# NTSB WPR09LA386: Airborne Windsports PTY XT-912-L, N44VZ, Lihue, HI, August 2, 2009 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: August 1, 2009, 14:45 local (Aug 2, 2009, 00:45 UTC) - Place: Lihue, HI - Coordinates: 22.102777, -159.471664 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=22.1028&lon=-159.4717&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-descent: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Serious injuries - Injuries: 2 serious - Status: Completed, report April 22, 2010 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 74456 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09LA386 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74456/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74456 - Page: https://openairdocs.org/ntsb/WPR09LA386 ## Probable cause The flight instructor's failure to maintain control of the airplane following an in-flight encounter with turbulence during descent. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Turbulence: convective turbulence](https://openairdocs.org/ntsb-findings/03032020): Environmental issues › Conditions/weather/phenomena · Effect on equipment; cases with it: [Airborne Windsports PTY EDGE XT-912-L, 1 case](https://openairdocs.org/ntsb-findings/03032020/cases.md?model=060003A), [All aircraft, 145 cases](https://openairdocs.org/ntsb-findings/03032020/cases.md) - [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Airborne Windsports PTY EDGE XT-912-L, 4 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md?model=060003A), [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Instructor/check pilot (probable cause); cases with it: [Airborne Windsports PTY EDGE XT-912-L, 8 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=060003A), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-descent: Turbulence encounter](https://openairdocs.org/ntsb-events/360); cases with it: [Airborne Windsports PTY EDGE XT-912-L, 1 case](https://openairdocs.org/ntsb-events/360/sequence.md?model=060003A), [All aircraft, 423 cases](https://openairdocs.org/ntsb-events/360/sequence.md) - [Enroute-descent: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Airborne Windsports PTY EDGE XT-912-L, 9 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=060003A), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Airborne Windsports PTY EDGE XT-912-L, 6 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=060003A), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot of the light sport weight-shift-control airplane said that they were descending through a "hole in the clouds" when the aircraft encountered severe turbulence, resulting in the flight instructor losing control of the aircraft. The flight instructor subsequently deployed the aircraft's onboard rocket-propelled parachute system before impacting mountainous terrain and coming to rest on a hillside, entangled in surrounding trees. The flight instructor reported no anomalies with the airplane prior to or during the flight. ## Factual narrative On August 1, 2009, about 1445 Hawaii standard time, an Airborne Windsports XT-912-L, light sport weight-shift-control airplane, N44VZ, sustained substantial damage following an uncontrolled descent and impact with terrain about 12 miles northwest of Lihue, Hawaii. Both the flight instructor and his student sustained serious injuries. The airplane was registered to a private individual and operated by Birds in Paradise, of Kapaa, Hawaii. Visual meteorological conditions prevailed for the local instructional flight, which was conducted in accordance with 14 Code of Federal Regulations (CFR) Part 91, and a flight plan was not filed. The flight departed the Fort Allen Airport (PAK), Hanapepe, Hawaii, about 1400. In a statement provided to the NTSB investigator-in-charge (IIC), the flight instructor reported that after departing with his student on the instructional flight to the east, and after reaching an altitude of about 3,000 feet, he turned north toward the Wailiali Crater. The flight instructor stated that as he approached the area of the crater, he determined that "…the area there provided more than enough VFR (visual flight rules weather) to the ground below, and I would begin a slow descent to the crater area." The flight instructor further stated that, "Everything was going fine. As I descended my aircraft became violently rocked about in a matter of just seconds. I vigorously held the control bar and applied full power to try and take the aircraft back up to where it was calm, but to no avail. The control bar was violently ripped from my hands with severe force." The flight instructor reported that, "I fought all I could to maintain control of the [air]craft. However, as I had clear visual the entire time of my surroundings, I paid close attention to the rate of speed at which the ground was approaching. It became my final decision, with all other opportunities exhausted, that pulling the parachute was going to be the only thing that would save [us]. Upon pulling the chute, maybe just 200 to 300 feet above the ground, I lost consciousness." The aircraft subsequently impacted a hillside with the parachute becoming entangled in the surrounding trees. In a statement submitted to the IIC, the student pilot reported that as the flight headed north towards the mountains and into overcast skies, the flight instructor said he had found a hole in the clouds to drop down [through]. The student pilot stated, "To me, it looked like a 'dark spot' [rather] than a hole. Just as [the flight instructor] was about to drop down into the hole, another flight instructor for the same company flying nearby radioed, 'No, it's closing up.' " The student pilot further stated that as soon as they entered "the hole" the aircraft stopped flying and "started bouncing around like popcorn in a popcorn popper." The student pilot reported that the aircraft started to rotate in a downward spiral. He then heard the parachute deploy, and "One or two seconds later we impacted[terrain]." The flight instructor reported that the local weather at the time of the accident was wind from the northeast at 17 knots, visibility 10 miles, scattered clouds with heights unknown, broken clouds at 4,000 feet, temperature, dew point and altimeter setting unknown, and the severity of turbulence as extreme. According to a Federal Aviation Administration (FAA) aviation safety inspector, the pilot was on top of a broken cloud deck trying to find a hole to descend through into a crater. The inspector stated that apparently the flight instructor saw what he thought was a hole to descend through and started to spiral down through it, but the hole closed up, and at about the same time severe updrafts and downdrafts caused the pilot to lose control of the aircraft. The inspector reported that after the flight instructor deployed the parachute, the aircraft impacted the side of a mountain cliff, with the parachute getting caught in a tree, which prevented the aircraft from sliding further down the cliff. ## Aircraft - Registration: [N44VZ](https://openairdocs.org/aircraft/N44VZ), registered now, S/N XT-912-0230, built 2007 (OpenAirDocs) - Reported make and model: AIRBORNE WINDSPORTS PTY LTD XT-912-L - Registry model: [Airborne Windsports PTY EDGE XT-912-L](https://openairdocs.org/model/airborne-windsports-pty-edge-xt-912-l) (registry code 060003A) (OpenAirDocs) - Registry engine: [Rotax 912UL series](https://openairdocs.org/engine/rotax-912ul-series) (registry code 55571, 4 cycle) (OpenAirDocs) - Category: Weight-shift - Serial number: XT-912-0230 - Airframe hours: 1053 - Engines: ROTAX 912UL 80 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Special, Experimental light sport (Special) - Last inspection: Annual, July 26, 2009 - Departed: PAK, Port Allen Airp, HI - Destination: PAK, Port Allen Airp, HI ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 44; injuries: serious; flight instructor; seat: front; flight hours: 278 total, 275 in this make and model, 145 in the last 90 days - Student pilot; injuries: serious; student; seat: rear; flight hours: 1 total, 1 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 17° at 17 knots, gusting 17 - Visibility: 10 statute miles - Lowest ceiling: 4,000 ft broken - Observed at: LIH, 12 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 20090801018259A](https://openairdocs.org/incident/20090801018259A), Aug 1, 2009: Airbor EDGEXT912L, Lihue, HI, Destroyed. 1. See attached for narrative. 2. Item #15, type of aircraft: light sport weight shift. 3. Item #23, weather briefing source:mr defino had flown several times… ## Docket (4 files) The files NTSB released with the investigation on January 15, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74456. 4.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40323289&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Report - FAA Inspector (item 2, .PDF, 369 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40323290&FileExtension=.PDF&FileName=Record%20of%20Report%20-%20FAA%20Inspector-Redacted.PDF - Student Pilot Statement (item 3, .PDF, 982 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40323291&FileExtension=.PDF&FileName=Student%20Pilot%20Statement-Redacted.PDF - Second Flight Instructor Statement (item 4, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40323292&FileExtension=.PDF&FileName=Second%20Flight%20Instructor%20Statement-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.