DEN89FA093 · Cessna 177RG
Cessna 177RG · Accident: abrupt maneuver during takeoff
From 4AC to Phoenix Deer Valley Airport (DVT)
Event
- NTSB case
- DEN89FA093
- 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
- 2 · all aircraft and ground
- Ground fatalities
- 0
- 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 177RG
- Aircraft type
- Cessna 177
- 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
- N2972X
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From 4ACTo Phoenix Deer Valley Airport (DVT), Phoenix, AZ
- 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
- Takeoff · roll/run
- 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
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Stall
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Pilot in command › Airspeed, inadequate
- Pilot in command › Lowering of flaps, excessive
- Pilot in command › Stall, uncontrolled
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
SURVIVING PAX SAID ACFT BANKED STEEPLY TO LEFT AFTER TAKEOFF AND SHUDDERED. HE SAW PLT REACH FOR FLAP CONTROL HANDLE. PAX REMEMBERED HORN BLOWING IN BACKGROUND. WITNESSES SAID ACFT SPEED AND CLIMB RATE WERE SLOW AND SAW ACFT WOBBLE AND DIP WINGS. ONE WITNESS, IN LINE WITH ACFT TAKEOFF PATH, SAW FLAPS BEING RETRACTED SLIGHTLY. EXAMINATION OF WRECKAGE DISCLOSED FLAP JACKSCREW EXTENDED 10 THREADS OR 1.66 INCHES, EQUIVALENT TO APRX 14 DEG FLAPS DOWN. MANUFACTURER SUGGESTS TAKE OFF WITH FLAPS UP OR 1/4 (7.5 DEG) DOWN. PLT WAS KNOWN TO HAVE HABIT OF STARTING TAKEOFF ROLL WITH FLAPS UP AND, AS LIFTOFF SPEED WAS ATTAINED, TO 'SLAP' FLAP HANDLE DOWN TO DETENT (1/4 OR 7.5 DEG SETTING). EXPERIMENTATION LATER SHOWED THAT IT WAS POSSIBLE TO SLAP FLAP HANDLE INADVERTENTLY PAST DETENT OR FULL DOWN POSITION.
Probable cause
THE PILOT'S IMPROPER USE OF FLAPS DURING TAKEOFF WHICH RESULTED IN INADEQUATE AIRSPEED, A STALL, AND LOSS OF CONTROL.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN89FA093
- Event ID
- 20001213X27872
- Case number
- DEN89FA093
- 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. 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: 7e42ee09420e794ceecb96eb1a9b0724de37c10dc85b06540ac1b579dcd41268; retrieved 2026-09-21T03:22:13.955Z.