Saturday, October 20, 2018

Guimbal Cabri G2, registered to American Helicopter Leasing Corporation and operated by Texas Rotorwing LLC, N722TX: Accident occurred July 28, 2017 at Beaumont Municipal Airport (KBMT), Jefferson County, Texas

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

Additional Participating Entity:

Federal Aviation Administration / Flight Standards District Office; Houston, Texas

Aviation Accident Factual Report - National Transportation Safety Board: https://app.ntsb.gov/pdf


Investigation Docket - National Transportation Safety Board: https://dms.ntsb.gov/pubdms

http://registry.faa.gov/N722TX

Location:  Beaumont, TX
Accident Number: CEN17LA290
Date & Time: 07/28/2017, 1532 CDT
Registration: N722TX
Aircraft: HELICOPTERES GUIMBAL CABRI G2
Aircraft Damage: Substantial
Defining Event: Loss of control in flight
Injuries: 2 Minor
Flight Conducted Under: Part 91: General Aviation - Instructional 

On July 28, 2017, at 1532 central daylight time, a Helicopteres Guimbal Cabri G2 helicopter, N722TX, was substantially damaged when it impacted terrain while maneuvering at the Beaumont Municipal Airport (BMT), Beaumont, Texas. The flight instructor and student pilot sustained minor injuries. The helicopter was registered to American Helicopter Leasing Corp and operated by Texas Rotorwing LLC as a Title 14 Code of Federal Regulations Part 91 instructional flight. Day visual meteorological conditions prevailed. The flight was not operated on a flight plan. The local flight originated from BMT about 1500.

The flight instructor reported that he and the student had completed three normal approaches and then practiced basic hover skills at the north ramp area of the airport. A high engine oil temperature condition occurred during the hovering maneuver due to the ambient air temperature and the reduced airflow available for engine cooling. To increase engine airflow and reduce the engine temperature, he performed a low altitude circuit at 60 knots, about 100 ft above ground level (agl), around the perimeter of the airport. About halfway around the perimeter, the oil temperature had returned to the normal operating range and all other engine indications were normal at that time. However, during the turn at the southwest corner of the airport, the helicopter began to lose altitude and would not respond to his control inputs. His efforts to regain control were not successful and the helicopter impacted the open grass area on the airport southwest of the runway.

The instructor noted that the helicopter was loaded within the gross weight and center-of-gravity limitations. He added that the turns were never more than 45 degrees angle of bank. He reported that there were no anomalies with regard to the helicopter, and that the high temperatures, low wind, and high density altitude likely resulted in the accident.

A Federal Aviation Administration inspector responded to the accident site and conducted an examination of the helicopter. The flight instructor informed him that he was completing a turn, during which the helicopter was unable to maintain altitude. The helicopter came to rest on its right side. The main rotor blades were fragmented, and the tail boom was partially separated. Impact marks suggested that the main rotor had struck the ground followed by a landing skid. His examination of the flight control system did not reveal any pre-impact anomalies.

Weather conditions reported by the BMT Automated Weather Observing System (AWOS) did not include any wind information. The most recent observation recorded a temperature and dew point of 35 degrees Celsius and 21 degrees Celsius, respectively. The calculated density altitude was about 2,650 feet.

Wind conditions reported by the Jack Brooks Regional Airport (BPT) Automated Surface Observing System (ASOS), located about 12 miles southeast of BMT, were variable at 4 knots at the 1453 observation and variable at 3 knots at the 1553 observation.

The maximum engine power was derated as installed in the Cabri G2 helicopter to 145 hp for both takeoff and continuous operation. However, under the accident conditions, the engine was capable of producing approximately 160 hp. Application of full throttle by the pilot would be expected to provide 160 hp under the accident conditions. Engine performance was referenced to the 145 hp continuous limit, with 100% power corresponding to 145 hp and 111% power corresponding to 160 hp. In addition, the helicopter geometry implied that an angle of bank in excess of 40° would result in the main rotors impacting the ground before the landing skids.

The helicopter manufacturer stated that at an operating weight of 1,440 lbs. (650 kg) about 90% engine power would be required to maintain an in-ground-effect (IGE) hover at 32 ft agl and 32°C. Application of full throttle (111% power) would have provided a 21% power margin for an IGE hover under the accident conditions. However, maintaining altitude in a 45° bank turn would require a 1.4 load factor which exceeded the available 21% power margin.

Flight Instructor Information

Certificate: Flight Instructor; Commercial
Age: 36, Male
Airplane Rating(s): None
Seat Occupied: Left
Other Aircraft Rating(s): Helicopter
Restraint Used: 4-point
Instrument Rating(s): None
Second Pilot Present: Yes
Instructor Rating(s): Helicopter
Toxicology Performed: No
Medical Certification: Class 2 Without Waivers/Limitations
Last FAA Medical Exam: 08/02/2016
Occupational Pilot: Yes
Last Flight Review or Equivalent: 11/08/2015
Flight Time:  715 hours (Total, all aircraft), 452 hours (Total, this make and model), 653 hours (Pilot In Command, all aircraft), 40 hours (Last 90 days, all aircraft), 20 hours (Last 30 days, all aircraft), 0 hours (Last 24 hours, all aircraft)

Student Pilot Information

Certificate: Student
Age: 60, Male
Airplane Rating(s): None
Seat Occupied: Right
Other Aircraft Rating(s): None
Restraint Used: 4-point
Instrument Rating(s): None
Second Pilot Present: Yes
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: None
Last FAA Medical Exam:
Occupational Pilot: No
Last Flight Review or Equivalent:
Flight Time:  3 hours (Total, all aircraft), 3 hours (Total, this make and model), 0 hours (Pilot In Command, all aircraft), 3 hours (Last 90 days, all aircraft), 3 hours (Last 30 days, all aircraft), 0 hours (Last 24 hours, all aircraft) 

Aircraft and Owner/Operator Information

Aircraft Make: HELICOPTERES GUIMBAL
Registration: N722TX
Model/Series: CABRI G2
Aircraft Category: Helicopter
Year of Manufacture: 2016
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 1171
Landing Gear Type: Skid
Seats: 2
Date/Type of Last Inspection: 07/01/2017, Continuous Airworthiness
Certified Max Gross Wt.: 1543 lbs
Time Since Last Inspection: 9 Hours
Engines: 1 Reciprocating
Airframe Total Time: 159.9 Hours at time of accident
Engine Manufacturer: Lycoming
ELT: C126 installed, activated, did not aid in locating accident
Engine Model/Series: O-360-J2A
Registered Owner: American Helicopter Leasing Corp LLC
Rated Power: 145 hp
Operator: Texas Rotorwing Academy
Operating Certificate(s) Held: None 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: BPT, 15 ft msl
Distance from Accident Site: 12 Nautical Miles
Observation Time: 1553 CDT
Direction from Accident Site: 125°
Lowest Cloud Condition:
Visibility:  10 Miles
Lowest Ceiling: Broken / 4800 ft agl
Visibility (RVR):
Wind Speed/Gusts: 3 knots /
Turbulence Type Forecast/Actual: /
Wind Direction: Variable
Turbulence Severity Forecast/Actual: /
Altimeter Setting: 29.9 inches Hg
Temperature/Dew Point: 35°C / 22°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Beaumont, TX (BMT)
Type of Flight Plan Filed: None
Destination: Beaumont, TX (BMT)
Type of Clearance: None
Departure Time: 1500 CDT
Type of Airspace: Class G

Airport Information

Airport: Beaumont Muni (BMT)
Runway Surface Type: Grass/turf
Airport Elevation: 32 ft
Runway Surface Condition: Dry; Vegetation
Runway Used: N/A
IFR Approach: None
Runway Length/Width:
VFR Approach/Landing: None 

Wreckage and Impact Information

Crew Injuries: 2 Minor
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 2 Minor

Latitude, Longitude:  30.070278, -94.215000 (est)

NTSB Identification: CEN17LA290
14 CFR Part 91: General Aviation
Accident occurred Friday, July 28, 2017 in Beaumont, TX
Aircraft: HELICOPTERES GUIMBAL CABRI G2, registration: N722TX
Injuries: 2 Minor.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

On July 28, 2017, at 1532 central daylight time, a Helicopteres Guimbal Cabri G2 helicopter, N722TX, was substantially damaged when it impacted terrain while maneuvering at the Beaumont Municipal Airport (BMT), Beaumont, Texas. The flight instructor and student pilot sustained minor injuries. The helicopter was registered to American Helicopter Leasing Corp and operated by Texas Rotorwing LLC as a 14 Code of Federal Regulations Part 91 instructional flight. Day visual meteorological conditions prevailed. The flight was not operated on a flight plan. The local flight originated from BMT about 1500.

The flight instructor reported that the student was practicing basic hovering skills at the north ramp area of the airport. He noted that a high engine oil temperature condition occurred while hovering due to the ambient air temperature and the reduced airflow available for engine cooling. To increase airflow and reduce the engine temperature, he performed an air taxi around the perimeter of the airport. About halfway around the airport perimeter, the oil temperature had returned to the normal operating range. All other engine indications were normal at that time. As he completed a turn at the southwest corner of the airport, the helicopter began to lose altitude and would not respond to his control inputs. His efforts to regain control were not successful and the helicopter impacted an open field southwest of the runway.

The helicopter came to rest on its right side. The main rotor blades were fragmented and the tail boom was partially separated.

No comments: