# NTSB CEN09CA511: Brantly B-2B, N9023Z, Martinsville, IN, August 9, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 9, 2009, 12:00 local (16:00 UTC) - Place: Martinsville, IN - Coordinates: 39.453609, -86.279998 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.4536&lon=-86.2800&mi=10 - Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping) - Defining event: [Autorotation: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report October 19, 2009 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 74489 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN09CA511 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74489/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74489 - Page: https://openairdocs.org/ntsb/CEN09CA511 ## Probable cause The pilot's improper recovery during the autorotation. Contributing to the accident was the pilot's delayed remedial action to abort the practice autorotation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: prop/rotor parameters](https://openairdocs.org/ntsb-findings/01062052): Aircraft › Aircraft oper/perf/capability · Not attained/maintained; cases with it: [Brantly B-2B, 2 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md?model=1440506), [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Brantly B-2B, 1 case](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=1440506), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Brantly B-2B, 1 case](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=1440506), [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. - [Autorotation: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Brantly B-2B, 8 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1440506), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Autorotation: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Brantly B-2B, 2 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=1440506), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) ## Analysis The pilot was practicing solo 180-degree autorotations in preparation for a private pilot helicopter add-on rating. During the accident autorotation, the helicopter was in a left turn at an altitude of 500 feet above ground level(agl). The helicopter exited the turn "a little low and lost some rotor speed." While attempting to recover the low rotor speed, the pilot had to extend his glide path more than he anticipated due to approaching terrain and obstacles, which in turn slowed the forward airspeed. The pilot reported, "Of course I wish I had abandoned the auto at this point. I flared [the helicopter] but with high density altitude and the out of ground effect of the soybeans, I still entered the thick-drilled soybeans, which piled up on my right skid." The helicopter then rolled over and came to rest on its right side. Examination of the helicopter revealed the main rotor blades were destroyed and the fuselage was buckled. No mechanical anomalies were noted with the helicopter. ## Factual narrative The pilot was practicing solo 180-degree autorotations in preparation for a private pilot helicopter add-on rating. During the accident autorotation, the helicopter was in a left turn at an altitude of 500 feet above ground level(agl). The helicopter exited the turn "a little low and lost some rotor speed." While attempting to recover the low rotor speed, the pilot had to extend his glide path more than he anticipated due to approaching terrain and obstacles, which in turn slowed the forward airspeed. The pilot reported, "Of course I wish I had abandoned the auto at this point. I flared [the helicopter] but with high density altitude and the out of ground effect of the soybeans, I still entered the thick-drilled soybeans, which piled up on my right skid." The helicopter then rolled over and came to rest on its right side. Examination of the helicopter revealed the main rotor blades were destroyed and the fuselage was buckled. No mechanical anomalies were noted with the helicopter. ## Aircraft - Registration: [N9023Z](https://openairdocs.org/deregistered/N9023Z-2018-06-08), registration cancelled 2018-06-08, S/N 2021, built 2001 (OpenAirDocs) - Reported make and model: BRANTLY B-2B - Registry model: [Brantly B-2B](https://openairdocs.org/model/brantly-b-2b) (registry code 1440506) (OpenAirDocs) - Registry engine: [Lycoming O-360-A1A](https://openairdocs.org/engine/lycoming-o-360-a1a) (registry code 41594, 4 cycle) (OpenAirDocs) - Category: Helicopter - Serial number: 2021 - Airframe hours: 523 - Engines: LYCOMING O-360-A1A 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Mcdaniel Mark O - Registered owner: Mcdaniel Mark O - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 21, 2009 - Departed: Martinsville, IN - Destination: Martinsville, IN ## Flight crew As NTSB recorded them. NTSB leaves out names. - Student pilot; age 50; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review June 17, 2006; seat: right; flight hours: 175 total, 80 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 9 knots, gusting 14 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 88 °F ## 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 20090809049149A](https://openairdocs.org/incident/20090809049149A), Aug 9, 2009: Brantly B-2B, Martinsville, IN, Substantial damage. In preparation for a scheduled rotorcraft rating check ride, the pilot was practicing autorotation maneuvers in close proximity to, and north of, a bean field.… ## Other investigations on N9023Z (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 ERA14CA259](https://openairdocs.org/ntsb/ERA14CA259), May 25, 2014: Brantly B 2B (N9023Z), Essex, MD, substantial damage. Probable cause: The pilot's failure to maintain helicopter control during landing resulting in a hard landing and a roll over. ## Docket (1 files) The files NTSB released with the investigation on August 31, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74489. 365 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 365 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40317666&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-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.