# NTSB NYC99LA138: Enstrom F-28, N9588, Cincinnati, OH, June 12, 1999 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 12, 1999, 15:45 local (19:45 UTC) - Place: Cincinnati, OH - Coordinates: 39.110095, -84.500404 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.1101&lon=-84.5004&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor, 2 uninjured - Status: Completed, report November 22, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46594 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC99LA138 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46594/pdf - Page: https://openairdocs.org/ntsb/NYC99LA138 ## Probable cause The pilot's inadequate evaluation of the weather conditions at the time of departure, which resulted in a downwind takeoff. A factor in the accident was the change in wind direction. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, takeoff - object - fence - weather evaluation - inadequate, pilot in command (cause) - weather condition - windshear (contributing factor) ## Analysis The pilot started giving helicopter rides to airshow spectators in the morning. Then stopped about noon, because airspace around the airport was being closed for airshow performers. After the show, he resumed giving rides, and had completed 4 to 6 rides prior to the accident. During those rides, he did not notice any problems with the helicopter. On the accident flight, the pilot brought the helicopter to a hover into the wind, then initiated the takeoff. The helicopter started to climb, but at 10 feet agl and prior to translational lift, the wind shifted, and the helicopter started to settle. The throttle was full open, and rotor rpm was in the 'normal' range. The pilot felt increasing collective would cause rotor rpm to decay. The left skid then went under a rope barricade, and the helicopter decelerated and yawed to the left. Then suddenly it yawed to the right, which the pilot identified as a tailrotor malfunction. He 'cut the throttle' and executed a hovering autorotation. The helicopter touchdown, the right skid collapsed, and the helicopter rolled onto its right side. ## Factual narrative On June 12, 1999, at 1545 eastern daylight time, a Enstrom F-28, N9588, owned and operated by North Star Helicopters Inc, was substantially damage after the left skid contacted a rope barricade and a hovering autorotation was executed at the Blue Ash Airport, Cincinnati, Ohio. The certificated commercial pilot, and a passenger were not injured. A third passenger suffered minor injuries. Visual meteorological conditions prevailed for the helicopter sight seeing flight. No flight plan was filed, and the flight was conducted under 14 CFR Part 91. The pilot arrived at the operator's facility about 0800, and preflighted the helicopter. About 0900, the pilot flew as a passenger to the airshow, which was approximately 1 mile away. After arriving at the airshow, the pilot attended a safety briefing conducted by airshow coordinators. The airshow started about 1000, and the pilot started giving helicopter rides around 1030. The pilot stopped giving rides about 1245, because the airspace around the airport was being closed from 1300 to 1500 for airshow performers. The pilot went back to the helicopter about 1445, and conducted a preflight. During the preflight, he noticed no anomalies, and resumed giving rides at 1500. The pilot estimated that he gave 4 to 6 rides prior to the accident. During that time, he did not notice any problems with the helicopter. On the accident flight, a man weighing approximately 200 pounds, and a woman weighing approximately 145 pounds were boarded. Prior to executing the takeoff, the pilot estimated he had 7 to 8 gallons of fuel onboard. In addition, he was advised by ground personnel that the helicopter was at maximum gross weight. Facing west and pointed into the wind, the pilot brought the helicopter to a hover, then initiated the takeoff. The helicopter started to climb, but at 5 feet agl and prior to translational lift, it started to settle. The throttle was full open, and rotor rpm was in the "normal" range. The pilot felt increasing collective would cause rotor rpm to decay, so he maintained collective position. The left skid then went under a rope barricade that was connected to 55 gallon drums, and the pilot felt the helicopter decelerate and yaw to the left. He then felt a "sudden" yaw to the right, which he identified as a tailrotor malfunction. He "cut the throttle" and executed a hovering autorotation. The helicopter touchdown, the right skid collapsed, and the helicopter rolled onto its right side. The pilot felt the mainrotor contact the ground about three times before coming to a stop. The pilot then secured the fuel, electrical master, and magnetos before egressing with the assistance of airshow spectators. Both passengers were also assisted out of the helicopter. According to the pilot, the winds were out of the west to southwest all day at 5 to 15 knots, and visibility was 3 to 4 miles in haze. According to a Federal Aviation Administration Inspector that was at the airshow, the wind changed from southwest to the northeast about the time of the accident. After the change in wind direction, the Inspector estimated wind gusts were between 20 to 25 knots. In addition, about 15 minutes after the changed in direction, it started to rain, and airshow spectators moved for shelter. According to a witness, the helicopter departed to the west, and reached an altitude of 15 to 20 feet agl. As the helicopter continued to accelerate the wind shifted from a headwind to a tailwind, and the helicopter settled to about 3 feet agl. The witness then heard an increase in engine noise, and saw one of the helicopter's skids snag a rope on a pedestrian barrier. The witness added that the weather was visual flight rules with gusty winds due to developing thunderstorms. ## Aircraft - Registration: [N9588](https://openairdocs.org/deregistered/N9588-2022-01-08), registration cancelled 2022-01-08, S/N 109, built 1973 (OpenAirDocs) - Reported make and model: Enstrom F-28 - Registry model: [Enstrom F-28A](https://openairdocs.org/model/enstrom-f-28a) (registry code 3300406) (OpenAirDocs) - Registry engine: [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series) (registry code 41515, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 109 - Airframe hours: 2594 - Engines: Lycoming HIO-360 205 horsepower reciprocating - Damage: Substantial damage - Flight: Part 91 - Registered owner: North Start Helicopters - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, June 4, 1999 - Departed: ISZ, OH - Airport: ISZ, Blue Ash ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; private, commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 1,792 total, 1,000 in this make and model, 1,606 as pilot in command, 25 in the last 90 days, 8 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 30° at 8 knots - Visibility: 6 statute miles - Lowest ceiling: 6,500 ft overcast - Temperature: 86 °F, dew point 66 °F - Altimeter: 30.00 inHg - Observed at: CVG, 20 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19990612006989A](https://openairdocs.org/incident/19990612006989A), Jun 12, 1999: Enstrm F28A, Cincinnati, OH, Destroyed. 1973 Enstrom F-28A helicopter encountered a wind shift on take-off and spun into some ropes around the take-off area, the ropes caught the left skid, the acft… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.