N204HF

HISTORY OF FLIGHT

On September 8, 2017, about 1300 eastern daylight time, a Schweizer 269C-1 helicopter, N204HF, was substantially damaged during a collision with terrain while performing a forced landing to runway 01 at Flying W Airport (N14), Medford, New Jersey. The commercial pilot and passenger were fatally injured. The helicopter was owned by Herlihy Helicopters Inc and operated by Helicopter Flight Services under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight.

According to the chief flight instructor for the operator, the purpose of the flight was to provide an orientation/pleasure flight to the passenger, who was scheduled to perform in a concert on the airport later that evening.

Several minutes after takeoff, the pilot reported over the airport UNICOM frequency that he was unable to control engine rpm with throttle inputs. He reported that he could "roll" the twist-grip but that there was no corresponding change in engine rpm when he did so.

The company flight instructor and another helicopter flight instructor, who was a designated pilot examiner (DPE), were monitoring the frequency and engaged the pilot in conversation about potential courses of action to accomplish a landing. A Federal Aviation Administration (FAA) inspector, who was also a helicopter instructor and examiner, joined the conversation on the radio.

Options discussed included a shallow approach to a run-on landing or a power-off, autorotational descent to landing. The instructors suggested that the pilot perform the run-on landing; however, the pilot reported that a previous attempt to perform a run-on landing was unsuccessful and announced that he would stop the engine and perform a power-off autorotation. The pilot stated that this was a familiar procedure he had performed numerous times in the past. When asked over the radio by the DPE when he had last performed an autorotation to touchdown, the pilot replied that 4 months had elapsed since his most recent touchdown autorotation. Subsequent attempts to convince the pilot to attempt a run-on landing were unsuccessful.

According to the DPE and the FAA inspector, the pilot was advised "multiple times" to aim to touch down "midfield" and not to initiate the engine shutdown and autorotation until over the runway. According to the DPE, his last reminder to the pilot came when the helicopter was on a 2-mile final approach.

A video forwarded to the NTSB by local police was recorded from a vantage point nearly abeam the approach end of runway 01. The video showed the helicopter about 1/4 mile south of the runway as it entered a descent profile consistent with an autorotation. Toward the end of the video, the descent profile became more vertical, and the rate of descent increased before the helicopter descended out of view. No sound could be heard from the helicopter.

During a postaccident interview with law enforcement, the company flight instructor reported that the helicopter entered the autorotation about 950 ft above ground level (agl) and that the helicopter was quiet during its descent "because the engine was off." During the descent, the rotor rpm decayed to the point where the instructor could see the individual rotor blades. The helicopter descended from view before reaching the runway threshold, and the sounds of impact were heard. Both the instructor and the FAA inspector reported that a high-pitched "whine" could be heard from the helicopter during the latter portion of the descent.

In a written statement, the flight instructor reported, "[the pilot] began the autorotative descent, but it was not long before it became apparent it was not being executed correctly. I began to see individual blades instead of a translucent disc. His vertical speed increased while his horizontal speed became almost non-existent. The nose of the [helicopter] rolled forward. Instead of being able to see the bottom of the [helicopter]… all I could see was the cockpit glass and rotor head."

PERSONNEL INFORMATION

The pilot held commercial and flight instructor certificates, each with ratings for rotorcraft-helicopter and instrument helicopter. His most recent FAA second-class medical certificate was issued April 12, 2017.

Excerpts of the pilot's logbook revealed that he had logged 480.9 total hours of flight experience, of which about 300 hours were in the accident helicopter make and model. The last entry logged was for 1.2 hours in the accident helicopter on the day of the accident.

Company training records indicated that the pilot had received the training required by the operator for employment as a flight instructor, and his last airman competency check was completed satisfactorily on April 19, 2017, in the accident helicopter.

AIRCRAFT INFORMATION

The helicopter was a single-engine, two-seat, light utility helicopter constructed primarily of aluminum alloy and powered by an air-cooled, Lycoming HO-360-C1A, 180-horsepower engine. It was equipped with conventional collective and cyclic control sticks and tail rotor control pedals.

The main rotor was a fully articulated, three-bladed design, and the tail rotor was a two-bladed, semi-rigid, anti-torque rotor design. Power was transmitted from the engine to the rotor system through a V-belt drive, which incorporated a free-wheeling (one-way) sprag clutch, a main drive transmission, a tail rotor transmission, and shafts.

According to FAA records, the helicopter was manufactured in 2000, delivered to the owner/operator, and had accrued about 7,899 total aircraft hours. Its most recent 100-hour inspection was completed on August 17, 2017, at 7,884 total aircraft hours.

A review of maintenance records revealed that the helicopter's engine was replaced with factory rebuilt or overhauled engines at the manufacturer's recommended overhaul intervals. Engine changes occurred in 2003, 2006, and most recently, on September 24, 2011.

The records reflected numerous entries regarding carburetor discrepancies. Carburetors were adjusted or removed and replaced with loaner carburetors then reinstalled following repairs. In February 2014, the carburetor was removed, sent out for repair, and reinstalled by the operator.

On August 31, 2016, the operator installed a throttle control cable manufactured by McFarlane Aviation Products, as documented on an FAA Form 337. A cable from the original equipment manufacturer was not available per the operator, and the FAA approved the manufacture and installation, which required the cable's inspection at 25-hour intervals. The inspections were documented; the most recent was completed concurrent with the annual inspection conducted 15 hours before the accident.

The operator was interviewed during a meeting with NTSB investigators and FAA inspectors regarding the maintenance history of the accident helicopter. He was later interviewed by telephone to gain more detail about the disassembly/reassembly and rigging of the throttle during carburetor/engine changes.

According to the operator, when the engine was changed for overhaul, the carburetor traveled with the engine, and the throttle control arm was removed at the carburetor splined shaft. The throttle control bellcrank was removed from the front of the carburetor, and the entire throttle control system remained with the helicopter. The throttle control arm, the throttle tie rod, the throttle control bellcrank, and the throttle cable all remained attached to each other and to the helicopter. He stated that, because of this, there was no need to disconnect or adjust the throttle tie rod that connected the bellcrank and the throttle control arm.

He also stated that, when a new engine was installed, the correct "angle" was measured for the installation of the throttle control arm on the carburetor. Adjustment of idle and mixture set screws was often required, as the carburetors were often set at the factory "for airplanes."

When asked about the most recent installation of the throttle control cable, the operator stated that the cable was a fixed measurement and changing the cable did not change the rigging of the throttle. He said that, when the cable was changed, no throttle rigging adjustments were necessary; the cable was disconnected at the bellcrank upstream of the tie rod and throttle control arm. He repeated that the cable installation was "plug and play" and that no adjustments were necessary to achieve/maintain proper throttle rigging.

The operator was asked specifically about the throttle rigging and the nominal measurement of the tie rod during the throttle rigging procedure following the most recent engine change. He stated, "I don't know if I did. I'm sure I did, because that's part of the procedure, but I'm not 100 percent [sure]."

According to the manufacturer's maintenance manual, actions that required compliance with the throttle rigging procedure included:

1. Installation of a new engine (Section 3-15, page 3-26)

2. Installation of a new throttle control cable (Section 4-19, page 4-19)

3. Installation of a new carburetor (Section 5-55, page 5-21)

METEOROLOGICAL INFORMATION

At 1254, the weather recorded at South Jersey Regional Airport (VAY), 2 miles west of N14, included clear skies and wind from 260° at 13 knots gusting to 18 knots. The temperature was 21°C, and the dew point was 9°C. The altimeter setting was 30.13 inches of mercury.

AIRPORT INFORMATION

N14 was at 49 ft elevation and was equipped with a single runway, oriented 01/19. The operator's hangar was positioned at the south end of the field, approximately abeam the numbers for runway 01. A creek, oriented east/west, crossed about 200 ft south of the approach end of runway 01. The creek bed was lined with small trees and low brush and bisected the area between the runway and an open field immediately south of the airport.

The field was about 1,400 ft long and ...