# NTSB ERA11LA429: Cessna 172M, N1443U, Pahokee, FL, July 28, 2011 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: July 28, 2011, 12:00 local (16:00 UTC) - Place: Pahokee, FL - Coordinates: 26.791944, -80.701942 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=26.7919&lon=-80.7019&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report August 7, 2012 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO, Airline Transport Professionals - NTSB case key (mKey): 81290 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA11LA429 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81290/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81290 - Page: https://openairdocs.org/ntsb/ERA11LA429 ## Probable cause The flight instructor's misjudgment of the airplane's position and airspeed relative to the runway while returning to the airport after a partial loss of engine power. Contributing to the accident was the separation of the engine's No. 3 cylinder exhaust valve head from the stem, and the operator’s exceedence of the engine manufacturer's recommended time between overhauls. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [Cessna 172M, 19 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=2072418), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Not serviced/maintained (probable cause); cases with it: [Cessna 172M, 4 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=2072418), [All aircraft, 497 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md) - [Maintenance: scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Cessna 172M, 3 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md?model=2072418), [All aircraft, 320 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md) - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Cessna 172M, 6 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=2072418), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Cessna 172M, 16 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2072418), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Ditching](https://openairdocs.org/ntsb-events/441); cases with it: [Cessna 172M, 2 cases](https://openairdocs.org/ntsb-events/441/sequence.md?model=2072418), [All aircraft, 186 cases](https://openairdocs.org/ntsb-events/441/sequence.md) ## Analysis The flight instructor stated that, as the airplane climbed through about 500 feet above the ground after takeoff on the intended dual instructional cross-country flight, the engine started shaking, sputtering, and making “alarming” noises. The flight instructor took control of the airplane, noted nothing abnormal with the mixture, fuel selectors, engine instruments, or fuel quantity, and decided to return to the departure airport to land. The flight instructor noted that there was not a total loss of engine power, but it was not possible to maintain the airplane’s altitude. When the flight instructor realized that the airplane was too high and too fast to land on the intended runway, she moved the throttle to idle; however, she did not use flaps or slip the airplane to reach the runway. The airplane overflew the entire length of the runway, and the flight instructor elected to land the airplane in a lake on the left to avoid obstacles straight ahead and on the right. Postaccident examination of the engine revealed that the No. 3 cylinder exhaust valve head had sheared off at the stem. The stem, spring, and rocker arm were still intact, and the No. 3 piston exhibited signs of mechanical damage from the sheared head inside the combustion chamber. At the time of the accident, the engine had 2,229.5 hours of operation since major overhaul. The engine manufacturer's recommended time between overhauls was 2,000 hours. ## Factual narrative On July 28, 2011, about 1200 eastern daylight time, a Cessna 172M, N1443U, was substantially damaged during a forced landing in Lake Okeechobee, near Pahokee, Florida. The certificated flight instructor was not injured and the certificated student pilot incurred minor injuries. Visual meteorological conditions prevailed. No flight plan had been filed for the flight, between Palm Beach County Glades Airport (PHK), Pahokee, Florida, and Fort Lauderdale Executive Airport (FXE), Fort Lauderdale, Florida. The instructional flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to the flight instructor, the accident flight was part of a series of cross country and student solo flights that day. Upon arrival at PHK, three practice landings were completed before a full stop landing. During a subsequent takeoff for FXE from runway 17, with winds from 100 degrees magnetic at 10 knots, the student pilot was at the controls. All of the gauges were "in the green," and the fuel tanks were half full. After the takeoff and a straight-out departure, as the airplane reached 500 feet, the engine started shaking, sputtering, and making "alarming" noises. The flight instructor immediately took control of the airplane, and quickly glanced at the mixture, fuel selectors, engine instruments, and fuel, without noting anything abnormal. The flight instructor then turned the airplane back toward runway 35, and transmitted via radio an engine failure, but saw that the engine did not completely quit. Instead, it was not producing any thrust, and the airplane could not maintain altitude. The flight instructor also stated that after turning the airplane back toward runway 35, she realized that it was too high and too fast. She pulled out the throttle; however, she did not use flaps or attempt to slip the airplane. The airplane then overflew the entire length of the runway, and the flight instructor had to consider other options. In front of her was a house, to the right was a road lined with power lines, and to the left was the lake. The flight instructor then turned the airplane over the lake, and "floated" it as long as possible before it touched down and nosed over. The flight instructor and student pilot exited the airplane and waited on its belly until rescue. After its removal from the lake, Federal Aviation Administration (FAA) inspectors and flight school maintenance personnel examined the airplane and the Lycoming 0-320-E2D engine, and found that the No. 3 cylinder exhaust valve head had sheared off the stem. The stem, spring and rocker arm were still intact, and the No. 3 piston exhibited signs of mechanical damage from the sheared head inside the combustion chamber. The airplane's engine was last inspected during a 100-hour inspection on July 21, 2011. According to the logbook entry, at that time, the engine had accrued 2,211.8 hours of operation since major overhaul. At the time of the accident, hours of engine operationsince major overhaul were 2,229.5. According to Lycoming Service Instruction 1009AU, dated November 18, 2009, recommended time between overhauls of the O-320-E engine is 2,000 hours. ## Aircraft - Registration: [N1443U](https://openairdocs.org/deregistered/N1443U-2012-12-27), registration cancelled 2012-12-27, S/N 17267110, built 1976 (OpenAirDocs) - Reported make and model: CESSNA 172M - Registry model: [Cessna 172M](https://openairdocs.org/model/cessna-172m) (registry code 2072418) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17267110 - Airframe hours: 6585 - Engines: LYCOMING 0-320 SERIES 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Atp Aircraft 2 LLC - Registered owner: Atp Aircraft 2 LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, July 21, 2011, 18 hours before - Departed: PHK, Pahokee, FL - Destination: FXE, Ft. Lauderdale, FL - Airport: PHK, Palm Beach County Glades ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 21; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review March 7, 2011; seat: right; flight hours: 404 total, 221 in this make and model, 339 as pilot in command, 182 in the last 90 days, 86 in the last 30 days, 4 in the last 24 hours - Student pilot; age 23; injuries: minor; student; medical: class 1, without waivers/limitations; seat: left; flight hours: 60 total, 55 in this make and model, 3 as pilot in command, 43 in the last 90 days, 43 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 100° at 10 knots, gusting 19 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 93 °F, dew point 75 °F - Altimeter: 29.97 inHg - Observed at: PHK ## 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 20110728016379A](https://openairdocs.org/incident/20110728016379A), Jul 28, 2011: Cessna 172M, Pahokee, FL, Destroyed. On July 28, 2011 at approximately 1215 EST, N1443U registered to ATP aircraft LLC departed ruwnay 17 at the Palm Beach county Glades airport (phk) in Pahokee,… ## Docket (5 files) The files NTSB released with the investigation on June 14, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81290. 6.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 464 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368230&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - FAA Inspector Statement (item 2, .PDF, 228 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368231&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Redacted.PDF - Excerpt, Engine Maintenance Log (item 3, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368232&FileExtension=.PDF&FileName=Excerpt,%20Engine%20Maintenance%20Log-Redacted.PDF - Statement of Party Representatives to NTSB Investigation (item 4, .PDF, 88 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368233&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Photograph - Inside No. 3 Cylinder with Exhaust Valve Head Sheared Off (Courtesy FAA) (item 5, .PDF, 5.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368234&FileExtension=.PDF&FileName=Photograph%20-%20Inside%20No.%203%20Cylinder%20with%20Exhaust%20Valve%20Head%20Sheared%20Off%20(Courtesy%20FAA)-Master.PDF 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.