CEN17CA114

NTSB accident investigation · Cessna 340A · Waukesha, WI · February 25, 2017

Accident · No injuriesData collectionFinal report
Date
February 24, 2017, 18:15 local (Feb 25, 2017, 00:15 UTC)
Place
Waukesha, WI
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N255BCCessna 340A
Defining event
Approach-IFR final approach: Loss of control in flight
Weather
Instrument (IMC) · Dusk
Status
Completed · report April 4, 2017
Report
Approved by Office Director
NTSB office
Central Region
Parties
Federal Aviation Administration
FAA report
20170224002979A
Case key
94793

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 decision to fly in in conditions conducive to structural icing and her subsequent failure to maintain airplane control during the instrument approach.

Findings · 6

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.

Ceiling/visibility/precip: freezing rain/sleetEnvironmental issues › Conditions/weather/phenomena · Effect on equipmentCessna 340A: 1 caseAll aircraft: 26 casesProbable cause
Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotCessna 340A: 10 casesAll aircraft: 9,295 casesProbable cause
Temp/humidity/pressure: conducive to structural icingEnvironmental issues › Conditions/weather/phenomena · Effect on equipmentCessna 340A: 1 caseAll aircraft: 103 casesProbable cause
Performance/control parametersAircraft › Aircraft oper/perf/capability · Not attained/maintainedCessna 340A: 3 casesAll aircraft: 1,269 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

Before the positioning flight, the airline transport pilot monitored the weather and noticed the weather conditions were deteriorating near the time of the planned departure. The weather conditions included low visibility, freezing drizzle, and mist. In an effort to reduce the time in the deteriorating weather conditions, the pilot performed some before takeoff checks while the airplane was in the hangar. During the pilot's "haste" to preflight and take off, she inadvertently selected the wrong switch for windshield heat. While on the instrument approach to the runway in night conditions, the pilot had no forward visibility due to ice accumulation on the windshield. The pilot executed a missed approach and contacted an instructor pilot at the departure airport to confirm the location of the windshield heat switch. The pilot then activated the windshield heat switch and enough ice had melted for the pilot to conduct another approach. During the approach, the pilot increased the airspeed due to "carrying a lot of ice." On short final approach, the airplane descended below the glidepath due to the ice accumulation. Subsequently, the airplane contacted the terrain short of the runway and then "skipped" onto the runway. The airplane came to rest upright and off the runway surface. Examination of the airplane revealed substantial damage to the left wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.

Factual narrative

Prior to the positioning flight, the pilot monitored the weather and noticed the weather conditions were deteriorating near the time of the planned departure. The weather conditions included low visibility, freezing drizzle, and mist. In an effort to reduce the time in the deteriorating weather conditions, the pilot performed some before takeoff checks while the airplane was in the hangar. During the pilot's "haste" to preflight and takeoff, she inadvertently selected the wrong switch for windshield heat. While on the instrument approach to the runway in night conditions, the pilot had no forward visibility due to ice accumulation on the windshield. The pilot executed a missed approach and contacted an instructor pilot at the departure airport to confirm the location of the windshield heat switch. The pilot then activated the windshield heat switch and enough ice had melted for the pilot to conduct another approach. During the approach, the pilot increased the airspeed due to "carrying a lot of ice." On short final approach, the airplane descended below the glide path due to the ice accumulation. Subsequently, the airplane contacted the terrain short of the runway, and "skipped" onto the runway. The airplane came to rest upright and off the runway surface. Examination of the airplane revealed substantial damage to the left wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.

Aircraft

Registration
N255BC
Reported as
Cessna 340A (A)
Category
Airplane
Serial number
340A0908
Built
1979
Airframe hours
5,644
Engines
Cont Motor TSIO-520 NB, 335 horsepower, reciprocatingCont Motor TSIO-520 NB, 335 horsepower, reciprocating
Damage
Substantial damage
Flight
Positioning · Part 91
Operator
Signicast LLC
Registered owner
Signicast LLC
Airworthiness certificate
Standard, Normal
Last inspection
Annual · August 12, 2016
Departed
UNU · Juneau, WI
Destination
UES · Waukesha, WI
Flight plan
IFR
Airport
UES · Waukesha County Airport, runway 10, 5,849 × 100 ft, asphalt
Equipment
Stall warning system

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
55
Injuries
None
Certificates
Flight instructor, Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Last flight review
August 5, 2016
Seat
Left
Restraint
3-point
Flight hours
10,200 total · 200 in this make and model · 10,200 as pilot in command · 60 in the last 90 days · 4.5 in the last 24 hours

Weather

Conditions
Instrument (IMC) · Dusk
Wind
320° at 8 knots
Visibility
2.5 statute miles
Lowest ceiling
700 ft overcast
Temperature
28 °F, dew point 28 °F
Altimeter
29.54 inHg
Icing
Rime
Observed at
UES

Docket · 1

The files NTSB released with the investigation on March 16, 2017, on NTSB’s docket system: statements, records, photos and specialists’ reports. 381 KB 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.