Aviation Accident Summaries

Aviation Accident Summary LAX06LA006

Eagar, AZ, USA

Aircraft #1

N7196J

Robinson Helicopter Company R-22 Beta II

Analysis

The helicopter impacted trees and terrain on the north side of a mountain slope as it presumably attempted to clear the rising terrain. Witnesses at the departure airport reported that they observed the pilots conduct a flight plan and obtain a weather briefing. The pilots had 13 gallons of fuel added to the helicopter and mentioned that they did not want the fuel tanks topped off due to the elevation. Witnesses observed the helicopter lift off the ground and wobble from side-to-side. The helicopter then settled to the ground and one of the skids made ground contact. The helicopter spun around 180 degrees and the helicopter lifted back up into the air. During the 180-degree rotation, the main rotor blade narrowly missed contacting the ground. The helicopter then settled back to the ground, narrowly missing ground contact with the tail rotors. The helicopter sat on the ground idling for a while before it lifted off again. The witnesses then observed the helicopter takeoff and climb slowly toward the mountains situated to the southwest of the airport. One witness commented that the helicopter was not climbing all that well. Post-accident examination of the wreckage revealed no anomalies with the helicopter systems or engine that would have led to the accident. The density altitude at the accident site was calculated as 10,219 feet and the helicopter was near its maximum gross weight around the time of the accident. Both pilots were certificated to fly the helicopter and both had similar flight experience, but neither had flown the mountainous route before. Toxicology findings for the left seat pilot were consistent with recent use of diazepam.

Factual Information

HISTORY OF FLIGHT On October 14, 2005, about 1145 Pacific daylight time, a Robinson Helicopter Company R-22 Beta II, N7196J, impacted trees and mountainous terrain approximately 12 miles west-southwest of Eagar, Arizona. The helicopter was registered to and operated by both pilots under the provisions of 14 CFR Part 91 as a personal flight. Both private pilots on board (a married couple) were fatally injured and the helicopter was substantially damaged. The helicopter departed the Springerville Municipal Airport in Springerville, Arizona, at 1127, and was destined for Chandler, Arizona. Visual meteorological conditions prevailed at the departure airport and a visual flight rules flight plan was on file for the cross-country flight, but not activated. According to the Springville Airport Manager, one of the pilots asked them to add 6 gallons of fuel in one tank and 7 gallons of fuel in the other and did not want the fuel tanks topped off due to the elevation. The manager added a total of 13.1 gallons of 100 low-lead aviation gasoline and observed the pilots planning their flight from Springerville to Chandler. The manager reported that they filed a flight plan and had obtained a weather briefing. The pilots then headed to the helicopter for their departure. The manager reported that he and two other individuals watched the helicopter lift off the ground and wobble from side-to-side. The helicopter then settled to the ground and one of the skids made ground contact. The helicopter spun around 180 degrees and the helicopter lifted back up into the air. During the 180-degree rotation, the main rotor blade narrowly missed contacting the ground. The helicopter then settled back to the ground, narrowly missing ground contact with the tail rotor. The helicopter sat on the ground idling for a while before it lifted off again. The manager observed the helicopter takeoff and climb slowly toward the mountains situated to the southwest of the airport. The manager commented that the helicopter was "not climbing all that well." The manager later received a call from the Civil Air Patrol (CAP) around 1700 on the 14th. The CAP reported receiving an emergency locator transmitter (ELT) signal near the Springville airport. The manager checked the airport fleet and noted no ELT signal. He then checked on the airplanes that had been through that day and was able to track all but two; the accident Robinson helicopter and a Cessna 340. The manager called the flight service station and checked to see if the Robinson pilots had cancelled their flight plan in Chandler and was informed that they had not activated it. The manager then called Chandler and learned that the helicopter had not arrived. He then conducted a local area aerial search with another pilot, to no avail. Upon returning to Springville, the manager noticed the fuel cap from one of the Robinson fuel tanks was lying on the ramp where the helicopter took off. The next morning, on the 15th, the CAP and the Apache County Sheriff's department continued search efforts, eventually locating the wreckage in mountainous terrain. PERSONNEL INFORMATION Left Seat Pilot The left seat pilot held a private pilot certificate with single-engine airplane and rotorcraft ratings. He held a third-class medical certificate, issued on February 15, 2005, with a limitation for corrective lenses. A review of his logbook revealed he had accumulated a total of 507.5 hours of flight time, of which 319.7 were in helicopters, and 200.7 were in the accident helicopter make and model. His last flight review took place on December 16, 2004. Right Seat Pilot The right seat pilot also held a private pilot certificate with single-engine airplane and rotorcraft ratings. She held a third-class medical certificate, issued on February 15, 2005, with a limitation for corrective lenses. A review of her logbook revealed she had accumulated a total of 485.2 hours of flight time, of which 329.5 were in helicopters, and 213 were in the accident helicopter make and model. Her last flight review took place on January 7, 2005. Discussions with the pilots' son revealed that they had not flown through these mountains prior to the accident. AIRCRAFT INFORMATION The helicopter (serial number 3171) was equipped with a Lycoming O-360-J2A engine (serial number L-37802-36A). Review of the maintenance records revealed that the helicopter had accumulated a total of 375 hours of operation. The last annual inspection took place on November 10, 2004, 48.7 hours prior to the accident. On February 19, 2005, the hour meter was replaced at an aircraft total time of 337.8 hours. The hour meter at the accident site read 37.2 hours. According to the pilots' son, the pilots had flown from Spencerville, Oklahoma, and were en route to Chandler for scheduled maintenance. He spoke with his parents on the evening of the 13th while they were staying in Portalles, New Mexico. During that conversation, the pilots reported a problem with the global positioning system (GPS) since its data card had expired, but no other mechanical problems with the helicopter. Utilizing weight and balance information obtained from maintenance records, documents recovered from the wreckage, and fueling records, a calculation of gross weight (GW) and center of gravity (CG) was conducted. The GW at the time of takeoff was approximately 1,381 pounds at a CG of 97.40 inches. The helicopter's maximum GW is 1,370 pounds with CG limits between 96.5 and 100.0 inches aft of datum. The density altitude limit listed for the helicopter is 14,000 feet. METEOROLOGICAL INFORMATION The weather observation facilities at the Show Low Airport (SOW; 30 nautical miles northwest of the accident site at an elevation of 6,415 feet mean sea level - msl) and the St. Johns Industrial Airport (SJN; 32 nautical miles north of the airport at an elevation of 5,736 feet msl) reported the following weather information: SOW at 1150 - wind from 110 degrees at 3 knots, visibility 10 statute miles, sky clear, temperature 18 degrees Celsius, dew point 01 degrees Celsius, altimeter setting 30.37 inches of mercury. SJN at 1154 - wind from 070 degrees at 10 knots with gusts to 17 knots, visibility 10 statute miles, sky clear, temperature 23 degrees Celsius, dew point 01 degrees Celsius, altimeter setting 30.31 inches of mercury. The pilots filed a flight plan and obtained a weather briefing from the Prescott Flight Service Station prior to departing for Chandler. The calculated density altitude at the accident site around the time of the accident equated to approximately 10,219 feet. WRECKAGE AND IMPACT INFORMATION The accident site was located at a GPS location of 34 degrees 03.601 minutes north latitude and 109 degrees 30.122 minutes west longitude. The accident site elevation was reported as 8,781 feet msl. According to the sheriff department personnel, there were a number of freshly cut trees in the vicinity of the helicopter with one of the main rotor blades coming to rest partly through a log. On October 16, 2005, the wreckage was examined at the accident site by a Federal Aviation Administration (FAA) inspector from the Scottsdale, Arizona, Flight Standards District Office (FSDO) and a representative from Robinson Helicopter Company (RHC). The following information was gleaned from documentation provided by those individuals. The helicopter came to rest on the north slope of rising terrain and to the east of a hollow. The wreckage was surrounded by pine and aspen trees ranging in height between 40 and 60 feet. The RHC investigator counted about 6 trees in the immediate area that appeared as if they had been freshly chopped. Some others displayed fresh scrape marks and gouges along the trunk. The helicopter came to rest on its right side with the nose pointing toward the north. The tail boom, with tail rotor gearbox attached, was separated and came to rest about 66 feet southwest of the main wreckage. One of the tail rotor blades remained attached to the hub, which in turn remained attached to the tail rotor gearbox. The other tail rotor blade was located 27 feet west of the main wreckage. The cockpit was examined and it was noted that all removable controls were installed. The collective control was 0.5 inches below the full up position when measured on the friction slider (86% of full travel). The collective friction was off. The cyclic control was bent forward and to the right. The left anti-torque pedal was in the forward position. There were no disconnects in the fuel system and the fuel cap for the main fuel tank (located on the right side) was secure. The fuel selector was turned off by first responders. Approximately 6-7 gallons of fuel remained in the auxiliary fuel tank (located on the left side) and no water was visible. The first responders reported that the magneto switch was in the right position when they arrived. A continuity check of the switch was performed and no anomalies were noted. The throttle and mixture controls in the cockpit remained attached to their respective arms on the carburetor. The mixture control was in the full rich position in the cockpit and at the carburetor. The throttle control at the carburetor was at the full open position though the arm had been pushed beyond the full travel stop. The stop had been fractured from the carburetor body. The carburetor control was in the off or cold position. The engine was displaced forward into the firewall, which resulted in damage to the magneto p-leads and ignition wires. The engine showed no evidence of internal damage or failure. Both v-belts, which convert the engine power to driving the rotor systems, were undamaged and in their respective position on the sheaves. The clutch actuator was undamaged and measured 1.4 inches between the scissor blocks. According to RHC, the normal distance between the scissor blocks is 1.0 to 1.5 inches for normally tensioned belts. The upper sheave rotated freely on the clutch shaft when it was manually rotated in the clockwise direction (when looking from the aft end forward). The sprag clutch engaged when the shaft was rotated counter-clockwise. The main rotor gearboxes internal components moved freely for several rotations when the main rotor system was manually rotated. The main rotor blades remained attached to the main rotor hub, which remained attached to the main rotor mast. The one main rotor blade was folded down about 140 degrees about 14 inches outboard of its pitch-change horn. The upper and lower skins were wrinkled along the trailing edge with many chordwise dents. The other main rotor blade was folded up about 90 degrees approximately 48 inches outboard of the pitch-change horn. It was then bent down about 20 degrees 20 inches inboard of the tip. The leading edge of this blade displayed red scuffmarks. The tail rotor drive shaft was separated at the tail boom fracture location. The tail boom displayed an impact impression on its left side. The impression was consistent in shape to the leading edge of the main rotor blades. The tail boom was white with a red stripe painted along the sides. The vertical and horizontal stabilizers remained intact, but separated from the tail boom at its mounting flange. The tail rotor gearbox continuity was confirmed via manual rotation of the blades. The pitch change links remained intact and did not display any binding. On October 17, 2005, the wreckage was transported from the accident site to Air Transport of Phoenix, Arizona, where it was again examined at a later date. MEDICAL AND PATHOLOGICAL INFORMATION The Apache County Medical Examiner's Office conducted an autopsy on both pilots. The cause of death for each was attributed to multiple injuries sustained in the accident. Also noted for the right seat pilot was the finding of "chronic obstructive pulmonary disease" with "mild to moderate parenchymal loss" and for the left seat pilot were the findings of "coronary atherosclerosis" with "severe occlusion of the circumflex" and "moderate occlusion of the left anterior descending and right coronary" arteries and "chronic obstructive pulmonary disease" with "emphysematous bullae" and "moderate parenchymal loss." Toxicological tests were conducted in conjunction with the autopsies on the pilots. The right seat pilot's toxicological test results were negative for drugs and alcohol. The left seat pilot's toxicological test results were positive for 0.29 mg/L of diazepam in his blood and an unquantified amount of benzodiazepines in his urine. Blood was also noted as having been specifically tested for the following with negative results: alprazolam, nordiazepam, clonazepam, temazepam, lorazepam, oxazepam, and alcohol. Both pilots' most recent applications for 3rd class medical certificate (dated 2/15/05) indicated "no" for use of any medications and for all medical history, including specifically "mental disorders of any sort; depression, anxiety, etc." The pilots' son noted that the left seat pilot took diazepam in the past for "anxiety attacks." He added that the left seat pilot used to take it quite often many years previously. TESTS AND RESEARCH On November 4, 2005, the Scottsdale FSDO inspector, RHC investigator, and an investigator from Lycoming examined the wreckage at Air Transport's facility. The engine was examined prior to a test run. The top spark plugs were removed and displayed coloration and wear that correlated to normal operations. The cylinders were examined via borescope and no anomalies were noted. The rotation of the cooling fan resulted in rotational continuity throughout the engine. The engine was started utilizing fuel from the auxiliary fuel tank. The engine ran for about 10 minutes and the magneto check revealed no anomalies. The engine could not be run to full power due to the impact damage sustained by the ignition leads. All control and control rod failures were examined closer and none revealed any evidence of a pre-existing problem or fatigue cracking.

Probable Cause and Findings

The pilots' inadequate in-flight planning, which led the helicopter toward rising terrain in excess of the performance capability of the helicopter. Contributing factors were the high density altitude, and the rapidly rising terrain.

 

Source: NTSB Aviation Accident Database

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