# NTSB ANC82DA075: Enstrom F-28F, N5698E, Near Sutton, AK, August 17, 1982

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Final report
- Date: August 17, 1982, 10:05 local (18:05 UTC)
- Place: Near Sutton, AK
- Coordinates: 61.740734, -148.220092 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=61.7407&lon=-148.2201&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 3 minor
- Status: Completed, report August 17, 1983
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 71940
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC82DA075
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/71940/pdf
- Page: https://openairdocs.org/ntsb/ANC82DA075

## Analysis

THE PILOT HAD APPROACHED AND LANDED ON A BLUFF TO DISCHARGE HIS TWO PASSENGERS. HOWEVER, BEFORE DISCHARGING THE PASSENGERS, HE DECIDED TO TAKEOFF AND FIND A BETTER LANDING AREA. WHEN THE HELICOPTER WAS ABOUT 10 TO 20 FT FROM THE TAKEOFF POINT, BUT APPROXIMATELY 200 FT AGL, THERE WAS A DECREASE IN RPM. INITIALLY, THE PILOT THOUGHT HE WAS SETTLING WITH POWER. HE LOWERED THE NOSE AND COLLECTIVE, BUT WAS UNABLE TO REGAIN THE RPM, BUT HE FELT THE HELICOPTER YAW TO THE LEFT. HE FELT MAST-BUMPING AND REALIZED HE MUST BE CROSS-CONTROLLING WITH TOO MUCH RIGHT PEDAL AND LEFT CYCLIC. HE THEN ENTERED AN AUTOROTATION. THE HELICOPTER COLLIDED WITH TREES ON THE SIDE OF THE BLUFF AND ROLLED TO THE BOTTOM OF THE HILL. AN EXAMINATION REVEALED THAT THE NO-2 CYLINDER COMPRESSION WAS LOW. THE NO-2 INTAKE VALVE HAD BECOME TULIPED AND WAS LEAKING. THERE WAS EVIDENCE THAT IT HAD BEEN POUNDING. ALSO, THERE WAS INDICATIONS OF HIGH ENGINE RPM AND TEMPERATURE. THE HELICOPTER HAD BEEN FLOWN 38 HRS SINCE THE LAST INSPECTION.

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, takeoff - initial climb
  - engine assembly,valve,intake - leak (cause)
  - powerplant controls - improper use of (cause)
- Forced landing, landing - flare/touchdown
  - autorotation - performed, pilot in command (cause)
- In flight collision with object, landing - flare/touchdown
  - object - tree(s) (contributing factor)
- In flight collision with terrain/water, landing - flare/touchdown
  - terrain condition - downhill (contributing factor)

## Aircraft

- Registration: [N5698E](https://openairdocs.org/aircraft/N5698E), registered now, S/N 506-2 (OpenAirDocs)
- Reported make and model: ENSTROM F-28F
- Registry model: [Enstrom F-28F](https://openairdocs.org/model/enstrom-f-28f) (registry code 3300412) (OpenAirDocs)
- Category: Helicopter
- Serial number: 506
- Airframe hours: 770
- Engines: LYCOMING HIO-360-F1AD 225 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: Kean & Associates
- Registered owner: Robert T. Kean
- Departed: NEAR SUTTON, AK
- Destination: NEAR SUTTON, AK

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 25; private; medical: class 2, valid medical--w/ waivers/lim; flight hours: 800 total, 600 in this make and model, 255 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 20 statute miles
- Temperature: 136 °F

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.

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