NYC07IA023

After flying a patient to a rooftop hospital helipad, 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 helicopter's doors were secure and all equipment had been secured. The pilot then completed the before takeoff checklist. The pilot "pulled" the collective pitch lever, the helicopter became airborne, and began to "back up." He then discovered that he had forgotten to disengage the cyclic control lock mechanism 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, the pilot "immediately" lowered collective pitch, resulting in a hard landing. Examination of the incident aircraft's cyclic stick locking mechanism revealed that the locking mechanism installed on the helicopter was non-contrasting, and dark gray in color. Only three different cyclic stick locking mechanism color schemes had been produced by the manufacturer (light gray, black, or light gray with a yellow tip) and prior to the accident, a service bulletin had been issued, recommending that a yellow area be painted on the end of the older locking mechanisms to provide contrast. All aircraft produced subsequent to the service bulletin came equipped with a light gray and yellow cyclic stick locking mechanism. The cyclic stick locking mechanism was secured by means of a locking pin mounted on the underside of the instrument panel. In the event of an emergency, due to it 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. The manufacturer evaluated the breakout force to be approximately 26.98 pounds of force at the stick grip. During a post incident interview, the pilot advised that he was unable to disconnect the cyclic stick locking mechanism even though he attempted to "jerk the stick." During an examination of the incident helicopter, breakout force was measured at approximately 44 pounds during one test and 42 pounds during another. Review of the operator developed checklist for the helicopter revealed that there was no reference to use of the cyclic stick locking mechanism, or inclusion of requirement to verify that the flight controls were free and correct. Additionally, the company operations manual did not address use of the cyclic stick locking mechanism during hot loading or unloading of passengers.

History of flight

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.

Personnel information

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.

Aircraft information

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.

Meteorological information

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.

Heliport information

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 tha