DEN02LA064 · Beech 35
Beech 35 · Accident: partial loss of engine power (mechanical failure) on approach
From Ryan Field (RYN) to Cortez Municipal Airport (CEZ)
Event
- NTSB case
- DEN02LA064
- 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
Beech 35
- Aircraft type
- Beechcraft 35
- 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
- N404B
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Ryan Field (RYN), Tucson, AZTo Cortez Municipal Airport (CEZ), Cortez, 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
- Approach · VFR pattern final
- 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
- Partial loss of engine power (mechanical failure)
- 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
- Substantial
Cause areas
- Pilot in command › Stall, inadvertent
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 took off at 0638, drawing fuel from the left main tank. At 0739, he switched to the right main tank. At 0840, he switched to the auxiliary fuel tank. As he approached his destination, the pilot noted that the main fuel tanks were half full and the auxiliary fuel tank was over half full. He reduced power and began a slow descent. As he approached the traffic pattern, he switched back to the left main fuel tank. On approach, he lowered the landing gear and as he started to lower the flaps, he noticed the airspeed had decreased so he added power. The airplane "started to wobble and became hard to handle," so the pilot applied full power. The airspeed "was not responding very quickly." He confirmed the fuel selector was on the left tank and the fuel boost pump was on. After clearing a rock wall cliff and ravine, the pilot flew underneath power lines and the airplane struck the ground. Flow testing of the carburetor at 10 pounds psi revealed an external leak at the idle diaphragm. Further tests indicated the carburetor would run rich at low power settings and lean at high power settings. The fuel pump was able to maintain 20 gph at 10 psi and 500 rpm. At 1,000 rpm, a leak was noted at the lower splitline surface. At 2,500 rpm, the fuel pump maintained 160 gph at 12 psi.
Probable cause
an inadvertent stall as the pilot attempted to clear a cliff and ravine and avoid power lines, resulting in a collision with the ground. Contributing factors were a loss of engine power for undetermined reasons, a leaking carburetor and fuel pump, and the cliff, ravine, and power lines.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN02LA064
- Event ID
- 20020702X01024
- Case number
- DEN02LA064
- 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: 2004d150ed29edbdf030e558b92934e353f8f8016e0d76e591cd48f2888960b0; retrieved 2026-09-21T09:37:44.550Z.