# NTSB WPR16LA156: Robinson R22, N22UH, Prescott, AZ, August 2, 2016 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: August 2, 2016, 10:27 local (17:27 UTC) - Place: Prescott, AZ - Coordinates: 34.660831, -112.416389 - Nearby events: https://openairdocs.org/map.md?lat=34.6608&lon=-112.4164&mi=10 - Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping) - Defining event: [Autorotation: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report September 10, 2018 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 93744 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR16LA156 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93744/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93744 - Page: https://openairdocs.org/ntsb/WPR16LA156 ## Probable cause The flight instructor’s delayed remedial action to address a low rotor rpm condition, which resulted in an excessive descent rate and a subsequent hard landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: descent/approach/glide path](https://openairdocs.org/ntsb-findings/01062040): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Robinson Helicopter R22, 4 cases](https://openairdocs.org/ntsb-findings/01062040/cases.md?model=7640102), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/01062040/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Student/instructed 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) - [Attention/monitoring: monitoring other person](https://openairdocs.org/ntsb-findings/02021535): Personnel issues › Psychological · Instructor/check pilot (probable cause); cases with it: [Robinson Helicopter R22, 3 cases](https://openairdocs.org/ntsb-findings/02021535/cases.md?model=7640102), [All aircraft, 200 cases](https://openairdocs.org/ntsb-findings/02021535/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Instructor/check 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) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Autorotation: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Robinson Helicopter R22, 9 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=7640102), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); 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 The flight instructor and student pilot were practicing straight-in autorotations in the helicopter. During the autorotative descent, about 400 ft above ground level with the student at the controls, the instructor noticed a high rate of descent and a decay in main rotor rpm. The instructor told the student that he had the controls and started applying collective and throttle to recover rpm. He felt the collective go up and again told the student that he had the controls. The instructor was unable to arrest the descent before the helicopter landed hard and rolled over. The instructor reported that there were no pre-impact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation. He further stated that the accident could have been prevented if he had stayed ahead of his student and the helicopter. ## Factual narrative On August 2, 2016, about 1027 mountain standard time (MST), a Robinson R22 helicopter, N22UH, landed hard at Ernest A Love Field Airport, Prescott, Arizona. The certificated flight instructor and student pilot received minor injuries. The helicopter sustained substantial damage to the fuselage and the tail boom. The helicopter was registered to Alba Leasing Services and operated by Universal Helicopters under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91 as an instructional flight. Visual meteorological conditions prevailed, and no flight plan was filed. The local flight departed Prescott, Arizona, about 0950. The student pilot and the flight instructor were practicing straight in autorotations. During the glide, with the student pilot at the controls, about 400 feet above ground level, the flight instructor noticed a fast rate of decent and a decay in rotor RPM. The flight instructor stated to the student that he had the controls and started applying collective and throttle control to recover RPM. The instructor felt the collective go up and stated again to the student that he had the controls. The flight instructor was unable to arrest the decent or recover RPM prior to the hard landing. During touchdown, the landing skids collapsed, the main rotor blades connected with and severed the tail boom. The helicopter came to rest on its left side. The flight instructor reported no pre-impact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation. ## Aircraft - Registration: [N22UH](https://openairdocs.org/deregistered/N22UH-2018-05-16), registration cancelled 2018-05-16, S/N 4676, built 2015 (OpenAirDocs) - Reported make and model: ROBINSON R22 (BETA) - Registry model: [Robinson Helicopter R22](https://openairdocs.org/model/robinson-helicopter-r22) (registry code 7640102) (OpenAirDocs) - Registry engine: [Lycoming O-360-J2A](https://openairdocs.org/engine/lycoming-o-360-j2a) (registry code 42314, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 4676 - Year built: 2015 - Airframe hours: 882.7 - Engines: Lycoming O-360-J2A 145 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, June 28, 2016, 30 hours before - Departed: PRC, Prescott, AZ - Destination: PRC, Prescott, AZ - Airport: PRC, Ernest A Love Field, runway 21R, 4,846 × 60 ft, asphalt - Equipment: Satellite tracking device, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 34; injuries: minor; flight instructor, commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review October 2, 2014; seat: left; restraint: 3-point; flight hours: 1,119.4 total, 779.9 in this make and model, 1,046.5 as pilot in command, 123.8 in the last 90 days, 71 in the last 30 days, 2 in the last 24 hours - Student pilot; age 26; injuries: minor; student; medical: class 1, without waivers/limitations; seat: right; restraint: 3-point; flight hours: 56 total, 56 in this make and model, 56 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 3 knots - Visibility: 10 statute miles - Temperature: 75 °F, dew point 64 °F - Altimeter: 30.26 inHg - Observed at: KPRC, 1 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 20160802012759A](https://openairdocs.org/incident/20160802012759A), Aug 2, 2016: Robinson R-22, Prescott, AZ, Substantial damage. At approximately 1027 MST at Earnest a. Love field (kprc), the certified flight instructor and student pilot had been on duty approximately three and one half… ## Docket (2 files) The files NTSB released with the investigation on July 5, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93744. 3.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 825 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40464801&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photos (item 2, .PDF, 3 photos, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40464802&FileExtension=.PDF&FileName=Photos-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.