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On November 7, 2006, at 0310 eastern standard time, a Eurocopter Deutschland EC135T1, N522ME, operated by CJ Systems Aviation Group incurred minor damage during an emergency landing after takeoff at Harrisburg Hospital Heliport (5PN9), Harrisburg, Pennsylvania. The certificated commercial pilot was not injured. Night visual meteorological conditions prevailed, and no flight plan was filed for the positioning flight destined for Harrisburg International Airport (MDT), Harrisburg, Pennsylvania, conducted under 14 Code of Federal Regulations Part 91.
According to the pilot, after flying a patient on an inter-hospital transfer from Hazelton Pennsylvania to Harrisburg General Hospital, the medical crew and pilot decided to "hot offload" the patient (engines running). After the medical personnel and patient were unloaded, the "thumbs up" was given to the pilot verifying the helicopters doors were secure and all equipment had been secured. The pilot then completed the before takeoff checklist.
After radioing his intentions to reposition to MDT to refuel, the pilot "pulled" the collective pitch lever, the helicopter became airborne and began to "back up." He then discovered that he had left the cyclic control lock mechanism engaged and had forgotten to disengage it after items, which had been carried on the front left seat, had been removed during the "hot offload."
Fearing that the rearward movement of the helicopter may have taken him over the edge of the helipad, which was located on the roof of the hospital, the pilot "immediately" lowered collective pitch, resulting in a hard landing.
According to Federal Aviation Administration (FAA) and pilot records, the pilot held a commercial pilot certificate with multiple ratings, including rotorcraft helicopter. He had accumulated 4,890 total hours of flight experience, of which, 4,029 hours were in rotorcraft, and 419 hours in the incident helicopter make and model.
According to FAA and operator records, the helicopter had been involved in three previous incidents, including a hard landing, which had resulted in minor damage. The helicopter was manufactured in 2000 and was owned by The Center for Emergency Medicine of Western PA Inc. It had been configured for emergency medical use by Metro Aviation Inc. prior to being placed on the CJ Systems Aviation Group certificate.
The helicopter's most recent 100 hour inspection was completed on October 26, 2006, and at the time of the incident, it had accumulated 4198.6 total hours of operation.
A weather observation taken about 14 minutes prior to the incident, at Capitol City Airport (CXY), Harrisburg, Pennsylvania, located approximately 3 nautical miles southeast of the incident site, recorded the wind as calm, visibility 7 miles, clear skies, temperature 1 degree Celsius, dew point minus 1 degree Celsius, and an altimeter setting of 30.31 inches of mercury.
Harrisburg Hospital Heliport was a private use heliport. It had a left hand traffic pattern and one helipad located on the roof of the hospital. The helipad was in good condition, and was 45 feet long by 45 feet wide. It was equipped with perimeter lighting and a white-green-yellow rotating beacon.
WRECKAGE AND IMPACT INFORMATION
The helicopter came to rest on the rooftop helipad with the aft portion of the skid tubes approximately two feet from the edge of the hard deck edge stripe. The tail boom extended out over the safety netting.
Airframe and Engine Examinations
Examination of the helicopter revealed that the landing skids were bent, the oxygen bottle fairing on the right side of the fuselage was cracked, the bottom of the right hand vertical stabilizer was chipped, and the bumper exhibited impact damage and cracking.
Visual examination of the engines and engine deck revealed no external damage. Data from both digital engine control units (DECU) were downloaded at the operator's facility under the supervision of a National Transportation Safety Board investigator, and the vehicle and engine multifunction display (VEMD) information was reviewed.
During the examinations, no preimpact mechanical malfunctions of the flight controls, main rotor, tail rotor, and drive systems were discovered. The engine DECU downloads and aircraft VEMD flight page review did not reveal any anomalies.
TESTS AND RESEARCH
According to the manufacturer, there had been several cases where lift-off of a helicopter was executed with a locked cyclic stick, which could lead to a loss of controllability of the helicopter. As a result on July 13, 2006 (four months prior to the accident), the manufacturer issued Alert Service Information EC135-A085 concerning operation of the cyclic stick locking mechanism.
Examination of Cyclic Stick Locking Mechanism
Examination of the incident aircraft's cyclic stick locking mechanism revealed that the locking mechanism installed on the helicopter was dark gray in color and displayed evidence of it being repainted. Examination of the back of the part revealed that its surface texture was rough, and it displayed evidence of having been built up with multiple layers of fiberglass cloth, each of different length. No part or serial number was visible.
Examination of cyclic stick locking mechanisms on two exemplar helicopters revealed two different color schemes; one was light gray, and one was light gray with a yellow tip. Examination of both revealed a smooth surface texture, with clearly visible part and serial numbers.
Examination of the rest of the operator's fleet of helicopters by the operator's maintenance department revealed that one helicopter had the solid light gray paint scheme, three helicopters had a solid black paint scheme, and the rest were black with a yellow tip. No other dark gray cyclic stick locking mechanisms were discovered and no repairs or replacement of the cyclic stick locking mechanism on the accident helicopter had been performed since delivery to CJ Systems Aviation Group.
According to the manufacturer, only three different cyclic stick locking mechanism color schemes had been produced (light gray, black, or light gray with a yellow tip). Prior to the accident, a service bulletin had been issued, applicable to the EC135 up to serial number 0028, which recommended a modification to the older cyclic stick locking mechanisms. This modification included the painting of a yellow area on the end of the mechanism. All aircraft produced subsequent to serial number 0028, came equipped with the light gray and yellow, cyclic stick locking mechanism.
A review of the accident helicopter's factory documentation verified that it was originally delivered with a light gray and yellow tipped cyclic stick locking mechanism (Part No. L671 M1003 103).
Examination of Breakout Force
The cyclic stick locking mechanism was secured by means of a locking pin mounted on the underside of the instrument panel. According to the manufacturer, in the event of an emergency due to the cyclic stick locking mechanism not having been unlocked by the pilot, the locking pin was designed to be "sheared through" by a "jerky movement" of the cyclic stick, which would then allow it to move freely.
In "practical tests" by the manufacturer, breakout force was evaluated to be approximately 26.98 pounds of force at the stick grip. During a post incident interview, the pilot advised however, that he was unable to disconnect the cyclic stick locking mechanism even though he attempted to "jerk the stick." During tests of the breakout force on the incident helicopter, breakout force on a calibrated spring scale was indicated to be approximately 44 pounds during one test and 42 pounds during another.
Items on The Front Left Seat
The pilot had advised the National Transportation Safety Board that he had left "the cyclic control lock engaged" and had forgotten to disengage it, after items which had been carried on the front left seat, had been removed during the "hot offload." When questioned as to why he had engaged the locking mechanism, he advised that the left cyclic stick had been installed, in front of the left front seat.
According to the operator, the left cyclic stick had been installed for night vision goggle training on November 4, 2006, and company policy would have required a maintenance action for its removal, which would have grounded the helicopter until the next day. The cyclic stick, however, had been installed three days prior to the accident. During that time the helicopter had been operated for 15.9 hours.
Company Provided Guidance
The "CJSAG EMS EC135 CHECKLIST" (Revision 2), dated May 17, 2006, did not reference the use of the cyclic stick locking mechanism, or include the requirement to verify that the flight controls were free and correct.
A review of the operator's FAA approved training program also revealed that the pilot in command did not make the determination as to when "hot loading" or "hot unloading" would occur. According to "Special Curriculum Segment S-7" (Hot Loading And Unloading of the BK117), "Special Curriculum Segment S-8" (Hot Loading and Unloading the EC-135), and "Special Curriculum Segment S-9" (Hot Loading and Unloading of Side Loading Helicopters) only the "medical flight crewmember" could determine when hot loading or unloading was required. This determination was to be based on patient status, the need for rapid departure with a specialty team, or for back-to-back flights. The company operations manual mirrored the above information. The manual, did not address use of the cyclic stick locking mechanism during hot loading or unloading of passengers, or address the continuation of flight after passengers were unloaded.
According to the EC135T1 Flight Manual (Rev.12), Section 4, Normal Procedures, the Cyclic Stick Locking Mechanism was to be unlocked after starting the first engine, and flight control movement was verified for proper operation with "small" cyclic stick, collective pitch, and pedal movements. No guidance for hot loading or unloading was provided, and locking of the cyclic stick locking mechanism was to be accomplished only after engine shutdown.
FAA Corrective Actions
On November 2, 2006, the FAA issued a Safety Alert for Operators (SAFO 06020), to promote the use of operationally appropriate and effective pretakeoff checklists for helicopter pilots.
Operator Corrective Actions
On November 21, 2006, the operator advised the Safety Board that the CJ EC135 checklist was modified to include under the heading "BEFORE TAKEOFF CHECKLIST, " 2. CYCLIC...UNLOCKED & CENTERED."
As an interim step (until the manufacturer could develop a corrective action), the operator issued CJ Field Information Notice (FIM 11-06/ALL/071) which directed the application of red and white reflective tape to make the EC135/EC145 cyclic locking mechanisms "highly visible" when engaged. They also issued Operations Note R115, mandating policy and procedures for use of the cyclic and collective locking mechanisms and Operations Note R119, which mandated that baggage and /or medical equipment could not be stowed on the copilot's seat, or anywhere else in the cockpit of an aircraft, when dual controls were installed.
A separate action by the operator, added guidance stating that the pilot in command is the final authority for decisions regarding hot loading and unloading, and on February 21, 2007, the operator advised the Safety Board that an air medical resource management program had been initiated to provide teamwork, communication, and decision-making training to flight crews, medical crews, and ground operations team members.
Manufacturer Corrective Actions
On October 2, 2007 the manufacturer added a "note" to the EC135T1 Flight Manual that included information on overriding the locking device in the event of an emergency.
Additionally, the manufacturer drafted an Alert Service Bulletin EC135-67A-015, which at the time of this writing, is under review by the European Aviation Safety Agency. This bulletin is intended to instruct operators to remove the slide and spring from the cyclic stick cantilever. This action will render the locking mechanism inoperative, and notify pilots that locking of the cyclic stick will no longer be possible.
The helicopter was released to the operator on November 16, 2006.