Sling Aircraft (Pty) SLING LSA N294JY

Summary

On 11 July 2023 at about 17:55 local time, a Sling Aircraft (Pty) SLING LSA registered N294JY, operated by Airplane Factory Inc, was involved in an accident near Palm Springs, California, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

11 July 2023 at 17:55

Classification

Accident

Location

Palm Springs, California, United States

Nearest airport

Palm Springs Intl (PSP)

Coordinates

33.8264, -116.5020

Aircraft

Sling Aircraft (Pty) SLING LSA

Registration

N294JY

Category

Airplane

Year built

2022

Engines

1

Operator

Airplane Factory Inc

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Unknown → Torrance

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR23LA270

Nobody was injured.

Failure of the landing gear strut during takeoff due to a preexisting cracks that were caused by a manufacturing anomaly during the composite fiber layup process.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The accident occurred during takeoff on an instructional flight. The instructor reported that before reaching rotation speed, the airplane felt as if it were sinking to the left as if they had a flat tire. The flight instructor took over control of the airplane, reduced engine power to idle, and applied the hand brake. The airplane then became uncontrollable and veered to the right. He applied corrective control inputs, but the airplane departed the runway, struck an embankment, and sustained substantial damage. The instructor reported that the inbound landing was uneventful, and the data recorded by the airplane’s primary flight display corroborated this. Examination revealed that the left main landing gear leg, which was comprised of composite glass fiber layups, was cracked in multiple areas along its length and had delaminated. Laboratory examination revealed the cracks occurred within the center bulk of fibers parallel to the lamina. Shiny areas consistent with voids and disbonded material, indicative of a manufacturing anomaly, were spread throughout the fracture surfaces. The voids would have affected the structural integrity and allowed cracking to be initiated more easily within the strut. Entrapped contaminants were also found within the strut matrix and in several locations on the fracture surfaces, which was further evidence of cleanliness issues during manufacturing. Flattened features were also present on the fracture surfaces and were likely caused by repeated contact between the two halves of the strut as the crack progressed, indicating the crack had been present for some time. Similarly, the presence of dirt/debris on the interior surfaces was likely the result of the gap between the fracture surfaces opening during aircraft operation and allowing dirt/debris to enter. Consequently, the flattened features and embedded dirt/debris are consistent with a pre-existing delamination in the strut before the accident flight. Both the instructor and the student performed preflight procedures, which included checking the landing gear legs for cracks. Both reported that they did not see any damage or anomalies. It could not be determined why they did not see the cracks, but it is possible that the fractures were imperceptible during a preflight examination, when the airplane was not loaded to an extent that the cracks would open and be visible. A service bulletin had been issued about 10 years before the accident warning of similar cracks in the landing gear caused by an apparent manufacturing defect. However, this bulletin was not applicable to the accident airplane based on its year of manufacture.

Quoted verbatim from the NTSB record.