# NTSB ERA22LA269: Walter S Johnson III AR-1, N688G, Butler, PA, June 11, 2022 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: June 11, 2022, 12:35 local (16:35 UTC) - Place: Butler, PA · On Airport - Coordinates: 40.776583, -79.951083 - Nearby events: https://openairdocs.org/map.md?lat=40.7766&lon=-79.9511&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 105269 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA22LA269 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105269/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105269 - Page: https://openairdocs.org/ntsb/ERA22LA269 ## Probable cause The pilot’s failure to monitor rotor disk speed on takeoff, which resulted in blade flapping and the main rotor blades striking the gyroplane’s tail assembly. ## 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 (probable cause); cases with it: [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md) - [Attention/monitoring: monitoring equip/instruments](https://openairdocs.org/ntsb-findings/02021525): Personnel issues › Psychological · Pilot (probable cause); cases with it: [All aircraft, 142 cases](https://openairdocs.org/ntsb-findings/02021525/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) ## Analysis The pilot said the traffic pattern was busy, so he began the pre-rotation process as he taxied the gyroplane onto the runway to depart. At that time, the rotor disk rpm was at 140 rpm, which was 20 rpm above the recommended takeoff speed. The pilot said he slowly applied power because he had a passenger onboard, which may have allowed time for the disk speed to decay and become susceptible to blade flap. During the takeoff roll, the gyroplane’s main rotor blades struck and severed the tail assembly, resulting in substantial damage. The pilot said there were no preimpact mechanical malfunctions or failures that would have precluded normal operation. ## Aircraft - Registration: N688G (not matched to a registry record) - Reported make and model: WALTER S JOHNSON III AR-1 - Category: Helicopter - Serial number: 0021 - Year built: 2017 - Airframe hours: 373.5 - Engines: Rotax 912ULS 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Beighey Mark W - Registered owner: Beighey Mark W - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, May 22, 2022 - Destination: Same as departure - Airport: BTP, Pittsburgh/Butler Rgnl, runway 26, 4,801 × 100 ft, asphalt - Equipment: Handheld GPS, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 64; injuries: none; sport pilot; airplane ratings: single-engine land; medical: sport pilot, with waivers/limitations; last flight review October 1, 2021; seat: front; restraint: 3-point; flight hours: 332 total, 330 in this make and model, 276 as pilot in command, 8 in the last 90 days, 6 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 5 knots - Visibility: 10 statute miles - Temperature: 72 °F, dew point 52 °F - Altimeter: 29.97 inHg - Observed at: KBTP - METAR: METAR KBTP 111656Z AUTO VRB05KT 10SM FEW041 22/11 A2997 ## 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 20220611010319A](https://openairdocs.org/incident/20220611010319A), Jun 11, 2022: Walter S Johnson III AR-1, Butler, PA, Substantial damage. During departure experienced blade flap causing the main rotor to strike the propeller and tail. The tail separated from the aircraft and the three propeller… ## Docket (2 files) The files NTSB released with the investigation on October 17, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105269. 2.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14178086&FileExtension=pdf&FileName=N688G%20Completed%20NTSB%20Form%206120-1%20-%20Final%202_Redacted-Rel.pdf - Investigative photos (item 2, PDF, 2 pages, 2 photos, 327 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14178129&FileExtension=pdf&FileName=Investigative%20Photos-Rel.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.