ERA15LA156

NTSB accident investigation · Kolb Twinstar · Reynolds, GA · March 15, 2015

Accident · FatalLimited investigationFinal report
Date
March 15, 2015, 18:15 local (22:15 UTC)
Place
Reynolds, GA
Injuries
1 fatal
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N193YKolb Twinstar
Defining event
Maneuvering-low-alt flying: Loss of control in flight
Weather
Visual (VMC) · Day
Status
Completed · report November 28, 2016
Report
Approved by Office Director
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO
FAA report
20150315003339A
Case key
90872

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 student pilot’s failure to maintain adequate airspeed while maneuvering, which resulted in the airplane exceeding its critical angle-of-attack and experiencing an aerodynamic stall. Contributing to the accident was the student pilot's decision to operate the airplane at a low altitude that did not allow for stall recovery.

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.

Performance/control parameters: angle of attackAircraft › Aircraft oper/perf/capability · Capability exceededKolb MK II: 1 caseAll aircraft: 990 casesProbable cause
Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedKolb MK II: 1 caseAll aircraft: 1,681 casesProbable cause
Use of equip/info: use of equip/systemPersonnel issues › Task performance · PilotKolb MK II: 1 caseAll aircraft: 1,391 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 student pilot was flying at a low altitude over a relative's residence. The airplane circled over the house twice before overflying a wooded area at the neighboring residence and, according to a witness, appeared to "hover" as it flew over the trees. Shortly thereafter, the airplane suddenly pitched nose-down and impacted terrain. Witness observations were consistent with the airplane flying at a very low groundspeed, and likely a very low airspeed. The nose-down impact angle, and absence of ground scars or debris path were consistent with a stall at the time of impact. Because the airplane was operating at low altitude, the airplane's altitude was insufficient to allow the student pilot to recover the airplane from the stall. Although oil was found on the engine case and empennage, no pre-impact mechanical malfunctions or failures were found with the engine or airplane that would have precluded normal operation.

Factual narrative

A handheld GPS receiver was recovered from the accident site by the FAA inspector, and was forwarded to the NTSB Vehicle Recorder Division for detailed examination. The unit recorded GPS data for two flight legs on the day of the accident. The first recording began at 1647 while on the ground at OPN. The airplane departed OPN to the south, and landed at the Butler Municipal Airport (6A1), Butler, Georgia, about 50 minutes later. The airplane departed 6A1 about 1753 and maneuvered easterly before turning south toward Reynolds. The recording ended at 1813, as the airplane was tracking southwest toward the accident site, at a GPS altitude of 725 feet, and a groundspeed of 48 knots. The recording stopped prematurely, about 1.5 miles northeast of the accident site. [Additional information can be found in the GPS Device Specialist's Factual Report, available in the public docket for this investigation.] The two-seat, high-wing, tailwheel equipped airplane was powered by a 47 horsepower Rotax model 503 DCSI engine, equipped with a three-blade fixed pitch propeller. The airplane was not equipped with a stall warning system, nor was one required. According to FAA and maintenance records, the airplane was built in 2007. The airplane did not have a current condition inspection. Its most recent condition inspection was completed on June 29, 2012. At the time of the inspection, the airplane had accrued approximately 252 total hours of operation and the engine had accrued approximately 105 total hours of operation. The airplane had accrued an additional 250 hours since that inspection. On March 15, 2015, at 1815 eastern daylight time, an experimental light sport Kolb Twinstar MK-II, N193Y, was substantially damaged when it impacted terrain near Reynolds, Georgia. The student pilot was fatally injured. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight which was destined for Thomaston-Upson County Airport (OPN), Thomaston, Georgia. The flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to a witness, who was related to the student pilot, the airplane approached her property and flew two oval shaped patterns over her house. It then proceeded west towards her neighbor's property, and flew "very close" to a group of pine trees. She described the airplane as appearing to "hover." Shortly thereafter, it "took a sharp pitch forward and turned right at the same time" and impacted the ground in a nose down attitude. The witness further stated "the engine was running" while the airplane was overhead and she did not hear the engine "sputter or stop." The Division of Forensic Sciences, Georgia Bureau of Investigation, performed the autopsy on the student pilot. The autopsy report listed the cause of death as multiple blunt impact injuries. The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicological testing of the student pilot. Thetesting was negative for the presence of carbon monoxide, ethanol, and drugs. The 1815 recorder weather observation at OPN, located 28 nautical miles northwest of the accident site, included visibility 10 statute miles, sky clear below 10,000 feet, and wind calm. According to Federal Aviation Administration (FAA) records, the student pilot held a student pilot certificate with Cessna model 172 solo, and solo cross-country endorsements. His most recent FAA third-class medical certificate (and student pilot certificate) was issued on July 1, 2014. According to pilot records, he had accrued approximately 25 total flight hours, with 0 hours in the same make and model as the accident airplane. However, according to FAA records, the student pilot purchased the airplane in September 2012. A "solo T-shirt" displayed in the office at his home airport indicated that he first soloed in the accident airplane on January 6, 2013. The wreckage was examined by an FAA inspector. All major components were accounted for at the accident location. The airplane came to rest in a nose down attitude with the entire length of the wing leading edge resting on the ground. There were no ground scars observed leading to the airplane. Flight control continuity was established from the flight controls to the respective control surfaces. An undetermined amount of blue fluid, similar in color to and smell as 100 low-lead aviation fuel was located throughout the entire fuel system. An oily substance was found on the exterior of the engine and on portions of the empennage; however, examination of the engine did not reveal evidence any preaccident malfunctions.

Aircraft

Registration
N193Y
Reported as
Kolb Twinstar (MK-II)
Category
Airplane
Serial number
CW011370
Built
2007
Airframe hours
502
Engine
Rotax 503DCSI, 47 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental light sport (Special)
Last inspection
Condition · June 29, 2012 · 250 hours before
Departed
6A1 · Butler, GA
Destination
OPN · Thomaston, GA
Equipment
Handheld GPS

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
Student pilot
Age
52
Injuries
Fatal
Certificate
Student
Medical
Class 3, With waivers/limitations
Toxicology
Performed
Flight hours
23.5 total · 1 in this make and model · 7.5 as pilot in command · 1.8 in the last 90 days · 0 in the last 30 days · 0 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
79 °F, dew point 37 °F
Altimeter
30.14 inHg
Observed at
OPN, 28 nm away

Docket · 8

The files NTSB released with the investigation on September 29, 2016, on NTSB’s docket system: statements, records, photos and specialists’ reports. 6.1 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.