DEN02LA051

NTSB accident investigation · Enstrom F-28C · Medicine Bow, WY · June 10, 2002

Accident · Serious injuriesLimited investigationFinal report
Date
June 10, 2002, 09:30 local (15:30 UTC)
Place
Medicine Bow, WY
Injuries
1 serious, 1 minor
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N5694ZEnstrom F-28C
Weather
Visual (VMC) · Day
Status
Completed · report December 6, 2002
Report
Approved by Office Director
Parties
Enstrom Helicopter Corporation, Textron Lycoming, Federal Aviation Administration
FAA report
20020610013889A
Case key
54892

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

the unsuitable terrain encountered during the emergency autorotation, following a partial loss of engine power. Factors contributing to this accident were fuel contamination (water), the low altitude, the high winds, and the tailwind.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(partial) - nonmechanicalManeuvering - turn to reverse direction
Fluid,fuel - contamination,waterFactor
Forced landingEmergency descent/landing
Autorotation - performedPilot in command
Hard landingEmergency descent/landing
Unsuitable terrain or takeoff/landing/taxi area - encounteredCause
Altitude - lowFactor
Weather condition - high windFactor
Weather condition - tailwindFactor

Analysis

The pilot reported that he was conducting pipeline patrol and marking the positions of pipeline valves using a global positioning satellite receiver. The pilot said weather was clear but windy. Approximately 1 hour into the flight, the pilot made a turn to the west to come around over a location, and continued in the turn back to the east downwind. The pilot said he rolled out of the turn and started to pull some power for the turn back to the right to pick up the pipeline again when the helicopter yawed right and started losing power. The pilot said he immediately "lowered the collective, added throttle, and turned left to the north." The pilot said he was approximately 100 feet above the ground and had an airspeed of about 60 miles per hour. "With the bank and the autorotation I was able to stop forward motion and ground speed. I flared the helicopter, pulled pitch, and hit flat." The pilot said he shut down the engine after impact. "As far as I could tell the power never came back during the autorotation." An examination of the helicopter's fuel system showed water in the left and right fuel tanks. No other anomalies were found.

Factual narrative

On June 10, 2002, at 0930 mountain daylight time, an Enstrom F-28C, N5694Z, operated by Falcon Helicopter, Inc., and piloted by a commercial pilot, was substantially damaged during a hard landing that occurred 10 miles south of Medicine Bow, Wyoming. Visual meteorological conditions prevailed at the time of the accident. The business flight was for conducting pipeline patrol under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot sustained serious injuries in the accident. The passenger on board the helicopter sustained minor injuries. The flight originated at Laramie, Wyoming, at 0830, and was to terminate at Rawlins, Wyoming .

The pilot reported that he was conducting pipeline patrol and marking the positions of pipeline valves using a global positioning satellite receiver. In his written statement, the pilot said they picked up the pipeline at the northwest side of Laramie and proceeded northwest. "The weather was clear but windy. At about 0930 we made a turn to the west to come around over a location, and continued in the turn back to the east downwind. I rolled out of the turn and started to pull some power for the turn back to the right to pick up the pipeline again when the helicopter yawed right and started losing power." The pilot said he immediately "lowered the collective, added throttle, and turned left to the north." The pilot said he was approximately 100 feet above the ground and had an airspeed of about 60 miles per hour. "With the bank and the autorotation I was able to stop forward motion and ground speed. I flared the helicopter, pulled pitch, and hit flat." The pilot said he shut down the engine after impact. "As far as I could tell the power never came back during the autorotation."

In a subsequent interview, the pilot reported that he had flown to Laramie, from Longmont, Colorado, earlier that morning. At Laramie, the pilot had the helicopter's fuel topped off. The pilot said that the fixed base operator at Laramie, told him that they were having trouble with their refueling truck, but didn't know what that was. The pilot said that the helicopter's attitude during takeoff, climb out, and during the flight to the location where they maneuvered, was level. He said that after completing the turn and on downwind, there was a stiff wind of about 25 knots. The pilot said that he was starting to initiate the turn to get back on the pipeline and was pulling power when the power started bleeding off. The pilot said, "It seemed like it sucked bad fuel."

The helicopter came to rest upright in an open field. A preliminary examination of the helicopter showed the left skid broken upward and the bottom of the fuselage crushed upward. The tail boom was broken off, aft of the baggage compartment. The forward windscreen and chin windows were broken out. The trailing edges of two of the three main rotor blades were bent downward, wrinkled, torn, and twisted. The tail rotor gear box was broken out and found resting on the ground in front of the helicopter cabin. The tail rotor blades were bent outward. The helicopter's engine was retained for further examination.

The National Transportation Safety Board examined the helicopter at Greeley, Colorado, on June 25, 2002. Fuel samples were taken at the sump drains to the left and right fuel tanks, and the fuel strainer. The fuel sample taken from the left tank showed approximately 2 ounces of water. Fuel samples from the right tank and the fuel strainer showed no water. The engine was started and run. No anomalies were found during the engine run. The helicopter was then defueled. Approximately 25 gallons of fuel was drained from the helicopter's two tanks. An additional 4 ounces of water was recovered from the bottom of the helicopter's right fuel tank.

Aircraft

Registration
N5694Z
Reported as
Enstrom F-28C
Category
Helicopter
Serial number
497-2
Airframe hours
1,999.9
Engine
Lycoming HIO-360-E1AD, 205 horsepower, reciprocating
Damage
Substantial damage
Flight
Business · Part 91
Operator
Falcon Helicopter, Inc., doing business as Falcon Helicopters, Inc
Registered owner
Timothy C. Rhoads
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · May 10, 2002 · 148 hours before
Departed
LAR · Laramie, WY
Destination
RWL · Rawlins, WY

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
47
Injuries
Serious
Certificates
Commercial, Flight instructor
Airplane ratings
Single-engine land
Instrument ratings
Helicopter, Airplane
Medical
Class 2
Last flight review
January 17, 2001
Seat
Left
Flight hours
10,418 total · 8,000 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
340° at 11 knots, gusting 14
Visibility
10 statute miles
Lowest ceiling
None
Temperature
48 °F, dew point 18 °F
Altimeter
29.97 inHg
Observed at
LAR, 36 nm away

Docket · 14

The files NTSB released with the investigation on October 29, 2002, on NTSB’s docket system: statements, records, photos and specialists’ reports. 3.1 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.