# NTSB CEN09CA078: Cessna 172S, N833SP, Waukesha, WI, November 26, 2008

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: November 26, 2008, 14:30 local (20:30 UTC)
- Place: Waukesha, WI
- Coordinates: 43.04111, -88.236946 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.0411&lon=-88.2369&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Defining event: [Takeoff: Loss of control in flight](https://openairdocs.org/ntsb-events/240)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report December 24, 2008
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: Federal Aviation Administration - Milwaukee FSDO
- NTSB case key (mKey): 69517
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN09CA078
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/69517/pdf
- Page: https://openairdocs.org/ntsb/CEN09CA078

## Probable cause

The pilot's failure to maintain aircraft control during takeoff and his failure to ensure that the elevator trim was properly set before takeoff. Contributing to the accident was the pilot's lack of autopilot system knowledge.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Knowledge: knowledge of equipment](https://openairdocs.org/ntsb-findings/02032015): Personnel issues › Experience/knowledge · Pilot (probable cause); cases with it: [All aircraft, 69 cases](https://openairdocs.org/ntsb-findings/02032015/cases.md)
- [Flight control system: elevator tab control system](https://openairdocs.org/ntsb-findings/01022731): Aircraft › Aircraft systems · Incorrect use/operation (probable cause); cases with it: [All aircraft, 37 cases](https://openairdocs.org/ntsb-findings/01022731/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Taxi-to runway: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md)
- [Takeoff: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)
- [Takeoff: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md)
- [Takeoff-rejected takeoff: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The pilot reported that the autopilot was inadvertently engaged while taxiing to the departure runway. The pilot and his passenger attempted to disengage the autopilot by depressing the "A/P" button on the unit's control panel. The pilot reported that there were warning buzzers sounding as they attempted to disengage the autopilot. The pilot eventually turned off the avionics master switch in order to completely power down the autopilot. After he reestablished power to the avionics, the autopilot appeared to be disengaged. He then contacted the control tower for a takeoff clearance. The airplane "prematurely" rotated and became airborne during the takeoff roll. The pilot stated that he immediately aborted the takeoff, but "struggled with elevator control because of a significant nose up pressure." The airplane landed off the left side of the runway, impacted a snow bank and another runway before coming to rest nose down. A post-accident examination of the airplane showed that the nose landing gear had collapsed, causing substantial damage to the engine firewall. The two-axis autopilot system had servos that controlled the elevator and elevator trim positions. The elevator trim was not in the takeoff position, with the indicator showing a nose-up trim setting of about 8/10 of its total travel. No anomalies were noted during an operational test of the autopilot system or after a download of its fault log. The autopilot was installed with the correct software version and was in compliance with all required airworthiness directives. The pilot reported that he had minimal experience with the use of an autopilot and that he had not received training on the autopilot system installed in the accident airplane.

## Factual narrative

The pilot reported that the autopilot was inadvertently engaged while taxiing to the departure runway. The pilot and his passenger attempted to disengage the autopilot by depressing the "A/P" button on the unit's control panel. The pilot reported that there were warning buzzers sounding as they attempted to disengage the autopilot. The pilot eventually turned off the avionics master switch in order to completely power down the autopilot. After he reestablished power to the avionics, the autopilot appeared to be disengaged. He then contacted the control tower for a takeoff clearance. The airplane "prematurely" rotated and became airborne during the takeoff roll. The pilot stated that he immediately aborted the takeoff, but "struggled with elevator control because of a significant nose up pressure." The airplane landed off the left side of the runway, impacted a snow bank and another runway before coming to rest nose down. A post-accident examination of the airplane showed that the nose landing gear had collapsed, causing substantial damage to the engine firewall. The two-axis autopilot system had servos that controlled the elevator and elevator trim positions. The elevator trim was not in the takeoff position, with the indicator showing a nose-up trim setting of about 8/10 of its total travel. No anomalies were noted during an operational test of the autopilot system or after a download of its fault log. The autopilot was installed with the correct software version and was in compliance with all required airworthiness directives. The pilot reported that he had minimal experience with the use of an autopilot and that he had not received training on the autopilot system installed in the accident airplane.

## Aircraft

- Registration: N833SP (not matched to a registry record)
- Reported make and model: CESSNA 172S
- Category: Airplane
- Serial number: 172S8724
- Airframe hours: 4498.1
- Engines: Lycoming IO-360-L2A 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Spring City Aviation, Inc.
- Registered owner: Spring City Aviation, Inc.
- Airworthiness certificate: Standard, Utility; Standard, Normal
- Last inspection: 100 hour, November 26, 2008
- Departed: KUES, Waukesha, WI
- Destination: K87Y, Cottage Grove, WI
- Airport: KUES, Waukesha County Airport, runway 28, 5,848 × 100 ft, concrete

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 52; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review July 16, 2008; seat: left; flight hours: 77 total, 8 in this make and model, 34 as pilot in command, 9 in the last 90 days, 2 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 310° at 5 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 37 °F, dew point 21 °F
- Altimeter: 29.96 inHg
- Observed at: KUES

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20081126854859A](https://openairdocs.org/incident/20081126854859A), Nov 26, 2008: Cessna 172S, Waukesha, WI, Substantial damage. (-23) [privacy data omitted] was the pilot in command of N833SP when it impacted the berm of an intersecting taxiway of runway 28 at Waukesha airport. [privacy…

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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