# NTSB CEN11LA315: Hughes 269B, N9561F, Edgerton, IN, April 29, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 29, 2011, 19:30 local (23:30 UTC) - Place: Edgerton, IN - Coordinates: 41.073055, -84.806114 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.0731&lon=-84.8061&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-hover: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 27, 2012 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA -- South Bend Flight Standards, Schwiezer Aircraft Corp. - NTSB case key (mKey): 79011 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11LA315 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/79011/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=79011 - Page: https://openairdocs.org/ntsb/CEN11LA315 ## Probable cause A loss of clearance between the tail rotor drive shaft and the tailboom bulkhead for undetermined reasons, which resulted in the overstress failure of the drive shaft. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Tail rotor drive system: tail rotor drive shaft](https://openairdocs.org/ntsb-findings/01046510): Aircraft › Aircraft propeller/rotor · Failure (probable cause); cases with it: [Hughes 269B, 1 case](https://openairdocs.org/ntsb-findings/01046510/cases.md?model=4470502), [All aircraft, 25 cases](https://openairdocs.org/ntsb-findings/01046510/cases.md) - [Fuselage: rotorcraft tail boom](https://openairdocs.org/ntsb-findings/01035302): Aircraft › Aircraft structures · Damaged/degraded (probable cause); cases with it: [Hughes 269B, 1 case](https://openairdocs.org/ntsb-findings/01035302/cases.md?model=4470502), [All aircraft, 12 cases](https://openairdocs.org/ntsb-findings/01035302/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Hughes 269B, 2 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=4470502), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-hover: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Hughes 269B, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=4470502), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Maneuvering-hover: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Hughes 269B, 2 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=4470502), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Autorotation: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Hughes 269B, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=4470502), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot reported a vibration in the helicopter antitorque pedals and a subsequent loss of directional control. The pilot initiated an autorotation to a field, and the helicopter sustained damage to the left landing skid and fuselage. A postaccident examination revealed that the tail rotor drive shaft failed due to an overstress fracture that resulted from contact with the tailboom bulkhead. Examination of the tailboom support structure was unable to determine the underlying cause of the contact between the tailboom and drive shaft. The operator reported that he was not aware of any events prior to the accident that would have compromised the tailboom support structure. ## Factual narrative On April 29, 2011, about 1930 eastern daylight time, a Hughes 269B, N9561F, experienced an in-flight loss of directional control and the pilot executed an autorotation to a field near Edgerton, Indiana. The pilot reported no injuries. The helicopter sustained substantial damage to the fuselage. The aircraft was registered to and operated by Heartland Helicopters, LLC, under the provisions of 14 Code of Federal Regulations Part 137 as an aerial application flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The local flight originated from a field near Edgerton, Indiana, about 1900. The pilot had reportedly finished spraying a field and was about 30 feet above ground level (agl) when he felt a vibration in the antitorque pedals. The helicopter subsequently started to yaw and rotated one full revolution before the pilot initiated an autorotation to a field. The helicopter came to rest upright, with damage to the left landing skid and fuselage. A postaccident examination revealed that the tail rotor drive shaft failed at the forward end of the tail boom, where the drive shaft passed through the tail boom bulkhead. Metallurgical examination determined that the drive shaft was deformed inward at the fracture, and the paint was cracked and flaked off the outer surface. Circumferential paint transfer was observed on the drive shaft in a color and shade matching the tail boom bulkhead. The fracture surface exhibited features consistent with overstress fracture that progressed under rotating bending stresses. A postaccident visual examination of the fuselage aft cluster fittings did not reveal any anomalies. The fittings appeared to be intact and the mating struts securely attached. One tail boom support strut was fractured midspan; however, the fracture appeared consistent with overstress failure due to the hard landing after the autorotation. Continuity of the tail rotor transmission was confirmed through simultaneous rotation of the aft drive shaft section and the tail rotor blades. The drive shaft-to-transmission input splines appeared intact. At the time of the accident, the helicopter had accumulated about 4,454 hours total time. Maintenance records indicated that the most recent annual inspection was completed on March 16, 2011, at 4,428.3 hours. The tail rotor drive shaft was installed on the helicopter in December 1997. At the time of the accident, it had accumulated about 2,648 hours. The operator stated that he was not aware of any hard landings or other events that might have compromised the tail boom support structure prior to the accident, and brought the tail boom into contact with the drive shaft. The operator noted that prior to the annual inspection, a pilot noted paint chipping from the drive shaft at the location the shaft passed through the tail boom bulkhead. Further examination by a mechanic did not reveal any damage to the drive shaft itself and the helicopter was returned toservice. According to the operator, pilots who flew the helicopter after the annual inspection did not report any anomalies related to the tail boom or drive shaft. ## Aircraft - Registration: [N9561F](https://openairdocs.org/aircraft/N9561F), registered now, S/N 200450, built 1970 (OpenAirDocs) - Reported make and model: HUGHES 269B - Registry model: [Hughes 269B](https://openairdocs.org/model/hughes-269b) (registry code 4470502) (OpenAirDocs) - Registry engine: [Lycoming HIO-360-A1A](https://openairdocs.org/engine/lycoming-hio-360-a1a) (registry code 41885, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 200450 - Airframe hours: 4454 - Engines: LYCOMING HIO-360-A1A 180 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Heartland Helicopters LLC - Registered owner: Heartland Helicopters LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 16, 2011, 25 hours before - Departed: NONE, Edgerton, IN - Destination: NONE, Edgerton, IN - Airport: VNW, Van Wert County ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 40; injuries: none; commercial, flight instructor; medical: class 2, with waivers/limitations; last flight review October 14, 2009; seat: left; flight hours: 462 total, 315 in this make and model, 368 as pilot in command, 36 in the last 90 days, 22 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point 46 °F - Altimeter: 30.02 inHg - Observed at: FWA, 19 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 20110429014659A](https://openairdocs.org/incident/20110429014659A), Apr 29, 2011: Hughes 269B, Edgerton, IN, Substantial damage. During the application of pestiside spray the pilot felt a very stronge vibration in th efoot pedals and a few secounds later he loss the tail rotor… ## Docket (5 files) The files NTSB released with the investigation on January 26, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=79011. 11.6 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348045&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Conversation Record -- Operator (item 2, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357387&FileExtension=.PDF&FileName=Conversation%20Record%20--%20Operator-Master.PDF - Materials Laboratory 15 - Factual Report 11-114 (with 8 embedded images) (item 3, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40356021&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%2011-114%20(with%208%20embedded%20images)-Master.PDF - Maintenance Records (item 4, .PDF, 7.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348070&FileExtension=.PDF&FileName=Maintenance%20Records-Redacted.PDF - Statement of Party Representatives to NTSB Investigation (item 5, .PDF, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357388&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.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.