N453AE

HISTORY OF FLIGHT

On July 7, 2007, about 1651 eastern daylight time, a Eurocopter EC 130 B4 helicopter, N453AE, registered to Meridian Consulting Company, Inc., and operated by Liberty Helicopters, Inc., sustained substantial damage following an in-flight separation of a section of one of the main rotor blades and subsequent autorotation onto the Hudson River, New York, New York. Visual meteorological conditions prevailed, and a company visual flight rules (VFR) flight plan was filed for the flight, which was operating under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91 and 136 as a revenue sightseeing flight. The flight departed from the West 30th Street Heliport (JRA), New York, New York about 1643. There were no injuries to the certificated commercial pilot or seven passengers.

The pilot stated that she had flown the accident helicopter on three previous flights that day and reported no discrepancies on those flights. The accident flight departed for a 10-minute sightseeing flight. All passengers were wearing inflatable life vests, which were contained in a pouch that was strapped around their waists. Approximately 8 minutes into the flight, while flying southbound on a left base leg, or approximately 1/2 mile from the point where she would have turned onto final approach for the heliport, she heard a loud bang, and felt an abnormal vibration (medium to low).

At that time, she said she was flying about 350 to 400 feet above the water and between 100 and 110 knots indicated airspeed. The bang was the first thing that got her attention, and noted there was no yawing motion associated with the noise. She saw gray colored debris that was rectangular in shape, and approximately 8 inches in length, fly from the aft left to front left, before it went out of sight. She then heard a "winding down" of the main rotor rpm, but did not hear the low rotor warning horn. The main rotor rpm decay was immediate. She looked at the dual tachometer, but did not recall the main rotor rpm reading. She entered autorotation by applying down collective and aft cyclic, and also deployed the pop-out floats. The vibration was prominent and abnormal. She made a slight flare at 25 feet, and the helicopter settled from that altitude. She applied forward cyclic and the helicopter landed "soft" on the choppy water. The helicopter was level at the point of touchdown and at that time, she had one-half “up” collective applied. She reported there was no binding of the flight controls from the time of hearing the sound to the point of touchdown on the water.

After touchdown on the Hudson River, she noted that the main rotor blades were tilted to the right, the tail rotor was still spinning, and the engine was still running. She did not report hearing any horn or seeing any lights, and she did not make any radio calls. She helped the front seat passengers remove their restraints and exit the helicopter. One passenger in the rear seat helped the other rear seat passengers exit the helicopter. All occupants were rescued from the water by private boaters.

A witness on a boat reported suddenly hearing a very loud banging noise. The banging noise continued until the main rotor blades contacted the water and became damaged along with what appeared to be pieces of the engine cowling. The banging sound decreased, but the engine remained running “very smoothly,” though it appeared to him to be out of its normally installed position. He said the banging sound as being a thumping sound, metallic in nature, that in his opinion was consistent with the main rotor blades contacting something metallic. The witness, who is an airplane mechanic, reported that the sound was consistent with the sound of tapping of a hard plastic screwdriver handle on aluminum skin.

PERSONNEL INFORMATION

The pilot, age 37, held a commercial pilot certificate with rotorcraft helicopter and instrument helicopter ratings, issued September 27, 2006. She also holds a private pilot certificate with an airplane single-engine land rating. She was issued a second-class medical certificate with no limitations on February 13, 2007. There was no record of any previous accidents or incidents or enforcement actions by the Federal Aviation Administration (FAA).

The pilot was hired by Liberty Helicopters, Inc., on February 8, 2007. Just prior to employment, she reported having a total time of 2,286 hours, of which 1,103 hours were in rotorcraft and 1,183 hours were in airplanes. Three of the 1,103 hours in rotorcraft were in Aerospatiale helicopters. Her last airman competency/proficiency check in accordance with 14 CFR Part 135.293 titled, “Initial and recurrent pilot testing requirements” and also 14 CFR 135.299 titled, “Pilot in command: Line checks: Routes and airports” was performed on February 8, 2007. The flight duration was recorded to be 1.0 hour and the results were listed as “Approved.” The flight was in the accident helicopter. She was qualified to act as pilot-in-command (PIC) in the following make and model helicopters: Eurocopter EC 130 B4, Aerospatiale models AS350B1, AS350B2, and AS350BA.

Since being hired by Liberty Helicopters, Inc., the pilot recorded approximately 239 hours in various make and model helicopters including time spent in flight training. She reported on the NTSB Pilot/Operator Aircraft Accident/Incident Report having a total time of 2,752 hours, of which 1,569 were in rotorcraft. In the previous 90 days she reported accruing 357 hours in rotorcraft, of which 214 hours were in the accident make and model helicopter.

AIRCRAFT INFORMATION

The helicopter was manufactured in December 2001, by Eurocopter as model EC 130 B4, with serial number 3487. It was equipped with an Arriel 2B1 engine, rated for 5 minutes at 747 shaft horsepower. Main rotor blades part number (P/N) 355A-11-0030.00, serial numbers (S/N’s) 22312, 22716, and 22741 were installed at the time of manufacture. Following manufacture, the helicopter was disassembled, shipped to Liberty Helicopters, Inc., and reassembled on January 3, 2002. At that time the main rotor blades were installed in accordance with (IAW) the maintenance manual. A Standard Airworthiness Certificate was issued on April 9, 2002.

The type certificate data sheet indicates that for the accident make and model helicopter, the maximum number of passengers is 6. On September 27, 2002, the helicopter was modified IAW Service Bulletin (SB) 25.028 which allowed the installation of 8 seats.

The helicopter was placed on Liberty Helicopters, Inc., Operations Specifications on April 22, 2002, and was maintained in accordance with a Federal Aviation Administration (FAA) Approved Aircraft Inspection Program (AAIP). With respect to the airframe, the following inspections are required: 3-day check, 100, 500, 1,000, 2,000, and 2,500-hour inspections.

The 3-day check stipulates that the main rotor blades are to be checked for security and general condition of the skin, trim tabs, and polyurethane protective strips. A visual inspection of the main rotor blade for scratches, cracks, impacts and distortions is also indicated. Following the 3-day check, a caution indicates, “Ensure all cowlings and fairings are closed and latched.” Review of the 100-hour inspection checklist revealed that the skin, and leading edge of the main rotor blades, are to be checked for delamination and cracks.

The inspection of the blades is accomplished IAW the manufacturer’s aircraft maintenance manual (AMM) 62-11-00, section 6-1.

Although the manufacturer Master Servicing Recommendation (MSR) manual specifies to inspect the main rotor blades at intervals of 110 hours, the AAIP work card specifies that the blades are to be inspected for cracks at intervals of 100 hours.

Review of the maintenance records revealed the helicopter had a 100-hour inspection on June 23, 2007. The helicopter total time at the time of the inspection was 7,992.5 hours. Additionally, the 3-day check was signed off as being complied with on July 7, 2007. The helicopter had been operated for approximately 85 hours since the last 100-hour inspection, and its total time at the time of the accident was approximately 8,077 hours.

On the day of the accident, prior to its first flight, the helicopter and engine total times were recorded to be 8,072.2 and 7,852.7 hours, respectively. The engine was started about 0848, and remained running throughout the day until after the accident. Excluding the accident flight, the helicopter was operated on 25 flights for a total of 4.95 hours.

Further review of the maintenance records revealed there was no record that any of the main rotor blades had been repaired or replaced since the helicopter was manufactured. Additionally, there was no record of replacement or major repair to any of the cowlings or fairings.

Main rotor blade P/N (P/N) 355A-11-0030.00, has a 20,000 hour service life limit. Eurocopter personnel reported that prior to the accident, there has not been one reported failure of the blade.

METEOROLOGICAL INFORMATION

A surface observation weather report taken at La Guardia Airport, New York, NY, at 1651, or the approximate time of the accident, indicated broken clouds existed at 7,500 and 25,000 feet mean sea level, the visibility was 10 statute miles, the temperature and dew point were 87 and 53 degrees Fahrenheit respectively, and the altimeter setting was 29.82 inches of Mercury.

FLIGHT RECORDERS

The helicopter was equipped with dual channels/modules Vehicle and Engine Management Display (VEMD), which is designed to store maintenance data, and is installed in the instrument panel. It displays vehicle and engine parameters, the computation and display of engine limitations, the fail management procedures, the computation and display of weight related to performance data and the number of engine cycles. Relevant VEMD stored data includes flight report, failure report, and over-limits report, which are not dated but ...