# NTSB LAX08IA032: Robinson R22 Beta, N805EH, Fresno, CA, December 4, 2007 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: December 4, 2007, 14:55 local (22:55 UTC) - Place: Fresno, CA - Coordinates: 36.732223, -119.820274 - Nearby events: https://openairdocs.org/map.md?lat=36.7322&lon=-119.8203&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report December 24, 2008 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 67213 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX08IA032 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/67213/pdf - Page: https://openairdocs.org/ntsb/LAX08IA032 ## Probable cause Failure of the tail rotor system support bracket during landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, landing - flare/touchdown - tail rotor/anti-torque control - restricted (cause) - rotorcraft flight control,tail rotor pedal - failure (cause) ## Analysis Just as the helicopter touched down while performing a hovering autorotation, the certified flight instructor (CFI) heard a loud 'snap’ coming from the right side. The CFI took the controls from the student and attempted to neutralize the anti-torque pedals, but reported that they were stuck in place, with the right pedal in the forward position. He reduced the engine rpm’s to 75 percent, and attempted to move the pedals to no avail. At that point, he instructed the student to start the shutdown procedures. Following a normal shutdown, they exited the helicopter, and began to inspect the cause of the stuck anti-torque pedal. Both the CFI and student observed a broken metal structure adjacent to the restraining block that retains the anti-torque pedals. The CFI reported that it appeared to be the actual metal structure that the entire pedal assembly bolts to. The helicopter inspection revealed that the right-hand support bracket (part number A359-2) of the tail rotor control system had failed. The operator reported that the airframe had a total time of 13,000 hours. The helicopter manufacturer reported that they had been aware of other failed support brackets on helicopters with over 7,500 hours in service. As a result, the manufacturer increased the thickness of the support bracket material, and changed their overhaul procedures requiring replacement of the A359-1 and -2 support brackets at overhaul for all R22 and R44 models. The manufacturer also issued service bulletin (SB) SB-97 for the R22 and SB-63 for the R44, which require the addition of a safety tab on the older thinner support brackets. ## Factual narrative On December 4, 2007, at 1455 Pacific standard time, a Robinson Helicopter Company (RHC) R22 Beta, N805EH, experienced a flight control malfunction as it touched down during a practice hover autorotation at Fresno Chandler Executive Airport (FCH), Fresno, California. Mazzei Flying Service, Inc., operated the helicopter under the provisions of 14 Code of Federal Regulations Part 91, as a training flight. The helicopter was not damaged. The Certified Flight Instructor (CFI) and student were not injured. Visual meteorological conditions prevailed for the local area instructional flight that departed the Fresno Yosemite International Airport (FAT), at 1405. No flight plan had been filed. In the CFI’s written report he reported that while on approach for the third hover autorotation, he noted a slight wind shift and instructed the student to do a pedal turn into the wind. The CFI reported that the student had done a good job, with minimal drift, a flat set down, and "good collective cushion." The CFI had been following the student on the flight controls and noted no unusual control inputs for the maneuver. As the helicopter settled onto the ground, with the student inputting right anti-torque pedal to compensate for the loss of engine torque, the CFI heard a loud 'snap’ from the floor area of the student's side (right side) of the helicopter. The CFI attempted to neutralize the anti-torque pedals, and found that they were stuck in place with the right pedal in the forward position. He reduced engine rpm’s to 75 percent, and again attempted to slowly move the pedals, but they seemed stuck. He instructed the student to begin the shut down procedures. Following a normal shutdown, they exited the helicopter and began an inspection as to the cause of the stuck right anti-torque pedal. The student pilot pointed out broken metal structure adjacent to the restraining block that retains the anti-torque pedals. The CFI reported that it appeared to be the actual metal structure that the entire pedal assembly bolts to. An inspection of the helicopter by the Federal Aviation Administration (FAA), and the operator's maintenance personnel revealed that the right-hand support bracket (part number A359-2) of the tail rotor control system had failed. The operator reported that the helicopter has a total airframe time of about 13,000 hours. TESTS AND RESEARCH The right-hand support bracket was inspected by the RHC laboratory. RHC had been notified of other failed support brackets on the R22 with over 7,500 hours in service. As a result, the support bracket was redesigned by RHC by increasing the thickness of the material. RHC also changed the overhaul procedures that require the A359-1 and -2 supports to be replaced at overhaul for all R22 and R44 helicopters. RHC also issued service bulletin (SB) SB-97 for the R22 and SB-63 for the R44, which require the addition of a safety tab on the older thinner support brackets. ## Aircraft - Registration: [N805EH](https://openairdocs.org/aircraft/N805EH), registered now, S/N 1907 (OpenAirDocs) - Reported make and model: Robinson R22 Beta - Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 1907 - Airframe hours: 13078 - Engines: Lycoming O-320-B2C 131 horsepower reciprocating - Damage: No damage - Flight: Instructional, Part 91 - Operator: Golden Eagle Enterprises, Inc., doing business as Mazzei Flying Service - Registered owner: Golden Eagle Enterprises, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, October 1, 2007 - Departed: FAT, Fresno, CA - Destination: FAT, Fresno, CA - Airport: FCH, Fresno Chandler Executive ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 45; injuries: none; commercial, private, flight instructor; airplane ratings: single-engine land; instrument ratings: helicopter, airplane; medical: class 2, without waivers/limitations; last flight review June 8, 2006; seat: left; flight hours: 897 total, 676 in this make and model, 823 as pilot in command, 164 in the last 90 days, 46 in the last 30 days, 1 in the last 24 hours - Student pilot; age 24; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; last flight review April 12, 2007; seat: right; flight hours: 1,476 total, 11 in this make and model, 1,465 as pilot in command, 36 in the last 90 days, 11 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 5 knots - Visibility: 9 statute miles - Lowest ceiling: 18,000 ft broken - Temperature: 66 °F, dew point 34 °F - Altimeter: 30.26 inHg - Observed at: FAT, 6 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). - [Incident 20071204828639I](https://openairdocs.org/incident/20071204828639I), Dec 4, 2007: Robsin R22BETA, Fresno, CA, No damage. (-23) During an instructional helicopter flight, which involved completing three (3) autorotations, the pilot depressed the pedal assembly while on the ground… ## Other investigations on N805EH (1) 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. - [NTSB LAX98LA146](https://openairdocs.org/ntsb/LAX98LA146), Apr 28, 1998: Robinson R-22 Beta (N805EH), Sacramento, CA, substantial damage. Probable cause: the CFI's failure to follow procedures and directives, and the use of an improper technique to transition from an autorotative descent to a hover, which exceeded the aircraft's performance… 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.