CEN14CA532

NTSB accident investigation · Airborne Edge X · Willow Springs, MO · September 1, 2014

Accident · Minor injuriesData collectionFinal report
Date
September 1, 2014, 06:50 local (11:50 UTC)
Place
Willow Springs, MO
Injuries
2 minor
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N2017AAirborne Edge X
Defining event
Landing: Windshear or thunderstorm
Weather
Visual (VMC) · Day
Status
Completed · report April 7, 2015
Report
Approved by Office Director
NTSB office
Central Region
Parties
Federal Aviation Administration, St. Louis FSDO
FAA report
20140901021299A
Case key
90399

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

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Probable cause

The pilot's loss of control after the weight-shift-control aircraft encountered low-level wind shear shortly before touchdown. Also causal to the accident was the pilot's inadequate preflight weather assessment that failed to correctly determine the actual location and speed of the approaching line of thunderstorms.

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.

Wind: windshearEnvironmental issues › Conditions/weather/phenomena · Ability to respond/compensateAirborne EDGE X: 1 caseAll aircraft: 90 casesProbable cause
Planning/preparation: weather planningPersonnel issues › Task performance · PilotAirborne EDGE X: 1 caseAll aircraft: 156 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 stated that, about 45 minutes before departure, he obtained the current weather conditions via an internet website and observed a thunderstorm located about 100 miles west of the departure airport. About 20 minutes into the local area flight, he recalled seeing a low cloud bank, with a base of about 1,000 feet above ground level (agl), about 1/4 mile east of the airport. At the same time, he noticed an area of heavy rain from clouds located about 15 miles west of his position. He decided to land as soon as possible due to the deteriorating weather. Instead of making an approach to the airport's single runway, he decided to land toward the west in an open pasture area that was located on the airport property. Shortly after clearing trees and hangars that were located on the east side of the airport, the weight-shift-control aircraft suddenly lost altitude, from about 20 feet agl, and impacted the ground in an upright attitude. After the impact, the aircraft rolled over onto its left side. The pilot reported that the aircraft did not appear to have any forward velocity when it impacted terrain, as indicated by a lack of damage to the surrounding vegetation. The aircraft sustained substantial damage to the wing and fuselage. He stated that there were no mechanical malfunctions of the aircraft that would have precluded normal operation. Additionally, he reported that the aircraft's operating limitations included a maximum headwind and crosswind component of 21 knots and 11 knots, respectively. Meteorological data collected during the accident investigation indicated that, at the time of the accident, there was a squall line of strong-to-severe thunderstorms within a few miles of the accident site. Local weather stations indicated that there was a wind shift from the south to the north that was associated with the passage of the frontal boundary. The weather stations also reported wind gusts reaching 24 knots. A review of weather radar imagery indicated that, at the time of the pilot's preflight weather check, there was a line of thunderstorms located about 40 miles northwest of the departure airport. The same line of thunderstorms was within a few miles of the airport at the time of the accident and moved through the area almost immediately thereafter. The meteorological data suggested that the aircraft likely encountered a gust front that was associated with approaching line of thunderstorms. Although the pilot checked the weather before departure, his failure to correctly identify the location and speed of the approaching line of thunderstorms contributed to the low-level wind shear encounter shortly before touchdown.

Factual narrative

The pilot stated that, about 45 minutes before departure, he obtained current weather conditions via an internet website and observed a thunderstorm located about 100 miles west of the departure airport. The pilot subsequently departed about 0630 for the local area flight. About 20 minutes into the flight, he recalled seeing a low cloud bank, with a base of about 1,000 feet above ground level (agl), about 1/4 mile east of the airport. At the same time, he noticed an area of heavy rain from clouds located about 15 miles west of his position. He decided to land as soon as possible due to the deteriorating weather. Instead of making an approach to the airport's single runway (17/35), he decided to land toward the west in an open pasture area that was located on the airport property. Shortly after clearing trees and hangars that were located on the east side of the airport, the weight-shift-control aircraft suddenly lost altitude, from about 20 feet agl, and impacted the ground in an upright attitude. After the impact, the aircraft rolled over onto its left side. The pilot reported that the aircraft did not appear to have any forward velocity when it impacted terrain, as indicated by a lack of damage to the surrounding vegetation. The aircraft sustained substantial damage to the wing and fuselage. He stated that there were no mechanical malfunctions of the aircraft that would have precluded normal operation. Additionally, he reported that the aircraft's operating limitations included a maximum headwind and crosswind component of 21 knots and 11 knots, respectively.Meteorological data collected during the accident investigation indicated that, at the time of the accident, there was a squall line of thunderstorm activity present within a few miles of the accident site. Additionally, the National Weather Service (NWS) Storm Prediction Center had issued a warning for the development of severe thunderstorms. The NWS storm warning called for scattered strong-to-severe thunderstorms associated with the passage of a cold front. Local weather stations indicated that there was a wind shift from the south to the north that was associated with the passage of the frontal boundary. The weather stations also reported wind gusts reaching 24 knots. A review of weather radar imagery indicated that, at the time of the pilot's preflight weather check, there was a line of thunderstorms located about 40 miles northwest of the departure airport. The same line of thunderstorms was within a few miles of the airport at the time of the accident and moved through the area almost immediately thereafter.

Aircraft

Registration
N2017A
Reported as
Airborne Edge X
Category
Weight-shift
Serial number
582-587
Built
2007
Airframe hours
431
Engine
Rotax 582, 65 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental light sport (Special)
Last inspection
Condition · April 14, 2014
Departed
1H5 · Willow Springs, MO
Destination
1H5 · Willow Springs, MO
Airport
1H5 · Willow Springs Memorial
Equipment
Handheld GPS, Airframe parachute

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

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
67
Injuries
Minor
Certificate
Sport Pilot
Medical
Sport pilot
Last flight review
October 24, 2012
Seat
Front
Restraint
Lap only
Flight hours
496 total · 356 in this make and model · 466 as pilot in command · 7 in the last 90 days · 2 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
200° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
72 °F, dew point 70 °F
Altimeter
30.02 inHg
Observed at
UNO, 7 nm away

Docket · 4

The files NTSB released with the investigation on March 9, 2015, on NTSB’s docket system: statements, records, photos and specialists’ reports. 4.3 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.