Aviation Accident Summaries

Aviation Accident Summary ERA11LA106

Cherry Point, NC, USA

Aircraft #1

N854EC

EUROCOPTER MBB-BK

Analysis

The pilot was conducting a night emergency medical services flight with no patient on board. When the helicopter was about 12 miles south of the airport, he radioed air traffic control (ATC) and declared an emergency, due to a personal medical incapacitation. He requested a vector to a nearby airport and in response the controller provided him with a position report and began giving him vectors. Subsequently, the pilot overflew the airport and was then given a vector back to the airport. The pilot landed on a runway at the airport with assistance on the flight controls by a flight nurse seated in the front seat. During the landing the helicopter bounced and experienced a hard landing. The helicopter, which was examined by personnel at the helicopter's manufacturer, sustained substantial damage to the structure. Postaccident interviews with the pilot revealed that while in cruise flight, and shortly after he disengaged the autopilot, his right arm fell to his side. Medical records of the pilot’s treatment following the accident documented the sudden onset of right hand weakness and slurred speech while piloting the helicopter, with the subsequent identification of two recent strokes on an MRI (magnetic resonance imaging). Federal Aviation Administration (FAA) medical records documented that the pilot also had experienced a small stroke approximately 4 years prior to the accident. There was no evidence in the FAA records of any formal evaluation of the risk of a recurrent stroke for this pilot or of any formal FAA neurology evaluation. The pilot's records did reflect that no definitive cause for a previous stroke was found, that the pilot had a family history of stroke, that the pilot was increasingly obese, and that the pilot’s physician had discontinued a medication prescribed in part to reduce the pilot’s risk of a future stroke.

Factual Information

HISTORY OF FLIGHT On December 29, 2010, at 0223 eastern standard time, a Eurocopter BK117-C2, N854EC, operated by Air Methods Corporation, was landed hard during an emergency landing at Cherry Point Marine Corps Air Station (Cunningham Field) (NKT), Cherry Point, North Carolina, after the pilot became partially incapacitated. The helicopter departed from Pitt County Memorial Hospital Heliport (NC91), Greenville, North Carolina at 0135 and was enroute to Carteret General Hospital, Morehead City, North Carolina. Night visual meteorological conditions prevailed and a company visual flight rules flight plan was filed. The certificated airline transport pilot suffered a medical incapacitation and the two medical flight crewmembers were not injured. The helicopter sustained substantial damage including the landing gear cross tubes. The flight was operated under the provisions of 14 Code of Federal Regulations Part 135. According to an interview provided to the Federal Aviation Administration (FAA), the pilot reported that they were "about two-thousand feet and about three to four minutes out" from the destination. He was flying the helicopter utilizing the autopilot and shortly after "I disengaged the autopilot, my right arm fell to my side." He informed his medical flight crewmembers as well as the Cherry Point Air Traffic Controller and declared an emergency. He further requested to land at NKT and the Air Traffic Controller provided radar vectors. A medical crewmember seated in the left front seat manipulated the collective control with the pilot's instructions and the pilot manipulated the cyclic control with his left hand. The pilot elected to make a run on landing and upon contact with the runway, the helicopter became airborne again, and then touched down again. According to a written statement provided by the secondary nurse seated in the left front seat, the flight had been a very smooth and uneventful flight. They were at 2,600 feet and preparing for descent into the hospital landing zone when the pilot stated that "he could not move his right arm." The pilot reported that he did not have any other symptoms or weakness but "his speech was becoming a bit slurred." During the flight to NKT the pilot had requested assistance from the secondary nurse. As the flight approached the airport, the nurse reported that the main runway was lit and they had been given directions to it. She further reported that even though she pointed towards the airport the pilot was unable to identify the runway and the flight subsequently flew over it. The controller vectored the helicopter back to the airport and the pilot subsequently acquired the airport. After landing, the primary flight nurse exited the helicopter to assist the pilot with the engine shutdown procedure. Emergency personnel that responded to the scene assisted the pilot out of the helicopter onto a stretcher for transport to a local hospital. PERSONNEL INFORMATION According to FAA and company documentation, the pilot, age 61, held an Airline Transport pilot certificate for helicopter and airplane single-engine land, with ratings for instrument airplane and helicopter. His most recent FAA second class medical certificate was issued on August 12, 2010, which contained some limitations including "not valid for any class after August 31, 2011." He had approximately 11,000 total hours of flight experience, 17 total hours of flight experience in make and model of the accident helicopter, and had flown 2 hours in the proceeding 24 hours prior to the accident. His most recent flight review was conducted on December 2, 2010, and was in the accident helicopter make and model. AIRCRAFT INFORMATION The helicopter was issued an FAA special airworthiness certificate on October 8, 2010, and was registered to the owner on June 28, 2010. It was equipped with two Turbomeca Arriel 1E2 engines. On December 24, 2010, the helicopter had undergone and inspection in accordance with an approved inspection program. At the time of the accident the helicopter and engines had each accumulated 121 hours total time in service. METEOROLOGICAL INFORMATION The 0154 recorded weather observation at NKT included wind from 260 degrees at 7 knots, visibility 10 miles, clear skies, temperature minus 1 degree C, dew point minus 7 degrees C, and an altimeter setting of 30.12 inches of mercury. COMMUNICATIONS About 0210, the pilot declared an emergency with Cherry Point Approach control. According to a transcript of the recording, the pilot reported to approach control that he had a medical problem and was having "trouble flying the aircraft." The controller reported to the pilot that their position was about one mile north of another airport and approximately 12 miles from NKT. The pilot requested and received clearance to proceed directly to NKT. About 0214, the pilot requested an instrument landing system (ILS) approach to the airport. The controller stated that the ILS was to runway 23. About 0219, the helicopter was approximately one miles south of NKT, subsequently overflew the airport, and was vectored by the controller for runway 32R. After completion of the turn back towards the airport, and about 0222 the pilot reported he had the airport in sight. AIRPORT INFORMATION The airport was equipped with a four runways; two runways were oriented southeast to northwest and designated as 14L/32R and 14R/32L, and two runways were oriented southeast to northwest and designated as 5L/23R and 5R/23L. The helicopter landed on runway 14L which was 8,984-feet-long and 200-feet-wide, constructed of asphalt, and was equipped with high intensity runway edge lights. The airport did have a Marine Corps staffed air traffic control tower which was operational and staffed at the time of the accident. WRECKAGE AND IMPACT INFORMATION According to photographs provided by an FAA inspector that responded to accident location, the helicopter stopped on the runway approximately 4,000 feet from the approach end of runway 14L. The helicopter's right vertical stabilizer was scraped along the bottom edge and substantial damage was done to the landing gear crosstubes which were bowed downward. MEDICAL AND PATHOLOGICAL INFORMATION The pilot’s FAA medical records dated prior to the accident documented that the pilot experienced a small ischemic stroke in the left thalamus on July 20, 2006. The pilot was hospitalized with right leg and arm heaviness and numbness, but recovered quickly with only abnormal sensation over the right forearm by July 25, 2006. No specific etiology was identified, though the pilot was noted to have a history of high cholesterol, and a family history of stroke. His neurologist noted a history of high cholesterol and recommended aspirin and a cholesterol-reducing medication to reduce his risk of stroke. At the time of his application for an FAA airman medical certificate on September 3, 2008, the pilot was noted not to be on a cholesterol-reducing medication (because his cholesterol was "good"), but was noted to be on aspirin and a combination blood pressure medication (for "borderline high blood pressure"). His height and weight were noted as 68 inches and 240 pounds on that application, and on two subsequent applications. The pilot was given an Authorization for Special Issuance of a second-class medical certificate on September 26, 2008. The pilot was given another Authorization for Special Issuance of a second-class medical certificate on September 17, 2009, in conjunction with an application for airman medical certificate on August 27, 2009, indicating the same height, weight, and medications. The pilot’s most recent medical certificate was issued on August 12, 2010 by his aviation medical examiner "in accordance with Authorization." FAA medical records included reports of a normal but "technically difficult" transthoracic echocardiogram, a normal magnetic resonance angiogram, an essentially normal exercise treadmill test, and essentially normal carotid artery ultrasounds. The records did not contain any documentation of, or requests for, formal cognitive or psychomotor testing, any report of or requests for the report of an MRI (magnetic resonance imaging) performed around July 2008, any documentation of or requests for reports of a transesophageal echocardiogram (though such a study was suggested if there was a "need to rule out cardiac source of emboli"), or any FAA neurology consultation. There were no indications in the FAA medical records of any cardiac symptoms. Medical records of the pilot’s treatment following the accident documented the sudden onset of right hand weakness and slurred speech while piloting a helicopter, with the subsequent identification on the MRI of recent left parietal and superior occipital strokes "in the posterior left middle cerebral artery distribution." Those records also documented elevated blood pressure, and indicated that the pilot "had high blood pressure in the past but had been taken off blood pressure medication." The pilot’s height and weight were noted as 68 inches and 253 pounds. His family history was documented in those records as including a stroke around age 60 in his mother, coronary heart disease in one brother, and another brother who died around age 60 with abdominal aortic aneurysm. ADDITIONAL INFORMATION After the accident, the helicopter was transported to American Eurocopter in Grand Prairie, Texas, where it was further inspected. According to a report produced by engineers at American Eurocopter, there was buckling of the exterior skin immediately aft of the right hand sliding door, above the clam shell doors along the aft edge of the airframe, buckling on the right hand side lower section of the slant frame, and the equipment deck below the tailcone on the left hand side. The right hand landing gear was damaged and exhibited crush damage around the aft end of the skid tube. The aft cross tube was bent and had a ground clearance measurement of 180 millimeters and the bearing rings were displaced from their originally installed position. The forward cross tube was bent and had a measured ground clearance of 503 millimeters. The tail stinger was bent in the positive direction and 26 of the 41 tail boom mating ring mount bolts were loose. According to documentation provided by the operator and the pilot, there was no mechanical malfunction with the helicopter prior to the accident.

Probable Cause and Findings

The pilot's impairment during cruise flight due to a recurring stroke. Contributing to the accident was the Federal Aviation Administration's inadequate oversight of the pilot's known medical condition.

 

Source: NTSB Aviation Accident Database

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