# NTSB SEA01IA113: Cessna 172S, N571SP, Monroe, OR, May 31, 2001 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: May 30, 2001, 18:55 local (May 31, 2001, 01:55 UTC) - Place: Monroe, OR - Coordinates: 44.339492, -123.329193 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.3395&lon=-123.3292&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 18, 2002 - Report: Approved by Office Director - Parties: FAA - Portland FSDO - NTSB case key (mKey): 52406 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA01IA113 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/52406/pdf - Page: https://openairdocs.org/ntsb/SEA01IA113 ## Probable cause A degradation of aircraft control for undetermined reasons. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, climb - reason for occurrence undetermined (cause) ## Analysis The aircraft was on an instrument training flight at the time of the occurrence. The flight was cleared to an altitude of 6,000 feet on departure. The trainee reported that as the aircraft climbed through 4,500 feet, with the instructor flying the aircraft, "the airplane pitched up, and rolled to the left followed by a pitch down, and a roll back to wings level, then a pitch back up and to the left." The instructor stated that as the aircraft climbed through that altitude, "the aircraft suddenly nosedived for about 3-4 seconds and pitched up into a climb." Both pilots reported that they susbsequently felt the pitch control stuck in a pitch-up position, and that they had to hold forward pressure to hold the nose down (the instructor stated both pilots had to apply full forward pressure to prevent a stall.) The instructor further reported that the aircraft would not roll; the trainee reported that the controls were stuck in roll to the left. The pilots reported that the instructor subsequently attempted to trim the aircraft nose-down, without success. The pilots declared an emergency with ATC and subsequently elected to land in a field directly in front of the aircraft by utilizing rudder and power for control, which they accomplished successfully. The pilots reported in their initial interview with the FAA inspector that they did not have the autopilot on at the time of the occurrence, and that they made no attempts to disengage the autopilot during the incident. Post-incident examinations of the flight controls, trim, and autopilot operation by the operator, an FAA inspector, and the autopilot manufacturer did not disclose any evidence of malfunctions or abnormal flight control or autopilot operation. ## Factual narrative On May 30, 2001, approximately 1855 Pacific daylight time, a Cessna 172S, N571SP, registered to R & D Leasing of Oregon, Inc., Hillsboro, Oregon, and operated by Hillsboro Aviation Inc. of Hillsboro, Oregon, experienced flight control difficulties while in climbing flight at an altitude of about 4,500 feet on a 14 CFR 91 instrument flight rules (IFR) instructional flight from Eugene, Oregon, to Hillsboro, Oregon. As a result of the flight control difficulties, the pilots performed an off-airport precautionary landing in a plowed field about 2 miles east of Monroe, Oregon. The pilots accomplished the off-airport landing successfully, without any reported damage to the aircraft, and neither the commercial pilot-in-command of the flight (a certificated flight instructor) nor a private pilot trainee were injured in the incident. Visual meteorological conditions were reported at Corvallis, Oregon, at 1915, and an IFR flight plan was filed for the flight. According to the pilots' accounts, the flight was cleared to an altitude of 6,000 feet on departure from Eugene, and departed Eugene between 1840 and 1850. The trainee reported that the flight departed behind a Horizon Air F-28 aircraft and received vectors behind the F-28 for wake turbulence avoidance. He stated that the instructor, who was sitting in the right seat, took control during this segment since the trainee was wearing a vision-restricting device and the instructor could keep the F-28 in sight. The trainee reported that as the aircraft climbed through 4,500 feet, "the airplane pitched up, and rolled to the left followed by a pitch down, and a roll back to wings level, then a pitch back up and to the left." The instructor stated that as the aircraft climbed through that altitude, "the aircraft suddenly nosedived for about 3-4 seconds and pitched up into a climb." Both pilots reported that they susbsequently felt the pitch control stuck in a pitch-up position, and that they had to hold forward pressure to hold the nose down (the instructor stated both pilots had to apply full forward pressure to prevent a stall.) The instructor further reported that the aircraft would not roll; the trainee reported that the controls were stuck in roll to the left. The pilots reported that the instructor subsequently attempted to trim the aircraft nose-down, without success (they did not indicate in their written statements to the NTSB whether they attempted to utilize manual or electric pitch trim, but they indicated to an FAA inspector in an initial interview that the manual trim wheel would not turn.) The pilots declared an emergency with ATC and subsequently elected to land in a field directly in front of the aircraft by utilizing rudder and power for control, which they accomplished successfully. The trainee reported to the FAA inspector that "After we landed we noticed that the controls were free as if something was stuck, and had bounced loose." The aircraft is equipped with mechanical cable-and-bellcrank-actuated flight controls, and is also equipped with a Bendix/King KAP 140 autopilot system with manual electric pitch trim. According to the aircraft pilot's operating handbook (POH) supplement on the KAP 140 autopilot system, at the time of autopilot engagement the aircraft initially enters vertical speed mode at the vertical speed existing at the moment of autopilot engagement (in the pitch axis), and wing leveler mode (in the roll axis). The POH supplement also states that activating manual electric trim with the autopilot engaged will disengage the autopilot. The pilots reported in their initial interview with the FAA inspector that they did not have the autopilot on at the time of the occurrence, and that they made no attempts to disengage the autopilot during the incident. Post-incident examinations of the flight controls, trim, and autopilot operation by the operator and the FAA inspector did not disclose any evidence of malfunctions or abnormal flight control or autopilot operation. Following the incident and subsequent troubleshooting by the operator and FAA inspector, the autopilot system components were functionally tested at the facilities of their manufacturer, Honeywell Aerospace Electronic Systems of Olathe, Kansas, under FAA supervision on July 12, 2001. The components tested comprised the KC 140 flight computer, KCM 100 configuration module, KS 270C pitch servo, KS 271C roll servo, and KS 272C pitch trim servo. According to Honeywell's report of this testing activity, the components were tested both as a system (connected together on a system test harness), and individually. The Honeywell test report stated: ...upon completion of all the previously described testing, both as a system and as individual components, the autopilot system demonstrated compliance with all of the design requirements and all of the components tested met all of the required specifications for a new unit. No anomalies were noted during any phase of the testing that would indicate the system had previously experienced a failure that might cause autonomous engagement or uncommanded servo drive. ## Aircraft - Registration: [N571SP](https://openairdocs.org/aircraft/N571SP), registered now, S/N 172S8496, built 2000 (OpenAirDocs) - Reported make and model: Cessna 172S - Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (registry code 2072439) (OpenAirDocs) - Registry engine: [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series) (registry code 41515, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 172S8496 - Airframe hours: 544.5 - Engines: Lycoming IO-360-L2A 180 horsepower reciprocating - Damage: No damage - Flight: Instructional, Part 91 - Operator: Hillsboro Aviation Inc. - Registered owner: R & D Leasing of Oregon Inc. - Airworthiness certificate: Standard, Utility; Standard, Normal - Last inspection: 100 hour, May 4, 2001, 56.7 hours before - Departed: EUG, Eugene, OR - Destination: HIO, Hillsboro, OR - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 37; injuries: none; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; last flight review December 7, 2000; seat: right; flight hours: 2,210 total, 22 in this make and model, 2,130 as pilot in command, 125 in the last 90 days, 55 in the last 30 days, 5 in the last 24 hours - Student pilot; age 26; injuries: none; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; last flight review August 23, 2000; seat: left; flight hours: 122 total, 50 in this make and model, 68 as pilot in command, 22 in the last 90 days, 13 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 345° at 15 knots - Visibility: 10 statute miles - Lowest ceiling: none ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 20010530013489I](https://openairdocs.org/incident/20010530013489I), May 30, 2001: Cessna 172S, Monroe, OR. (-23) On an IFR dual instruction instrument flight from eugene, OR (eug) to hillsboro, OR (hio). PIC esuk indicated control problems. Experienced a stuck trim.… 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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.