ERA19LA050

NTSB accident investigation · Ultralite Sro Stingsport · Clermont, FL · November 17, 2018

Accident · Minor injuriesClass 3 · LimitedFinal report
Date
November 17, 2018, 11:20 local (16:20 UTC)
Place
Clermont, FL
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N494NUltralite Sro Stingsport
Defining event
Maneuvering: Aircraft structural failure
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO
FAA report
20181117022659A
Case key
98653

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

An inflight failure of the airplane’s horizontal stabilizer.

Findings · 1

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.

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 he was in cruise flight when he received an automatic dependent surveillance-broadcast traffic alert of traffic approaching from his one o'clock position and closing at "a high rate of speed." The pilot went on to describe control inputs and airplane attitudes during his response to the perceived threat, which ultimately resulted in a loss of control and aerodynamic spin. During the pilot’s attempted recovery from the spin, the nose of the airplane pitched forward uncontrolled and the airplane entered a high-speed, nose-down descent. It is likely that during these remedial actions to regain control, the structure surrounding the horizontal stabilizer failed, and the stabilizer separated from the airplane. The pilot then successfully deployed the airplane’s ballistic parachute system, and it landed in a pasture. Examination of the failed structure surrounding the horizontal stabilizer revealed areas of delamination with dry glass fibers indicative of improper material layup with inadequate resin application. It could not be determined to what extent the inflight separation of the horizontal stabilizer was due to this defect, or whether the pilot’s control inputs during the response to the traffic warning, departure from controlled flight, and subsequent attempted recovery attempt imparted forces onto the horizontal stabilizer that were beyond its nominal structural capability.

Factual narrative

On November 17, 2018, about 1120 eastern standard time, a TL-2000 StingSport, N494N, was substantially damaged when it was involved in an accident near Clermont, Florida. The sport pilot received minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. In a written statement, the pilot stated he was in cruise flight when he received an automatic dependent surveillance-broadcast traffic alert via a commercial application he had running on portable electronic device. The traffic was approaching from his one o'clock position and closed at "a high rate of speed." The pilot stated that he then entered a shallow, descending turn to the left to increase separation with the traffic. As he levelled the airplane following the descent, he noted that his airspeed had increased to 138 knots. When he noted the airspeed, he "rapidly" reduced engine power below 50% at which point the airplane yawed and entered a counterclockwise spin. The pilot said he arrested the spin and that the airplane initially responded to elevator inputs to raise the nose and level off. Then, the nose of the airplane pitched forward uncontrolled, and the airplane entered a high-speed, nose-down descent. About this time, the pilot’s head impacted the cockpit canopy and shattered it. The pilot deployed the airplane’s ballistic parachute system and the airplane landed in a pasture. Air traffic control services were not provided to the accident airplane, but examination of automatic dependent surveillance-broadcast track data revealed that if each airplane maintained its heading, airspeed, and altitude, the airplanes paths would have passed close to each other but would not have intersected. Photographs of the accident site showed that the accident airplane came to rest upright with the nose landing gear collapsed. The horizontal stabilizer was separated from its mount and was located intact about 1,000 feet east of the main wreckage. The stabilizer mount plate and mounting studs were intact and undamaged, but the composite structure and adhesive joints surrounding them were torn and peeled away from the main tail structure. The elevator push-pull tube was fractured at the point where the tube exited the empennage, and the fracture surfaces displayed signatures consistent with overstress failure. Postaccident examination of the horizontal stabilizer and its corresponding mount structure from the airplane revealed that the shelf (mount plate) was delaminated and partially separated from the aft fuselage between the vertical flange and forward end of the shelf. Examination of the delaminated area revealed areas of dry glass fibers with little or no resin present. The dry areas encompassed about 30% to 40% of the delaminated area and were concentrated above and forward of the vertical flange location.

Aircraft

Registration
N494N
Reported as
Ultralite Sro Stingsport
Category
Airplane
Serial number
TLUSA150
Built
2006
Airframe hours
337.5
Engine
Rotax 912ULS, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Special light-sport (Special)
Last inspection
Annual · December 1, 2017 · 18 hours before
Departed
X06 · Arcadia, FL
Destination
X04 · Apopka, FL
Equipment
Unknown

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
53
Injuries
Minor
Certificate
Sport Pilot
Airplane ratings
Single-engine land
Medical
Sport pilot
Last flight review
May 27, 2017
Seat
Left
Restraint
4-point
Flight hours
182.8 total · 67.4 in this make and model · 79 as pilot in command · 8.3 in the last 90 days · 4 in the last 30 days · 2.5 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
90° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
72 °F, dew point 55 °F
Altimeter
30.18 inHg
Observed at
ISM, 17 nm away

Docket · 6

The files NTSB released with the investigation on October 7, 2021, on NTSB’s docket system: statements, records, photos and specialists’ reports. 30.5 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.