CEN23LA110

NTSB accident investigation · Titan Tornado II · Windom, MN · February 18, 2023

Accident · No injuriesClass 3 · LimitedFinal report
Date
February 18, 2023, 12:15 local (18:15 UTC)
Place
Windom, MN · Landed on frozen lake
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Takeoff
Aircraft
N9168PTitan Tornado II
Defining event
Takeoff: Sys/Comp malf/fail (non-power)
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Central Region
Parties
FAA
FAA report
20230218001429A
Case key
106748

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 fatigue failure of the right landing gear leg that resulted in its separation from the airplane during takeoff.

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.

Landing gear system: main landing gearAircraft › Aircraft systems · Fatigue/wear/corrosionWeber Larry D TITAN TORNADO II: 1 caseAll aircraft: 241 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 while taking off on a frozen lake with hard-packed snow, the right main landing gear separated from the airplane. He continued the takeoff and landed the airplane without further incident on a snow-covered lake near his home. The airplane sustained substantial damage to the vertical stabilizer due to impact from the right main landing gear. A metallurgical examination of the right main landing gear leg assembly revealed that bilateral fatigue cracks originated from the inner wall of a cross-drilled hole near the right gear leg socket. Eventually, overload and bending stresses in the direction of the fatigue cracks resulted in the right gear leg separating. It was unclear why the hole was drilled. There is an identical hole in the same spot on the left landing gear leg.

Factual narrative

On February 18, 2023, about 1215 central standard time, a Titan Tornado II, N9168P, was substantially damaged when it was involved in an accident near Windom, Minnesota. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he departed Cloquet Airport (COQ) near Cloquet, Minnesota, and flew south to Fish Lake, near Windom, Minnesota, to attend an event. After the event was over, he taxied to an area of the lake where the “snow was hardpacked with no bumps, ruts, or [snow] chunks visible” to take off. After reaching rotation speed, the right main landing gear leg sheared off and struck the vertical stabilizer. The pilot was able to control the airplane with aileron and safely became airborne. The pilot flew back to COQ and advised Duluth Air Route Traffic Control Center that he was going to land on Big Lake, Minnesota, about five miles west of COQ, to prevent any further airplane damage from landing on asphalt. During the landing, he applied full left aileron input and touched down on the left main landing gear wheel first and then lowered the nosewheel. The right wing dropped and slid along the ice. He counteracted with left rudder, spun 90° to the right, and came to a full upright stop. Postaccident examination revealed that the airplane sustained substantial damage to the vertical stabilizer from the impact of the right gear leg after it separated from near the fuselage gear leg socket. An examination of the landing gear revealed that bilateral fatigue cracks originated from the inner wall of a cross-drilled hole near the right gear leg socket. Eventually, overload and bending stresses in the direction of the fatigue cracks resulted in the right gear leg separating. There was an identical hole drilled in each landing gear strut. The purpose of the hole is unknown. The pilot stated the hole was covered by a zip tie that was used to secure the brake line.

Aircraft

Registration
N9168P
Reported as
Titan Tornado II
Category
Airplane, amateur-built
Serial number
D00912COHK0376
Built
2007
Airframe hours
1,212.8
Engine
Rotax 912 ULS, 100 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental light sport (Special)
Last inspection
Condition · October 1, 2022 · 14.7 hours before
Departed
NA · Fredenberg Township, MN
Destination
KCOQ · Cloquet, MN
Equipment
Handheld GPS, Electronic multifunction display

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
66
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, With waivers/limitations
Seat
Front
Flight hours
1,248.2 total · 1,069.6 in this make and model · 1,198 as pilot in command · 10.4 in the last 90 days · 4.1 in the last 30 days · 1.9 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
210° at 9 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
30 °F, dew point 21 °F
Altimeter
29.96 inHg
Observed at
KCOQ, 7 nm away
METAR
KCOQ 181815Z AUTO 21009KT 10SM CLR M01/M06 A2996 RMK AO2 TSNO

Docket · 3

The files NTSB released with the investigation on April 18, 2024, on NTSB’s docket system: statements, records, photos and specialists’ reports. 37.1 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.