# NTSB ERA15CA055: Mcdonnell Douglas Helicopter MD500, N8371F, Decatur, AL, November 18, 2014 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: November 18, 2014, 09:30 local (15:30 UTC) - Place: Decatur, AL - Coordinates: 34.714443, -87.156112 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.7144&lon=-87.1561&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 9, 2015 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 90405 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA15CA055 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/90405/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=90405 - Page: https://openairdocs.org/ntsb/ERA15CA055 ## Probable cause An undetermined pilot's failure to maintain clearance from an electrical transmission tower resulting in substantial damage to a main rotor blade. Postaccident investigation could not determine which of two pilots was flying the helicopter at the time the damage occurred. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Mcdonnell Douglas Helicopter 369E, 3 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=3027369), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Other (probable cause); cases with it: [Mcdonnell Douglas Helicopter 369E, 2 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=3027369), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) (defining event); cases with it: [Mcdonnell Douglas Helicopter 369E, 2 cases](https://openairdocs.org/ntsb-events/220/sequence.md?model=3027369), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md) - [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Mcdonnell Douglas Helicopter 369E, 9 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=3027369), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis According to the operator, a preflight was completed before the helicopter was moved to the landing zone and no anomalies were noted. The helicopter was then equipped with an aerial platform and measuring equipment to perform the planned work in the vicinity of powerlines. Subsequently, the helicopter departed the landing zone. Due to the atmospheric condition at the aerial work site, the pilot discontinued the aerial work and returned to the landing zone. A "senior" pilot was consulted, and replaced the first pilot. The "senior" pilot decided to depart and assess the situation from the air. A short time later the flight returned to the landing zone. The first pilot performed a "short" postflight examination of the helicopter and noticed that a main rotor blade was substantially damaged. The operator reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operation. In addition, neither pilots nor crew members noticed any abnormal flight characteristics of the helicopter prior to discovering the main rotor blade damage. The investigation was unable to determine which flight the main rotor blade incurred the substantial damage. ## Factual narrative According to the operator, a preflight was completed before the helicopter was moved to the landing zone and no anomalies were noted. The helicopter was then equipped with an aerial platform and measuring equipment to perform the planned work in the vicinity of powerlines. Subsequently, the helicopter departed the landing zone. Due to the atmospheric condition at the aerial work site, the pilot discontinued the aerial work and returned to the landing zone. A "senior" pilot was consulted, and replaced the first pilot. The "senior" pilot decided to depart and assess the situation from the air. A short time later the flight returned to the landing zone. The first pilot performed a "short" postflight examination of the helicopter and noticed that a main rotor blade was substantially damaged. The operator reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operation. In addition, neither pilots nor crew members noticed any abnormal flight characteristics of the helicopter prior to discovering the main rotor blade damage. The investigation was unable to determine which flight the main rotor blade incurred the substantial damage. ## Aircraft - Registration: [N8371F](https://openairdocs.org/aircraft/N8371F), registered now, S/N 0399E, built 1990 (OpenAirDocs) - Reported make and model: MCDONNELL DOUGLAS HELICOPTER MD500 - Registry model: [Mcdonnell Douglas Helicopter 369E](https://openairdocs.org/model/mcdonnell-douglas-helicopter-369e) (registry code 3027369) (OpenAirDocs) - Registry engine: [Allison 250-C20 series](https://openairdocs.org/engine/allison-250-c20-series) (registry code 03020, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 0399E - Year built: 1990 - Airframe hours: 21486.7 - Engines: Rolls Royce 250-C20B 375 horsepower turbo shaft - Damage: Substantial damage - Flight: External load, Part 133 - Operator: Haverfield International Inc - Registered owner: Haverfield International Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, October 25, 2014 - Departed: DCU, Decatur, AL - Destination: DCU, Decatur, AL - Flight plan: Company VFR - Equipment: Onboard weather, Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; injuries: none ## Weather - Conditions: Visual (VMC), Day - Wind: 320° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 25 °F, dew point 9 °F - Altimeter: 30.43 inHg - Observed at: KDCU, 11 nm away ## Docket (3 files) The files NTSB released with the investigation on May 28, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=90405. 1.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 833 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427110&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Memorandum of Record – Weather observations (item 2, .PDF, 127 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427111&FileExtension=.PDF&FileName=Memorandum%20of%20Record%20%E2%80%93%20Weather%20observations-Master.PDF - Photo 1 - Main Rotor Blade (Photo Courtesy of FAA) (item 3, .PDF, 97 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427112&FileExtension=.PDF&FileName=Photo%201%20-%20Main%20Rotor%20Blade%20(Photo%20Courtesy%20of%20FAA)-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.