WPR09LA386

NTSB accident investigation · Airborne Windsports PTY XT-912-L · Lihue, HI · August 2, 2009

Accident · Serious injuriesLimited investigationFinal report
Date
August 1, 2009, 14:45 local (Aug 2, 2009, 00:45 UTC)
Place
Lihue, HI
Injuries
2 serious
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N44VZAirborne Windsports PTY XT-912-L
Defining event
Enroute-descent: Loss of control in flight
Weather
Visual (VMC) · Day
Status
Completed · report April 22, 2010
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
Federal Aviation Administration
FAA report
20090801018259A
Case key
74456

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

The flight instructor's failure to maintain control of the airplane following an in-flight encounter with turbulence during descent.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Turbulence: convective turbulenceEnvironmental issues › Conditions/weather/phenomena · Effect on equipmentAirborne Windsports PTY EDGE XT-912-L: 1 caseAll aircraft: 145 cases
Performance/control parametersAircraft › Aircraft oper/perf/capability · Not attained/maintainedAirborne Windsports PTY EDGE XT-912-L: 4 casesAll aircraft: 1,269 casesProbable cause
Use of equip/info: aircraft controlPersonnel issues › Task performance · Instructor/check pilotAirborne Windsports PTY EDGE XT-912-L: 8 casesAll aircraft: 9,295 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

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
Reported as
Airborne Windsports PTY XT-912-L
Category
Weight-shift
Serial number
XT-912-0230
Airframe hours
1,053
Engine
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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Flight instructor
Age
44
Injuries
Serious
Certificate
Flight instructor
Seat
Front
Flight hours
278 total · 275 in this make and model · 145 in the last 90 days
Role
Student pilot
Injuries
Serious
Certificate
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

Docket · 4

The files NTSB released with the investigation on January 15, 2010, on NTSB’s docket system: statements, records, photos and specialists’ reports. 4.0 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.