# NTSB CEN11CA453: Powrachute Airwolf 912, N734MP, Oconto, WI, June 30, 2011 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Data collection · Final report - Date: June 30, 2011, 06:27 local (11:27 UTC) - Place: Oconto, WI - Coordinates: 44.868331, -87.966667 - Nearby events: https://openairdocs.org/map.md?lat=44.8683&lon=-87.9667&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed, report October 6, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA- Milwaukee FSDO - NTSB case key (mKey): 81010 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11CA453 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81010/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81010 - Page: https://openairdocs.org/ntsb/CEN11CA453 ## Probable cause The powered parachute pilot's decision to execute an in-flight full-flare which resulted in exceeding the angle of attack capabilities of the parachute wing, and subsequent inadvertent stall. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Powrachute AIRWOLF 912ULS, 1 case](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=0690004), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Powrachute AIRWOLF 912ULS, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=0690004), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) (defining event); cases with it: [Powrachute AIRWOLF 912ULS, 1 case](https://openairdocs.org/ntsb-events/241/sequence.md?model=0690004), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Powrachute AIRWOLF 912ULS, 3 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=0690004), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The powered parachute pilot performed two in-flight flare maneuvers at altitude. He performed the first one, released the flare, and the powered parachute recovered. He performed the second one, but released more slowly and the parachute stalled. The pilot stated that all the cells of the parachute were open as he applied full throttle. The parachute wing remained open and slightly back from vertical. The parachute remained in this condition until it struck the ground. The large increase in parachute wing drag experienced during the full-flare, and the quick full throttle input, created a climbing dynamic pendulum effect that loaded the wing, and resulted in the stall. Federal Aviation Administration guidance stated that a full-flare is normally used and recommended only for landings, as it is a situation that could contribute to a stall. ## Factual narrative The powered parachute was on its third flight, and was carrying the pilot and a passenger. The pilot stated that a normal takeoff was performed. During the flight, the pilot elected to perform an in-flight flare maneuver. The maneuver was similar to a flare used for landing except that it was performed at a higher altitude. The first in-flight flare was performed and released, and the powered parachute recovered. Another in-flight flare was performed and released more slowly, and the parachute stalled. The pilot stated that all the cells of the parachute were open and he applied full throttle. The parachute remained open and slightly back from vertical. It stayed in this condition until the powered parachute struck the ground. Federal Aviation Administration publication "FAA-H-8083-29 - Powered Parachute Flying Handbook" states that powered parachutes have two basic flight controls; steering controls and throttle. The throttle controls thrust and therefore controls altitude for climbing and descending, but does not measurably affect airspeed. Powered parachutes fly at a relatively constant airspeed and angle of attack for normal flying conditions. The handbook also states that, although a powered parachute wing is resistant to stall, conditions that can contribute to a stall include a large increase in wing drag as experienced during a full-flare, and a quick full RPM throttle input, creating a climbing dynamic pendulum effect loading the wing. It also states that a full-flare is normally used and recommended only for landings. The damage to the powered parachute included bending of the cart structure, engine mounting structure, and propeller shroud tubing. ## Aircraft - Registration: [N734MP](https://openairdocs.org/deregistered/N734MP-2017-10-26), registration cancelled 2017-10-26, S/N A153ULS, built 2011 (OpenAirDocs) - Reported make and model: POWRACHUTE Airwolf 912 - Registry model: [Powrachute AIRWOLF 912ULS](https://openairdocs.org/model/powrachute-airwolf-912uls) (registry code 0690004) (OpenAirDocs) - Registry engine: [Rotax 912ULS series](https://openairdocs.org/engine/rotax-912uls-series) (registry code 55572, 4 cycle) (OpenAirDocs) - Category: Powered parachute - Serial number: A153ULS - Airframe hours: 2.5 - Engines: Rotax 912ULS 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental light sport (Special) - Last inspection: Condition, June 28, 2011, 2.5 hours before - Departed: PVT, Abrams, WI - Destination: PVT, Abrams, WI ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: serious; sport pilot; medical: sport pilot; last flight review June 25, 2011; seat: front; flight hours: 159 total, 159 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 3 knots - Visibility: 12 statute miles - Lowest ceiling: none - Temperature: 59 °F - Altimeter: 30.05 inHg ## 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 20110630014619A](https://openairdocs.org/incident/20110630014619A), Jun 30, 2011: Powrachute LLC AIRWOLF 912ULS, Oconto, WI, Substantial damage. The aircraft reportedly stalled during a maneuver and decended, impacting thr ground tail first. The pilot in the front seat sustained serious injuries and the… ## Docket (2 files) The files NTSB released with the investigation on August 11, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81010. 2.6 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40352014&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Excerpt from "FAA-H-8083-29 Powered Parachute Flying Handbook" (item 2, .PDF, 205 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40351940&FileExtension=.PDF&FileName=Excerpt%20from%20%22FAA-H-8083-29%20Powered%20Parachute%20Flying%20Handbook%22-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.