Wingtip To Wingtip, LLC PANZL S-330 accident near Battle Creek, Michigan, July 3, 2011
On July 3, 2011, a Wingtip To Wingtip, LLC PANZL S-330, registered N330JK, was substantially damaged in an accident during maneuvering (aerobatics) near Battle Creek, Michigan (W K Kellogg Airport). It was an air show or air race flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The inadequate aileron hinge design, which resulted in the in-flight separation of the left aileron following a fatigue failure of the center hinge rod-end.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 3, 2011
- Place
- Battle Creek, Michigan · W K Kellogg Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Wingtip To Wingtip, LLC PANZL S-330
- Registration
- N330JK · registry record · serial 009
- Damage
- Substantial damage
- Flight
- Air show or air race flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The entire left aileron separated from the airplane as the pilot was performing an aerobatic aileron-roll maneuver during an airshow aerobatic demonstration flight. The pilot was able to recover into level flight and make an uneventful landing. The pilot stated that his preflight inspection before the accident flight did not reveal any mechanical issues with the airplane, including loose jam nuts or any other aileron anomalies. However, the pilot reported that his aviation mechanic had to retighten the jam nut for the center aileron hinge rod-end after it had been found loose on several occasions before the accident flight. A postaccident examination revealed that the center aileron hinge had failed in the shank region of the rod end due to reverse bending fatigue. No material issues were identified with the center aileron rod end, which met the part specifications. A design analysis confirmed that the aileron rod ends were adequate for the limit loads on the structure but were inadequate for fatigue tolerance. The stress levels in the rod end shank were at or above the endurance limit for the specified rod end material, regardless of a loose or tight jam nut. However, a loose jam nut further increased the stress in the rod end about 28 percent and would have reduced the cycles to a fatigue failure. Following the accident, the airplane manufacturer redesigned the aileron bracket assemblies by increasing the diameter of the rod end shank and reducing the moment arm between the bearing and the aileron bracket. The redesign yielded a total stress reduction of about 83 percent in the rod end, which was significantly below the endurance limit for the specified material.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Part(s) separation from AC during maneuvering (aerobatics) defining event
The NTSB's findings
- cause Aircraft › Aircraft systems › Flight control system › Aileron control system › Design
- cause Aircraft › Aircraft systems › Flight control system › Aileron control system › Fatigue/wear/corrosion
- cause Aircraft › Aircraft systems › Flight control system › Aileron control system › Failure
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 13,000 hours in all; 180 in this make and model; 100 in the last 90 days; 50 in the last 30 days; 10,000 as pilot in command; 2,000 on instruments
- Last flight review: October 8, 2009
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: sngl
- Injury: no injuries
The aircraft
- Airframe total time: 180 hours
- Last inspection: condition inspection, April 20, 2011
- Maximum gross weight: 1,900 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming AEIO-540-EXP (piston); 0 hours total
- Operator: John Klatt Airshows, Inc.
The flight
- Departed from: BTL Battle Creek MI
- Destination: BTL Battle Creek MI
- Flight plan: none
- Runway 23R, 10,004 ft by 150 ft
Weather at the time
- Light: dusk
- Wind: from 260° at 8 knots
- Visibility: 8 statute miles
- Sky: overcast at 3,500 ft
- Temperature: 79°F (26°C), dew point 70°F (21°C)
- Altimeter: 29.97 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.