CEN25LA392 · Diamond Aircraft DA20-C1
Indiana State University Diamond Aircraft DA20-C1 · Accident: system/component malfunction/failure (non-power) during takeoff
From Terre Haute Regional Airport, Hulman Field (HUF) to Terre Haute Regional Airport, Hulman Field (HUF)
Event
- NTSB case
- CEN25LA392
- 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
- Event fatalities
- Unknown
- 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
Diamond Aircraft DA20-C1
- Aircraft type
- Diamond DA20
- 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
- N544KC
- Operator
- Indiana State University
- Onboard fatalities
- Unknown
- Route
- From Terre Haute Regional Airport, Hulman Field (HUF), Terre Haute, INTo Terre Haute Regional Airport, Hulman Field (HUF), Terre Haute, IN
- Aircraft age
- About 16 years (built 2009)
- 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
- Takeoff
- 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
- System/component malfunction/failure (non-power)
- 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 systems
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The flight instructor and pilot-receiving-instruction were conducting an instructional flight when the nosewheel separated from the nose landing gear strut during takeoff. The flightcrew reported that the takeoff was normal and that there was no indication that the nosewheel had separated from the airplane. However, after the nosewheel was located on the runway, the flight instructor received a phone call from the airplane operator and then via subsequent radio calls over the operator dispatch frequency it was determined that the separated nosewheel was likely from their airplane. Then the airplane operator and airport tower controller each visually confirmed that the nosewheel was indeed missing from the airplane. During the subsequent landing, the nose landing gear strut collapsed aft when it contacted the runway. The composite fuselage structure sustained multiple cracks, the nose landing gear box delaminated, and the firewall delaminated from the fuselage during the landing.
The lower portion of the nose landing gear strut welded assembly terminates with a threaded stud where a castellated nut and cotter pin secure the nosewheel fork assembly to the strut pivot. A postaccident examination determined that the threaded stud fractured which allowed the nosewheel fork to separate from the strut pivot. The castellated nut and cotter pin remained installed to the threaded portion of the fractured stud.
In January 2023, the airplane manufacturer issued Service Information Letter (SIL) No. SIL20C1-014 to address cracks at the top of the nose landing gear strut pivot and/or at the top of the threaded stud. Additionally, the airplane manufacturer cautioned that a single hard landing may severely reduce the service life of the nose landing gear strut, and that improper assembly of the nose landing gear could result in cracking at the threaded stud which may result in the separation of the nosewheel fork assembly. The airplane manufacturer recommended a thorough examination of the nose landing gear strut pivot and threaded stud every 100 hours in accordance with the airframe maintenance manual instructions. The airplane manufacturer further stipulated that it was imperative that “all suspected hard landings are reported and the airplane inspected.”
According to a postaccident review of maintenance documentation, there were no cracks observed on the nose landing gear strut when it was last examined during a 100-hour examination completed about 30.7 flight hours before the accident flight.
Probable cause
The failure of the nose landing gear strut and associated nosewheel separation during takeoff.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN25LA392
- Event ID
- 20250925201718
- Case number
- CEN25LA392
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (5)
- 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, cause areas. 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: b54cb7d9a274fd56642dcf7b6eeaff83603b0a5836524ac39bae409e1a8844dd; retrieved 2026-09-16T20:23:02.282Z.
- Corrected after a review of the NTSB narrative, which states these values explicitly: departure, destination. Misspelled city name; HUF is Terre Haute Regional Airport, Terre Haute, IN, as the location field spells it. Misspelled city name; HUF is Terre Haute Regional Airport, Terre Haute, IN, as the location field spells it.