. The runway surface is composed of asphalt.

TESTS AND RESEARCH

Investigators from the FAA and American Eurocopter examined the wreckage at Lone Mountain Aviation, Inc., North Las Vegas, on September 19, 2002, under the supervision of the Safety Board IIC.

Examination of the hydraulic pump assembly revealed a rust color surrounding the interior of the pump to include the coupling sleeve (S40 coupling). The visible splines of the coupling sleeve were worn down beyond serviceable limits, and investigators noted a lack of lubrication (grease) inside the coupling, as well as bluing inside the pump. The Safety Board IIC retained the hydraulic pump and coupling...