# NTSB CEN14LA517: Robinson Helicopter R22 Beta, N115DD, Cahokia, IL, September 19, 2014 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 19, 2014, 10:30 local (15:30 UTC) - Place: Cahokia, IL - Coordinates: 38.569366, -90.170288 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.5694&lon=-90.1703&mi=10 - Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping) - Defining event: [Autorotation: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 5, 2016 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 90138 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN14LA517 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/90138/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=90138 - Page: https://openairdocs.org/ntsb/CEN14LA517 ## Probable cause The pilot’s poor decision to take off with the clutch warning light illuminated, which resulted in the total failure of the fan assembly due to a lack of lubrication. Contributing to the accident was the mechanic’s failure to lubricate the lower actuator bearing at the last annual inspection. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Robinson Helicopter R22 BETA, 17 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7640110), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Inspection: scheduled/routine inspection](https://openairdocs.org/ntsb-findings/02061520): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Robinson Helicopter R22 BETA, 2 cases](https://openairdocs.org/ntsb-findings/02061520/cases.md?model=7640110), [All aircraft, 167 cases](https://openairdocs.org/ntsb-findings/02061520/cases.md) - [Maintenance/inspections: scheduled maint checks](https://openairdocs.org/ntsb-findings/01010520): Aircraft › Aircraft handling/service · Incorrect service/maintenance (probable cause); cases with it: [Robinson Helicopter R22 BETA, 1 case](https://openairdocs.org/ntsb-findings/01010520/cases.md?model=7640110), [All aircraft, 76 cases](https://openairdocs.org/ntsb-findings/01010520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330); cases with it: [Robinson Helicopter R22 BETA, 6 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=7640110), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Autorotation: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Robinson Helicopter R22 BETA, 6 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=7640110), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) ## Analysis The pilot reported that the helicopter's clutch warning light illuminated shortly after departure, which he did not think was abnormal because, when the belts heat up and re-tension, it causes the light to briefly illuminate; this was corroborated by the Pilot's Operating Handbook (POH). He continued the takeoff and then watched to see if the light would go out in 10 seconds. However, the POH stated that a pilot should never take off before the clutch warning light goes out. The light did not turn off, so he pulled the clutch circuit breaker and chose to land immediately in a parking lot. After landing, the pilot locked the controls, got out of the helicopter, and looked inside the engine compartment, but he did not see anything abnormal. The pilot said that he did not feel safe in his surroundings, so he chose to get back in the helicopter and make the short flight back to the airport. The pilot then departed and was about 500 yards from landing at the airport when the helicopter began to vibrate and make noise. The pilot initiated an autorotation, but, as he slowed and flared the helicopter, it yawed left as he pulled on the collective. The skids contacted and then dug into the soft ground, and the main rotor blades severed the tail boom. It is likely that the accident could have been prevented if the pilot had not taken off after the clutch warning light illuminated or if he had turned back and landed at the airport after the warning light did not extinguish. A postaccident examination of the helicopter's fan assembly, including the lower sheave and lower actuator bearing, revealed no evidence of lubrication and heat damage, consistent with a lack of lubrication. The helicopter had undergone an annual inspection about 9.1 hours before the accident. Although the mechanic who performed the last annual inspection made an entry in the engine logbook that he lubricated the lower actuator bearing, it is likely that he did not perform that task given the lack of lubrication on the bearing. ## Factual narrative On September 19, 2014, at 1030 central daylight time, N115DD, a Robinson R-22 Beta helicopter, landed hard during a forced landing near the St.Louis Downtown Airport (CPS), Cahokia, Illinois. The commercial rated pilot was not injured. The helicopter was registered to a private corporation and operated by the pilot. No flight plan was filed for the local flight that originated at CPS about 1000.Visual meteorological conditions prevailed for the personal flight that was conducted under the provisions of 14 Code of Federal Aviation Regulations Part 91. The pilot stated that shortly after takeoff the clutch warning light came on. He did not think this was abnormal because the belts would heat up and re-tension themselves causing the light to briefly illuminate. However, as a precaution, and as directed by the manufacturer, he waited to see if the light would go out in 10 seconds. The light did not turn off, so he pulled the clutch circuit breaker and landed immediately in a parking lot. After landing, the pilot locked the controls, got out of the helicopter and looked inside the engine compartment. He did not see anything abnormal. At this point, the pilot said a group of young men, who "didn't look friendly" were waving their arms and saying that he wasn't allowed to land there. The pilot was unable to find his cell phone to call for help, so he elected to get back in the helicopter and make the short flight back to the airport. The pilot then departed and was about 500 yards from landing on runway 5, when the helicopter began to vibrate and "make a lot of noise." The pilot entered an autorotation. He said, "As I slowed and did the flair to land the helicopter yawed to the left as I pulled collective to run it on. I realized there was no tail rotor. The skids contacted the ground and dug into the soft ground. I think that's when the tail boom lifted and the blade cut it off." The pilot said that the accident could have been prevented if he had turned back and landed at the airport after the clutch warning light illuminated. He also told an FAA inspector that he "screwed up" and should not have take off after the caution light came on. According to the Robinson R22 Pilot's Operating Handbook, page 3-9, its states that when the clutch warning light illuminates, the clutch actuator is on, either engaging or disengaging. When the switch is in the ENGAGE position, the light stays on until the belts are properly tensioned. Never take off before the light goes out. It also says, "Clutch light may come on momentarily during run-up or during flight to retension belts as they warm-up and stretch slightly. This is normal. If, however, the light flickers or comes on in flight and does not go out within 10 seconds, pull CLUTCH circuit breaker and land as soon as practical. Reduce power and land immediately if there are other indications of drive system failure (be prepared to enter autorotation)." A postaccident examination of the helicopter was conducted bythe Federal Aviation Administration (FAA) with the assistance of the helicopter manufacturer and the mechanic that performed the last annual inspection, which was conducted on August 30, 2014. The helicopter had only accrued 9.1 hours since the inspection. According to an FAA inspector, the fan assembly had sustained extensive damage and the bolts that secured the fan puller were loose. It appeared that the head of one of the bolts was extensively worn away and had rubbed against the lower actuator bearing. The mechanic told the FAA that "they" may have "messed up" and may not have properly tightened the bolts during the annual inspection. The fan assembly was then removed, which exposed the lower sheave and lower actuator bearing (Part No. A181-4). There was no evidence of grease and the bearing exhibited extensive damage. The fan assembly, fan shaft, lower actuator bearing and clutch actuator were sent to the NTSB's materials laboratory for further examination to determine what caused the fan assembly to fail. The forward face of the fan wheel and some of the fan wheel airfoils exhibited circumferential scrape marks. The inner diameter of the fan wheel had galling damage and discoloration from heat tinting. Some denting was observed on the edges of the fan wheel out diameter. The fan shaft had mated to the inner diameter of the fan wheel and was discolored from heat tinting, and there were scrape marks around the outer diameter. The fan shaft was severely distorted and had thinning of the shaft diameter. The lower support bearing assembly exhibited scoring on one of the faces and a portion of one side was separated. Disassembly of the lower support bearing revealed most of the rollers were deformed and some were flattened and melted. The race on the inner ring had galling and circumferential scrape marks. The inner diameter of the inner ring was also heat damaged and deformed. The bearing cage was deformed and had separated into multiple pieces. One side of the lower bearing support housing was deformed along the outer edge. The mating ring still pressed inside the housing had smeared material on the race on the area of the deformed housing. The deformation and extensive heat damage observed on these components was consistent with a lack of lubrication and not a loose bolt. A review of the engine maintenance logbook revealed that the mechanic, who performed the last annual inspection, made a certified entry that he lubricated the lower actuator bearing. ## Aircraft - Registration: [N115DD](https://openairdocs.org/aircraft/N115DD), registered now, S/N 3494 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER R22 BETA (BETA) - Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs) - Registry engine: [Lycoming O-360 series](https://openairdocs.org/engine/lycoming-o-360-series) (registry code 41575, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 3494 - Year built: 2003 - Airframe hours: 1805.7 - Engines: LYCOMING O-360 SERIES 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Ded Aviation LLC - Registered owner: Ded Aviation LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 30, 2014, 1 hours before - Departed: Cahokia, IL - Destination: CPS, Cahokia, IL - Airport: CPS, St Louis Downtown - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 71; injuries: none; flight instructor, commercial; airplane ratings: single-engine land; instrument ratings: airplane, helicopter; medical: class 2, without waivers/limitations; last flight review August 25, 2013; seat: right; flight hours: 5,600 total, 3,800 in this make and model ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Observed at: CPS ## 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 20140919017779A](https://openairdocs.org/incident/20140919017779A), Sep 19, 2014: Robinson Helicopter R22 BETA, Cahokia, IL, Substantial damage. Helicopter was 9.1 hours out of annual inspection. Shortly after takeoff, the clutch warning light illuminated and stayed on. Pilot made an immediate landing… ## Docket (6 files) The files NTSB released with the investigation on November 27, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=90138. 3.6 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434334&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - FAA Inspector's Statement, Blakely (item 2, .PDF, 445 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434335&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Statement,%20Blakely-Master.PDF - FAA Inspector's Statement, Joyce (item 3, .PDF, 363 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434336&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Statement,%20Joyce%20-Master.PDF - FAA Inspector's Statement, Joyce (Engine Exam) (item 4, .PDF, 324 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434337&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Statement,%20Joyce%20(Engine%20Exam)-Master.PDF - Maintenance Record, Last Annual Inspection (item 5, .PDF, 253 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434338&FileExtension=.PDF&FileName=Maintenance%20Record,%20Last%20Annual%20Inspection-Master.PDF - Materials Laboratory, Factual Report (item 6, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434339&FileExtension=.PDF&FileName=Materials%20Laboratory,%20Factual%20Report-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.