Wednesday, June 05, 2019

Loss of Control in Flight: Enstrom F-28C, N5691Y; accident occurred October 07, 2018 in Bridgeville, Sussex County, Delaware

The National Transportation Safety Board did not travel to the scene of this accident.

Additional Participating Entity: 

Federal Aviation Administration / Flight Standards District Office; Philadelphia, Pennsylvania

Aviation Accident Factual Report - National Transportation Safety Board:

Investigation Docket - National Transportation Safety Board:

Location: Bridgeville, DE
Accident Number: ERA19TA005
Date & Time: 10/07/2018, 1340 EDT
Registration: N5691Y
Aircraft: Enstrom F28
Aircraft Damage: Substantial
Defining Event: Loss of control in flight
Injuries: 4 None
Flight Conducted Under: Part 91: General Aviation - Aerial Observation - Sightseeing 

On October 7, 2018, at 1340 eastern daylight time, an Enstrom F-28C helicopter, N5691Y, was substantially damaged when it impacted terrain shortly after takeoff from a field in Bridgeville, Delaware. The commercial pilot and three passengers were not injured. The helicopter was operated by J&J Shop HeliAir LLC as a local sightseeing flight conducted under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight.

According to the pilot, during takeoff with power lines and farm equipment nearby, he increased the throttle to the maximum engine and rotor rpm, and began a climbing left turn, where he subsequently noticed a "slight decaying of rotor rpm." While headed toward the power lines, he "slightly" reduced the collective, while increasing the throttle, in effort to increase rotor rpm, but his corrections did not increase the rotor rpm. Nearing the power lines, he reported that he "pulled collective" which "further degraded" the low rotor rpm state, as the helicopter cleared the power lines. After clearing the power lines, the helicopter was about 50 to 75 ft above ground level, and the engine and rotor rpms were "well below minimums." With the helicopter sinking, the pilot pulled "full collective" just prior to impact with terrain, and the helicopter touched down hard.

The pilot reported that he had previously flown 12 flights with passengers prior to the accident flight and did not notice any abnormalities with the helicopter, nor was he aware of any "mechanical issues" with the helicopter during the accident flight.

According to a Federal Aviation Administration (FAA) inspector who examined the helicopter at the accident site, it impacted terrain about 1,000 ft northeast of the departure point in an upright configuration. The tail boom had separated from the fuselage, which resulted in substantial damage to the tail rotor drive shaft, tail boom, and tail rotors. Control continuity was established for the throttle, cyclic, and collective controls. A subsequent engine examination and test run did not reveal evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation.

The operator held an FAA Letter of Authorization to conduct commercial air tour operations under Title 14 CFR Part 91.147. The operator reported that their policy was to conduct flights with a maximum of two passengers, however, the accident flight commenced with three passengers. Following the accident, the operator reiterated to all company pilots and staff that flights cannot have more than two passengers.

According to FAA airman records, the pilot held a commercial pilot certificate with ratings for helicopter and instrument helicopter. His most recent second-class medical certificate was issued in September 2018. He reported a total of 1,864 flight hours, 74 hours of which were in the accident helicopter make and model.

According to FAA airworthiness records, the helicopter was powered by a Lycoming HIO-360-E1AD, 205-horsepower engine, and had 3 seats. The most recent annual inspection was completed in August 2018.

At 1332, the weather conditions reported at Dover Air Force Base, Dover, Delaware, about 25 miles from the accident site, included wind from 240° at 6 knots, visibility 10 statute miles, scattered clouds at 2,400 ft above ground, temperature 28°C, and dew point 22°C.

The pilot's operating handbook stated in part:


Conditions may occur in which the helicopter must be operated from confined areas in which take-off distances (from hover to best rate of climb speed) are not sufficient to clear obstacles that may be in the flight path (trees, buildings, wires, etc.). In order to clear such obstacles safely, the climb portion of the take-off must utilize the best angle of climb airspeed (30 MPH safe side of height velocity curve). This angle of climb will substantially shorten the distance required to clear obstacles. To accomplish this type of take-off, hover helicopter at 3 to 5 feet altitude and 2900 RPM. Apply forward cyclic smoothly. As the helicopter begins to accelerate forward, apply collective and throttle until 36.5 inches of manifold pressure is obtained at 2900 engine RPM. Do not increase collective beyond this point (over pitching) as this will cause engine and rotor RPM to decrease. Maintain 3 to 5 feet altitude by use of cyclic control. As translational speed is reached (15-20 MPH) apply aft cyclic to seek climb angle that will maintain 30-35 MPH (refer to height ~ velocity diagram in flight manual). After clearing all obstacles at this airspeed, apply forward cyclic and readjust collective and throttle as desired for further flight.

Pilot Information

Certificate: Commercial
Age: 62, Male
Airplane Rating(s): None
Seat Occupied: Left
Other Aircraft Rating(s): Helicopter
Restraint Used: 4-point
Instrument Rating(s): Helicopter
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 2 With Waivers/Limitations
Last FAA Medical Exam: 09/20/2018
Occupational Pilot: Yes
Last Flight Review or Equivalent: 08/14/2018
Flight Time:   1864 hours (Total, all aircraft), 74 hours (Total, this make and model), 939 hours (Pilot In Command, all aircraft), 44 hours (Last 90 days, all aircraft), 27 hours (Last 30 days, all aircraft), 5 hours (Last 24 hours, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: Enstrom
Registration: N5691Y
Model/Series: F28 C
Aircraft Category: Helicopter
Year of Manufacture: 1979
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 479-2
Landing Gear Type: Skid
Seats: 3
Date/Type of Last Inspection: 08/14/2018, Annual
Certified Max Gross Wt.: 2350 lbs
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time: 5462.8 Hours as of last inspection
Engine Manufacturer: Lycoming
ELT: Not installed
Engine Model/Series: HIO-360-E1AD
Registered Owner: J&J Shop Heliair LLC.
Rated Power: 205 hp
Operator: J&J Shop Heliair LLC.
Operating Certificate(s) Held: Certificate of Authorization or Waiver (COA)

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KDOV, 28 ft msl
Distance from Accident Site: 25 Nautical Miles
Observation Time: 1332 EDT
Direction from Accident Site: 10°
Lowest Cloud Condition: Scattered / 2400 ft agl
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 6 knots /
Turbulence Type Forecast/Actual: None / None
Wind Direction: 240°
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 30.19 inches Hg
Temperature/Dew Point: 28°C / 22°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Bridgeville, DE
Type of Flight Plan Filed: None 
Destination: Bridgeville, DE
Type of Clearance: None
Departure Time: 1337 EDT
Type of Airspace: Class G

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries: 3 None
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 4 None
Latitude, Longitude: 38.715278, -75.570556

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