# NTSB LAX89FA238: Enstrom F28F, N288, Oakland, CA, July 11, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Field investigation · Final report
- Date: July 11, 1989, 13:25 local (20:25 UTC)
- Place: Oakland, CA
- Coordinates: 37.749187, -122.130187 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.7492&lon=-122.1302&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report July 22, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26234
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX89FA238
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26234/pdf
- Page: https://openairdocs.org/ntsb/LAX89FA238

## Probable cause

FAILURE OF THE PILOT TO PROPERLY MAINTAIN ROTOR RPM THROUGHOUT THE AUTOROTATION.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Hard landing, landing - flare/touchdown
  - autorotation - performed, pilot in command
  - rotor rpm - not maintained, pilot in command (cause)
  - flare - not attained, pilot in command

## Analysis

THE CERTIFICATED PRIVATE PILOT ELECTED TO CONDUCT A PRACTICE AUTOROTATION WITH TURN AND RECOVER WITH POWER. THE PILOT WAS FLYING WITH A PASSENGER. THE PILOT ALLOWED THE ROTOR RPM TO BLEED OFF AND WAS UNABLE TO RECOVER THE RPM BEFORE TOUCHDOWN. THE HELICOPTER LANDED HARD COLLAPSING THE SKID TYPE LANDING GEAR SYSTEM. THE MAIN ROTOR THEN CONTACTED THE TAILBOOM. THE HELICOPTER SLID ABOUT 100 FEET AFTER TOUCHDOWN AND ROTATED 90 DEGREES TO THE LEFT.

## Aircraft

- Registration: [N288](https://openairdocs.org/deregistered/N288-1992-02-05), registration cancelled 1992-02-05, S/N 742 (OpenAirDocs)
- Reported make and model: ENSTROM F28F
- Registry model: [Enstrom F-28F](https://openairdocs.org/model/enstrom-f-28f) (registry code 3300412) (OpenAirDocs)
- Category: Helicopter
- Serial number: 742
- Airframe hours: 3304
- Engines: LYCOMING HIO-360-F1AD 225 horsepower reciprocating
- Damage: Substantial damage
- Flight: Public aircraft, Part 91
- Registered owner: Oakland Police Dept.
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, June 15, 1989, 63 hours before
- Departed: OAK, OAKLAND, CA
- Airport: OAK, Oakland Int'L

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; private; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 207 total, 78 in this make and model, 65 as pilot in command, 63 in the last 90 days, 17 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 20 statute miles
- Lowest ceiling: none

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19890711021899A](https://openairdocs.org/incident/19890711021899A), Jul 11, 1989: Enstrm F28F, Oakland, CA, Substantial damage. Allowed rotor RPM to decay on practice autorotation with power recovery. Unable recover hit hard. Collapsed skids.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.