WPR09CA051

NTSB accident investigation · Beech B60 · Rock River, WY · November 29, 2008

Accident · No injuriesData collectionFinal report
Date
November 29, 2008, 09:00 local (16:00 UTC)
Place
Rock River, WY
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N6693ABeech B60
Defining event
Enroute-cruise: Structural icing
Weather
Visual (VMC) · Day
Status
Completed · report January 22, 2009
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
Federal Aviation Administration
FAA report
20081129852629A
Case key
69514

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

On this page

Probable cause

The pilot's failure to maintain clearance from a power line due to the lack of forward visibility because of an ice-covered windshield. Contributing to the accident was the flight's encounter with icing weather conditions.

Findings · 4

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Object/animal/substance: wireEnvironmental issues › Physical environment · Ability to respond/compensateBeech B-60: 1 caseAll aircraft: 588 casesProbable cause
Temp/humidity/pressure: conducive to structural icingEnvironmental issues › Conditions/weather/phenomena · Effect on operationBeech B-60: 1 caseAll aircraft: 103 casesProbable cause
Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedBeech B-60: 2 casesAll aircraft: 1,681 cases
Physical workspace: visibilityEnvironmental issues › Task environment · Effect on personnelBeech B-60: 1 caseAll aircraft: 25 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The pilot reported that during a cross-country flight conducted under instrument flight rules, he encountered clouds that contained clear ice. Ice built up rapidly on the airplane, which was in cruise flight at 16,000 feet. In an effort to get out of the icing conditions, he requested and received clearance to progressively lower altitudes down to 10,000 feet. The airplane continued to accumulate ice. He requested a turn, and this was denied by the controller as there were two other airplanes in the vicinity with similar icing problems. He then requested and received clearance to descend to 9,000 feet, where he could see portions of the ground. At this point, "both windshields were completely covered with clear ice as were the unprotected portions of the aircraft" and both engines were operating at full power. The pilot informed the controller that he needed to descend further. At an altitude of 7,500 feet, he circled several times attempting to see if he could reach an airport for landing. No ice had melted or come off the airplane, and the weather was deteriorating. The pilot decided to land on a highway. On final approach to land, the airplane collided with a power line, which severed the upper half of the rudder and vertical stabilizer. The pilot turned the airplane slightly left, and landed the airplane with the landing gear down in a terraced field next to the highway. During the landing roll, the landing gear was sheared off when the airplane encountered a ditch. The pilot stated that he had "no forward visibility due to the clear ice that completely covered the windshields."

Factual narrative

The pilot reported that during a cross-country flight conducted under instrument flight rules, he encountered clouds that contained clear ice. Ice built up rapidly on the airplane, which was in cruise flight at 16,000 feet. In an effort to get out of the icing conditions, he requested and received clearance to progressively lower altitudes down to 10,000 feet. The airplane continued to accumulate ice. He requested a turn, and this was denied by the controller as there were two other airplanes in the vicinity with similar icing problems. He then requested and received clearance to descend to 9,000 feet, where he could see portions of the ground. At this point, "both windshields were completely covered with clear ice as were the unprotected portions of the aircraft" and both engines were operating at full power. The pilot informed the controller that he needed to descend further. At an altitude of 7,500 feet, he circled several times attempting to see if he could reach an airport for landing. No ice had melted or come off the airplane, and the weather was deteriorating. The pilot decided to land on a highway. On final approach to land, the airplane collided with a power line, which severed the upper half of the rudder and vertical stabilizer. The pilot turned the airplane slightly left, and landed the airplane with the landing gear down in a terraced field next to the highway. During the landing roll, the landing gear was sheared off when the airplane encountered a ditch. The pilot stated that he had "no forward visibility due to the clear ice that completely covered the windshields."

Aircraft

Registration
N6693A
Reported as
Beech B60
Category
Airplane
Serial number
P-527
Airframe hours
5,151
Engine
Lycoming TSIO-540, 380 horsepower, reciprocating
Damage
Substantial damage
Flight
Executive/Corporate · Part 91
Operator
Rice Air LLC
Registered owner
Rice Air LLC
Airworthiness certificate
Standard, Normal
Last inspection
Annual · June 26, 2008
Departed
BFF · Scottsbluff, NE
Destination
SAA · Saratoga, WY
Flight plan
IFR

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
62
Injuries
None
Certificates
Commercial, Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
June 25, 2008
Seat
Left
Flight hours
25,019 total · 834 in this make and model · 11,179 as pilot in command · 70 in the last 90 days · 30 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
310° at 16 knots, gusting 22
Visibility
10 statute miles
Lowest ceiling
3,300 ft broken
Temperature
28 °F, dew point 21 °F
Altimeter
29.89 inHg
Observed at
LAR, 30 nm away

FAA reports on this event · 1

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