# NTSB FTW01LA039: Robinson R22, N7187W, Sunnyvale, TX, December 17, 2000 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: December 17, 2000, 11:40 local (17:40 UTC) - Place: Sunnyvale, TX - Coordinates: 32.790744, -96.549812 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.7907&lon=-96.5498&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 8, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 50806 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW01LA039 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/50806/pdf - Page: https://openairdocs.org/ntsb/FTW01LA039 ## Probable cause The flight instructor's inadequate supervision of his student and his failure to maintain control of the helicopter. Factors were the student pilot allowing the airspeed and main rotor RPM to get too low during the simulated emergency. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, approach - vfr pattern - final approach - emergency procedure - simulated, pilot in command(cfi) - airspeed - low, dual student (contributing factor) - rotor rpm - low, dual student (contributing factor) - supervision - inadequate, pilot in command(cfi) (cause) - aircraft control - not maintained, pilot in command(cfi) (cause) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - ground ## Analysis While en route at 1,000 feet agl, the instructor pilot gave the student a simulated engine failure over a field and instructed the student to make an autorotation with a power recovery. The student pilot made a gradual 360-degree turn while descending to the field. The instructor stated that the student leveled the helicopter on final approach. The instructor made one last search for obstacles, and looked back into the cockpit to find the airspeed was at 45 knots and the main rotor RPM was at the bottom of the green arc (approximately 97%). The helicopter was approximately 100 feet agl when the instructor pilot took over control of the helicopter and attempted a 'high power recovery.' He rolled on the throttle, pulled up on the collective, felt a 'slight hesitation,' and the helicopter then 'snapped to the right.' At that time, the instructor applied left pedal and heard the low rotor RPM warning horn. The instructor stated that he thought that the helicopter did not touch down level due to the rotation to the right. The helicopter touched down in the field, 'hopped to the right approximately 40 degrees' and then became airborne again. The instructor stated that he thought that he still had either full throttle applied to the engine and/or the collective raised. As the helicopter became airborne, it rotated 360 degrees to the right, contacted the ground with the tail rotor, then the right skid. Subsequently, the helicopter rolled over onto its right side. ## Factual narrative On December 17, 2000, at 1140 central standard time, a Robinson R22 helicopter, N7187W, was substantially damaged when it impacted terrain while maneuvering near Sunnyvale, Texas. The flight instructor and private pilot receiving instruction were not injured. The airplane was registered to and operated by Sky Helicopters, Inc., of Garland, Texas. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 instructional flight. The local flight departed Mesquite, Texas, approximately 10 minutes prior to the accident and was enroute to Garland, Texas, when the accident occurred. During a telephone interview conducted by the NTSB investigator-in-charge, the instructor pilot stated that the student was practicing "low RPM recoveries, settling with power, normal and steep approaches, and emergency procedures." They flew from Garland to Mesquite, where they practiced 4 straight-in autorotations. While returning to Garland at 1,000 feet agl, the instructor gave the student a simulated engine failure over a field and instructed the student to make an autorotation with a power recovery. The student pilot made a gradual 360-degree turn while descending to the field. The instructor stated that the student leveled the helicopter on final approach. The instructor made one last search for obstacles, and looked back into the cockpit to find the airspeed was at 45 knots and the main rotor RPM was at the bottom of the green arc (approximately 97%). The helicopter was approximately 100 feet agl when the instructor pilot took over control of the helicopter and attempted a "high power recovery." He rolled on the throttle, pulled up on the collective, felt a "slight hesitation," and the helicopter then "snapped to the right." At that time, the instructor applied left pedal and heard the low rotor RPM warning horn. The instructor stated that he thought that the helicopter did not touch down level due to the rotation to the right. The helicopter touched down in the field, "hopped to the right approximately 40 degrees" and then became airborne again. The instructor stated that he thought that he still had either full throttle applied to the engine and/or the collective raised. As the helicopter became airborne, it rotated 360 degrees to the right, contacted the ground with the tail rotor, then the right skid. Subsequently, the helicopter rolled over, and came to rest on its right side. At 1153, the Redbird Airport's weather observation facility (located approximately 15 miles southwest of the accident site), reported the wind as variable at 3 knots, the visibility 10 statute miles, and clear skies. According to the FAA inspector, who responded to the accident site, the helicopter sustained structural damage to the right side of the fuselage, the vertical stabilizer, and horizontal stabilizer. The tail rotor blades were separated from the helicopter and the tail rotor gearbox sustained damage. ## Aircraft - Registration: [N7187W](https://openairdocs.org/aircraft/N7187W), registered now, S/N 0955M, built 1989 (OpenAirDocs) - Reported make and model: Robinson R22 - Registry model: [Robinson Helicopter R22 MARINER](https://openairdocs.org/model/robinson-helicopter-r22-mariner) (registry code 7640115) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 0955M - Engines: Lycoming O-320-B2C 131 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Sky Helicopters, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, December 7, 2000 - Departed: HQZ, MESQUITE, TX - Destination: T57, GARLAND, TX ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 30; commercial, flight instructor; instrument ratings: helicopter; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 412 total, 264 in this make and model, 355 as pilot in command, 230 in the last 90 days, 80 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 36 °F, dew point 14 °F - Altimeter: 30.00 inHg - Observed at: RBD, 15 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 20001217027909A](https://openairdocs.org/incident/20001217027909A), Dec 17, 2000: Robsin R22MARINER, Sunnyvale, TX, No damage. (-23) On December 17, 2000, a Robinson R-22 helicopter lost control while practicing turning autorotations and contacted the ground in a field near Sunnyvale,… 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.