DEN05LA093 · Cessna 172N
Aviation Services Cessna 172N · Accident: abrupt maneuver during initial climb
From Platte Valley Airpark (18V) to 1V5 · Boulder, CO
Event
- NTSB case
- DEN05LA093
- 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
Cessna 172N
- Aircraft type
- Cessna 172
- 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
- N733RL
- Operator
- Aviation Services
- Onboard fatalities
- Unknown
- Route
- From Platte Valley Airpark (18V), Hudson, COTo 1V5 · Boulder, CO
- 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
- Initial climb
- First occurrenceThe 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
- Abrupt maneuver
- 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
- Flt control syst, wing flap control › Activated
- Pilot in command(cfi) › Raising of flaps, improper
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The flight instructor and his private pilot student were practicing touch and go landings. The student did not turn the carburetor heat off or put up the flaps after his touch and go, so the instuctor took control of the airplane. He turned off the carburetor heat and he said he got "hasty" and retracted the flaps completely instead of in gradual increments. The aircraft experienced a loss of lift and touched down on soft ground and nosed over. The temperature at the time of the accident was 92 degrees Fahrenheit with a calculated density altitude of 7713 feet msl.
Probable cause
The flight instructor's improper use raising of the flaps. Contributing factors were the student pilot's misunderstanding of the instructor's intentions, the instructor's inadequate supervision of the student pilot, the density altitude, and the soft terrain.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN05LA093
- Event ID
- 20050628X00882
- Case number
- DEN05LA093
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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: b76f9f9523a1202934e8f50b9cffdc49354dd30379402d6a7e49e00fb18ad062; retrieved 2026-09-22T05:45:51.688Z.