DEN01FA090 · Piper PA-39
Piper PA-39 · Accident: loss of engine power during initial climb
From 3V5 · Fort Collins, CO to Iowa City Municipal Airport (IOW)
Event
- NTSB case
- DEN01FA090
- 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
Piper PA-39
- Aircraft type
- Piper PA-39
- 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
- N8984Y
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From 3V5 · Fort Collins, COTo Iowa City Municipal Airport (IOW), Iowa City, IA
- 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
- Loss of engine 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
- Engine assembly
- Induction air control, alternate air/door › Flow restricted
- Induction air control, alternate air/door › Separation
Approximate · Estimated position: the centre of Fort Collins, CO, the place the record names. Not the accident site.
NTSB narrative
According to the pilot, take-off was normal, the airplane rotated at 95 mph, accelerated to 110 mph. During the initial climb, and at approximately 150 feet above ground level (agl), the left engine lost power and "quit." The pilot attempted to restart the left engine, but before he could, the right engine lost power and "quit." The pilot conducted a forced landing in a open field just north of the runway. Following touch down, the aircraft slid across two railroad tracks, impacted a ditch, struck a power pole and spun 90 degrees to the left, coming to rest on a city street. Examination of the left engine compartment found that the alternate air door was stuck in the open position, corrosion was present on the actuating cable and the cable end was broken. Examination of the right engine compartment found the alternate air door was separated from its mounting rivets and was lodged in the alternate air box, completely covering the inlet on the fuel injector servo. The pilot stated that when they arrived in Fort Collins on April 24, he had the aircraft fuel tanks topped off. According to the Fort Collins Downtown Airport daily fuel record sheet for April 24, 2001, N8984Y, received 61.8 gallons of 100 low lead fuel. An examination of the remaining fuel in the airplane, and the fuel in the refueling truck, provided no evidence of fuel contamination. Six other aircraft were serviced and refueled the same day with no reported problems. A sample of an unknown substance/debris found in the left main fuel tank gascolator, was sent it to SEM-EDAX for spectra-analysis. SEM-EDAX analyzed the substance/debris and identified it as silica sand.
Probable cause
the loss of right engine power on take-off as a result of the separation of the right engine's alternate air door, which lodged in the fuel servo air inlet. A factor was the lack of suitable terrain for a forced landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN01FA090
- Event ID
- 20010504X00884
- Case number
- DEN01FA090
- 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: 83f0e10469753cfd236181d9e450e85ead44a766caf3498962d845e9afff5ba6; retrieved 2026-09-21T10:09:17.711Z.