SEA08LA128 · Moravan Zlin 50LX
Moravan Zlin 50LX · Accident: collision with terrain/object (non-CFIT) while maneuvering
From Modesto City Co-Harry Sham Field (KMOD) to Modesto City Co-Harry Sham Field (KMOD)
Event
- NTSB case
- SEA08LA128
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Moravan Zlin 50LX
- Aircraft type
- Moravan ZLIN 50
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N6660K
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Modesto City Co-Harry Sham Field (KMOD), Modesto, CATo Modesto City Co-Harry Sham Field (KMOD), Modesto, CA
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Maneuvering · low-altitude flying
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Collision with terrain/object (non-CFIT)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft oper/perf/capability
- Personnel issues › Action/decision
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot was performing in an airshow that was conducted at a controlled airport serviced by airlines. Two Federal Aviation Administration (FAA) inspectors acting as the FAA monitors, witnessed the accident. Performances, as a rule, are timed so that they do not conflict with inbound and landing airline traffic. If there is a timing conflict, normally the show is temporarily stopped so as not to delay the airline traffic. During the accident pilot's performance, the pilot was transmitting directly to the crowd, as well as communicating with an on ground safety observer, the airshow waiver holder, and an air traffic control tower controller. The air traffic control tower controller advised the pilot to stop the performance due to an inbound arriving airliner and make a right base entry for landing. The pilot had completed a normal sequence and then requested to make one more pass and the tower controller approved the request. The pilot then added the additional maneuver as his final routine before exiting the performance box. The FAA inspector indicated that during the added maneuver, the right wing impacted the ground. The pilot stated that during the airshow briefing, he had requested a sterile frequency for maintaining communication with airshow and ground support staff, which he indicated was standard operating procedures at other airshows. The air traffic control tower personnel elected to have the airshow pilots monitoring and communicating on the same frequency as the tower controllers. The pilot stated that during the flight, he was interrupted numerous times by tower personnel and incoming aircraft, which prevented his ground safety observer from communicating with him and not only added to his workload, but affected his concentration during the maneuver.
Probable cause
The pilot failed to maintain clearance from terrain during a low-altitude maneuver at an airshow. Contributing to the accident was the task overload in the increased frequency congestion.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA08LA128
- Event ID
- 20080515X00671
- Case number
- SEA08LA128
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 4567c476f682adba6450c80e8a4f43dc12cfd89e1bcb700951d07c3874ce69a9; retrieved 2026-09-15T09:39:09.342Z.