# NTSB LAX08CA298: Robinson R22B, N227GH, Prescott, AZ, September 11, 2008 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: September 11, 2008, 16:20 local (23:20 UTC) - Place: Prescott, AZ - Coordinates: 34.652778, -112.418334 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.6528&lon=-112.4183&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: Minor injuries - Injuries: 2 minor - Status: Completed, report January 22, 2009 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 68923 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX08CA298 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/68923/pdf - Page: https://openairdocs.org/ntsb/LAX08CA298 ## Probable cause The student pilot's failure to maintain adequate main rotor rpm and the instructor's inadequate supervision and delayed remedial action. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Student/instructed pilot (probable cause); cases with it: [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) - [Attention/monitoring: monitoring other person](https://openairdocs.org/ntsb-findings/02021535): Personnel issues › Psychological · Instructor/check pilot (probable cause); cases with it: [All aircraft, 200 cases](https://openairdocs.org/ntsb-findings/02021535/cases.md) - [Performance/control parameters: prop/rotor parameters](https://openairdocs.org/ntsb-findings/01062052): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) - [Landing: Roll over](https://openairdocs.org/ntsb-events/097); cases with it: [All aircraft, 261 cases](https://openairdocs.org/ntsb-events/097/sequence.md) ## Analysis A certified flight instructor (CFI) and a student were practicing 180-degree autorotations. While turning final, the airspeed decayed and the student responded by pushing forward on the cyclic. The main rotor rpm dropped to 95 percent as the helicopter was descending. The instructor added throttle but was unable to arrest the descent rate or to recover the main rotor rpm. The right front skid contacted the ground, then the rotor struck the tail boom. The helicopter entered a right spin, drifted to the left, and rolled over. The pilots reported that there were no mechanical failures or malfunctions during the flight. ## Factual narrative On September 11, 2008, about 1630 mountain standard time, a Robinson Helicopter R-22, N227GH, impacted the taxiway and terrain during a practice 180-degree autorotation at the Ernest A. Love Field Airport (PRC), Prescott, Arizona. Guidance Helicopters, Inc., was operating the helicopter under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The certified flight instructor (CFI) and the student pilot undergoing instruction (PUI) sustained minor injuries. The helicopter sustained substantial damage to the rotor system and tail boom. The instructional flight departed PRC about 1545. Visual meteorological conditions prevailed, and no flight plan had been filed. The CFI reported that they had performed four 180-degree autorotations successfully. The final 180-degree autorotation was progressing normally until turning final. At that time, the helicopter experienced a sudden drop in airspeed approximately 150 feet agl. Airspeed indicated 52 knots, and rotor rpm was 101 percent. The PUI responded by pushing forward on the cyclic. The rotor rpm dropped to 95 percent, and the helicopter altitude was down to 75 feet agl. This resulted in lower rpm's and an excessive descent rate. The CFI attempted to perform a power recover, but the rpm's did not build quickly enough to avoid the skids striking the taxiway. The CFI leveled the helicopter before impact. The right front skid contacted slightly first. The rotor then struck the tail boom, and the helicopter entered a right spin. After spinning several times, the helicopter drifted to the left, the skids contacted sod, and the helicopter rolled over. The PUI confirmed that they were performing 180-degree autorotations. As they rolled out on final, the airspeed started to drop. The PUI pushed forward on the cyclic and applied a little down collective. The helicopter descended quicker than the PUI expected, with the rpm dropping below 101 percent. Both the PUI and the CFI rolled on the throttle and leveled the aircraft. The helicopter hit the taxiway with the right skid first. The helicopter started to spin until it hit the dirt and rolled over. The pilots reported that there were no mechanical failures or malfunctions during the flight. ## Aircraft - Registration: N227GH (not matched to a registry record) - Reported make and model: Robinson R22B - Category: Helicopter - Serial number: 4044 - Airframe hours: 2254 - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Guidance Helicopters, Inc. - Registered owner: Guidance Helicopters, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 1, 2008, 54 hours before - Departed: PRC, Prescott, AZ - Destination: PRC, Prescott, AZ - Airport: PRC, Ernest A. Love Field Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 42; injuries: minor; flight instructor, commercial; instrument ratings: helicopter; medical: class 1, with waivers/limitations; last flight review May 18, 2008; seat: left; flight hours: 582 total, 502 in this make and model, 521 as pilot in command, 169 in the last 90 days, 59 in the last 30 days, 2 in the last 24 hours - Student pilot; age 23; injuries: minor; student; medical: class 2, without waivers/limitations; last flight review September 3, 2008; seat: right; flight hours: 84 total, 83 in this make and model, 11 as pilot in command, 14 in the last 90 days, 9 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 37 °F - Altimeter: 29.97 inHg - Observed at: PRC 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.