COPPER HARBOR, AK, USA
N204AQ
BELL 204B
AEROLOGGING OPERATION REQUIRED A STEEP DESCENT FLIGHT PATH FROM THE LOG PICKUP SITE AT 1200 FT ELEVATION TO THE LANDING SITE AT 70 FT ELEVATION. DESCENT ESTIMATED TO TAKE 11-12 SECS, AND DESCRIBED AS 'STRAIGHT DOWN IN AUTOROTATION AND DROPPING THE LOGS.' PILOT EXPRESSED RESERVATIONS ABOUT 'BEING ABLE TO DO IT.' FOLLOWING A DESCENT, AND WHILE IN A HOVER, THE TAIL ROTOR & 90 DEG GEAR BOX SEPARATED. METALLURGICAL EXAM REVEALED FATIGUE SIGNATURES ON GEAR BOX CASE STUDS. GEAR BOX OF MILITARY ORIGIN. RECORDED WEIGHTS INDICATED THAT THE AIRCRAFT HAD BEEN OPERATING IN EXCESS OF THE GROSS WEIGHT HOOK LIMIT. THERE WAS NO RECORD OF SURVEILLANCE BY THE POI OR PMI FROM THE FAA OFFICE HOLDING THE OPERATOR'S CERTIFICATE.
HISTORY OF FLIGHT On May 2, 1993, at approximately 1250 Alaska daylight time, a Bell 204B helicopter, N204AQ, collided with the ground during a precautionary landing at Copper Harbor, Alaska. The helicopter was operated by Chet Rasberry, Inc., d.b.a. CRI Helicopters, under 14 CFR Part 133, for aerologging business purposes. Operating in visual meteorological conditions on a company VFR flight plan, the helicopter had been engaged approximately 5 hours in aerologging at the site, 30 miles southwest of Ketchikan, Alaska. The commercial pilot, as sole occupant in the left pilot's seat, sustained fatal injuries and an employee of CRI on the ground received minor injuries. The helicopter was destroyed. Witnesses told investigators that the chief pilot, referred to as "Doc," had told the accident pilot, during the previous few days prior to the accident, to adopt a new flight path from the pickup site to the drop area, described as "straight down in an autorotation and dropping the logs." The NTSB and FAA investigators were told by the logging crew at Copper Harbor on May 3, 1993, the pilot had expressed reservations to logging camp employees about "being able to do it" (the new procedure) on the evening of May 1, 1993. In a statement provided investigators, a ground crewman whose job it was to hook logs to the helicopter's long line cable, estimated the new descent procedure to take "11 to 12 seconds to descend from me to the landing." He described the log pick up elevation to be approximately 1200 feet above sea level. Investigators estimated the log landing site and crash site to be at approximately the 70 foot elevation. Witnesses at the site told investigators that the helicopter had hoisted a log with its long line at the 1200 foot elevation when ground observers radioed that smoke was coming from the tail rotor. Following a descent and while in a 75 foot hover at the maintenance site, the tail rotor and 90 degree gear box reportedly separated with a "loud bang," followed by a loss of control, entering three rapid turns to the right and colliding with the ground. The maintenance mechanic said that the Bell 204B pilot had been hovering over the maintenance trailer and landing site, and "coiling the longline while descending in a hover straight down." He said "all of a sudden I saw the tail rotor come off and the helicopter started spinning, (and) I dove for cover under the trailer." Records indicated that the pilot had flown logging operations in the Bell 204B (N204AQ) between March 30, 1993 and April 18, 1993, followed by 10 days off at home in Washington state. Company representatives provided a schedule indicating that the pilot had returned to Ketchikan on April 31 and had resumed flight operations on Prince of Wales Island on May 1st. Since there was no April 31st on the calendar, witnesses recalled that the pilot had returned to Prince of Wales on the night before the accident. (May 1, 1993). INJURIES TO PERSONS The pilot in command, as sole occupant in the left seat of the helicopter received fatal injuries as a result of the crash. Witnesses at the scene of the accident told investigators that they did not remove the pilot from the helicopter for fear "of hurting his back." They said that they had no medical help for about one hour when the medical evacuation helicopter from Ketchikan arrived. The Ketchikan emergency medical service told investigators that the pilot had vital signs when they departed Copper Harbor, however the injured pilot lost vital signs during the medical evacuation, saying that he "coded en route" to the hospital. The mechanic employee received minor injuries when he fell or dove for cover upon seeing the tail rotor depart and the helicopter lose control while in a hover over the maintenance trailer. OTHER DAMAGE Investigators saw the side windows and windshields of a dump truck and a pickup truck shattered. Projectiles found on the insides of the vehicles consisted of golf ball size rocks and gravel. Investigators did not find aircraft parts to have struck those vehicles other than the frame damage on a boat trailer struck by the tail rotor. The tail rotor, attached to the 90 degree gear box struck the ground and an empty small boat trailer, 75 feet southeast of the helicopter impact point. The trailer received minor damage consisting of a 1/4 X 2 inch dent on its frame, and evidence was found that the tail rotor blades fractured at that point. PERSONNEL INFORMATION Captain Hugh R. Mackay Captain Mackay held a Commercial Pilot's certificate with ratings in airplane's single and multiengine land , rotorcraft helicopter pilot and instrument qualification in airplanes. He was employed as a pilot in command with CRI since January of 1993. Company records provided to the NTSB indicated that Captain Mackay completed a Bi-Annual Flight Review on January 27, 1993 and completed "initial, ground and flight phase of 133 only phase of the C. R. Inc. Pilot Training Program." The aircraft listed in that record was a Bell 204B. No curriculum or lesson plans were found reflecting this training program, nor were they required by federal regulation for companies of external load helicopters. The pilot provided a statement to AIG Aviation Insurance on January 4, 1993 which indicated that he was employed as a logging pilot by Northwest Helicopters, Inc., of Olympia, Washington. On that insurance application he reported having an estimated 7400 hours flight time in helicopters, 2000 hours of which were in the UH1B (Bell 204B). His application also stated that he had 1500 hours of "sling load" flight hours. In records provided by CRI, the company chief pilot certified the qualification of Captain Mackay to pilot "helicopters conducting Class B and Class C external loads." No records for flight training were found, nor were they required to be maintained by CRI. In a telephone interview with Captain Rick Leishman, chief logging pilot for CRI, the NTSB was told that Mr. Mackay was given "a check ride" at the time of employment and that he had been required to demonstrate emergency autorotations. The NTSB asked Captain Leishman if Mackay was required to demonstrate or was he trained in steep descents or autorotations with a load attached. He replied "no, I consider autorotations as an emergency (procedure) only." In records provided by the operator, Mr. Mackay had listed his initial airplane and helicopter training as from civilian instructors. His initial training in airplanes was in Cessna 150 and 172 airplanes in 1968 and helicopter training in Hiller 12E and Hughes 300 aircraft at the Olympia Flight Center in Washington State. The date of that training was not recorded in the information provided. AIRCRAFT INFORMATION The Bell model 204B helicopter, serial number 2198, helicopter was operating as a commercial aircraft in the normal category, and had a maximum gross weight of 8500 pounds. The weights of the logs recorded on individual flights indicated the aircraft to have been operating in excess of the 8500 lb gross weight limit and 4000 lb hook limit before the accident. The certificated weight and balance of the helicopter limited the weight of the external loads, depending on the fuel on board the helicopter, to between 3418 and 4018 pounds. Investigators calculated the fuel burn of approximately 600 pounds per hour to allow logs to be carried at a weight of 10 pounds increasingly heavier for each minute of helicopter operation. Records made during the previous month of "turn" weights (a turn is a single lift of a log or logs) found in company files, indicated many turns were recorded over the allowable 3418 pounds within the first few minutes of each hourly cycle. Investigators found that 20 percent of the turns exceeded the weight and balance limit and the heaviest recorded turn was 4500 pounds. The investigation reviewed the log books and data plates from the helicopter and forty one (41) of its drive train and control components. Of the 41 components, nine (9) were found to be manufactured and delivered to the U.S. military for use on a UH-1 helicopter, two (2) were manufactured and delivered for use on a commercial 204B, and thirty (30) parts could not be verified as to origin or manufacturer. The log books and data plates were examined, as well, by the manufacturer. In a statement to the NTSB, an official of Bell Helicopter Textron stated, "No delivery history documentation was found on the following part number/serial number combination:" The nine (9) parts manufactured as UH-1 parts and delivered to the U.S. military include: tail rotor hub; (2) tail rotor grips; main transmission (1971); driveshaft (for a UH-1H in 1970); 42 degree gearbox (1969); both main rotor blades (1971 and 1972) and the failed 90 degree gearbox. The 90 degree gear box, serial number B13-4638, according to manufacturer's records, had been manufactured and delivered to the U.S. military. The inspection and delivery date indicated April 16, 1966. FAA airworthiness representatives said that records indicated that the 90 degree gear box was removed from service "by the military in 1986, coded as having excessive wear." Operator records are not available predating 1991. The manufacturer indicated that records showed the main rotor blades have been previously sold to the military in 1971. The FAA airworthiness inspector assigned to the investigation reviewed the component cards, data plates and historical service records of components on the helicopter. He told the NTSB that the origin and applicability to the commercial helicopter could not be determined from the CRI records provided. The FAA airworthiness inspector returned the records to the NTSB with attached statements, questioning the origin of several components. In addition to the 90 degree gear box, the following components could not be traced beyond the recent entry in CRI records; elevator L/H, part number 204-030-858-53; stabilizer bar assembly, part number 212-010-300-1; collective lever, part number 212-010-403-5 and the swashplate and support assembly , part number 204-011-400-11. The inspector wrote, "the dataplate numbers appeared to be altered". Bell Helicopter Textron representatives told NTSB and FAA investigators on scene that records showed that the 90 degree gearbox was not considered an "approved part" by the manufacturer. In a report written by the manufacturer (see attached article by Jim Tuggey, Director of Customer Relations), surplus U.S. Government parts may be considered Bell-Approved when they are purchased directly from the U.S. Government in the original Bell Helicopter packaging, unopended with the seals intact. A warning in the Bell 204B Illustrated Parts Breakdown, indicating "Some parts are installed as original equipment on both military and commercial helicopters and may have a lower retirement life and/or time between overhaul (T.B.O.) when used on a military helicopter than when used on a commercial helicopter. In addition, circumstances surrounding their use may call for operation of the military helicopter outside of the approved military flight envelope. Consequently, some parts that have been used on military helicopters should not be used on commercial helicopters." The operator produced records that the 90 degree gearbox was overhauled by its own FAA certified repair facility prior to installation on the accident helicopter. The operator told investigators that the part had been acquired from the Los Angeles Fire Department in 1991. Investigators could not verify the facts of this acquisition. CRI records provided to investigators indicated that the 90 degree gear box was opened, cleaned, inspected, refitted with seals, painted and placed in service. On a CRI work order (number 0875, dated 1/25/91) the details of the 90 degree gearbox overhaul was outlined. The condition at that time was "due O/H (overhaul)." The work order indicated that the gearbox was disassembled, visually inspected, stripped of paint, prepared for M/P inspection (magnetic part inspection) and sent out, prepared for dye penetrant inspection. The work order states, " All part inspected I.A.W. O/H (in accordance with overhaul manual) and found serviceable." The CRI work order stated, "performed dy-pen inspection, received parts form M.Q.S. '(Mag part insp)' Reassembled and repacked I.A.W. Bell C/R/O/M. sec 6 unit T.S.O. O,O. Painted light grey." A parts list for the 90 degree gear box overhaul on work order 0875 showed that (2) seals, (8) packings and (1) gasket was installed at the time. There was no indication that moving parts, other than seals, packings and a gasket, were worn or replaced. The manufacturer's investigator, assisting in the investigation, stated that the described overhaul did not, according to manufacturer's standards, constitute a factory-approved overhaul of that component, due to the previous military service of the gearbox, the classification by the military as "excessively worn" and the lack of manufacturer's approval of the facility involved in the work to place the unit back into service. A U.S. Army form was found by investigators in CRI records which indicated the 90 degree gear box to be installed in a military UH-1V helicopter, Army serial number 68-15214. The last date of record was 16 May 1986. No other record for the use of that gearbox was found. On May 5, 1993, CRI Inc., faxed the same form to investigators, with a "Maintenance Release" photocopied over the "UH-1V 68- 15214" section of the U.S. Army form. That maintenance release indicated that the gear box had been inspected and found "Airworthy R.F.I. (ready for installation) and had been removed previously as "due overhaul." (See attached forms) METEOROLOGICAL INFORMATION Visual meteorological conditions existed at the time of the accident. The wind was observed by witnesses to be northerly to north easterly at approximately 20 knots. The accident helicopter was reportedly descending with logs from the pick up site to the log landing area with the 20 knot wind as a tail wind component.
FATIGUE FAILURE OF THE TAIL ROTOR GEARBOX, AND IMPROPER HELICOPTER OPERATIONS BEING CONDUCTED BY THE OPERATOR RESULTING IN REPETITIVE AT AND OVER MAXIMUM LOADS. FACTORS IN THE ACCIDENT WERE: MATERIAL DEFECT OF THE TAIL ROTOR GEAR BOX (INADEQUATE QUALITY CONTROL) BY THE COMPANY/OPERATOR, AND INADEQUATE SURVEILLANCE OF BOTH THE COMPANY OPERATIONS AND MAINTENANCE FACILITY BY THE FAA.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
