# NTSB ERA13LA045: Robinson Helicopter R22, N231TM, Alexander City, AL, November 1, 2012 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: November 1, 2012, 15:46 local (20:46 UTC) - Place: Alexander City, AL - Coordinates: 32.908889, -85.957778 - Nearby events: https://openairdocs.org/map.md?lat=32.9089&lon=-85.9578&mi=10 - Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping) - Defining event: [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed, report April 23, 2014 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO, Robinson Helicopter Company - NTSB case key (mKey): 85492 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA13LA045 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/85492/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=85492 - Page: https://openairdocs.org/ntsb/ERA13LA045 ## Probable cause The pilot’s delayed decision to initiate an autorotation and her subsequent improper conduct of the autorotation, which resulted in a hard landing, after the helicopter started vibrating for reasons that could not be determined because postaccident examinations revealed no anomalies that would have precluded normal operation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: landing flare](https://openairdocs.org/ntsb-findings/01062041): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Robinson Helicopter R22, 3 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md?model=7640102), [All aircraft, 1,285 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Robinson Helicopter R22, 7 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=7640102), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Robinson Helicopter R22, 18 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7640102), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Unknown or undetermined](https://openairdocs.org/ntsb-events/000); cases with it: [Robinson Helicopter R22, 1 case](https://openairdocs.org/ntsb-events/000/sequence.md?model=7640102), [All aircraft, 1,703 cases](https://openairdocs.org/ntsb-events/000/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Robinson Helicopter R22, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=7640102), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Robinson Helicopter R22, 13 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=7640102), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis After departure, the helicopter began to vibrate at an altitude of about 300 feet above ground level (agl). The pilot chose to return to the airport to perform a precautionary landing. The pilot initiated an autorotation about 100 feet agl at an airspeed of between 45 to 50 knots but could not control the helicopter. The pilot applied aft cyclic to flare the helicopter; however, it did not lose airspeed. The low rotor rpm aural warning activated during the maneuver, and the helicopter subsequently landed hard and rolled over on its right side. Postaccident examinations of the engine and airframe did not reveal any anomalies that would have caused the vibration the helicopter experienced after takeoff. If the pilot had initiated the autorotation sooner, she may have had adequate airspeed to establish the glide and a sufficient amount of rotor rpm to cushion the landing and retain positive control of the helicopter. ## Factual narrative On November 1, 2012, at 1546 central daylight time, a Robinson R22, N231TM, sustained substantial damage during a precautionary landing at Thomas C. Russell Field Airport (ALX), Alexander City, Alabama. The commercial pilot was seriously injured, and the commercial pilot-rated passenger received minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight, which was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The flight was originating at the time of the accident. According to the pilot, she and her co-worker were en route to Sarasota, Florida and were departing ALX after stopping for lunch. The pilot rated passenger was conducting the takeoff when, shortly after departure while turning crosswind, the helicopter started to shake. The pilot assumed control of the helicopter and elected to return to the airport to perform a precautionary landing in the grass. The pilot did not observe any abnormal indications on the flight instruments, but stated that she did not look at the manifold pressure gauge. About 100 feet above ground level and approximately 45 to 50 knots, the pilot initiated an autorotation, but "could not control" the helicopter. She then reduced the collective pitch and applied forward pressure on the cyclic control to gain airspeed for landing. As the helicopter approached the landing site, the pilot applied aft cyclic to flare the helicopter. The low rotor rpm horn activated, and the helicopter impacted the ground and came to rest on its right side, resulting in substantial damage to the main rotor blades and fuselage. The pilot-rated passenger stated that, about one minute after takeoff at an altitude of 300 feet, the flight controls began to "vibrate." The pilot assumed control of the helicopter, and the passenger declared an emergency over the radio. The passenger reported that the pilot "appeared to have difficulty" controlling the helicopter during the return to the airport, and "may have" entered an autorotation. He stated that the helicopter did not lose airspeed and did not appear to flare prior to impact, contacting the ground at an airspeed of 40 to 50 knots with the low rotor rpm horn activated. The helicopter rolled to its right side after impact, and the pilots egressed. The pilot held a commercial pilot certificate and flight instructor certificate with a rating for rotorcraft-helicopter. Her most recent Federal Aviation Administration (FAA) second-class medical certificate was issued on May 21, 2012. At the time of the accident, the pilot reported 1,165 total hours of flight experience, all of which were in the accident helicopter make and model. The 1555 automated weather observation at ALX included winds from 300 degrees at 7 knots with gusts to 14 knots; 10 statute miles visibility; sky clear; temperature 21 degrees Celsius (C); dew point -4 degrees C, and an altimeter setting of 29.97 inches of mercury. According to FAAairworthiness records, the helicopter was manufactured in 1993 and was equipped with a Lycoming O-320-B2C, 160-hp, reciprocating engine and float-type landing gear. Review of the helicopter's maintenance records revealed that its most recent annual inspection was completed on September 14, 2012, at a total airframe time of 1684.2 hours, and a time since engine overhaul of 531.6 hours. Records also indicated that the governor had been replaced on October 31, 2012. The main wreckage came to rest east of the runway prior to the threshold of runway 18, oriented on a heading of about 180 degrees magnetic. A postaccident examination conducted by an FAA inspector revealed impact damage to the flight control tubes and rods. Flight control continuity was established from the cockpit area to the main rotor and to the tail rotor gearbox. The main rotor driveshaft and mast were separated from the gearbox and located near the main wreckage. The swashplate system displayed minor impact damage.. One main rotor blade was separated at the hub, exhibited significant impact damage and was located approximately 500 feet away from the main wreckage. The other blade remained attached to the hub and also exhibited impact damage. No foreign objects or debris were observed in the vicinity of the engine cooling fan, and the fan remained on its shaft. The V-belts and alternator belt were examined and found to be intact. The strap connecting the floats to the skids remained attached. A postaccident examination of the engine by an overhaul facility revealed normal wear of the engine components, including the crankshaft, camshaft, lifters, rods, gears, cylinders and crankcase. Bench testing of the magnetos revealed no anomalies, and examination of the carburetor revealed no evidence of fuel contamination. Examination of the main rotor blades was conducted by the NTSB materials laboratory and revealed no evidence of corrosion, leading edge paint erosion, or debonding between the blade spar and skin. Examination of the fracture surfaces revealed signatures consistent with separation due to overstress. The manufacturer's pilots operating handbook (POH) stated that autorotations should be conducted at an airspeed between 60-70 knots while maintaining rotor rpm within the green arc. The POH further cautioned, "The R22 has a light, low-inertia rotor system. Most of the energy required for an autorotation is stored in the forward momentum of the aircraft, not in the rotor. Therefore, a well-timed cyclic flare is required and rotor rpm must be kept in the green until just before ground contact." ## Aircraft - Registration: [N231TM](https://openairdocs.org/aircraft/N231TM), registered now, S/N 2317M, built 1993 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER COMPANY R22 - Registry model: [Robinson Helicopter R22](https://openairdocs.org/model/robinson-helicopter-r22) (registry code 7640102) (OpenAirDocs) - Registry engine: [Lycoming O-320-B2C](https://openairdocs.org/engine/lycoming-o-320-b2c) (registry code 42139, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 2317M - Airframe hours: 788 - Engines: LYCOMING O-320-B2C 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Helicopter Academy - Registered owner: Casablanca Helicopter LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 14, 2012, 50 hours before - Departed: ALX, Alexander City, AL - Destination: K16J, Dawson, GA - Airport: ALX, Thomas C. Russel Field Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; injuries: minor; commercial, flight instructor; medical: class 2, with waivers/limitations; last flight review October 29, 2012; seat: left; flight hours: 1,165 total, 1,165 in this make and model, 994 as pilot in command, 163 in the last 90 days, 17 in the last 30 days, 9 in the last 24 hours - Other flight crew; age 28; injuries: serious; commercial, flight instructor; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review May 15, 2012; seat: right; flight hours: 300 total, 270 in this make and model, 200 as pilot in command, 80 in the last 90 days, 40 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 300° at 7 knots, gusting 14 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F, dew point 25 °F - Altimeter: 29.96 inHg - Observed at: ALX ## 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 20121101024929A](https://openairdocs.org/incident/20121101024929A), Nov 1, 2012: Robinson Helicopter Company R22, Alexander City, AL, Substantial damage. On November 1, 2012, at 1645, central daylight time a Robinson helicopter, R22, registered to casablanca helicopter, LLC., departed alx on runway 36 heading… ## Docket (18 files) The files NTSB released with the investigation on March 4, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=85492. 16.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - (Left Seat Pilot) (item 1, .PDF, 3.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382078&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20(Left%20Seat%20Pilot)-Redacted.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - (Right Seat Pilot) (item 2, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382080&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20(Right%20Seat%20%20Pilot)-Redacted.PDF - Excerpts from Alexander City Police Department Report (item 3, .PDF, 145 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384185&FileExtension=.PDF&FileName=Excerpts%20from%20Alexander%20City%20Police%20Department%20Report-Master.PDF - Memorandum of Record - (Left Seat Pilot) (item 4, .PDF, 118 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382071&FileExtension=.PDF&FileName=Memorandum%20of%20Record%20-%20(Left%20Seat%20Pilot)-Redacted.PDF - Memorandum of Record - (Passenger) (item 5, .PDF, 118 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382073&FileExtension=.PDF&FileName=Memorandum%20of%20Record%20-%20(Passenger)-Redacted.PDF - First Responder Statement (item 6, .PDF, 94 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382643&FileExtension=.PDF&FileName=First%20Responder%20Statement-Redacted.PDF - NTSB Materials Laboratory Review of Thrown Main Rotor Blade (item 7, .PDF, 85 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40401867&FileExtension=.PDF&FileName=NTSB%20Materials%20Laboratory%20Review%20of%20Thrown%20Main%20Rotor%20Blade-Redacted.PDF - Engine Examination (item 8, .PDF, 59 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40400572&FileExtension=.PDF&FileName=Engine%20Examination-Redacted.PDF - Record of Conversation, FAA Inspector Wreckage Examination Notes (item 9, .PDF, 105 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40403283&FileExtension=.PDF&FileName=Record%20of%20Conversation,%20FAA%20Inspector%20Wreckage%20Examination%20Notes-Master.PDF - Record of Converation, Robinson Helicopter Counterweight Observations (item 10, .PDF, 98 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40403284&FileExtension=.PDF&FileName=Record%20of%20Converation,%20Robinson%20Helicopter%20Counterweight%20Observations%20-Master.PDF - Memorandum of Record - Weather (item 11, .PDF, 135 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382074&FileExtension=.PDF&FileName=Memorandum%20of%20Record%20-%20Weather-Master.PDF - Robinson Practice Autorotation Procedure from POH (item 12, .PDF, 73 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40385138&FileExtension=.PDF&FileName=Robinson%20Practice%20Autorotation%20Procedure%20from%20POH-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 13, .PDF, 92 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384187&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Retention / Release of Wreckage Form (item 14, .PDF, 34 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384184&FileExtension=.PDF&FileName=Retention%20%2F%20Release%20of%20Wreckage%20Form-Redacted.PDF - Photo 1) View of the Wreckage (Courtesy of FAA) (item 15, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384178&FileExtension=.PDF&FileName=Photo%201)%20View%20of%20the%20Wreckage%20(Courtesy%20of%20FAA)-Master.PDF - Photo 2) Close-up View of the Helicopter Wreckage (Courtesy of FAA) (item 16, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384179&FileExtension=.PDF&FileName=Photo%202)%20Close-up%20View%20of%20the%20Helicopter%20Wreckage%20(Courtesy%20of%20FAA)-Master.PDF - Photo 3) Aft View of the Helicopter Wreckage (Courtesy of the Alexander City Police Department) (item 17, .PDF, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384181&FileExtension=.PDF&FileName=Photo%203)%20Aft%20View%20of%20the%20Helicopter%20Wreckage%20(Courtesy%20of%20the%20Alexander%20City%20Police%20Department)-Master.PDF - Photo 4) An Overall View of the Wreckage and Recovered Main Rotor Blades (Courtesy of FAA) (item 18, .PDF, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384182&FileExtension=.PDF&FileName=Photo%204)%20An%20Overall%20View%20of%20the%20Wreckage%20and%20Recovered%20Main%20Rotor%20Blades%20(Courtesy%20of%20FAA)-Master.PDF 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.