Aviation Accident Summaries

Aviation Accident Summary MIA03FA120

Madison, FL, USA

Aircraft #1

N217ES

Aerospatiale AS355F1

Analysis

The pilot stated that after the patient had been loaded on the helicopter, and the other crewmembers had secured themselves inside, he picked the helicopter up into a 3-foot hover, glanced at the gauges, and then looked up again and the helicopter rolled hard to the right with the blades impacting the ground. He said the main rotor blades struck the ground the helicopter rotated 90 degrees to the left, and came to rest on its right side. A flight crew member in the back of the helicopter said that after they had all been secured for takeoff, she looked out through the right window and advised "all clear." She further stated that the helicopter then lifted off, and immediately started falling, with the rotor blades impacting the ground, which caused it to fall. A witness stated that he observed the helicopter lift off the ground, perform a quarter turn to the left, facing north, and hover for a few seconds, before starting to roll to the right side, which immediately caused the main rotors to strike the ground, and the helicopter crashed on its right side. Examination of the helicopter and its systems did not reveal the existence of any preaccident anomalies.

Factual Information

HISTORY OF FLIGHT On June 11, 2003, about 1329 eastern daylight time, an Aerospatiale AS-355F1 helicopter, N217ES, registered to Banc One Leasing Corp., and operated by CJ Systems Aviation Group, for Doctor's Memorial Hospital, Perry Florida, as a Title 14 CFR Part 135 aeromedical flight, crashed while attempting to take off from an open sports field in Madison, Florida. Visual meteorological conditions prevailed, and a company visual flight rules flight plan was filed. The commercial-rated pilot was not injured, and the two flightcrew members and one passenger received minor injuries. The helicopter incurred substantial damage. The flight was originating at the time of the accident. The pilot stated to the NTSB that he landed the helicopter on the ball field to pick up a patient. The helicopter was oriented about 090 degrees magnetic, into the wind. He said he idled the helicopter engines with the main rotors turning for about 10 minutes while waiting for the patient to arrive. After the patient had been loaded on the helicopter, and the other crewmembers had secured themselves inside, he picked the helicopter up into a 3-foot hover, glanced at the gauges, and then looked up again and the helicopter rolled hard to the right with the blades impacting the ground. He said when the main rotor blades struck the ground the helicopter rotated 90 degrees to the left, and came to rest on its right side. After it came to a stop, the pilot said he tried to pull the fuel controls to the off position, and turn off the engines, but was unable. He said he then activated the fuel shutoff, interrupting the fuel supply to the engines, and then turned off the overhead switches and the battery power. According to a flightcrew member in the back of the helicopter, after they had all been secured for takeoff, she looked out through the right window and advised "all clear." She further stated that the helicopter lifted off, and immediately started falling, with the rotor blades impacting the ground, which caused it to fall. A witness stated that he observed the helicopter lift off the ground, perform a quarter turn to the left, facing north. He further stated that at this time the helicopter's skids were about 3 or 4 feet off the ground. He said the helicopter then hovered for a few seconds, before starting to roll to the right side, which immediately caused the main rotors to strike the ground, and the helicopter crashed on its right side. When the helicopter came to rest on its right side a fire ensued. An official with the Madison Fire Department stated that the fire department had equipment and personnel standing by as part of their standard operating procedure for "off helipad" aeromedical operations within city limits, and the firefighters quickly responded and applied water which immediately extinguished the fire. They then extricated all occupants of the helicopter. PERSONNEL INFORMATION According to information obtained from the Director of Operations for the operator, CJ Systems Aviation Group, the pilot of the accident helicopter had been hired on April 1, 2003, two months prior to the accident, and had undergone initial training. At the time of the accident, he reported having accumulated about 2,500 hours total flight experience, of which 42 hours were in the same make and model helicopter as the accident helicopter, and 42 hours had been flown in the last 90 days. On the day of the accident the pilot had flown the accident helicopter for 0.3 hour from Perry, Florida, to the location where the accident occurred. Records obtained from the FAA showed that the pilot held a commercial pilot certificate, with multiengine land, rotorcraft helicopter, and instrument helicopter ratings. He also held an FAA second class medical certificate, issued on March 18, 2003, with no stated limitations. AIRCRAFT INFORMATION N217ES, is a 1981 Aerospatiale AS355F1, serial number 5059. The helicopter was powered by two 420 horsepower, Allison-Rolls-Royce 250-C20F turbo-shaft engines. According to information obtained from the operator, the helicopter was maintained in accordance with the manufacturer's inspection program as well as a Part 135 Operator's Approved Aircraft Inspection Program (AAIP). The last inspection performed on the helicopter was a 100-hour/AAIP inspection, and it was completed on June 3, 2003. At the time of the accident, the helicopter had accumulated a total of 6,321.8 hours, about 7.0 hours since its last inspection. METEOROLOGICAL INFORMATION Daylight visual meteorological conditions prevailed at the time of the accident. The Tallahassee Airport, Tallahassee, Florida, 1253, surface weather observation, was scattered clouds at 5,500 feet, a broken cloud layer at 13,000 feet, visibility 10 statute miles, wind from 190 degrees at 5 knots, and the altimeter setting was 30.02 inHg. Tallahassee, Florida, is located about 50 miles west of the accident site. WRECKAGE AND IMPACT INFORMATION Examination of the crash site showed the helicopter was located in geographic position 30 degrees, 28.3 minutes North latitude, 083 degrees 25.2 minutes West longitude, at Lanier Field, Madison, Florida. The helicopter was lying on its right side, and was oriented about due north, with loose accident-related debris being present, consisting mainly of main rotor blade foam and after body skin. All three composite main rotor blades had shattered, and there were multiple ground scars in the vicinity, consistent with the main rotor's impact. The main rotor head and swash plate mechanism had been damaged. There was buckling the left side aft fuselage, but no damage to the undersurface of the helicopter. Both forward windshields had been shattered, and the window above the pilot's position had also been cracked. The skids had not been damaged, and the aft inside section of the right trailing extension of the skid had incurred a gouge and streaking/paint related discoloration. There was fire damage to the aft section of the engines in the area of the tailpipe, and the grass had been burned. Burn marks were consistent with the fire occurring at the point where the engine was on contact with the ground. One blade exhibiting a wrinkle and there was a single gouge in the grass consistent with the tail rotor having impacted the ground. Limited rotational damage was noted, and preimpact continuity of the tail rotor assembly was verified. The tail rotor drive shaft had been severed and had about a 12-inch section of the drive shaft removed. The section of the tail rotor drive shaft which had been severed had been located above and was about equal to the width of the horizontal stabilizer, and exhibited signatures consistent with it having been stricken by the main rotor blades. The stinger's lower surface had scratches on the lower surface, but was otherwise not damaged. The right horizontal stabilizer had been bent downward at about the midpoint of the stabilizer as the helicopter laid on its side, and the top of the left horizontal stabilizer also exhibited surface gouges and scars. All arms of the star were sheared approximately 1 inch from the "thick part". The lower panels were removed and control continuity was verified. The pitch change links were intact but bent at the rod ends. The scissors drive adapter (swashplate drive) had dislodged. The stove pipe (swashplate guide) rivets were sheared at the attachment to the main rotor shaft assembly upper case. The lower swashplate scissors were intact. All servos/P/C links/scissors were disconnected and examined. The swashplate rotated freely and with no binding or roughness. No contamination was found to be present in the lubrication grease. The swashplate bearing and PC links were disconnected and examined, and no anomalies were noted. The hydraulic filter assembly were accessed for hydraulic systems No. 1 and 2 and slight amounts of sludge were observed. The underside of the helicopter was opened and the flight controls were examined. The cyclic adjustable control rod was found intact and visibly undamaged. Its measured setting and compliance with airworthiness directives was checked and verified. The lower panels were removed, at which time a visual inspection verified integrity of controls. The pilot's friction cup was examined and no visible damage was noted. The mixing bell cranks forward of the #1 fuel cell were intact and smooth when moved with the cyclic and collective after servo inputs were disconnected. The cyclic grip was broken at the area just above the attach bolt. The strike tabs were not bent. The stinger lower surface was free of grass and dirt but displayed evidence of abrasion. The No. 1 (left) cowling and the tail boom attach areas were singed by fire, and both engines had disconnected from the gear box and the engine mounts. The transmission deck had incurred heavy damage, and all four gear box suspension bars had separated. Both engine inputs had sheared at the flex coupling, and the coupling flanges were still attached to the drive shafts. Oil lines, wiring harnesses, and control cables were still attached. The crossbeam, lateral/longitudinal bearing was attached to the transmission deck fitting, and other deck fittings had been torn from the transmission deck. The transmission door was removed and all servos were examined and found to be mechanically connected to the controls. The servos were disconnected and freedom or movement/continuity was confirmed. On both the longitudinal and the right lateral servos, the sealant at the upper rod end was attached but had been disturbed. The servos and hydraulic pumps were removed and retained for additional examination and testing. During the removal and initial examination of the helicopter's two hydraulic pumps, the C-box drives were found to be intact and no problems were noted to exist with the splines. During manual rotation of the drive shafts was conducted and in both cases, no bending was present and smooth rotation was confirmed. TESTS AND RESEARCH Both hydraulic pumps were checked on a test stand, and no anomalies were noted. The test stand was set to operate the pumps at 1,500 rpm. Three function tests were performed on the first hydraulic pump and two were performed on the second. During the first and second tests, the first hydraulic pump, serial number A5026780, produced 1,529 rpm at a pressure of 700 psi. During the third test, the pump produced 1,500 rpm at a pressure setting of 580 psi. During the first test, the second hydraulic pump, serial number 20251090, produced 1,518 rpm at a pressure setting of 700 psi, and during the second test, it produced 1,529 rpm at a pressure setting of 580 psi. The three main rotor servos were examined at Hawker Pacific Aerospace, Sun Valley, California, and no preaccident anomalies were noted. On each of the left hand servos, normal wear was observed on the piston rod assemblies, inside bodies of each servo, and on all remaining moving components, and these servos were noted to have met "return to service" standards. Inspection of the third servo, serial number 151, revealed an impact mark on both the lever assembly and the body assembly. During the teardown inspection, normal wear was observed in body No. 2 and on the piston rod, and a wear mark in the shape of a ring was found in body No. 1. Excessive input lever-to-output movement friction was observed; the required force measured to move the input was about 46 ounces, and the maximum allowable input friction is 9 ounces. According to the examiners, this was consistent with damage incurred during impact. Additional impact evidence was observed on a corner of the input lever. They further added that no report had been previously noted from pilots of the aircraft, regarding stiffness in the control system. ADDITIONAL INFORMATION On June 13, 2003, the NTSB released the wreckage of N217ES to Mr. Paul McConnell, Field Support manager, CJ Systems Aviation Group. The NTSB retained three servos and two hydraulic pumps for further examination. All parts which were retained by the NTSB were returned to Mr. McConnell, and he acknowledged receipt on May 19, 2005.

Probable Cause and Findings

The pilot in command's diverted attention and loss of control while attempting to takeoff, which resulted in the main rotor blades being dragged, and the helicopter rolling over.

 

Source: NTSB Aviation Accident Database

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