CHI07CA049

NTSB accident investigation · Beech 99 · Mosinee, WI · December 23, 2006

Accident · No injuriesData collectionFinal report
Date
December 22, 2006, 19:00 local (Dec 23, 2006, 01:00 UTC)
Place
Mosinee, WI
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N799CZBeech 99
Weather
Instrument (IMC) · Night/dark
Status
Completed · report March 26, 2007
Report
Approved by Office Director
Parties
Milwaukee, WI, FSDO
FAA report
20061222028979A
Case key
65130

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 pilot encountering the unsuitable terrain during the landing. Factors were the dark night and the snowbank.

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.

On ground/water encounter with terrain/waterLanding
Unsuitable terrain or takeoff/landing/taxi area - encounteredPilot in commandCause
Facility inadequateAirport personnel
Terrain condition - snowbankFactor
Terrain condition - ground
Light condition - dark nightFactor

Analysis

The airplane, on a non-scheduled domestic cargo positioning flight, sustained substantial damage on impact with a snowbank and terrain during landing. The pilot, in part, stated, "I executed a routine [instrument landing system] approach ... during moderate to heavy snowfall at Central Wisconsin Airport. The runway conditions were reported as poor and it was snow covered. A crosswind existed as well as some wind shear as noted during the approach. Central Wisconsin Tower also advised me of a snow berm that remained on the west side of RWY 35 because it was not plowed to the full width of the runway. After I got a visual on the runway lights, I judged the runway centerlines by the runway lights and my position in between them. After the main wheels touched, I let the nose wheel down and I could see via the landing lights that I was close to the berm on my side and I gradually pushed right rudder pedal to steer away from the snow berm. I did not apply any braking action to avoid skidding and I was above 60 kts and had plenty of runway remaining to bleed off speed. Just as I positioned the power levers in the beta range, the left outer main landing gear tire began to make contact with the edge of the remaining snow berm left by the plows. The aircraft then began to yaw to the left and I applied more right rudder to compensate, but to no avail. The nose wheel hit the snow berm and broke off sending the aircraft sailing over the berm. The main landing gear wheels collapsed completely and the aircraft slid to a stop approximately 200 ft. west of RWY 35 off of the runway."

Factual narrative

The airplane, on a non-scheduled domestic cargo positioning flight, sustained substantial damage on impact with a snowbank and terrain during landing. The pilot, in part, stated, "I executed a routine [instrument landing system] approach ... during moderate to heavy snowfall at Central Wisconsin Airport. The runway conditions were reported as poor and it was snow covered. A crosswind existed as well as some wind shear as noted during the approach. Central Wisconsin Tower also advised me of a snow berm that remained on the west side of RWY 35 because it was not plowed to the full width of the runway. After I got a visual on the runway lights, I judged the runway centerlines by the runway lights and my position in between them. After the main wheels touched, I let the nose wheel down and I could see via the landing lights that I was close to the berm on my side and I gradually pushed right rudder pedal to steer away from the snow berm. I did not apply any braking action to avoid skidding and I was above 60 kts and had plenty of runway remaining to bleed off speed. Just as I positioned the power levers in the beta range, the left outer main landing gear tire began to make contact with the edge of the remaining snow berm left by the plows. The aircraft then began to yaw to the left and I applied more right rudder to compensate, but to no avail. The nose wheel hit the snow berm and broke off sending the aircraft sailing over the berm. The main landing gear wheels collapsed completely and the aircraft slid to a stop approximately 200 ft. west of RWY 35 off of the runway."

Aircraft

Registration
N799CZ
Reported as
Beech 99
Category
Airplane
Serial number
U-68
Airframe hours
29,609
Engines
Pratt & Whitney PT6A-28, 680 horsepower, turbo propPratt & Whitney PT6A-28, 680 horsepower, turbo prop
Damage
Substantial damage
Flight
Positioning · Part 91
Registered owner
Freight Runners Express Inc
Airworthiness certificate
Standard, Normal
Last inspection
AAIP · December 1, 2006
Departed
OSH · Oshkosh, WI
Destination
CWA · Mosinee, WI
Flight plan
IFR
Airport
runway 35, 6,500 × 150 ft, concrete

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
42
Injuries
None
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Without waivers/limitations
Seat
Left
Flight hours
3,500 total · 230 in this make and model · 110 in the last 90 days · 44 in the last 30 days · 6 in the last 24 hours

Weather

Conditions
Instrument (IMC) · Night/dark
Wind
280° at 5 knots
Visibility
1 statute miles
Lowest ceiling
300 ft overcast
Temperature
32 °F, dew point 32 °F
Altimeter
29.56 inHg
Observed at
CWA

FAA reports on this event · 1

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

Other investigations on N799CZ · 1

Matched to the same aircraft by N-number and date.