# Accident 19970817022499A: Aviat PITTSS1S, Van Nuys, CA, August 17, 1997

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: August 17, 1997, 13:00 local time
- Place: Van Nuys, CA
- Airport: Van Nuys Airport
- Damage: Destroyed
- Phase of flight: In Traffic Pattern-Circling
- Operating rules: General operating rules (Part 91)
- Location: 34.1902° N, 118.4907° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=34.1902&lon=-118.4907&mi=10
- Aircraft: N10HJ, a cancelled registration (https://openairdocs.org/deregistered/N10HJ-1999-01-27) (OpenAirDocs)
- Registry model: Hefner Jeffrey R PITTS S1S (registry code 72206CJ, https://openairdocs.org/model/hefner-jeffrey-r-pitts-s1s) (OpenAirDocs)
- Reported make and model: AVIAT PITTSS1S
- Reported engine: LYC HIO360D1A
- People aboard: 1
- Fatal injuries: 1
- Pilot flight hours: 238 total, 43 in this make and model
- NTSB investigation: [NTSB LAX97FA291](https://openairdocs.org/ntsb/LAX97FA291) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19970817022499A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

SHORTLY AFTER DEPARTURE. ISSUED MAY DAY. SEEN SPIRAL TO IMPACT. CRANKSHAFT BROKE OFF AT PROP ASSEMBLY IN FLIGHT. (.19) ON AUGUST 17, 1997, AT 1300 HOURS PACIFIC DAYLIGHT TIME, AN EXPERIMENTAL HEFNER-PITTS, S1S, N10HJ, WAS DESTROYED DURING A FORCED LANDING AT VAN NUYS, CA. THE PILOT RECEIVED FATAL INJURIES.  VISUAL METEOROLOGICAL CONDITIONS PREVAILED FOR THE PERSONAL FLIGHT, AND NO FLIGHT PLAN WAS FILED.  THE FLIGHT DEPARTED FROM RUNWAY 16R AT THE VAN NUYS AIRPORT AND THE PILOT REQUESTED A RIGHT-HAND DOWNWIND DEPARTURE TO THE PRACTICE AREA.  DURING THE DEPARTURE, ABOUT 1.5 MILES NORTHWEST OF THE AIRPORT, THE PILOT DECLARED "MAYDAY" THREE TIMES ON THE TOWER FREQUENCY.  TOWER PERSONNEL OBSERVED THE AIRCRAFT SPIRALING DOWNWARD.  WITNESSES STATED THAT THE AIRCRAFT DESCENDED AT A 45-DEGREE ANGLE INTO THE FOUR LAND RESIDENTIAL AREA STREET.  A PATH OF WRECKAGE DEBRIS PARALLELED THE EAST-WEST STREET OVER A DISTANCE OF 281 FEET. (.4) THE PILOT DEPARTED AND REQUESTED A RIGHT-HAND DEPARTURE TO THE PRACTICE AREA.  DURING THE DOWNWIND DEPARTURE HE DECLARED AN EMERGENCY AND WITNESSES OBSERVED THE AIRCRAFT SPIRALING DOWNWARD AT A 45-DEGREE ANGLE INTO A RESIDENTIAL STREET.  PARTS FROM THE AIRCRAFT  WERE FOUND SOME DISTANCE FROM THE ACCIDENT SITE. THE PROPELLER ALONG WITH THE SEVERED CRANKSHAFT FLANGE WERE FOUND STILL BOLTED TOGETHER LESS PART OF ONE PROPELLER BLADE.  METALLURGICAL EXAMINATION REVEALED THAT A BLADE HAD FAILED MIDSPAN DUE TO FATIGUE.  THE PROPELLER WAS BEING OPERATED ABOVE THE DESIGN RPM RED LINE OF 2,700.  ADDITIONALLY, THE PROPELLER WAS BEING SUBJECTED TO GYROSCOPIC AEROBATIC LOADS.  AN RPM RESTRICTION FOR THE PROPELLER MANDATED BY AN AIRWORTHINESS DIRECTIVE WAS NOT PLACARDED ON THE INSTRUMENT PANEL PER THE AD.  THE ENGINE WAS DESIGNED FOR A TYPE CERTIFICATED HELICOPTER APPLICATION AND WAS APPROVED FOR A 3,200 RPM RED LINE.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB LAX97FA291](https://openairdocs.org/ntsb/LAX97FA291), Aug 17, 1997: Hefner Pitts S1S (N10HJ), Van Nuys, CA, destroyed, 1 fatal. Probable cause: the operation of the propeller beyond the design rpm limitations and the resultant gyroscopic loads from aerobatics. Contributing to the accident was the lack of a required instrument panel rpm…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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